I'm going to dredge up an old topic, but am wondering if anybody has any insights into how much to add to the dimensions of the hollowed section to compensate for the weight reduction in the hollow rod section.

After doing a search of the archives, I would have to agree with some comments that state that the balance of the rod is off when you hollow and don't add anything to the overall dimensions. I have read Milliard's book and the section on hollow building, but unless I missed anything, I still can't come up with an amount or a calculation. The graph he gives is unclear and just can't see how much to add.

Tom Smithwick writes in an old post to add 2% or 3% to the overall hollowed dimensions. Does anybody have anything else to add or is this the accepted amount.

I have tried to hollow build a Thramer 8' 4 wt rod and love the rod, but the balance is out. I planed off the pith and reduced the dimensions by a third. Seemed like a good place to start off. Rod is light in the hand, but its almost like I have to add some mass to the reel seat area to balance the rod out. Seems to be defeating the purpose. Have not found it practical as of yet to load up a 9 wt reel with 4 wt line.  (Mark Babiy)

Suggest you read Bob Milward’s book. Treats this subject quite well. 

If you look at his charts of equal bending resistance it is just a job of increasing the area at a given point. On a quad figure the area, increase by the factor then translate the increase in area by taking the sq. root. Found factors for determining the area of hex's in one of my old machining handbooks. (Jerry Young)

I was not talking about balance with the 2-3%, but rather compensating for a loss of casting power when the center of the rod is removed. I don't know if there is a real rule of thumb on this, and I suspect it is influenced by the type and amount of hollowing you do. Did you hollow any portion of the tip? (Tom Smithwick)

Did not hollow the tip, only the butt and I went straight through the ferrule section also. Was worried, but have fished the rod for about 2 years with no adverse affects. Rod is great, but seems almost too light in the butt and off balance.  (Mark Babiy)

For what it's worth, I'm working on finishing up a Leonard Tournament 8' 3 piece 3 wt like the one Miles brought to SRG. I did no hollowing on tips (as usual), took the walls to .065 in the mid and .070 in the butt with dams every 3.5" and solid under ferrules +2". I increased the taper on a slope from 1% to 4.5% from the top of the mid down to the butt swell. It seems to have worked out very well (per test-casting). I increased the butt more since a greater % is taken out to get to .070.

When I've hollowed on faster tapers, I've made no adjustment and just gotten a smoother rod. (Jerry Madigan)

Here is an idea I came up with after talking to a few listmembers who use a hand held belt sander for doing hollowing and who use a belt sander for node work (taking pith away and displacing nodes with a notched vise).

I tape the strips together as if I was going to glue up, and I open them with the scalpel I use. The trigger clamps hold the taped together strips parallel to each other. The rubber feet of the clamp have a good grip and do not damage the apex like metal hold downs would. You could easily mark the spline exactly where you want to hollow. If you use a carrier like cedar (I never have) you would know exactly when to stop sanding because you would be almost through the cedar.

It is not as good for glue up as fluting ALA Winston, but it sure is an easy way to do a one off steelhead rod. (Bob Maulucci)

Bob stated the following after talking to him: I made a back plate out of aluminum. Strips go through the middle and are held flat against the plate with my hands. There is a "curb" on each side of the backing plate that is raised up .070". When the belt hits the metal I know I am done. All the scallops are more even now.

Thanks for the idea and the link to the pic. I have used a similar setup in the past to sand the interior of the node in the past. Works great, but it sure is easy to get carried away.  (Mark Babiy)

How in the heck do you control how much the best sander takes off, or maintain any consistency from one hollowed section to the next? I've used the belt sander on the inner part of the nodes, but can see that operation getting away from me in a BIG hurry. (Harry Boyd)

Go really slow. Use your dial calipers. My mistake on the first few was to not use something to stiffen the way the strips are held. Now I am experimenting with some flat stock help in the clamps behind the enamel. Keeps the strips from twisting. No offense meant, but from what I have heard about the Powell process, it wasn't really all that accurate. Even if you just did this belt sander method by eyeballing the strips, it may work just as well. I am not even sure that extreme accuracy would matter. After all, is the glue being distributed evenly in the strips? This is obviously not as good as the Hand Mill fluting set up or some others, but it sure works. I cannot find a spline that has a kick, or a real big difference in dimensions when glued up. (Bob Maulucci)

For those of you that are hollow building, how thick have you left the wall? Do you decrease the wall in the tip section? Where do you leave dams (end of the grip, ferrules stations, last 10" of the tip?).

If you look at this purely from the perspective of Garrison stress type model, the walls can get pretty thin without sacrificing much strength at all (less than 5%). Depending upon the taper, rod length, line weight, etc., one can theoretically cut the wall in the tip section to about 0.040, and the butt to about 0.060, and still retain almost all of the original strength. Using the same model, one can then determine a new diameter to regain the loss in material strength.... typically only need to add back 0.005 or less from my limited study so far.

This is all great in theory, I am just wondering what some of you have found that really "works" when fishing a hollow built rod. From what I have learned so far there is a benefit of weight savings in the butt for longer rods, and it can significantly speed up the action in the tip. (Kyle Druey)

I've built a few hollow rods. I generally leave the walls from .060" - .080" on butts, and a little smaller on tips and mids. I leave things solid for a couple inches at the ferrules, just to be safe. And I leave things solid for 1.5" at each node, just for peace of mind.

My last project with hollow-building was a direct comparison with the Payne 101 that I've built so often. I used Bob Milward's charts to help me know how much to increase each station to give the same strength as building it solid. Hollow building to .070" in the butt, and to .050" in the tip gave me a weight savings of .6 oz overall. That's about 30% -- a significant weight savings in my mind.  I've cast the hollow and solid versions side-by-side, and they are very much alike. So I guess I'd say that the project was a success.

In my mind, what limits the wall thickness isn't as much strength as practicality in building. If you get much thinner than .060", there really isn't much gluing surface left.

Tom Smithwick was a big help to me as I got started in hollow building. Please let me know how I can help you. (Harry Boyd)

Were you hollowing the sections flat or fluting? Seems like if hollow fluting is used it might be possible to get down to a 0.040 wall thickness and still have enough surface area for gluing. The hollowing jig I've built is based on using a Dremel, and they make ball end cutters that have diameters of 1/8, 1/16, and 1/32. Seems like the small diameter cutter could be used on thin walled tips to provide more of "dished" cut for gluing.

Did you use the full corrected diameter from the chart or half the correction? One thing Milward suggests is to increase the diameter by only half of what is calculated for the correction. He says there is no engineering basis for this, but it is based on his estimate that 50% of the energy transmitted in the rod via a cast is used to move the self-weight of the rod. He seems to think that the only correcting for 50% works well.

I'm surprised you did not notice a difference in the two Payne 101s you built. (Kyle Druey)

We had a discussion of hollow building at Corbett Lake this past April. The general consensus was about what Harry stated below - most folks leave a wall thickness .070-.080, some go thinner for tips, and up to .090 for the butts of steelhead and salmon rods. Powell had a problem with rods shattering at much below .070 (though that might have been related to a number of factors such as less glue strength using the scalloping, rather than fluting method; choice of glues; the way the rods were cast (most were tournament rods really pushed to the max).

The general recommendation to convert a solid to hollow rod was to add 5% to the diameter in the hollowed area as a starting point.

Always leave the area under the ferrules solid (and at least 1.5" - 2" on either side).

As to weight savings, to my mind it isn't so much as how much lighter the rod is (though it is noticeable) but more how the rod "balance", or feel in the hand, changes for the better (the rod feels like it has less swing weight, therefore feels crisper and lighter in hand).

Just some food for thought. (Chris Obuchowski)

It should be mentioned that most EC Powells, if they do fail. they fail with lengthwise splits. Some of the old beast distance casting rods have lengthwise splits through the center of a flat -- not along a glue line.  One way I determine if a rod is a hollow-built or solid rod, with Buddy Powell rods that are rarely if ever marked for example, is to sight down a flat. If I see what looks like a minor crease in the center of a flat, I know the rod is hollow-built.

I have never had an EC rod fail and I have a lot of them and even abuse them steelheading. (Chris Lucker)

I currently have been doing my hollow building with my Grizzly minimill. Bob Venneri built me a wonderful little jig that clamps to my table and holds down 60 or 90 degree strips. I can easily set the cutter depth/wall thickness (I usually use shims) and I use the table's cross slide to cut the strips either fluting down the center of the strip with a ball end 1/8" milling cutter or with a flat cutter and doing a Powell style hollowing with dams. The problem is that the process is painstakingly slow, and when I move the strip down in the clamps, it can often throw the center off when fluting.

My question is...what are some other effective ways that listers have been able to do hollow strips under power. I would prefer to do a fluting style set up and make one pull through the whole strip. I figure that will help ensure the cutters stay on center. Yes, I am missing my Hand Mill and the fluting jig! Could I just use some round milling cutters and flute right on my bamboo mill? (Obviously, I would need some spacers to center the cutters on the strip.) (Bob Maulucci)

For the Powell method my vertical scalloper can cut 6 strips at a time and do all the hollowing in a short time. As for fluting I suggest you look at Milward’s book. His design for fluting is simple and inexpensive. (Adam Vigil)

The jig I made for fluted hollowing will cuts a strip in about 5 minutes. This may not be fast enough for you but the idea is based around a Dremel drill press. I made a hollowing jig that uses design ideas from the Milward book grooved strip guide) and the roughing beveler sold by Golden Witch (spring loaded hold downs). This jig fits in conjunction with the Dremel drill press. The wall thickness is set with the drill press using shims and the strips are fed through and pushed by hand. Dremel has a large selection of diameters for ball end cutters.  (Kyle Druey)

I have reworked my jig so that I can pull the strips through by hand. Now, what I am wondering, is the minimill running at too low a speed? Would I be better off trying this jig in a router or Dremel based set up? The top speed on the minimill is something like 2700 RPMs. The minimill seems to have some chatter when feed by hand. Of course, it is fine when I am taking 15 minutes a strip!!! (Bob Maulucci)

I have for sometime now been trying to create in my mind a jig for hollow building rods. How can you have a continues pull through when the hollowing is made in two inch sections down the length of the strip. Also how are you holding the strip from moving off center while milling? (Mark Dyba)

If you want to make an easy fluting tool, use a router with a biscuit slot cutter. They have three wings with a carbide blade with square corners. They are called slotting cutters. They come in 1/8 to 1/4. I have used the 1/8 and 5/32. Take a diamond stone and round the corners as desired and Bingo, you have a good cutter for fluting.

All you need is a guide for pushing the strip through. The easiest way to make the thing adjustable is to use a MicroFence -- look it up on Google -- it is a micrometer adjustable fancy router guide. Make a simple bed with a couple of holddowns and adjust the depth of cut so you do not cut deeper than say 0.080" or whatever.

If you want to try an EC Powell scalloping method, you were REALLY doing it the slow way by using a mill. Simply clamp all six strips side by side as though you were applying glue. Take a common hand held belt sander and touch the END of the sander to the points where you want to scallop. It is easier to see when to stop sanding when you have Port Orford Cedar laminated to the inside of the cane because you simply sand only through the cedar. You will probably need to make sander-stopper rails alongside the bamboo to stop the sander when it reaches a depth of 0.072" or so. Make the stops out of steel so you can see sparks or feel the contact, or probably hear the contact.

Hope that helps. I have tried both and do the EC Powell method. (Chris Lucker)

Seems like the hollow building thing raises it's head every now and then I took a shot @ Vince Marinaro's. rod taper based on his book drawing last winter. Found out the taper I made from how I understood the drawing was a lot more heavy than VM's.

The questions are:

1] Can the weight of a finished blank without varnish, guides, cork etc. be calculated from tapers.

2] Can the weight of a hollowed out finished blank be calculated?

3] Can the weight of a hollowed out finished blank be calculated if some of the pith is retained.

I would assume that a series of 60 degrees strips would have to be measured and weighted accurately. Some with pith - some without. Different power fiber depths would also require weighing.

Anybody out there in radio land want to take a shot @ it? I will make the strips + weight if someone would do the math.

What I envision is a neat and tidy program where the taper was put in and the weight puked out.

Another program where the guides & ferrules were "bridged" by pith and the rest hollowed. This program would get a lot more complicated as the bridging would have to be entered in terms of inch of rod travel. (Don Anderson)

1] Can the weight of a finished blank without varnish, guides, cork etc. be calculated from tapers.

I think you might be able to make an reasonable estimate but as the rod got bigger the possible error would be greater

2] Can the weight of a hollowed out finished blank be calculated?

I think one would be increasing the margin for error again.

3] Can the weight of a hollowed out finished blank be calculated if some of the pith is retained.

I think the difference from culm to culm is only one of the variables in the equation you suggest.

I would assume that a series of 60 degrees strips would have to be measured and weighted accurately. Some with pith - some without. Different power fiber depths would also require weighing.

Again, I think you could define a range for a variable but there could not be a constant, hence the comparison of strips.

Anybody out there in radio land want to take a shot @ it? I will make the strips + weight if someone would do the math. What I envision is a neat and tidy program where the taper was put in and the weight puked out.

Come on, Don! You're being short sighted. Be a visionary. I'm shooting for a machine that I can toss my shavings in one end and have it poop out a varnished rod on the other. Now that would be something to see! :^) (Timothy Troester)

Probably not worth the effort to add too many details. Many of the Hexrod programs can compute the weight of the blank using an average bamboo density. You just compute the weight of the solid blank (with or without the extra 3% diameter). Then compute the weight of the tiny rod consisting of hollowed part. Use the original diameters less twice the wall thickness. Subtract the weights of the two; and, viola. Guesstimate how much to add back in for the bridging if you want. (Jim Utzerath)

Let's say I build two theoretically identical rods, one solid built, and one hollow built, to the same taper. Would there be any differences in the two rods characteristics, other than the obvious one of one rod being lighter than the other? (Mark Wendt)

The hollow built rod would have slightly different flexing characteristics, depending on wall thickness, etc. Milward's book has a good discussion to use as a starting point. (Harry Boyd)

Care to expound? I don't have the Milward book as of yet, so I look forward to your inspiration. (Mark Wendt)

There are a tremendous number of variables to consider... how thick are the walls? Is wall thickness the same in all areas? Is it fluted or scalloped? Is it solid at grip and ferrules, or hollowed? How far up the tip is it hollowed?

Generally speaking, I'd say that the hollow built rod is 3% - 10% less stiff, based on Milward and a simple wild guess from a little personal experience. Adding 3% to a taper is usually about .010" at the butt. That's not much material, and it makes the rods pretty close to even in action. If hollow building decreases the weight by 25-30%, adding three percent more "wood" doesn't hurt your weight savings very much.

I've just finished two 8' 7 weight blanks, very loosely based on the Dickerson 8015. One is hollow in butt only. The other hollow in the tips, too. Wall thickness for butts ranges from .078" to .060". In the tips, wall thickness is from .060" to .045". Just wiggling them, the one with the solid tips seems much stiffer. Unfortunately, the one hollowed in butt only is for a customer, so we won't be able to cast them side by side at SRG. I'll have the one which is all hollow with me, if someone doesn't buy it first <g>.

Now, if you make a hollow built taper and it seems a little soft, you can fix it. Add some intermediate wraps. It is absolutely amazing how much they stiffen up a rod. (Thanks Tony Y, and Reed and others) Adding three wraps between each guide makes the rod go from medium to medium fast. Adding five wraps moves you from medium to almost fast. That's as far as I have gone. Why do intermediates quicken the taper? My guess is that by adding thread you simply increase the diameter. (Harry Boyd)

Interesting information. I wonder how much weight putting 3% more in the diameter of your taper would really add. After all, you are adding back weight in the densest part of the strip, in the power fiber area. Whereas, when you hollow out the inside, you are hacking away at the least dense part of the strip.

I like the idea of the intermediate wraps though. Nice easy way to influence the action of the rod. How many wraps do you need for each individual intermediate for it to actually have some effect? (Mark Wendt)

Keeping all other factors unchanged between the two rods, except that the wall thickness of one rod is reduced, will slow down the action of the hollow built rod. You have to add wood to the Hollow Built rod if you want it to have the same action as the solid built rod. (Kyle Druey)

I understand that John Long and Bill Waara had long and detailed discussions concerning what happens to a rod when hollowed. When John gets his book finished someone might ask him about it. Personally, I think adding to the diameter of the rod defeats the purpose of hollowing. When I have hollowed I have found that the rebound is quicker I assume from the less weight of the rod itself. When I have added diameter to a rod that I have hollowed I ended up with a completely different, stiffer, taper not so when I did not add to the final dimension. Go figure! There's an odd ball in the bunch.  (Timothy Troester)

The true test then would be to get the two rods together and let a group cast them and not tell them which was which and then see if they can tell the difference. (Dave Norling)

You don't really have to add all that much extra wood to the hollow built rod when trying to achieve the same stiffness profile of the solid rod parent taper. For example, a recent 8' hb quad I made had the following corrections:

30" 0.000 (no hollowing due to wall thickness)
60" 0.002 (about 0.9%)
80" 0.006 (about 2.1%)

The corrections for the in between stations are not proportional to those listed above, and are not generic, but are taper specific. The amount of extra weight added is minimal but improved performance enhancements are provided, in my opinion, in most any rod length. Less input energy from the caster is absorbed by the rod to rotate and accelerate the wood, which provides more energy to the cast... IE., more efficient than the solid built rod. (Kyle Druey)

Am I assuming correctly with your dimensions that the increase is linear from 0.000" at the tip to .006" at the butt? If not, using your example, how do you determine where to add the weight to the rod? (Mark Wendt)

It's not linear but rather it is based on equivalent moment of inertia. The MOI of the hollowed cross-section is made to be equivalent to the MOI of the solid cross-section.  (Kyle Druey)

Sounds similar to what I'm doing:

1. Through anecdotal observations, it appears that 3.5% to 4% is about right for a butt of about .310 with a .070 wall thickness.

2. Anchor my calculations at 3.5% or 4% for .310 and then make adjustments in proportion to the bamboo removed for various cross-sections and wall thicknesses.

I leave dams, so that has some impact.

Just slightly more scientific than a WAG. (Jerry Madigan)

I have done exactly what you are proposing. Built 2 rods from the same culm. Alternated the strips so that each rod had strips in them as close as I could match them. Same guides & pattern. Same node pattern. Left 0.080" side wall. Was about the maximum of power fiber. Left bridges on each side of the guides and at ferrule. Finished the same.

Took them out on the lawn and the solid rod out cast the hollowed one by about 15' feet. So the trade off seems weight Vs. performance. (Don Anderson)

Then the next step would be to make three rods, one solid, one hollow built with the same taper as the solid, and one hollow built, increasing the taper by 3%, like Harry mentioned. Problem is, you'd need mighty wide culm to get three rods out of it. (Mark Wendt)

I came to the conclusion that offsetting the taper to get the same performance was not worth the effort. The rod would gain in weight. Seemed like a "why bother" for trout lengths. For longer rods, a real saving could be made in weight. (Don Anderson)

Exactly, the hollow-building was done as a finagle to give maximum power fiber within the rod weight restrictions of tournament casting... these were long rods. I don't see the advantage for short rods or normal casting ranges for trout. After all, the mass of the rod can actually be of benefit in loading for short casts. (Reed Curry)

I'm just wondering. I'm building a 8 1/2" 9 wt salmon rod, and on Harry's suggestion, hollow building it. I too am wondering if it's worth the effort to off set the taper. The 3% that Harry mentioned doesn't seem like that much. (Mark Wendt)

In my opinion and experience, hollow-building a rod of less than 6 wt. and 8'6" is pointless in terms of a weight savings. Obviously, the higher the line weight, or the longer the rod, or both, the more benefit is seen from hollow-building. (Martin-Darrell)

This one's going to be an 8 1/2' 9 wt salmon rod, that's why I'm considering the hollow building. (Mark Wendt)

The weight saved by hollow-building an 8 1/2' rod won't be very much. You're still casting a 9-wt. line and that's where you'll feel the weight. (Ron Grantham)

Probably true, but look at the knowledge and experience I'll gain. (Mark Wendt)

For me, weight savings is not close to the main reason for hollow building. For fast tapers, I typically don't adjust and end up with a smoother feeling action. Other tapers, I adjust up to 3.5%, varying by how much cane is removed. The rod ends up slightly lighter, more lively. In both cases, I think that tracking is improved.

Since most of the cane comes out of the butt, hollowing gets you closer to what might the ultimate rod: a graphite butt with a bamboo tip. (Jerry Madigan)

Ray Gould was doing something along those lines. He'd hollowed out the butt section completely, and used a tapered carbon fiber tube glued up inside of the bamboo. He discussed it a bit in his book. (Mark Wendt)

Following what I feel to be very good advice by some of you that this may be the best method of building hollow sections I wonder how one should go about this.

Being in the UK I don't have ready access to some of the books you all seem to have, but please don't let that stop you recommending one!

My best guess so far is to flute the straight triangular section obtained from my Medved type beveller using a rather special router bit, then plane up the final taper. But I did say it was a guess! (Robin Haywood)

Make a jig that allows you to hold the strip enamel side down with V-notched (spring loaded) hold downs. Clamp the jig to your milling machine table. Use a ball end 1/8 milling cutter and set the depth and pull the strip through. Keep the hold down blocks close together, barely big enough to fit the cutter between.

If you do not have a milling machine, make a platform to hold a router or Dremel tool inverted. Use a set screw to determine the depth of cut.

Or use a biscuit cutter on your router and make something to hold the strips as you push them through, (Bob Maulucci)

Ah! Thank you.

I had in mind cutting something like a 60 degree inverse flute, but a ball end cutter is easier to obtain! (Robin Haywood)

Bob Milward's book (Bamboo: Fact, Fiction and Flyrods) has plans for a fluting jig using a router, as well as other mills and binders and a wealth of information about bamboo. It's one of the most thought-provoking books on bamboo available.

As far as I know it's only available from

Bob Milward Bamboo Flyrods
1851 Rufus Drive
North Vancouver, BC V7J 3L8
(604) 985-0860

(Robert Kope)

I'd like to ask a question on hollow building. What approach is used when gluing up to minimize the amount of glue that gets squeezed into the cavity? On my solid rods I have always been generous with the glue and as a result plenty of excess is squeezed out, if I did the same on a hollow rod I think the hollowing effort will be wasted. However the glues I have used - Epoxy or Aerodux - both resent being applied too thinly, any thoughts? (Gary Marshall)

Slather the glue on as usual, but when you are done clean out the hollows. I like to to Q-tips as they are cheap and plentiful and readily absorb the glue. I typically use 2 or 3 Q-tips per section to clean up the excess glue before binding. (Kyle Druey)

Do any of you take the weight of the pith you take off to make a hollow built butt, thinking perhaps in an 8' #6. I was doing some test and I do not obtain reasonable weight off going near the power fibers in a spiral hollow design vs. action or strongest problems to perhaps I would find. I can obtain important lost off weight with my bamboo ferrule design but the pit I take off from the hollow prototype don't weight nothing.

Any of you have a good reason to encourage me to continue with my test rod? (Marcelo Calviello)

How much pith are you removing? To attain substantial weight savings one must take off most of the inner portion of the bamboo. I've built several hollow rods with wall thickness of .070". On an 8 foot 6 weight rod, I would expect a weight savings of about 25-30%. (Harry Boyd)

Perhaps an equally important point is the diameter of the section that you are hollowing. If you are leaving .070 wall thickness on a Gillum 86 for example, the average diameter of the hole in the is about .184". On the other hand, if you hollow build a Paul Young Perfectionist, the average diameter of the hole is only .115". The difference in weight will be much greater on a big rod than on a smaller one. (Bill Lamberson)

I went ahead and built the hollow rod. When I tested the Hollow build I don't noticed a great less of power but a great balance improve that result in the feeling of a lighter rod. (Marcelo Calviello)

I just finished building a fixture for the drill press to hollow flute bamboo strips. I don't have a clue as to what size router bit/end mill I should use for this. The rod taper is based on a Garrison 212E that has been modified to a 7 weight with RodDNA. The plan is to mildly hollow the butt and the first third of the tip. (Jerry Drake)

I have 3/32 and 1/8 ball end mills. That is a good starting point. (Bob Maulucci)

I did not read if anyone posted this already, but when I fluted a rod, I used a biscuit slotting router bit with two wings. It had carbide blades and I rounded the carbide by eye using a diamond stone. I used a MicroFence to make the bed and make the depth adjustable. You can find the MicroFence using a Google search. (Chris Lucker)

Under the tutelage of another member of this list, I use a chisel to help out in hollow building my rods. I just finished up a couple of hollow built blanks and realized I know next to nothing about working with a chisel. I'm fairly competent with a block plane, but chisels are a vast unknown. The good news is that I know some of you are quite competent woodworkers and have some knowledge and experience.

Here's my questions: Is it possible to buy good chisels without taking out a small mortgage? At what angle do you sharpen a chisel? Do you use a micro bevel? Do you spend as much time on the back of the blade as the bevel? And so on. (Harry Boyd)

I have sometimes found really good chisels at flea market type antique shows. Buck Bros. made chisels in the late 1800's that beat anything I can afford in modern tools. Look for the words "Cast Steel" on them. I only buy antique tools if they are in good shape though. "Buyer Beware" as usual. I don't spend a LOT of time on the backs and I DO use a micro bevel. A plane is essentially a tool for holding a chisel at a predetermined angle. (Neil Savage)

Piggybacking on Neil's line - a chisel is a plane blade with a handle. Treat them exactly the same as you would a plane blade. I've gotten a few chisels over the years, and like Stanley or Hock blades, some are good, some not so good. Woodcraft has an updated line of Swiss chisels that are pretty nice, and they average around $30 a piece. They also carry the Sorby line of chisels, for a bit more money, most of the sizes we would use are around $50 a piece. (Mark Wendt)

I have 4 Buck Bros. chisels I purchased new in the early 70's. I can't imagine a better chisel. They are as good today as the day I got them. Says right on them "Life Time Warranty". Sharpen them the same as a plane iron with a micro bevel, scary sharp. As far as I know they still make them in Millbury, MA. I use them to plane nodeless splices, much faster than a plane. Count your fingers before and after use. :>) (Don Schneider)

The newer Buck Bros. chisels have gotten really cheesy. They don't look to have the same quality or feel that the old ones have. They're probably being out-sourced now... I saw a set of the in the local Home Despot the other day. (Mark Wendt)

As in sharpening a plane blade, once the back is ground flat and polished mirror smooth you won't need to do it again, unless you sharpen past the polished area.

Buying used chisels - old plane blades too for that matter, pay attention to the length. The hardened part that takes and holds a good edge is only about a couple inches long. Some old chisels and plane blades have that hardened part sharpened away over the years of their use and the only thing left is the softer unhardened steel. Date of manufacture seems to play a big role in the quality of the steel in old chisels. Before the late 1930's or early 1940's they were made of an excellent steel - or perhaps they were hardened better, but after that they don't hold an edge nearly as well. Again as everyone else has been saying, this is with the low to midrange quality. You can still spend megabucks and get excellent chisels today. If you are doing this as a living perhaps you should consider it. Do some research in old chisels and look on eBay. I got a few great planes from eBay, but in retrospect maybe I should have just popped for the Lie-Nielsen planes from the start. (Darryl Hayashida)

Just want to brag a bit. I built a new Steelhead rod this spring and just returned from a week of fishing in Michigan. The new rod is everything I expected plus. The rod started life as a Garrison 212 E taper that I used RodDNA to bump up to a 7 weight. Then I hollow fluted the strips for both the butt and tops. The butt was fluted with a 3/32 inch ball nose end mill to a wall thickness of 0.085'. The tips were fluted with a 1/16 inch ball nose end mill to a thickness of 0.075'. The fluting stopped 1 1/2 inches from the ferrule station. The finished rod weight is a bit over 5 ounces. If I were to change anything it would be to make the rod 8 1/2 foot long to help in rolling split shot on a floating fly line. This rod is a replacement for serial number one which is going into retirement. (Jerry Drake)

Way cool! I did a hollow built version of Jim Wilcox's 8 1/2' Wolverine Creek taper that I fished up in Meechigan last year. I fluted mine also, and it worked beautifully! Hope you have as much fun with yours as I do with mine. Salmon or Steelhead on cane is a trip! (Mark Wendt)

Did you alter the taper in any other way to accommodate the loss of material? Do you think that removing the central power fibers alters the action or makes the rod more appropriate for a lighter line than it would be if not hollowed? I'd like to make a Dickerson 8615 if I could make it lighter. (Henry Mitchell)

To answer your questions. It all depends. On how you hollow and how much you hollow and how large a rod you are hollowing. Often making the rod about 3% larger in the butt and less as you go to the tip of the butt will get you close but that also depends on how you hollow. I use a MHM but I have used a red devil scraper before I bought the MHM. Using the MHM there is very little removal of power fibers. Tom Morgan using the MHM that you hollow the butt to .070 mids to .060 and tips to .050. I hollowed a Garrison 229 with a red devil to .070 with dams too far apart and I caught lots of bass up to 24 inches and catfish to 25 inches before it broke in the handle. Repaired that and later it broke again above the handle but I had the dams too far apart. This is not an exact process just go for it. (David Ray)

But how would this compare to hollow-fluting? I believe that Jerry hollow-fluted this rod instead of hollowing with dams. I wouldn't think you'd use nearly as much in the taper fluting as you would using the dams. (Todd Talsma)

I have done it both ways and much prefer hollow fluting I would agree with you. I normally hollow flute to .070 on the butt, .060 on the mids and .050 on the tips. (David Ray)

On the Wolverine Creek taper rod that I fluted, I didn't change the taper at all. An interesting test. At last years CRG, Jim Wilcox and another fella brought out their Wolverine Creek rods, that weren't hollow built. We did a sorta test, since we all had different kinds of line on the rods, and the hollow built rod was definitely lighter... I have a Wulff TT 9 wt line on mine, I think Jim had a WF 9 on his, and the other guy had a WF 9 on his also. The hollow built rod felt a little nicer with shorter line out, but the solid rods came alive with longer lines in the air. I guess to be more scientific, we should have swapped lines to see how they felt, but we were just having too much fun with three almost identical rods side by side, throwing line...(Mark Wendt)

Todd is correct. The rod is hollow fluted, no dams. I can run a wire from the butt to the ferrule station. Hollow all the way. (Jerry Drake)

I think that is the best way. Then there is the question as to how wide is the flute etc etc etc. I would not worry about it. I have three widths on the MHM. Tom Morgan also suggests that you plug the end with a dowel. (David Ray)

I did not alter the taper to accommodate the loss of material due to the fluting process. The fly line I used was a SA Steelhead taper in a 7 wt. This line has a very long back taper to aid in mending. The head length on this line is about 65 foot long before you get into the running line. Not having a 7 wt. of the same taper to compare with the hollow one, I can't say what the difference is for sure. The hollow rod does seem to be a little quicker in response than you might expect. I am going to try it with a RIO Nymph taper in an 8 wt. I suspect it will handle that line just fine. I will post the results. (Jerry Drake)

The next question is how do you keep unnecessary glue from getting into the hollow, as any glue there would add back some of the saved weight. (Henry Mitchell)

When I glued mine up, I took a Q-Tip and just ran it down the fluted channel to sop up the excess epoxy. (Mark Wendt)

How did it perform with a fish on the end? (Nick Kingston)

The rod performed great with Steelhead on the end of the line. 11 landed and at least that many more lost. Some logs in tight places you just can't keep them out of. You usually know that going in but fish there anyhow. There are two places I fish that I have not landed a fish in three years. Hooked plenty. Maybe next year I will get lucky and hook a dumb one. (Jerry Drake)

I'm planning on taking a Garrison 212E and extending it 2" and hollow fluting it in the butt section, starting about 2" above the grip and stopping 2" before the ferrule station. Anybody with experience in hollow building, have any ideas on how this will effect the action? Crisper, slower, no difference? I'm planning on making this as a tailwater rod for streamers and some distance but, would like to lighten it up a little with minimum change in the action. I haven't built anything in a hollow built configuration before, so if you have any suggested changes to how I'm doing it, would love to hear that as well (also, suggested wall thickness for this application would help). (Bill Walters)

I just completed a Steelhead rod in March on that very taper. I used the 212E and boosted it to a 7 weight. The butt is hollow fluted with a 3/32 inch ball nosed end mill from 1 1/2 inches from the ferrule station to the butt. Before installing the butt cap you can see the fluted hollow. The tip is fluted with an 1/16 inch ball nose end mill from 1 1/2 inch from the ferrule station to a point that the end mill no longer cut any material at the tip end. The wall thickness of the butt is 0.085 inches and the wall thickness of the tip is 0.075 inches. Gluing the rod is a trick to keep the glue out of the center of the rod. I used Nyatex Epoxy spread with a stiff brush. Put it on, wait 10 minutes then brush off all you can. Wipe the channels clean and bind. The fit of your strips must be near perfect to use such a small amount of glue. So far, so good. The PM Steelhead couldn't damage the rod.

How does the rod perform? GREAT!

A week of Steelhead fishing on the Pere Marquette River ended with a dozen Steelhead brought to hand and probably that many more lost to the wood piles. At no time were there any doubts that the rod was not up to the task. The rod is lighter and I think a bit crisper in action. People who cast this rod always have the same reaction. They are amazed that the light yet powerful feel of the rod. (Jerry Drake)

I also use the hollow-fluting technique and have found that a pencil eraser works well to clean the glue out of the flutes. First, hold the eraser to a sander and give it a sort of conical (bullet) shape, then just run it down the length of the grooves. Wait for several minutes, as Jerry suggests, to let the excess glue flow downward, off the strips. That way, the glue is less likely to squeegee back into the grooves when you roll the strips together for binding. (Bill Harms)

If you recalculate the outside diameter to allow for hollow building properly it will make no difference at all to the action. Milward is probably the best source on this, but you will still have to take a view on the actual percentage area of the total that you are removing, since the fluting does not remove an exactly circular cross sectional area, but the mathematics are really very basic. Because you are removing mass from the butt, but not from the tip(s) the balance will be altered because the center of mass will inevitably move towards the tip. Strictly, you should remove a constant percentage of the outside diameter all the way to the tip, but I am well aware that this is easier said than done! (Robin Haywood)

I was just wondering whether anyone had tried just shaving off the inner apex all through the rod, by a conservative amount, say 50% of the section thickness, gluing it up and testing it?  I suppose one could always plug the ferrule stations afterwards by about a couple of inches, but I wonder if it is necessary?

If it works, if...., then it makes a quick and easy way of hollowing the whole thing, although a bit of measuring will be necessary. The reason I fancy it is that, apart from simplicity, it gives a nice predictable hollowing effect which should not alter the action or affect the balance. As far as i can calculate an increase in overall diameter, or section height of only 1.5% should retain the original stiffness, or line rating, if you prefer.  Don't worry about shooting this down, it was just a notion that came to me in my bath. The 25% weight reduction seems an appealing benefit on longer rods. (Robin Haywood)

I have shaved off 60 to 70 percent off two three piece rods except for the tip sections. They work. I have never had a problem. I never built the taper solid so I have nothing to compare them to. They have have heavy stresses put to them. I always shave the inner apex some. I guess a lot of people do that though. (Timothy Troester)

I always plane a little off the apex. The six strips nestle better since they don't have to fight for room in the middle. This makes for smaller or no glue lines. Of course, some will say that, when the strips are planed perfectly, they always nestle well. Am I the only one with imperfect strips?? So sometimes I plane off a little more; not really measuring, and not doing more than 50%. Works fine. There must be some weight savings, but not too much I think. The shavings I have after planing the apex sure don't weigh much... Is the feeling different? I never made the same rod hollow and full, so I can't say. (Geert Poorteman)

I did just that a few years ago with a rod. I just started planning off the apex prior to glue up and kept going. It did not seem like I removed a lot. I just made it hollow. It definitely worked to lighten up the rod. The rod however, just did not feel right. What I should have done is added a small percentage to each dimension to beef it up a little before I did this hollowing. The rod just did not feel right. It was lighter, but I did not seem to have the feeing that I wanted when I cast the rod. I think that since I removed pith, I decreased mass and in turn also decrease/changed the action of the rod. Describing the action is difficult on the best of days. Maybe the balance point was off.

That being said, I like the rod, but I found that I added a heavier reel to it and it helped a little. I also do not have anything to compare it to.

If I were to do it again, I would add a certain percentage to the dimensions of the rod. Say 3% to 5% along the entire rod and then would hollow it. I think that this way I could preserve the feel or character of the rod while making the rod feel lighter in the hand. (Mark Babiy)

The figure I gave of plus 1.5% is correct for a 50% reduction in wall thickness all through the blank, if you went further, say to removing 60% you need to add 3.5%.

These figures will very slightly underread, no harm in adding another .5%!

There is rather more to this, for instance, removing 60% will increase the tendency to ovality in the butt section under load. This will be more obvious in any butt section which does not have a concave taper form. Heretical to the last I firmly believe that all butt sections should be of concave taper because all cantilever beams either are, or should be, designed like that!

Don't get me going on this one! (Robin Haywood)

Is a hollow rod that great? Do they plane the one side of 60 degree strip flat? Why are they so expensive? (Durick Schonfeldt)

You could search this list's archives - I think I sent you that address?

On the other hand for more specific questions this place is the best.

As for your questions

Is a hollow rod that great ?

I haven't made one yet but can well believe that for longer heavier line-weight rods (9 ft plus 5 wt plus), where self weight becomes an issue, hollowing must be better, provided the rod is still well balanced. I am sure others will chime in here.

Do they plane the one side of 60 degree strip flat?

I think some have. eg Wayne Maca apparently does (in a manner of speaking because I don't think it is as simple as that), but then he uses highly toxic epoxy glues, vacuum chambers and other esoteric processes. Most common are various forms of scalloping the strips or fluting them. Basically you need enough remaining wall thickness for strength and enough surface area for gluing.

Why are they so expensive?

Because they are handcrafted and take so much longer to build? (Stephen Dugmore)

Thank you to all who helped me with the design for a hollow fluting mill. It's almost done and I promise to post some pics, but I do have on more question: I based it on 3 flute slot cutting router bits, 1/16 to 1/8 width in 1/32 increments, and my question is do any of you know someone who can grind a radius on these bits? I'm looking to keep the width of each cutter, but I just am going for that half round scallop similar to Winston. Any help, once again and I again promise to share the goods when I am done. (Eamon Lee)

Perhaps you could consider using ball end mills instead. (Ralph Tuttle)

I found a guy that makes custom bits. I'm sending him drawings and he 's going to get back to me with a quote. Let you know. Thanks to all who replied. You've been very helpful. (Eamon Lee)