I've glued up 2 rods with the new Aerodux resorcinol glue and I want to give the list a brief report on my experiences.
This is a two-part LIQUID resorcinol glue...both the resin and hardener are liquid. That was the main attraction of the glue for me, to get the strength of resorcinol without the walnut flour filler. The resin appears the same as what we are used to, while the hardener is a dark brown goo about the consistency of molasses.
A secondary benefit is that it cures at any temp above 50F which means I can leave everything in the basement shop even in winter.
Aerodux is a product of Britain so it is possible that some of our builders from that side of the pond are familiar with it. It is imported into the US by Custom Pak, and they list two formulations on their website, a Medium and a Fast cure. (A web search indicated that there is also a Slow cure which apparently Custom Pak chose not to import.) These are available in gallons for about $160. Since I didn't need a gallon, I resisted the urge to buy it until I found it on Aircraft Spruce's website, in quart kits, for $65.
When I received it, I was pleasantly surprised to have a quart of each, hardener and resin. (I was expecting a quart total.) The cans were clearly marked as being packaged by Custom Pak. The hardener had an "F" which I guessed meant it was the "Fast" cure formulation. I was hoping for the Medium cure but there was no choice or indication on the Aircraft Spruce page.
There was no data sheet with the glue. I emailed Custom Pak to see if they would fax me one but they did not answer. I have not pursued this yet. The Custom Pak web site says the shelf life is 1 year at 70F and something I read implies its considerably longer at lower temps.
I mixed the glue by weight and applied it with a tooth brush as I normally do. The mixed glue is fairly thick but spreads thinly. For the second rod I added 10 percent denatured alcohol by weight to make it a little thinner.
The glue does set up fairly fast. After binding you have a few minutes to straighten, but just a few, before things stop moving. If you like taking a long time to fiddle with the blank, this is not the glue for you. It would be a service to the rodbuilding community if we could get access to this glue in the Medium, or even better, the Slow cure formulations.
The resulting glue lines are still the characteristic resorcinol plum brown, but they seem thinner and less noticeable at this early stage than ordinary resorcinol glue lines. We will see what happens after a couple years.
- Liquid hardener leads to thinner glue lines
- Cures at cool temps
- Long shelf life if kept refrigerated
- General resorcinol toughness
I believe someone came up with a formula to "bleach" the color out of Resorcinol glue, but I also think I heard that the effect was not permanent for some reason. Would any of you know of further experiments to get rid of those damn, purple railroad tracks? Probably, if it weren't for the color, ALL of us would be using the glue. Where are all those chemical engineers when we really need them? (Bill Harms)
That was in the Garrison book. Hoagy said you can add universal pigments (I forget which, I think white and mustard) to the glue and it will turn it tan, but if you have to heat straighten, it will turn pink where it was heated. Sounds like more bother than it's worth, I'll just stick to Epon. (John Channer)
I've been convinced for sometime now that there has to be a way to deal with the purple color that's more permanent. Maybe we just to need to find a chemist and convince him somehow that its worth the effort. (Bill Walters)
I'm wondering if that Resorcinol can stand 350 for say ten minutes? Anyone with any experience there? Maybe 300? Do I dare? (John Silveira)
It most certainly will. The only downside is that it will turn jet black. (Tom Smithwick)
The heat treating process is done before gluing up the rod section. Most people do it before final planing, although some do it afterwards. Even if you are building nodeless, I think the heat treating is done before scarfing and gluing.
The sequence I use - your milage may vary - is this:
- Flame for cosmetics (optional)
- Soak (optional)
- Rough Plane
- Air dry (strips shrink from soaking - this helps keep binding tight during heat treating)
- Heat Treat
- Final Plane
- Glue and bind. (Kurt Clement)
To anyone interested in trying resorcinol, I'd suggest the British Aerodux liquid catalyst version. No powder to worry about. Its not cheap but available in quart kits from Aircraft Spruce, and seems to keep a long time (years) stored in the refrigerator. Working time is short, however. If you are used to epon, it might catch you by surprise.
There might be other sources besides Aircraft Spruce now. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)
I have also used Aerodux for my last two rods with very satisfactory results - nice thin even glue lines!
I used alcohol to thin the glue which could explain some additional soak in and it certainly makes it easier to paint on to the strips. But in my case at least there is no way that lines can be eliminated as the Aerodux is supplied with a fine filler in one of the notionally liquid components.
This glue is also strictly a phenol formaldehyde and those more knowledgeable have commented in the past that it is not quite as strong as the pure version. It is however more than adequate! Strong smell and very unhealthy, make sure you are in a ventilated area, strangely I don't notice the smell when painting it on but when binding up by hand it can get a bit OTT. (Gary Marshall)
PS: yes I can get zero glue lines but only by using epoxy!
If you keep your glue pot in a bowl of ice and mix it right out of the fridge you get a longer working time. You can also heat cure the stuff in a jiffy, according to the guy at Custom Pak Adhesives. (Brian Creek)
You learn something every day.........
Where do you get Aerodux from over here (UK), how much is it £ and in what quantities is it sold in? I have never even heard of it. (Paul Blakley)
I'm answering your first question as your web search has thrown up a few other points. the following link should take you to Skycraft. As the name suggests they supply spares and materials to Aero fanatics. Aerodux is a certified adhesive for wooden airframes. They also sell Aerolite but I don’t think this is a viable rodmaking adhesive.
Of the other adhesives you have found, Cascophen is a type of resorcinol glue but has one liquid and one powdered component, it is available from most chandlers as it is used in boat making.
Extramite is different this is what used to be called Cascamite and is (I think) a casein based glue. It is certainly not a resorcinol. It is supplied as a white powder and mixes with water to give a paste. It is decent strong stuff and I have used it for various jobs in the past but it sets up much too quick for my speed of assembly. I did try it once!
If you try the Cascophen I would be interested to hear how you get on. (Gary Marshall)
Cascophen is now sold as Extraphen and I have been using this for the last ten years plus. It's marketed by Humbrol as is Cascamite (now called Extramite). Since my posting to the list I have done a web search for Aerodux and this is very similar if not identical to Cascophen. You should note that the color of Cascophen (as is that of Aerodux) is brown and NOT the famed red/wine of a 'true' resorcinol. My last five rods have been bonded with some resorcinol that I imported from Tony Young (now off the list and on his way to a new life in NZ) and this glue leaves the famed red/wine glue lines. Cascamite was the adhesive used by the old rodbuilders e.g Hardy, Allcocks etc. during the late 50's and sixties. The problem with this being over the years the adhesive crystallizes and breaks down leading to a gradual delamination. Aerolite 308 (with GBPX hardener) is a very fine rodmaking adhesive (note I state 308 as 306 is totally unsuitable) and is used by Chapmans etc.
The problem with this adhesive is that one has to buy the stuff in bulk and I know of a few UK rodbuilders who club together to get a batch mixed but it is very expensive for the amateur. Guess I am stuck with Cascophen (Extraphen). (Paul Blakley)
That’s cleared it all up nicely! I was interested in your comments on glue usage from past UK makers. I had wondered what was used particularly as neither the Hardy nor the Allcocks rods that I have show glue lines whereas the Sharpes one does. (Gary Marshall)
If I remember correctly, I read that there is a powdered die that you can add to resorcinol to help eliminate the purple glue line.
Also, I have never used resorcinol how ever my next rod will be will be with this glue. My question, If I flame my rods is the purple line still visible. (Denny Dennis)
Not as visible, but it's still there. Another problem I've had with resorcinol is even after sanding the glue off, after varnishing and time somewhere a resorcinol stain shows up on the surface of the rod where I didn't get all of it off. I've heard others complain about this also, and don't know if there's a good solution. (Brian Creek)
The glue showing up on the rod after the varnish was a problem this is what I did. First of all I stopped cleaning the glue from the blank with sand paper and stated using a file. Tricky but doable. Then I started examining close after first varnish. I have planned on sacrificing the first coat of varnish at times. (Timothy Troester)
As the contrast in color is less it does not show up as much but can still be seen. From my perspective the fine lines look great on brown toned or flamed rods but not so on blond rods. This is however purely subjective! With the Aerodux I use the glue line is a plum/brown color perhaps the pure resorcinol is more distinctly purple? (Gary Marshall)
One solution I've heard of, but never tried (and I think this is the one listed in Garrison), is to add powdered titanium white (paint) to the resorcinol to lighten it up. I have been told by another rodmaker who did try it, that after a few years the base color of the resorcinol bleeds thru, an eventually the glue lines turn dark.
I actually like the way resorcinol looks on a flamed or ammonia toned rod, and it's the only glue I use for gluing up sections. (Chris Obuchowski)
The pigment to use is as manufactured wholesale by the Tioxide (IE: Titanium Oxide) Company.
based in the UK and about ten miles from my home! I believe Tioxide are the largest manufacturer in the world of this white pigment 'paint' additive. (Paul Blakley)
I have never used resorcinol before but I have some that Todd gave me to try out and I want to use it on the 2 rods I have ready to glue up. There was some talk about the mixture for this. What is the best formula that people are using? I know it is not the same as on the cans. (Bret Reiter)
I've used resorcinol on dozens of rods with excellent results every time. I mix by volume, and use plastic disposable picnic teaspoons. It's a ratio of 3:4 (I can't offhand remember which is which, but it says which on the can), with one part denatured alcohol. With the powder, it's important to level the measure with a flat object (scrape the flat edge of a scrap of cane over the top of the spoon - just like if you're baking a cake.
Some folks are careful about sifting the powder, but to tell the truth, I don't bother anymore, and haven't had any problems with gaps or glue lines. (Chris Obuchowski)
Wear gloves. It stains and is narsty! I wear goggles when I glue with it, but that's just me. (Brian Creek)
I just finished gluing up a blank using Resorcinol glue for the first time. After 24 hours I have it out of the string and sanded. How long should I wait before beginning to remove the slight twist I ended up with on this one? How much heat will this glue tolerate in the straightening process? Searching the archives tells me that the blank will continue to cure and get a lot harder for possibly a week. Somewhere there must be an optimal time to do this. (Steve Shelton)
I don't think 24 hours is quite long enough. you will have to be gentle with it. I would wait a couple more days. when it is dry the timber of the sound you hear when you run you hand over the section will sound different than when yet damp. I discovered this right off so you will be able to distinguish this also. then again if you have sanded off the glue you might not be able to distinguish the difference, I suppose. I would wait a couple more days. you can straighten out out twists after weeks. I have done it. (Timothy Troester)
Resorcinol is very tolerant to heat have no fears here. As for time I usually leave my blanks in string for three weeks before continuing with the process but I have a friend who is happy to continue within a few days of gluing up. (Paul Blakley)
My reading of the Garrison (Carmichael's) rationale for the appearance of the purple glue lines was that they were due to the color actually 'soaking into' the bamboo at the very thin edges at the junctions of the splines. The question in this time frame, is where is Borden's resorcinol glue available if someone does want to use it? (Vince Brannick)
This is an interesting observation about the purple color being due to the glue sinking into the cane. The Orvis rods, because they are/were impregnated with Bakelite may not have had the same amount of absorption thus limiting the purple color at the glue lines. Mine is also a very dark brown rod so this may also have contributed to the color difference. Wonder if anyone who uses resorcinol has used it on darkly flamed cane and/or on impregnated rods and seen any color variations as a result? (Larry Puckett)
Borden is now doing business under the name Hexion (same Columbus, OH address) and seems to market adhesives under the Hexion, Borden and Casco brand names.
The Cascophen PRF are the phenol resorcinol resins; there are several. You can get Cascophen PRF in small quantities in the US from Aircraft Spruce.
You can also get Aerodux resorcinol. It is expensive but mine has stayed good a long time (years) kept in the refrigerator.
Its amazing what you can get in a few minutes with Google. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)
Thanks for the web addresses. The original Borden's resorcinol glue available, was made in the Borden plant in Bainbridge, NY, but at some 'point in time,' it was discontinued, and subsequent inquiries, generated replies from the personnel at the plant, indicated no knowledge of the product. I think 'Weldwood' at some time also made the same or a similar product. (Vince Brannick)
As I posted yesterday, DAP Weldwood still makes resorcinol, it's available from several sources. (Neil Savage)
And it's good stuff. Can be easily mixed by volume, and thinned with denatured alcohol. (Chris Obuchowski)
I’m looking for info about Resorcinol glue, I came across this web site for aircraft building supplies.
Aircraft Spruce and Specialty Co.
I thought it was interesting all the different offerings they have for adhesives! When I was starting out making rods, I had a boss that was into home built aircraft. He had just finished building a "Two Holer" (Tony), and he gave me some left over T-88 adhesive. I really liked it, but it didn't seem too popular with the rodmaking community. So, I went with Nyatex and Epon. I did make several rods with it and they are still holding up well. I get real nervous when it comes to heat straightening rod sections, no matter what adhesive I use! I still use the T-88 for cork rings, because I like the extended working time, color, and thin glue lines in the cork handle. (David Dziadosz)
Can anyone tell me of a source for resorcinol glue that would be from a fresh batch....that has not exceeded the shelf life? The only product that I have found locally is about five years old. (Larry Fraysier)
I think you would be safe with Wicks Aircraft, or Aircraft Spruce, or a big boat building outfit like Jamestown Distributors. All have web sites. (Tom Smithwick)
Sometimes you can find resorcinol at boating supply stores which has turned over more recently than at most hardware stores.
Look online for Aerodux 500. There appear to be some U.S. suppliers. Its kinda pricey unless you can find small quantities, but its worth it, IMHO.
FWIW I tested some really old DAP resorcinol I had on the basement shelves for at least 10 years. It seemed fine to me. But I trust Aerodux more I guess. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)
Why not go right to the source. http://www.cpadhesives.com (1-800-454-4583) Ask for the rodmakers pack. (Timothy Troester)
Try McMaster-Carr. I've gotten it from them in the past and they were selling it in pint cans at the time. (Brian Smith)
If I use resorcinol on a blond blank, will the glue stain (discolor) the flats? I assume not, but I've never tried it. I don't mind the purple seams. I just don't want purple stains all over the flats. (David Bolin)
You should scrap/sand all of the glue off the flats. No worries with it staining. (Todd Talsma)
Sand/scrape or i use a file. (Timothy Troester)
Depends on who you are. Everett Garrison and Bill Phillipson didn't have any problems with it, but H-I and South Bend either couldn't get it off or couldn't be bothered with it and theirs were flamed. (John Channer)
I was thinking the other day about glue entering the fibers of cane. I read somewhere that Resorcinol glues actually go into the power fibers 0.002>0.003" resulting in glue lines. Is this true of other glues? And if the glue does really go into the fibers, does anyone take this into account in the taper?
I know from sad experience that glues that enter wood fibers results in stains applied later not entering the wood unless the glue is removed entirely. Would a similar glue result diminish the ability of the cane to accept finishes. Or are all finishes essentially "top" coats. (Don Anderson)
Varnish and polyurethane are top coats, pure tung oil and linseed oil soak into wood, but I question if they do the same or at least to the same extent in bamboo, it is so dense. Oil based stains aren't effective on bamboo, so I doubt there is any harm to any finish from whatever glue you choose to use. I've refinished plenty of cheap old rods that had glue residue left on the surface under the original finish, as far as I could tell there wasn't any worse finish failure in those areas than anywhere else. (John Channer)
Resorcinol thinned with alcohol does penetrate into the bamboo fibers, but only at the cut ends (think of thin glass straws and capillary action). The glue does darken with age, and so glue lines do look like they "grow" over time. I don't know about the other adhesives (the only one I use other than resorcinol is URAC, and that far less frequently). Since most of the others are neutrally colored, it'd be hard to tell if they do the same (though the epoxies all seem quite a bit thicker than resorcinol). (Chris Obuchowski)
Wolfram Schott covers this in his "Bamboo Under the Microscope" which can be downloaded from the Power Fibers site. Schott also says Garrison's dilution and penetration figures are not accurate. (Ralph Moon)
My thanx for the pointers @ the download from Power Fibers. Good stuff there. Read both of the downloads - Schott makes some enlightening observations based on his test results. Particularly liked the observations on planing Vs milling + heat treating regimes. Looks like resorcinol is the only glue that can be "seen". That is too bad. Would by great to see if other glues also "went into" the fibers. (Don Anderson)
Given that resorcinol is the only colored adhesive, the thought occurred to me to stain the adhesives with oil based "paint" stains and see if one could learn anything. This would assume the stain would not preferentially migrate to the fibers. It is a good bet the oil based stains would not, at least some of them. You could likely distinguish the glue line anyway. (Dave Burley)
Did an "experiment" rod about 8 years ago that I did a lot of things to:
- Stained it with leather stains
- Stained it with marking pens
- Stained it with Aniline Dyes
- Taper evolved from the Ring of the Rise
- Handle/reel seat of Cottonwood bark
- Soaking expansion/heat treating contraction experiment
And on and on.
Thing learned - don't use flour catalyst for Urac. Dies soaked into seam. All in all, the stains worked poorly on rod shaft - blotchy - may have been problem with glue not totally removed. (Don Anderson)