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Planing - Final - Apex Removal


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Rule

Several years ago I bought this book because it was cheap (The Bamboo Rod and How to Build It by Claude Krieder - originally published in the 1950s).  Now, I'm rereading it to see if anything makes more sense.  There are a couple of issues, though, that I thought I would ask y'all about.

Krieder recommends sanding  the sharp edge off the finished strips.  Any value to this process?  Any detriment?  I can see that this may cause a problem is there are any inconsistencies in the finished taper, but...  (Jason Swan)

    Sanding the very points off the blank aids some finishes. Some finishes like to "travel" to the points and others to the "flats" making the finish thicker @ these areas. Sanding the points reduces the chances of the finish that likes points a chance to build. Sanding of the point makes very little change in the taper.  (Don Anderson)

    As soon as I get done planing a strip I flip it over and give it two passes with the plane on the apex of the pith side.  I have my plane set at .004 for this procedure.  I have done this ever since rod #1 and it seems to work well.  I do it this way so I don't have to worry about anything sticking to the tape.  I then tape my strips together(making sure that there is no foreign material in between), then I cut open my tape and lay out the strips for gluing.  I do take a soft paint brush and whisk off the strips before I glue and I also blow them of with a blast of air.  (Bret Reiter)

    I generally use the Garrison stagger on strips from one culm. If I use strips from separate culms if the nodes are set differently between the culms I go to a 3x3 or 2x2x2 spacing so as not to waste any more cane than I have to.

    As far as Garrison's stagger, number your strips 1 thru 6, set em up in a 1, 5, 3, 6, 2, 4 rotation and stagger them an inch and 3/8ths, cut to length, and glue 'em up 1, 2, 3 , 4 , 5, 6.  (Hank Woolman)

    If you use more than one culm to build a section, be sure that you locate culms with fairly similar node spacing.  That's often very difficult, however, since very few culms will match one another.  Also, if you build with different culms, take care to use no fewer than three strips from each culm, and locate them alternately in the finished section.

    Kreider's recommendation to spiral the nodes is not original with him. Payne and others used to stagger the nodes in this spiral fashion as well. I have never used any other method, myself, in over 25 years of building. There are various opinions on the importance of the staggering issue, but to me, it has always seemed to make good sense to support each node with five "neighbors" whose fibers are straight.

    Nodes may be thought of as either stronger or weaker than the internodal fibers, depending upon whether you're talking about resistance to breaking (like willow) or to bending (like oak). But either way, nodes are different from the straight fiber, and for that reason alone, I do not want them placed near one another.

    I have heard that the spiral staggering may induce "torque" to the rod while casting, but I have never found that to be the case.  Even so, I will spiral the nodes one direction in the butt, and the opposite direction in the tips. I have no idea whether this matters or not, but like chicken soup, "it can't hoit."

    Finally, Kreider's suggestion to sand off the apex of each finished strip is an excellent piece of advice.  Someone on the list a few months ago explained this idea well.  Basically, as you have six apexes all competing for the position of "dead center," you may be inviting accuracy problems in the glued-up section.  In theory as in practice, the six strips can't all occupy that same position.  Sanding off just a few thousandths from each apex will obviate the potential problem and allow the strips to nestle comfortably together.  (Bill Harms)

      I also take away a bit of the apex of each strip and I see an improvement, less and thinner glue lines. I used to make a pass or two with the plane, but now I give it a couple of passes with sand paper. I don't think it takes away much strength. Take a pass on the apex with a plane and ask yourself, seeing the bamboo hair coming off the spline, if it represent much power.  (Geert Poorteman)

        "Bamboo hair" is a really good description. Very poetic.

        I agree that it doesn't represent any threat to strength - it usually mikes out at about .00125" using my very pretentious digital micrometer. I would prefer to take it off with my plane, as it seems to be a cleaner job than sanding, and no dust.

        The oxymoron "about  .00125" incidentally, arises from a machinist friend of mine; I cannot quite work out whether he was pulling my leg or not.  (Peter McKean)

        You can remove quite a bit from the apex without affecting the strength of the cross-section... you can remove up to 0.030 per strip safely from my analysis and experimentation.  (Kyle Druey)

        Both you and Harry B say you sand the apex.  I have always taken one very thin pass with the plane.  It seems to me that by sanding you run the risk of sanding dust between the glued strip surfaces.  I guess you could blow it out, but???  (Ralph Moon)

          I mentioned that I sanded the apices off, when I should have said "planed". Also, if I'm hollow building I tape the 6 strips together, open them as I would for gluing and plane the inner apices down to where the planed flat is a little greater than 1/3 the width of the face of the strip. Not very scientific but it works for me.  (Hank Woolman)

          Yes, I have no compressor, but a fairly good lung capacity. My head is a bit dizzy afterwards.  (Geert Poorteman)

            I take one or two passes on the inner apex with a plane set to about .006". There is often a thin wire edge to the finished splines that may get stuck in the glue line and this removes it.  (Ted Knott)

          After planing to final dimensions, and sanding off the apex, I wipe each strip down with an old leather golf glove moistened with mineral spirits.  Then just before gluing, I give the bundled strips several bursts of air from one of the "canned air" computer cleaning gizmos.  (Harry Boyd)

            I sand the apex off, two passes with 320 grit wet/dry, then wipe each strip with a thick bristle brush to remove the dust.  (Martin-Darrell)

            Using a solvent before gluing is probably a very good idea.  I have concerns (unproven) that petroleum distillates might leave a residue that probably won't effect epoxies but might weaken UF or resorcinol glues.  I like to use isopropyl alcohol thinking that the water it leaves behind is beneficial to the curing of these adhesives  should the cane be very dry. Just a comment.  If I'm all wet, I will gladly stand corrected.  (Jim Utzerath)

              You may be right in that.

              There are some rain forest timbers that need to be washed with petrol before they can be glued with success. These same timbers are not normally ones you can use resorcinol and UF glues on as it happens, especially casien based glues. It could be a coincidence or it could be the preparation of washing with petrol (or what ever solvent) is what causes the problems. These timbers normally glue OK with epoxy.  (Tony Young)

              Alcohol certainly shouldn't be a problem with resorcinol since we add a bit to the glue anyway.  Don't know about UF.  (Neil Savage)

          I make two passes with my finishing plane with the strips taped together like they would be glued. After making the passes, the strips are brushed with a stiff bristle brush. A lot of the trash will stick to the sticky part of the tape that is exposed. Remove the tape and re- tape for gluing.  (Tony Spezio)

Rule

I am curious as to how many of you sand or plane the apex of finished strips before gluing. I have done it both ways, and it seems the strips nestle together slightly better if I don't sand. I am talking about taking off maybe a quarter to a half thousandth on each strip. I am wondering if it is even worth the time considering the infinitesimal amount of glue in this part of the joint compared to the glue contact/surface area of the rest of the bamboo we are  gluing.   (Tom Vagell)

    I always take off a coupla thou's with the plane.  Two passes with the plane set for as fine a cut as I can manage.  Like you, I think it greatly helps the settling in of the strips and may even reduce the chance of glue lines.  Maybe.  (Harry Boyd)

      I think Harry may be right, although I have no hard proof. I did this planing of apexes for a long time while hand planing. I stopped doing it for some reason, or maybe for no reason at all other than laziness.  I started doing it again when glue lines appeared on rods made with the Hand Mill. While I know this removal of the apex was not the only solution I tried, I really do think that it has helped the strips settle in better during glue up. Doug Easton recommended that I start doing it again, and so far it seems to have worked.   (Bob Maulucci)

        I've noticed that I sometimes get a "wire" edge on the inner pith edge of a strip, but rarely on the enamel corners.  These can be quite small, as little as .003" in thickness.  On one occasion I had a bit of this jam into the small end of the planing form, causing under size strips at this point.  There is also a risk that a small bit of "wire" could get bound into the strips when gluing.  I always make a couple of passes over the inner corner to remove the "wire", and also check the form to make sure there are no bits of bamboo jammed into the bottom of the groove.  (Ted Knott)

          I've got a small piece of soft buckskin.  I pinch each strip gently in the folded leather and roll the strip back and forth and work along from big to small end.  It takes off the wire edge slivers. Otherwise they come off when you are applying the glue.  (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)

            I use my hand scraper to take just one swipe off the apex of each strip. The strips seem to nestle together better and no noticeable glue lines.  (Jack Follweiler)

    I use a sanding block on the apex's just before glue up, doesn't seem to hurt anything.  (John Channer)

    I believe I heard a wood working tip about easing a corner ever so slightly to help parts fit.  Or was is metal working?  I don't remember.  But I do remember that the reason given was because 2 things can't occupy the same space at the same time.  In what we do that is actually the apex of 6 strips plus glue competing for the center of the rod.  (Tim Wilhelm)

Rule

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