If you have a string instrument of any kind that needs fixing, a mistake you made in building a new instrument that you need to "disappear," or a question about the ethics of altering an older instrument, ask here. Please note that it will be much easier for us to help you decide on the best repair method if you post some pictures of the problem.
I wondered if anyone has ideas about possible fixes to an issue I just ran into. I was performing the tummy-cut on this instrument when I came across a distortion in the laminates that was likely caused by uneven clamp pressure when gluing the pieces together. Anyway, I would be interested in your thoughts on a possible remedy so that I can get a nice white line gently arcing between the zebrawood and walnut.
If you used a heat reactive glue, you might be able to smooth down the high spots by heating the area with a hot household iron. After heating it up apply a caulk and clamps.
I understand that at this point how to fix is more important than what caused it, but I've been trying to envision how those ripples could have formed if the layer above stayed flat during clamp up... Do the ripples run the full length of the blank, or does the stripe layer just lumped up in that one small area? Seems like if it was sheet slippage while clamping maybe the ripples would be full length?
Any change there was grit /glue chunks in there that raised those up like that?
I’m having a hard time understanding what I’m seeing. That said, I’m wondering if moisture in the glue caused some expansion of one of the woods so that it didn’t fit in the space between the clamping cauls. The ripples and the grain seem to coincide. To repair, maybe that edge could be covered with some binding?
Kent Everett showed a technique to laminate (for veneering an arm bevel) where veneer surfaces were coated with Titebond and allowed to dry. Then, the two surfaces were hot-ironed together. I’ve done it. It works amazingly well.
Thanks for your responses, I ended up routing out the impacted area using a template and then filled it and levelled it back again. It gave me the stripe I needed, i just need to clean it up a little more. I suspect that there was some warpage due to the clamping / gluing process which caused the affected part to distort like that. I think in retrospect Barry's solution would have been the one I should have gone with since the glue I use is heat responsive.
Bob Gramann wrote: ↑Thu Nov 13, 2025 1:36 pm
I’m having a hard time understanding what I’m seeing. That said, I’m wondering if moisture in the glue caused some expansion of one of the woods so that it didn’t fit in the space between the clamping cauls. The ripples and the grain seem to coincide. To repair, maybe that edge could be covered with some binding?
Kent Everett showed a technique to laminate (for veneering an arm bevel) where veneer surfaces were coated with Titebond and allowed to dry. Then, the two surfaces were hot-ironed together. I’ve done it. It works amazingly well.
Bob, I must try that, I didn't immediately think of a heat-solution, since I have had unpredictable results in the past, but I think this would have been the better way to fix the issue.
The repair I recommended works well especially if you don’t wait too long. If you rework the area within 24 hours of the original glue up the glue will react more and you will have better results.
