I built a R/D bow, maple core with zebra wood lams under clear glass on the back and belly. glued up with smooth on and cured in the heat bow. After about 100 shots it began to develop some white specks under the glass where the limbs work the most. The lams were .025 What kind of prep is necessary for this combination? The specks are only on the back at this time
Thanks guys................James
These may be air bubbles between the veneer and glass. If they are and they appeared a while after glue up then it could be that the veneer was a little green and it is off gassing. Maybe???
James,
With that combination I don't think any special prep is required. My procedure is to clean the glass and laminations with acetone before gluing, after several hundred bows none have delaminated.
I can think of several possible causes, one being a dry glue joint, or the bow being over drawn. Could you post a photo of the limb?
I had a similar problem with my first ever laminated bow. I guess it was due to fades on the riser that were to steep and almost all of the bending of the limbs was done very close to the riser. That part of the limbs is constantly overstrained and after a while started to show some white freckles.
BTW I still have that bow, but I haven't shot it for a long time.
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Andy
i had that problem in the recurve-section of a bow. that spots went whiter and expanded, till one day that section delaminated. i think that spots came from a non-degreased palisander veneer, which gased out.
greets
Without seeing it,I would guess it is not the glass. You would have seen it when you pulled the tape.
Most likely glue or lam prob.
Can you post a pic of it?
Thanks guys,
Being my first clear glass bow with veneers I had a lot going on and didn't clean the glass or veneers. The specks are very small and only show when the light is just right. Another 200 shots and no change so hopefully it will be alright and the problem is only a slight cosmetic defect. The learning proscess of building bows has been the fun part and you guys have been great helping me over the humps. Thanks again guys........James
I saw a bow that had air trapped in the pores of the wood. They showed up as tiny light spots under the glass. Where Zebra wood is a very coarse wood it might be a possibility.