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a little glue testing
mmattockx:
--- Quote from: simk on October 06, 2022, 02:37:29 am --- For some reasons I wanted to get away from 2k for my glueups and use white pva wood glue instead(D3).
--- End quote ---
The biggest question is if your white glue dries truly hard or stays a bit rubbery.
I have used Titebond 3 for the risers on a couple bows and did all the lam gluing with it for my last multilam bow. I wouldn't recommend it for the laminating because it stays a bit rubbery and I think it lost a bit of reflex due to that. The bow shoots fine and has not failed after maybe 1200 shots, but it also lost some performance with the glue creep.
I think your wood glue will be fine for risers and handles and such, as long as your fades are nice and gentle to avoid prying the handle off. I have used TB3 and plain yellow carpenter glue for handles and tip overlays with no problems and will continue to do so for woods such as red oak and maple.
Flntknp17 has done some testing of BBO bows comparing TB3 and EA40 and found he kept a couple inches more reflex with the EA40. My next bow will be glued with EA40, though I expect any quality epoxy will also work the same.
Mark
BowEd:
By getting away from 2K glue,do you mean epoxy?
simk:
thanks for interesting input guys!
maybe Del was right and I should repeat with bowwood scraps :)
I remember your postings making bladder glue dave...did you post pics of the ripped apart woodblocks?
I did once check the data sheet for titebond because I wanted to know temperature resistance. They say its around 100deg.cel. Useful information Eric, thanks!
I had been thinking quite a bit on that same "biggest question" Mark, a while ago. For me there are other factors seem to be more important when it comes to keep reflex. A (reflex)significant creep should be seen or felt on the tips imho. And my friend, using tb3, makes faster bows than I do (-:
yes, Epoxy, BowEd
will break the samples tomorrow.
cheers
superdav95:
--- Quote from: simk on October 06, 2022, 04:10:08 pm ---thanks for interesting input guys!
maybe Del was right and I should repeat with bowwood scraps :)
I remember your postings making bladder glue dave...did you post pics of the ripped apart woodblocks?
I did once check the data sheet for titebond because I wanted to know temperature resistance. They say its around 100deg.cel. Useful information Eric, thanks!
I had been thinking quite a bit on that same "biggest question" Mark, a while ago. For me there are other factors seem to be more important when it comes to keep reflex. A (reflex)significant creep should be seen or felt on the tips imho. And my friend, using tb3, makes faster bows than I do (-:
yes, Epoxy, BowEd
will break the samples tomorrow.
cheers
--- End quote ---
Simk. No I did not post pics of the test pieces. All 8 but one broke at the wood and not the glue line. The one that failed (sort of) was I believe my fault in clamping. The glue line on that piece was thicker then the others. All pieces were wetted with thinned down glue and grooved as well. All had decent squeeze out but on the one that failed the underside had an air pocket in the glue line and why I believe it failed. Even then it failed taking the majority of the wood with the break. All the others broke on wood only or the glue line with layer of saturated wood with dried glue. I was happy with this test as it was merely testing the 20 Lpi grooves and the homemade glue and sizing. The sturgeon glue seemed to quite good for strength. A proper test for my purposes may have included some grooved horn scraps I suppose. I think there is merit in conducting a test with hide glues, fish bladder glues, ea40 and other wood glues and epoxy. A break test could be set up with a press with a measure scale to compare results in footpounds at the breakpoint. This would test the holding strength of the glue. There is also another test that can be done the reflex return test. This test would show how much reflex creep is returned with each type of epoxy, natural glue or wood glues. This test could be done using a simple single laminated bow limb placed in a vice and measure the amount in inches the reflex immediately returned and then at intervals of each min or 5 mins. To me this would be an invaluable test and I may do this one myself one day as this has been in the back of my mind as well. My gut tells me that ea40 utilizing the hot box and mixing 2 parts a and 1 part B as the can instructs my show the better results. One day we shall see.
simk:
Ok, I havent been able to shear apart any of the samples on my strong workbench: however breaking the samples was easy and all broke in the wood.
Superdav, it would relly be interesting to conduct real tests, including measuring the forces required to destroy the samples. Now I do have a friend who runs a paragliding shop and does maintenance. They as a standard test lines and have a device to rip them under contolled enviroment. Maybe this setup could be used for our purpose...breaktests including force measurments. I will ask him weather i could give it a go at his workshop. Lets do this a little more sophisticated 🤗
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