a little glue testing

[simk]

 For some reasons I wanted to get away from 2k for my glueups and use white pva wood glue instead(D3). Alone the white wood glue has -according to the data sheets - a very short open time (10-20min) which will hardly allow me a careful glueup-process. I now decided to make a little test and glued 6 samples of wood blocks: 2 samples are glued according the manual....meaning put glue on the surface and immefiately press. 2 samples are smeared with glue but then pressed together only after open time of glue was clearly exceeded (25min). In addition, out of pure curiosity, I glued 2 samples with a rest of old, ready to use, fishglue.

I will later today try to shear apart the samples. As long as it breaks in the wood and not in the gluelines I will hopefully be fine with the bows also. I'm curious now 🤞

[Del the cat]

I wouldn't use anything other than glues with a proven bow making track record.
Dunno what you mean by white wood glue ... hopefully not ordinary PVA.
Also is your test being done with actual bow wood or just some random pine lumber which probably will fail befor the glue line?
Del

[simk]

 I know what you mean Del, thanks.
But I know more than one bowyer making bows with ordinary pva wood glue of D3 quality. There are many brands around, most famous is titebond.
Actual bowwod would have been better than pine 😅 but I made, long time ago, a trilam with a pine core too 😅
So this setup sure is not perfect, but at least semi-conclusive for me.
If its sucessful I will glue a bow as next stage. Any glue that is stronger than the surrounding wood will do its job. I dont mind if it fails in the end. I will not sell this bow but give it to the clubhouse for everybody to shoot...
Cheers

[superdav95]

Interesting.  I did a similar test last year but with sturgeon glue. I think I used 8 test glue ups with pairs of scrap pieces of bow wood blocks.  I grooved them all as I would do for a bow lamination for horn.  This was home made sturgeon bladder glue and the results were very good. I wanted to be sure my glue was gonna hold before applying it to a bow naturally.   I think tests like this are great and what us bowyers should be doing more of.  Sometimes we catch ourselves getting stuck in “the way it’s done mentality” and can forget to think outside the box.  We should experiment as much as we can.  Every once in a while we stumble on something new that works and even an improvement on things.

 Keep it up!   

Dave

[Eric Krewson]

I like tests like yours, no telling what the outcome will be but it will be interesting.

I have a friend who makes trilam bows exclusively and always uses TB3 with no problems, he even does heat corrections of his glue-ups without any delamination. He said he contacted the manufacturer and they told him the glue wouldn't turn loose until it reached 600 degrees (I think, my old memory fails me at times, the temp could be lower).

[mmattockx]

For some reasons I wanted to get away from 2k for my glueups and use white pva wood glue instead(D3).

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]

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

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 🤗

[freke]

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

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.

There is also another test that can be done the reflex return test.   

[simk]

 I personally do not believe, that the type of glue change reflex-return behaviour. Many other, more important factors in play here. But I still would be interested in test results. If somebody approaches I would suggest working with xxxxx-glass to eliminate the random factors of wood 😅

[superdav95]

What test were you thinking freke???

[freke]

What test were you thinking freke???

Na, it was just a reaction to you post, I was actually thinking about it when I come to you post. I think most wood glue test would show pretty similar results and will break in the wood (should do). I am not experienced with lamination but learning, I believe most glue will work if we only ask the question if its strong enough to hold together - but dose some glue perform better, interesting?

[superdav95]

Ok gotcha.