URAC failure

[RBLusthaus]

Hi Guys

Last nite I took a new BBI off the glue form, sanded and planed the sides true to the boo, and generally got her ready for tillering.  I drew my handle marks, where I was to cut the fades, etc. and it all seemed to be going great.  Then disaster struck.  I gave the bow a little bend via floor tillering to see how easy she would bend, and POP, the boo backing popped off from one tip clean to the handle.  A little pull and the backing came the rest of the off - wo any real damage to the boo or the ipe belly.   Both glue surfaces were covered in dry URAC and yes, the glue surfaces were scored with a hack saw blade prior to gluing.   

In thinking back to the glue up - the only thing I can think that I may have done wrong is I wiped the glue surfaces clean just before gluing with mineral spirits.   If I glued to quickly and the MS did not fully evaporate, could that have messed with my glue?  Otherwise, I have no clue as to what went wrong. 

I have used URAC for years, so please don't  tell me it could have been my mixing ratio.  Of course it could have been, but in my mind, very unlikely.  It could also be a bad can of glue, but find that explanation unlikely as well - although it was a new can that had never been used before.  I have had it lying around for a few months.  Could that be the problem?  I don't think so.

I ran both the belly and boo over the sander and brought them back to sound wood, and re-glued last nite.  I used the URAC again, same can.  I really thought about using TBIII, but went with the URAC. 

Any thoughts? 

Russ

[Prarie Bowyer]

 I had an explosion today.  Mostly along the Urac seam.  URAC is stopping production so it's time to be looking for something else anyway.  it could be the MS thing or Ipe possibly is oily.  I groove my Ipe DEEP and realy work the glue into the seam and don't scrape too much of when I spread it around.  I'm switching to a G-2 Epoxy I think.

[bigcountry]

Whats your date on the side of your URAC?  3rivers tried to say self life was one year after opening, but I called nelson and they said negitive, one year from the date of filling the can.

[Prarie Bowyer]

Whats your date on the side of your URAC?  3rivers tried to say self life was one year after opening, but I called nelson and they said negitive, one year from the date of filling the can.

I duno.  Could be a batch thing.  A mix thing, or in my case I cooked it twice.  You can WAY extend it by keeping it in the fridge.  So I do that.  I have bows that are still hodling made from the thick old stuff.

[DGF]

I ran both the belly and boo over the sander and brought them back to sound wood, and re-glued last nite.  I used the URAC again, same can.  I really thought about using TBIII, but went with the URAC. 

Just curious, any problems or abnormalities with your second glue up with the same can of urac?

Dan

[PEARL DRUMS]

Im not a fan of "degreasing" with anything prior to glue.  Be it a hard back or sinew or rawhide.

[Marc St Louis]

I would never de-grease with mineral spirits.  If I do any it is with acetone or alcohol.

[RBLusthaus]

Whats your date on the side of your URAC?  3rivers tried to say self life was one year after opening, but I called nelson and they said negitive, one year from the date of filling the can.

That might explain it then - the date on my can was May, 2011.  It had never been opened and I thought it would be fine.  I guess I was wrong.

As to my re-glue - - it failed too, but not as bad as the first time (which is worse because the back and belly broke trying to separate them).  This time, the URAC held at the handle area and the bamboo from mid limb to both tips came free easy.  All I was able to salvage was my handle, once it was free from the mess.

I normally degrease with DNA -  not sure why I used MS the first time - and that is why I thought I had my failure, till the second failure. 

So, do you suggest that I try again with TBIII, or should I use something else?  Try to get a new can of URAC before they are all gone?  Welldwood Urea Glue?  Can I get that stuff at say - - True Value?

Thanks for your thoughts

Russ

[PEARL DRUMS]

I have some older than that and it still works. I had some go bad and it turned a darker brown color and it was evident it was bad. The date may not be 100% reliable. I store my in the fridge.

[RBLusthaus]

I have some older than that and it still works.

That is what I thought  -  especially since it had not been opened.  When mixed, it looked fine.  It must be me, someway, some how.  I am hesitant to try the same can again.  Will probably just throw it away. 

Now, what to use in the future.  Hmmmmmm..........

Russ

[PEARL DRUMS]

I wouldnt attempt another from that can either Russ.

[mikekeswick]

TB 3 would work but DON'T roughen the glue surfaces. Sand them to as perfect a fit as you can get. I've used bamboo/ipe countless times with no degreasing and no problems.
Good luck on the next one!

[bubby]

tb3 will work fine, i hit both surfaces with 36 grit on my belt sander, Bub

[Eric Krewson]

I don't degrease, a waste of time in my opinion.  I don't think your URAC was too old but I do think you used the wrong thing to degrease with and suspect this caused your failure.

[bushboy]

The big thing with tb111 and the most painful part is letting it properly cure! I leave it clamped up for 24hr then throw it behind my cloths dryer for3 days.then I give the thumb nail test. If you can barely leave a mark it's ready to work,anyways this is what has worked for me ,bobbyjoe!