Primitive Archer

Main Discussion Area => Bows => Topic started by: Pat B. on July 20, 2014, 08:08:51 pm

Title: Unibond.....
Post by: Pat B. on July 20, 2014, 08:08:51 pm
I used Unibond in a project yesterday...  While it seems to be holding the small amount i had left in the mixing cup has the consistency of very hard rubber..   I've used it before and the leftover dried almost glass hard.  Something is amiss..
Title: Re: Unibond.....
Post by: mullet on July 20, 2014, 08:12:31 pm
Hot weather and glue not kept in a cool place? I keep my glue in the fridge.
Title: Re: Unibond.....
Post by: Prarie Bowyer on July 21, 2014, 12:50:44 am
I've had that happen also.  It needs to be kept in a fridge.  Mix wasn't off was it?  Dries best in a hot box.
Title: Re: Unibond.....
Post by: Pat B. on July 21, 2014, 01:00:28 am
So do you guys think it will finally cure  ??   

The glue was only a month old and i've used it a few times..  While I haven't kept it in the fridge it has been in my air conditioned shop...  However, I did the glue up yesterday in the barn where temps were in the low 90's..

And it's possible that the mix was off a bit, I just eyeballed it..  I was using a small mixing cup so had a pretty good reference for a correct volume mix...
Title: Re: Unibond.....
Post by: PatM on July 21, 2014, 01:12:49 am
The smaller the cup, the more likely your ratio will be off. That will be what it is. Try mixing up another batch and use a scale
Title: Re: Unibond.....
Post by: mullet on July 22, 2014, 06:58:46 pm
What PatM said and maybe moisture in the air. When I used to glass Surf boards on rainy or high humidity days we would have to put a heater in the room to "kick it off". You might try dusting it with a heat gun.
Title: Re: Unibond.....
Post by: Pat B. on July 22, 2014, 07:53:27 pm
The project was a hickory backed Ipe bow... I glued the hickory on with the unibond..

When it failed to set like I thought it should I contacted Nelson Paint Co. who distributes Unibond.. They sent me the MSDS sheet and instructions.. Apparently the mixing ratios vary quite a lot..  After a couple of days the cup of leftovers from the glue up hardened more

I was tilllering that bow today and had it up to 76 pounds and it held together fine, so I call the glue joint successful.. However the bow developed a lot of set during my enthusiasium !!!
Title: Re: Unibond.....
Post by: mullet on July 22, 2014, 10:02:03 pm
Still sounds like moisture was involved.
Title: Re: Unibond.....
Post by: tom sawyer on July 22, 2014, 10:14:57 pm
I'm on my last quart of resorcinol, after that it's unibond for me.  I generally try to weigh the two part glues.
Title: Re: Unibond.....
Post by: Pat B. on July 23, 2014, 01:28:32 am
I expect you guys are absolutely correct, very humid when I did the glue up.... And the glue didn't react as it has for me previously..
Title: Re: Unibond.....
Post by: mikekeswick on July 23, 2014, 05:27:55 am
I'm on my last quart of resorcinol, after that it's unibond for me.  I generally try to weigh the two part glues.

What's wrong with resourcinol? In all the tests i've done with wood glues it has always come out on top. Resourcinol is one of the very best glues for what we do.
I always recommend getting the data sheet for any glue - it just makes sense  :)
Title: Re: Unibond.....
Post by: tom sawyer on July 23, 2014, 09:34:25 am
I'm on my last quart of resorcinol, after that it's unibond for me.  I generally try to weigh the two part glues.

What's wrong with resourcinol? In all the tests i've done with wood glues it has always come out on top. Resourcinol is one of the very best glues for what we do.
I always recommend getting the data sheet for any glue - it just makes sense  :)
I agree, people told me it was discontinued though.  I'm being careful to mix up just what I need so I can make this last quart last.  I also liked URAC.
Title: Re: Unibond.....
Post by: Hamish on July 23, 2014, 09:08:45 pm
Urea formaldehyde is excellent stuff(so is resorcinol), but it doesn't have a very long shelf life, months rather than years.  Even though you might have only bought it recently, it could have been sitting in storage in the shop or at the distributers  for a while.
 Like the other guys have said keeping it in a fridge extends the shelf life.