I have used URAC 185 with mixed results.On 4 bows glued with reflex, I have lost 3 of them. I am not saying the URAC 185 is the cause of the failure but I'm losing faith in it. On all of the breaks, the URAC looked like it crystalized and was kind of bubbly if this makes any sense. I started mixing it 2 parts liquid to 1 part powder, but it seemed to thick, so I now add liquid till I get a smooth mix. This could be the problem so some advice on ratios would be appricated. The one bow that survived is an osage with hickory backing like the 3 I lost. The only difference is on the one that is still shooting, I used the heat from a kerosene heated to cure. Any thoughts would be greatly appricated as I'm going to glue a hickory backed hickory up tomorrow and am torn between URAC 185 and tightbond III. Thanks, Don
You can mix Urac by weight or volume. I always mixed by volume and never had a failure. The can gives the correct mixture for both methods.
The literature that comes with the Urac recommends a ratio of 18:100 hardener to liquid by weight. Mike Westvang recommends a 13:100 ratio by weight in his chapter on laminated bows in BB4. Dean TOrges recommends weight vs volume measurements. I have tried both above ratios and my only glue failure came from a poor glue line. How old is your Urac? Apparently it degrades with time. Keeps longer at cooler temps.
I got my URAC from a member here and keep it in the frig. It is probably about a year old. Don
I keep my URAC in the fridge, use it at 18:1 and it is weighed out on the same scale I use to weigh broadheads. Never had a failure, this is my experience.
Using rough measure by volume, 2:1 liquid to powder I've never had a problem. Be mindful of the temperature requirements, appropriate clamping pressure (not too much either) and prep. You want rough, well mated surfaces. I'm guessing your glue was cold. Warm it to 80 degrees or so before you start. The warmer it is, the thinner it gets.
All my urac glued bows are still operating...and believe me, I am NOT the best wood worker out there.
Did you get that Urac from me Don?