How many of you use smooth on glue, but use no heat to cure it? Let's say like on a hickory backed osage bow? And how many of you use urac and do not heat cure it?
I use smooth on and no heat but it takes at least 24 hours for it to set if at all possible use heat. I am trying urac185 right now I have had a bow sit all night with urac so I will let you know on that one.
I have built race car parts airplane parts canoes and bows and many other things using epoxies. The reason for using heat to cure epoxie is not that it will not cure. All epoxie will cure with temperatures in the 70 degree range. It may take longer but it will totally cure. Also all epoxie will soften when the surrounding temperature reaches a certain temperature. An exhample of this could be your recurve bow or your hybred long bow in a closed up car trunk on a hot day in the summer. The epoxie will soften and allow the laminations to slip and therefore your bow is no longer a recurve or a hybred long bow. This has been known to happen at temperatures as low as 125 degrees. When the epoxie is cured in a heat box at a temperature of 160 to 185 degrees the temperature that the glue gets soft also is increased to a temperature higher than it was cured at. (THIS IS TRUE WITH SMOOTH ON AND OTHER INDUSTRIAL EPOXIES I HAVE USED) I do not know for sure that urlac185 or other types of hardware brand epoxie will have the same features as smooth on. Therefore using smooth on now you can store your bow with confidence that it will have the shape it started with after being stored in an area with higher than normal temperatures.
milehi is right, a bow not heat cured is a bomb
Recently there was a similar topic on this matter. I know someone that didn't have a hot box, so they curred their bow by putting their form in their truck and parking it in direct sun during glue up. IMO, it wouldn't reach the temp I personally would want, but it is certainly better than nothing.
The technicians at Smooth-on said 4-8 hours at 150 degrees was best. They also told me to mix 2 parts A to 1 part B for the best heat resistant properties.
I read basically the same thing that 7 Lakes stated on their website. Also, it stated to let it set overnight and then put it in the heat box.