Laminate glue up question

[wharvey]

Looking at the build along post it looks like it is common to glue up a riser, then glue the riser to the lams when gluing them up. It is my understanding that you don't leave a strung bow in a car during hot weather because it will delaminate.

When doing the final glue up of the lams, is a different glue used?  Same glue at a reduced temperature, or does the clamping prevent problems?

Also, what about overlays and limb tips?

[LC]

Same glue at a reduced temperature, would be my guess. I only make TD recurves so my riser is glued and baked seperate. Someone who's done that and been there with more knowledge will be a long shortly.

[str8sh2ter]

Ibeleive that gluing up the lams. with a heatbox actually makes them more heat tolerant,so reheating them wouldn't hurt.probably lower the heat abit.
 Don't do anything though til we hear from someone that knows.I posted a similiar question on LW but didn't get much feedback.Good luck

[bjansen]

Good questions.  Overall, the glue up process is made in several steps to enhance sucuess (i.e. depending on your design you could probably glue up e/t on a bow, riser tips and all...but with all those moving pieces it would be extremely dificult).

Depending on the glue you use, and the tempature at which it cures will determine its delam temp (or failure temp)....That beign said, i do not have the magic formula, nor am I certain there is one (i.e. I do not know at what temp a bow will delam if you use Smooth On and bake it at 150 degrees for 6 hours).

However, like you were thinking, if you subject the first part of your glue up to the highest heat, and then subsequently apply lower levels of heat as you go, you should be successful.  

That is what I do personally. I use Smooth On (EA40).  I generally glue up my riser and put it in the oven at 160.  Then shape the riser to get it ready for glue up, glue on the lams and bake it at 150 or so...then when I add tip overlays bake it even lower (125 or so).  You can use superglue, 5 min epoxy or some other glue for the overlays, but you can achieve the best results (seamless sanding) with EA40 in my opinion.

[kennym]

What he said! I go down in temp a little each step if possible. Never had a prob so far. When you get to the tips,just a lite bulb will suffice,not too close tho!

Actually if you do the riser on a 1pc and then clamp it back down for the lam stack glue up,it will be under pressure during the heating /cooling , so it isn't quite like being in a hot car strung with the string pulling on it.

Would like to hear other opinions on this too!