I found it interesting in the link that Crooked Stic posted in an earlier topic on smooth-on and room temp curing.
The official Smooth-on Directions found here http://www.smooth-on.com/tb/files/EA40.pdf, says 2 hours @ 185 then a 6 hour wait to cool BEFORE removing the clamps and to attain Maximum Heat Distortion Temperature room cure followed by 2 hours @ 250*F.
I dont know anyone that does this building bows, do you?
Once I hit temp with the heat strips I cook the limb for 20 minutes then let cool for an hour or so. With many limbs under my belt I have never had any issues or delaminations.
For those of you cooking your limbs with heat strips whats your time and temp?
As long as your surface temp comes up Meaning once everything is at 160 or whatever temp you go to I don't think the time is real critical. The reason you leave them in a hotbox so long is to give everything time to heat up. All you are really doing is speeding the cure time. As soon as you are cooled to room temp you should be able to start grinding.
I agree with that CS but had just been taken back to the length of times and temps they had listed in their instructions.
250 sounds like a lot for wood!!might be good for the glue -but for the wood???
I cook my limbs at 140 for 25min. I use to go about 170 but I had a limb get a few hair line cracks in the glass and I believe that the high temp was the problem. When I do overlays with the heat strips I only cook them at 115 for about 15 min.
That's what works for me! :thumbsup:
I know this from experience, anything near 200*F will cause your glass to start to break down... made a bow and had to paint the limbs due to what looked like snail tracks across the limbs, horizontally. I was assured it was ok and so far is doing fine. But 250*, I wouldnt :)
Dave
I use heat strips on my LBs and homemade direct heat on my TD RC. I set the bow for 130 for 10 minutes then crank it to 170 for 30 minutes, deflate hose, pull the hot limb from the form, let it cool till its not too hot to touch and start grinding. I am usually grinding in less than 10 minutes after the limb or blank comes out of the form. I heat them slow at first so I get the air bubbles out of the glue before it begins to set. I've done a bunch with no problems this way. I too have streaked/spotted glass with too much heat. I use 170ish because that is hotter than my truck gets with the windows up in August and I leave my personal bow unstrung in my truck most of the time with no issues.
Bonner