Question about shaping limbs on a fiberglass bow

[kiltedcelt]

How long after you take a bow out of the heat box do you let it sit before laying out and shaping limbs? I use Smooth-On and run my stuff in the heat box for 6 hours at 150F. I've done some bows in the past, both fiberglass and bamboo/ipe and I usually let them sit until the next day before I do any shaping of the limbs. I'm just wondering if since it's been cured at temperature as long as you let it cool for two or three hours, could you then begin shaping the limbs or is it better to let it sit much longer?

[Stagmitis]

Thats a really good question Kilted and wish I knew the answer for sure.

I use heat strips and have left bows alone overnight after cooking...Yet other times I have had nocks cut and shooting the bow within a couple hours after it finished cooking.

I havent noticed a difference...Yet..

[Robertfishes]

I use an oven with light bulbs. I have the oven on a timer. Because of my schedual I glue up at night, usually arround 8pm, after warm up and glue up I set timer for 5 hours,after cooking I pull the slightly warm (90 degree??) form out of oven at 6:30am, check air hose pressure (its always over 50psi), let form set on bench to cool down to room temp till  later in the day, then I deflate air hose and pull blank out of form..So to answer your question, I let form and blank cool down to under 90 degrees,  remember the inside of form will take longer to cool down than outside..The guys with heat strips can glue up and cook another 2 bows while I am still cooking and cooling down..

[Jason Scott]

I have started bending the limbs in just a few hours out of the hot box too with out any problems. I remember one time, I use c-clamps, that the clamps were so hot I could barely hold them long enough to impatiently pull the form out of the box. I was grinding the glue boogers off that one within an hour. I know I had it layed out and started cutting the width taper on the band saw in less than two hours out of the oven. It is a great bow.

[jsweka]

From the responses so far, it doesn't look like it matters too much.

I turn the oven off and let it cool to ambient temperature and start shaping.  Haven't had any problems yet.

[jess stuart]

I to use the light bulb method.  I have always let the bow cool on the form real good before taking it off the form and working on it.  I usually glue up in the afternoon and let it set overnight.  I may rethink that after reading the above posts.

[Kanga]

I usually start shaping the first limb when I put the second one in the oven, which is about an hour after the first one comes out.

Been doing it this way for a long time and have yet to have a failure.

[Robertfishes]

ok, but when someone asks about fixing a twisted limb the advise given is to warm limb to soften then twist...so I guess you want it to cool down some before working on it

[Jason Scott]

yeah, it should be cool before you flex it for sure. But as far as laying out the profile and shaping it has never hurt mine. It takes me at least an hour or two to clean up the afterbirth, layout and cut outside the lines and then sand down to the lines. I'm not that fast. I usually stare at the center line and double check it a couple times before I get the courage to cut to the lines on the band saw. By then it has cooled to ambient temp.