Don't tell me to cool down...

[skeaterbait]

So I have recently read, and many of you may have read the same post at another place, that the cool down period for EA-40 (and maybe others) isn't really necessary. It's said that once the epoxy is cured and hard you can take it right out of the form without a cool down.

Please tell me your thoughts?!   

[buddyb]

I've always waited for mine to cool down because I was worried about the recurve in my limbs springing back a little  until they were at room temperature.

[Roy from Pa]

I'd just turn the heat off and let it cool for a couple hours.

Ya can't be in that big of hurry.

[skeaterbait]

Nope, no hurry at all, cuz I can only afford one build at a time. Mostly I was curious since this is the first time I have heard this said.

[Crooked Stic]

WOOD LAMINATING / BOWMAKING
EA-40® has been used for many years for laminating fine woods. It is
preferred by bow makers around the world and offers longevity, flexibility
and memory required for making award winning performance bows.
Suggested laminating procedure;
1. Plane or lightly sand all surfaces to be laminated with 120 grit sand paper
2. Blow off dust with compressed air and wipe all surfaces clean using
acetone (Warning – acetone is flammable. Follow acetone manufacturer
procedures for handling). Let acetone evaporate for 10 minutes.
3. Mix and apply EA-40® as directed between layers of laminate to sanded
surfaces using a brush.
4. Carefully clamp laminated pieces together applying even pressure.
5. Place in oven and use the following step-cure schedule:
Temperature Duration
120°F / 48°C 2 hours
150°F / 65°C 2 hours
185°F / 85°C 2 hours
Important; Let cool for at least 6 hours to room temperature before
releasing clamps or handling.

[Flem]

Cured and hardened don't necessarily coincide. The stuff will be cross linked, but still soft at 160 degrees.
EA-40 and most other 24hr room temp cure epoxies will cure in 1hr at 160 and be hard at 70. Thats if you were to take and mix some up in a shallow container, remove from heat and cool down right after cooking it.

[kennym]

WOOD LAMINATING / BOWMAKING
EA-40® has been used for many years for laminating fine woods. It is
preferred by bow makers around the world and offers longevity, flexibility
and memory required for making award winning performance bows.
Suggested laminating procedure;
1. Plane or lightly sand all surfaces to be laminated with 120 grit sand paper
2. Blow off dust with compressed air and wipe all surfaces clean using
acetone (Warning – acetone is flammable. Follow acetone manufacturer
procedures for handling). Let acetone evaporate for 10 minutes.
3. Mix and apply EA-40® as directed between layers of laminate to sanded
surfaces using a brush.
4. Carefully clamp laminated pieces together applying even pressure.
5. Place in oven and use the following step-cure schedule:
Temperature Duration
120°F / 48°C 2 hours
150°F / 65°C 2 hours
185°F / 85°C 2 hours
Important; Let cool for at least 6 hours to room temperature before
releasing clamps or handling.

This looks to be right off Smoothons tech sheet.  Go with it, if a bow will come apart in the sun, it may slide if you take it right out of the form ....

So cool down there bro.

[Bvas]

I can't say for sure, but I believe I have one bow that had more springback because it was removed from the form without allowing enough time to cool.

I have two bows off the same form. One was built 58" and one 60". When unstrung and sitting one behind the other on pegs, one definitely has more springback. And I can remember one was removed from the form while still slightly warm, but don't remember which one. I must say, that the bows have different stack thickness. So this may be a contributing factor as well.

From now on, I will allow bows to cool completely before removing. Not only does it make sense as far as making sure the epoxy is set, but also makes sense for the wood lams. You wouldn't heat bend an all wood bow and release it without allowing it to cool and take a set.

[Pat B]

I've never used E-40 but for any glue up, cooked or not I always give at least 24 hours before removing it from the form. It just isn't worth a screw up after the work already done.

[monterey]

Only suggestion I have is if you use acetone or alcohol to clean up lams, let them sit for an hour at least. 

[Roy from Pa]

I always let my bows in the form 24 hours.

[Holm-Made]

Those specs from smooth on only show the bows being heat cured for only two hours.  Then for sure you need to give it another 6 hours to cure/cool down.

  If you have it in the oven for 5-6 hours and let it cool to room temperature, AND the squeeze out is hard then the bow can be pulled out of the form.  An additional 6 hours won't hurt a thing but not necessary.

[Roy from Pa]

Skeeterboy, looks like ya took your hat out of the form too soon cause one of yer horns is crooked:)

[skeaterbait]

Skeeterboy, looks like ya took your hat out of the form too soon cause one of yer horns is crooked:)

Too much spring back

[Roy from Pa]

I think ya otta take it off when working on bows.

It's prolly causing head shock and trauma as ya move around.

Send it to me and I'll make horn tip overlays out of em horns....

[Flem]

Hey skeater, I'll trade ya...
[attachment=1]

[skeaterbait]

 

Hey skeater, I'll trade ya...
[attachment=1,msg2855292]

[Mike L.]

I've been curing at 180 degrees for 4 hours.

[Crooked Stic]

Just about as important to leave them under pressure about 4 hours before putting in the heat to.

[Garman]

I had a bow I was building for my boy last year, nothing fancy just a tri lam type deal, took it out of form fairly soon and started working on it. I started sanding etc. and it split apart at the glue lines. I let sit until the next day now.