Another ? from the redundant dept. of redundancy

[skeaterbait]

When you make a composite bow and you compare curing in an oven as to room temp... does the oven give any advantage other than time saved? Do you gain any performance characteristics by curing with heat?

[Dazzad]

G'day skeaterbait! I think the epoxy when heat-cured is meant to be a little more resistant to ambient (hot car) temperatures once it has made a bow......
Myself, I don't have a hot box, and so simply resolve to not leave my bows in a hot car, which anyone would agree is good practise anyway:). Many people cure their epoxy at room temperature and if they are stored responsibly - will never have any issue with the integrity and durability of their bows. Good luck!!

[Dazzad]

....just re-read your query....in regards to actual performance - no I'm pretty certain there is no performance per se to be gained from heat curing.
 Slight gains of durability and integrity in your glue lines when exposed to intense ambient heat- yes.
 Extra performance - pretty certainly - no.

Dazza

[skeaterbait]

Thanks Dazzad.

[Mad Max]

Data on EA-40
On the General purpose it said it would increase performance(what does that mean on a table that has been glued?)

"GENERAL PURPOSE BONDING APPLICATIONS...
Application - Apply to prepared surface and let cure for 24 hours. Applying
mild heat will cure EA-40® faster – 150°F/65°C for 6 hours.
Post Curing - After EA-40® has cured at room temperature, heating the
epoxy to 150° F (65° C) for 4 to 8 hours will increase physical properties and
performance. Let cool to room temp. before moving bonded substrates,
machining, etc.
To Attain Maximum Heat Distortion Temperature - let cure for 24 hours
at room temperature, heat cure for 2 hours at 250°F (122°C).
At mix ratio 1A:1B – HDT will be 163°F (73°C).
At mix ratio 2A:1B – HDT will be 217° F (103 °C)
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".

[Crittergetter]

I've tested two bows of identical length, stack, weight, wood to glass ratio, ect....  they both performed the same .  They have both been shot thousands and thousands of times .  They both retain the same cast . And on and on. The only test I did not do was subject them both to high heat. I know what the results of thatwould be.

[Bowjunkie]

Anyone ever make alignment corrections later with a heat gun on a bow blank that was cured at room temperature? I'm not sure how well or often it would work, but I've done it with blanks cured in a hot box... multiple times, without a single issue.

[LittleBen]

If you keep the bow clamped it should work fine. I heat corrected a tri-lam bow glued with titebond 3. Too much heat cause it to start delaminating maybe 2" at the tip. I clamped it tight with a c clamp at the tip and reheated to finish the correction. Kept clamped until cool, never had a problem. I suspect a similar thing would happen with ea-40. I would probably clamp the the area I was heating though.

[Krasus]

Only difference I find is that my ea40 when not cooked, still feels slightly tacky even though it's fully cured. I always put it in the oven though. Supposedly it has better performance properties when heated but maybe that's only in a lab test..