just to throw this out there....if you are going to cook your riser more than once...ensure that the wood is properly dried before doing so...when i first started out, i ordered a beautiful piece of bocote. Glued a couple riser accent stripes in and it was summer time. everything looked fine...finished the bow up and then had it in the car and all the glue lines separated...not from getting hot but because the wood shrunk from loss of moisture...didn't realize this was the case until the same thing happened with a cocobolo riser. After that, i always let my exotics rest for a month or so before I would glue them. Just a warning.

Stic, my test glue up was 1 to 1.  I have since gone to the 2 to 1 mix for the better heat resistance.   I will say that breaking on the glue line was using an excessive amount of force in a direction normal shooting would never cause

Tim, do you use a moisture meter?  I don't and wonder if it might not be a good idea?

I have one but don't use it for blocks. It is the push in type so for a block it's not really useful.

Your experience is what has had me shying away from laminated risers.   

Moisture meters that work the best are about $300. And by what Big Jim sez is still a SWAG.

If you don't want to pony-up $300. for a meter, you can weight your wood on a gram scale daily. When it stops loosing weight, it's reached equilibrium. I've got an inexpensive Timber Check by Lee Valley. They say it's accurate to 0.5%, close enough for me.

Good tip, Flem.

Epoxy is stronger when heat cured . 120 to 190 degrees will work . Just for making a couple of bows you can make a disposable heat box with aluminum foil and a cardboard box heated with a couple of heat lamps .

Quote from: Tim Finley on February 16, 2020, 01:01:35 PM
Epoxy is stronger when heat cured . 120 to 190 degrees will work . Just for making a couple of bows you can make a disposable heat box with aluminum foil and a cardboard box heated with a couple of heat lamps .

True, but strength is relative to the properties you are trying to enhance. Heat curing can enhance the cross-linking of the epoxy molecules (hardness)and increase the glass transition temperature of the cured material, but can decrease the thin film elongation properties. Which is important in flexing.

Quote from: Flem on February 16, 2020, 01:30:13 PM

Quote from: Tim Finley on February 16, 2020, 01:01:35 PM
Epoxy is stronger when heat cured . 120 to 190 degrees will work . Just for making a couple of bows you can make a disposable heat box with aluminum foil and a cardboard box heated with a couple of heat lamps .

True, but strength is relative to the properties you are trying to enhance. Heat curing can enhance the cross-linking of the epoxy molecules (hardness)and increase the glass transition temperature of the cured material, but can decrease the thin film elongation properties. Which is important in flexing.

??????????????????  Ok, i guess??????

Hmmmmm,  so luke warm is best... 

I'll be the first to admit, it don't make a bit of difference what temp we use to cure bows, relative to strength. What we make will never come close to taxing the ultimate flexural strength of EA-40, no mater the cure temp. And if you are getting close to glass transition temp storing or transporting your bow, well... your f-ing up. The only real benefit to cooking a bow is to shorten the cook time. I use Smooth-on Epoxamite and cook for 1hr @ 200deg. Only because it's more efficient.

I agree---only I think you meant shorten the cure time.