Hot box

[Phil]

I now have all the materials for making my very first English Long Bow
The backing is Guadua Angustifolia (Chinese Mountain Bamboo) the belly/core is a laminate of Maccassar Ebony (Diospyros Celobica) and Osage.
There is however, one piece of advice I'm looking for.... do I need to build a hot box?
To glue the laminations I'm using Cascamite by Humbrol. It's a powder / hardener mixture adhesive, that most, if not all the bowyers use here in the U.K. I know hot boxes are used to decrease the curing time of the resin adhesive but does the heat have an effect on the strength and quality of the bond.
Any advice would be appreciated. :thankyou:

[OZ in MT]

I'm no expert, Phil, but I've made a few successful bows - all woods and fiberglass composites. While I haven't used the bond you describe, most all epoxies have the following characteristic: The heat exposure during the last few hours of cure is directly proportional to the amount of heat they can later stand without delaminating. Additionally, epoxies aside, heat curing an all-wood laminate also allows easier bending of the laminations on the form. So, if you plan to induce any substantial amount of reflex, curing at about 160 - 180 degrees will cause the final product to conform better to the form and not be so subject to "set" when you draw and shoot it in after production. Finally, I have not seen this but have been told be some very knowledgeable "all-wood" bowyers that bamboo takes on greater strength when it has been heated up.

[OZ in MT]

As I reread my last, Phil, I realized I hadn't made it clear that using epoxies at room temperature is OK. I made all-wood and glass laminates at about 70 degrees for quite a while before I got off my butt and built a hotbox. None of my bows ever delaminated, but I didn't use them at temperatures much above 80 degrees. If that concept (80 degrees or less) works in Merry Olde England, then go for it. However, the biggest advantages I found from the hotbox were better bending with thicker laminations ( .100" and up) and less set after forming and initially shooting.

[Windknot]

Phil,

You don't need heat to cure Cascamite/ Extramite, but this time of year it will help.

Have you considered Extraphen? It's the local equivalent of Urac 185, and gives a totally waterproof bond. I've got plenty, if you're in need of some- let me know.

I've been playing with the idea of using an electric blanket to speed up curing time- stick the glued up stave in a bow, drape the blanket over it, set it on low and retire to the pub.

Might just work.

(Seriously, I wouldn't leave it unsupervised- fire risk)