Post-curing epoxy

[charlesrider]

I'm going to be gluing up some spars this winter and I want to explore post-curing the epoxy I use to glue em up. I have a COLD garage in which to do the gluing. Hence, I am going to be heating the spars anyway so I have hatched a plan. I am going to use two 10" "Sonotube"s stuck (duct taped) together ( each 12' long for $14 each) as an enclosure, put the element from a 220V baseboard heater in it, and suspend the spars on a web strung across the middle of the tube. I should be able to get and keep it at almost any temperature between 80 and 150 degrees. Yes, I will be careful not to start a Spar-B-Que.

This opens up the nice possibility of using a slow-cure resin at low temperatures during the glue-up which should reduce the anxiety over getting the thing together and clamped before it becomes unworkable. I know little about epoxy and promoters and hardeners and even less about post-curing. What resources does anyone recommend?

I was thinking about parcelling (or is it serving?) it together using a spiral wrap of stretchy nylon cord. I've used a hammer as a tensioner when doing this kind of wrap before and it generates quite a bit of squeeze. Any suggestions?

Chad

[Frank Hagan]

You don't really need too much "squeeze" with epoxy ... in fact, you're better off with less compression as too much squeezes out the epoxy.  I think Charlie mentioned he uses giant rubber bands made from bicycle inner tubes for his spar glue ups. 

[PAR]

Post curing is little more then completing the chemical reaction started when the resin was mixed with the hardener, typically in colder temperatures.

Your little kiln will work, so will a cardboard box. As long as you can maintain the temperature long enough to insure a complete cross link of the molecules (total cure of the plastic). The amount of time of course is dependant on the temperature and the hardener used.

Frank is correct, in that you don't need or want a lot of pressure. Only enough to insure contact of the joint surfaces, with a little goo ooze out all around.

I use the bicycle inner tube trick too, also Spanish windlass, ratchet straps, hose clamps, the new style of flexible ace bandage that sticks to itself and just about anything else that's handy.