Which epoxy

[Dave Macy]

Can't believe how expensive west system is. Which one do you use 207 or 209? Any good cheaper alternative? Thx

[Jamie Buxton]

I use West System 105 epoxy, and for catalyst I use 205 in the winter, and 206 in the summer. My shop has no heating or air conditioning.

[Dave Macy]

Sorry for the dumb question but are you saying that temperature decides what hardener to use

[Malcolm Schweizer]

Sorry for the dumb question but are you saying that temperature decides what hardener to use

West has fast and slow cure hardeners. Warmer temps can speed up the cure time for epoxies, and cool temps slow it down. 205 is their fast hardener. Beware that I find it does not keep well and turns purple and stops hardening if kept too long. I suspect this is due to my humid environment. 206 is the slow hardener. I use it because in my climate 205 kicks too fast. 209 is extra slow hardener for really warm climates and for when you want a slow cure, i.e. more working time. It is really slow, even in my warm environment. 207 is their special clear hardener that kicks about like the 206, but is formulated for a clear finish like when building strip-built boats and you want a clear resin. This is what I buy because I build boats so I want a clear wet out when applying epoxy and cloth. I use it for glue-ups as well simply because it's what I keep on hand.

It is expensive, yes, but keep in mind that you use way less epoxy than yellow wood glue or other glues. Epoxy does not compress like other glues and you only need to wet the surface to get a strong bond.

[Malcolm Schweizer]

By the way, I also use Raka epoxy. They have one with a UV inhibitor in it. It's great stuff and cures clear. It costs a lot less than West System, but holds up just as well in long-term tests. If you buy their pumps please keep in mind that they are not metered pumps like West System. West pumps are calibrated so you give one pump if resin, one of hardener, and the resin pump puts out more so you get the 2:1 mix. Raka pumps are the same for resin and hardener, so you have to put two pumps if resin to one pump of hardener. Also keep in mind that due to the 2:1 ratio, you need less hardener than you do resin. That's why West usually sells hardener in smaller containers than the resin.

[Jamie Buxton]

Sorry for the dumb question but are you saying that temperature decides what hardener to use

Malcom's answered the question, but if you're asking this one, you might want to be reading on West System's web site. They have loads of info about epoxies and curing times and other stuff you might want to know.

[Wayne Cannon]

System 3 has a line of epoxies formulated with more "give" to support wood's natural expansion and contraction, which puts less stress on the wood at the glue line compared with normal epoxy formulations. Saying that, I haven't seen any problems with standard epoxies for normal woodworking.