West System 205 fast hardener vs. 206 Slow Hardener

[Clueless1]

I went to the marine store today to pick up some West System Resin & Hardener. I was going to get the 206 but they were out till maybe Wed. Being impatient and wanting to move along with my build I went ahead and bought the 205. The boat I'm building is the 39" ML GP400 and the west system will be used over the entire hull. Should I go back Wed. and exchange the 205 fast hardener for the 206 slow or would i have plenty of working time with the 205?

Thanks!
Todd

[detox]

I have allways used the slow, but the fast will work. I have both fast and slow. My slow hardener is just about all gone...if that tells you anything.

[detox]

You will also need a thickener for filling. Micro balloons for filling and fumed silica for strong joints

[Clueless1]

How necessary are these two? When I built the GP335 I borrowed a friends West Systems but didn't use either of these.

[longballlumber]

I went to the marine store today to pick up some West System Resin & Hardener. I was going to get the 206 but they were out till maybe Wed. Being impatient and wanting to move along with my build I went ahead and bought the 205. The boat I'm building is the 39" ML GP400 and the west system will be used over the entire hull. Should I go back Wed. and exchange the 205 fast hardener for the 206 slow or would i have plenty of working time with the 205?

Thanks!
Todd

Keep in mind that ambient temperature makes a difference how quickly your "pot" time is between the 205 or 206. Seeing how you’re located in Texas I would suggest the 206 (slow) for the majority of your work. However, like Detox, I keep both. Lately, I have been using more of the 205 (fast). The only reason I use the 205 more often is because I am located in MI and my workshop is in my basement which only averages in the low to mid 60’s. Because it’s so cold down there I use the fast more often; otherwise the 206 (slow) can take more than 24 hours to fully cure.

Later,
Mike

With you being in Texas; the amient tempature makes a difference how quickly your "pot" time is.

[Clueless1]

With temps this week mid sixties and mid 40's in the evening then I should have a good window to use the 206 and not sweat it?!

[longballlumber]

With temps this week mid sixties and mid 40's in the evening then I should have a good window to use the 206 and not sweat it?!

Depends, I probably should have used a better term rather than ambient temperature. What is the temp of your work area or shop? My basement isn't heated very well. The cooler the temp is the faster the hardener you want.

This image from the West Systems web site shows recommendations per room temperature...

http://www.westsystem.com/ss/hardener-selection-guide/

Good Luck,
Mike

[Clueless1]

My main concern is having enough time to paint a 40'' hydro before the "Pot life" ends? I guess I don't have to get the entire top of hull done all at once.
Thanks for the thoughts!

Todd

[iamandrew]

I use 206 as im in australia and summer temps over 25 degrees C make the 205 too fast to use

[longballlumber]

My main concern is having enough time to paint a 40'' hydro before the "Pot life" ends? I guess I don't have to get the entire top of hull done all at once.
Thanks for the thoughts!

Todd

Do it in batches, that is what most do. Your going to sand the boat before priming and painting anyhow.

Later,
Mike

[detox]

How necessary are these two? When I built the GP335 I borrowed a friends West Systems but didn't use either of these.

Its not naeessary, but really conveniant when you can thicken your epoxy so that it does not run. The fumed silica works verygood to thicken thin finishing resin epoxy. One good example is the stuffing tube area.

[Richie the shipwright]

Warming your resin before you add the hardener is also a good idea when working in cool temps. You can do this with a metal can and a heatgun. (dont preheat hardener tho) :-)

[longballlumber]

Warming your resin before you add the hardener is also a good idea when working in cool temps. You can do this with a metal can and a heatgun. (dont preheat hardener tho) :-)

This is OK, but once mixed it can minimize the pot life. Personally, I would only heat the surface that your coating (wood surface) and I only do that when I want the epoxy to smooth or flow better. It will not extend the pot life.

Later,
Mike

[tlandauer]

I use 206 as I live in So Cal. That said, I had to do some work a month ago and outside day time temp was in the low 40's, I had to turn the heater on later so temp inside was really 70's to get the mix to harden. ( Inside temp was in the 50's)
As we rarely have this kind of temp, I was surprised how temp affects the curing time---should have known but just never had any first hand experience.

[detox]

Using faster cure hardener will make cured epoxy more brittle. Slower cure is less brittle