Resin and Hardner Question

[saurav16]

I am confused as which hardner to choose. I think its based on temperature of the pot and working time. How do I choose the right hardner for the west system resin?

[rheaton]

West systems has extensive documentation. I would start there.

[Tartan34C]

Without knowing what you are doing and if its downhand or overhead it’s hard to make a recommendation. Now having said that I use the 205 for almost everything. I use 206 if I need more time to work and 209 if the shop is hot.
All the best,
Robert Gainer

[Freesail99]

Also the more resin - hardner you mix the slower the pot heats up. I use mas epoxy and the medium hardner.

[sailingdog]

Freesail-

In my experience, the greater amount you mix up, the deeper the container you have it in both increase the curing activity, not reduce it.

Saurav-

It really depends on what you're doing with it. In some cases, you may want it to kick a bit faster, since it will sag less if it has less time to run. In others, you may want to extend out the working time. I generally use 206 during the summer, and 205 during other times.

[Tartan34C]

It’s an exothermic reaction and the greater the mass the faster it heats up. If I need to mix a lot I spread it over the job to slow down the reaction amd get more time to work or I put it into a large tray so the surface area is great and the thickness is less. It heats up more slowly that way. A pail of resin will kick very fast unless you use less catalyst and that means weaker reason.
All the best,
Robert Gainer

[Freesail99]

I have not noticed that to be the case. When I mixed a very small amount and was touching up an area, ( such as tabbing ) I could fell the container suddenly get hot in my hand. When I have even 10 oz. mixed it took much longer to get hot. I'm only reporting what I experienced not what I read.

I also agree that putting mixed resin in a tray slows it down.

[wind_magic]

I don't have much experience in this, but I also understand that it depends on how large a volume you are doing. If it's large then the heat from the reaction can cause cracks in the material if it sets up too fast, in that case better to have it set up cool and steady and take away heat as it reacts ?

[saurav16]

Sorry, I should have described what I was doing. I have a small wet spot in the deck. I wanted to drill out holes like it says to do in the don casey book. Take a bent nail or allen wrench and clear out the soggy wood core and vacum it out. Then I have to fill the area with some epoxy. Thats why I was wondering what kind of hardner I should use. Its getting cooler here though is about 60-75 degrees. Seems that most of you would use 205 harnder is that right?

[Freesail99]

You need to use thicken epoxy and the 206 hardner is the one to use. Remember you'll still have the sun beating on that deck while it is drying.