West Systems Epoxy Help

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David Santistevan

Well-Known Member
Joined
Aug 5, 2011
Messages
1,391
I finally broke down and bought West Systems Epoxy, primarily I was tired of trying to get the others out of the little bottle. I purchased the 207 resin with the 205 (Fast) hardener with the mini pumps setup. Yesterday I tried it for the first time. I primed both pumps until I got a solid stream. I then made my first batch, 1 pump each. It has been over 30 hours and it has not cured. Still tacky and I am not sure why. I am working in my basement where it can get to be cool (65-70).
Thanks,
 
Dave, #105 is the resin, #207 is a hardener. If you've mixed #205 and #207, they will not cure, as they are both hardeners.

Steve Ball
 
West Systems 207 is the special clear hardener...You will want to mix either the 207 or 205 with the 105 epoxy resin. They require different ratios (3 or 5 to 1) so follow the instructions for whichever one you are using.
Chris
 
I finally broke down and bought West Systems Epoxy, primarily I was tired of trying to get the others out of the little bottle. I purchased the 207 resin with the 205 (Fast) hardener with the mini pumps setup. Yesterday I tried it for the first time. I primed both pumps until I got a solid stream. I then made my first batch, 1 pump each. It has been over 30 hours and it has not cured. Still tacky and I am not sure why. I am working in my basement where it can get to be cool (65-70).
Thanks,
You need to use 105 Resin with either of those two hardeners (Both 207 & 205 are just the hardener component). I personally use 105 w/207 for everything.
 
Okay my bad, guess it helps to have the right information. I mixed 105 resin with 205 hardener.
And your sure you have the correct pumps in the correct product.
As a test.
Mix in a small amount
5 parts resin
to
1 part hardner
IE: from a squeeze bottle
50 drops resin to 10 drops hardener (mix thoroughly,,, piss the molecules off)
I mix it this way all the time for small amounts
IF you mix too much hardener into the resin, it will not kick properly and stays rubbery and tacky.
 
Also, mix it thoroughly for at least a minute. I haven't used west in a while but if I remember correctly you are supposed to mix for 2 minutes.
 
Be careful if you got the 3 pump package that you use the correct two of them per the instructions.

The proper pumps deliver 5 parts resin to 1 part hardener.

I think if you used the 5 parts resin pump with hardener already it is better to just buy new pumps when you buy the quart of resin.

You don't want to contaminate a new quart of fresh resin.
 
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Thanks guys, solved. You were all right. I had selected two hardener pumps so I was getting equal portions of hardener and resin. I have the correct pumps in and I have a test batch curing now but I suspect it is going to be fine. Thanks for all the help.
D
 
Hi guys, I use west systems most of the time. I can't think of any where I would use the 205 hardener because it is only the same as 5 minute epoxy which I would only use for a quick repair. I normally use 105/206 for sealing plywood or when using clothe. I 105/207 when I am going over bare wood, such as Mahogany. It is clear and does produce the amine blush which has to be washed off. Never use these combinations to build your boats as they will fail. You need to use CA, Z-poxy or equivalent for construction. G flex is the only West product to use for building. I learned from experience. Thank you, Gary
 
That's funny, Gary. I use West Systems for everything and have never had a problem, as long as it's used properly. I use the 206 medium hardener for smaller areas and the 209 slow for larger ones. I have a can of 205, very rarely use it as it cures too fast to do much with. I also have a can of 207, don't know if I've ever opened it since it's, as you said, for coating and glassing. I would never use the 207 for structural bonding since it's not made for that. I also found CA is only good for tacking and Z-Poxy is too brittle to hold up. Might have different results if I was building from materials such as balsa, bass or mahogany. Not sure what kind of boats you build but I build sport and scale hydroplanes from plans with various thicknesses of birch ply and spruce stick stock.
 
That is cool then. Your all set, swap resin pumps and rock and roll.

The 650 Gflex is great for building. 1:1 ratio for easy small batch mixes. Incredible adhesion and absorption. Thick enough to stay put a little more without even using filler/thickeners.
 
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As a novice builder, best advice I got was to mix west system epoxy & hardener using a cheap digital scale in grams with little plastic medicine cups like others mentioned. I quickly learned the real time pot life's & characteristics of the 205, 206, 207 hardeners, without wasting a lot of epoxy/money. I built my JAE 12 Rigger using 105 & 206, sealed it with 105 & 207. Those 2 hardeners worked best for me allowing 20-30 min pot life, 205 kicked to fast for me as well. Their cans have detailed instructions on various ways to measure & mix each product. Finished off boat with SprayMax 2K Glamour Gloss Clear Coat 2-part Aerosol spray paint. For a 1st time build & using epoxy I think it turned out well. 7 years racing it & still looks new w/o structural issues. No regrets using 206 & 207. The small batches saved $ and helped me learn how to use epoxy, fillers/additives without rushing the build. If a batch kicked, the loss was minimal. Not knocking anyone else's products or methods at all, just sharing what worked best for me. I want to try G-Flex next, may be even better than 206 for certain areas during the build.
Brian N.
 
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