West System Epoxy help

[Lepke]

I used a lot of West Systems commercially and for my own stuff. I used it up to 95° F. For new users, it's worthwhile to use their pump system and you always get the correct mix. Mostly I've used the gear pumps, but they're not for small amounts. However for small amounts see the West ad.

[chris95040]

Originally Posted by Mithril Bham

My guess is that you used too much hardener. I see no other way that the epoxy would melt the cup and smoke. I know from experience how easy it is to make simple mistakes.

Epoxy properly mixed, even with slow hardeners, can absolutely get hot enough to smoke and melt a cup.

Have you ever read the instructions for epoxy? Have you ever even used epoxy?

[Franziska]

By the way, a cheap digital kitchen scale does the same job as the WEST scale too, BUT, for a much lower price.

[Dave_S]

Originally Posted by chris95040

Nothing in the instructions about thinning the ratio, either, yet you went ahead with that experiment! In fact I'm quite sure they caution you against it for obvious reasons.

Admit it, you didn't actually read the instructions, did you?

Go to Google, type in West System Epoxy. 3rd response was westsystemepoxy.com.au, clicked on that, LH menu clicked on products, then resin and Gardners, then click the pdf on " Download 105 " brings you to this.........
WEST SYSTEM epoxy| Products | Resins and Hardeners - WEST SYSTEM by ATL Composites

It gives you suggested mixing ratios, expected cure time uses of different hardners colour etc. But nothing about using a wide flat mixing tin.

[Group9]

Originally Posted by Lepke

I used a lot of West Systems commercially and for my own stuff. I used it up to 95° F. For new users, it's worthwhile to use their pump system and you always get the correct mix. Mostly I've used the gear pumps, but they're not for small amounts. However for small amounts see the West ad.

Exactly. The pumps are like $16. As much as the resin and hardeners cost, why would anyone not use the pumps to insure proper mixing ratio? I do and I've never mixed a bad batch and I use West System epoxy for lots of things. It's a great product.

[valhalla360]

So did you grind out the 8-1 mix. If it's any kind of structural use, I wouldn't trust it.

West System has great online documentation that really gives you good insight into how to use their product for a host of projects. Read up before wasting a lot of expensive epoxy.

[chris95040]

Originally Posted by Dave_S

Go to Google, type in West System Epoxy. 3rd response was westsystemepoxy.com.au, clicked on that, LH menu clicked on products, then resin and Gardners, then click the pdf on " Download 105 " brings you to this.........
WEST SYSTEM epoxy| Products | Resins and Hardeners - WEST SYSTEM by ATL Composites

It gives you suggested mixing ratios, expected cure time uses of different hardners colour etc. But nothing about using a wide flat mixing tin.

I'm not sure what your point is. The first thing I saw when I clicked that link, in bold text, was "Do not attempt to control the cure time by altering the hardener ratio."

[Lake-Effect]

I went through a gallon of EAST epoxy, which mixes at the same ratio as WEST Systems, so i could use WEST pumps. I only ever had one load kick in the cup - it was about 4 oz. Exciting!

[bailsout]

I’ll never buy West System epoxies again. If you do use any epoxy, follow all precautions.

[SuW]

We're not keen on WS, although we still use it occasionally. We don't use the pumps direct into the mix but always dispense into mixing cups that we keep just for the hardener or resin; the pumps are a pain, you often don't know they've lost their prime, or the can runs out halfway. For small amounts we use syringes from the pharmacy, available in a variety of sizes. Otherwise pour into graduated mixing cups.

We also don't much care for the really hard-to-sand surface of cured WS, its less-than-great wetting of wooden surfaces and the blush that repeatedly comes up sometimes even after days, making painting a slow business. We've found other better epoxies for most purposes. (MAS and System 3 G2 glue and Cold Cure).

Some other products have a 2:1 or 3:1 ratio, some kick off less violently.

[Flyingriki]

Note to West Haters....the Gougeon Brothers have been building beautiful boats for years with their products.
https://www.westsystem.com/gbi-history/
When you can match that record maybe we'll listen to you. In the meantime, there are several other brands of Epoxy that also work well but none have the terrific range of products and instructional data available for boat building and repair as West.
Flame on....

[Dave_S]

Originally Posted by chris95040

I'm not sure what your point is. The first thing I saw when I clicked that link, in bold text, was "Do not attempt to control the cure time by altering the hardener ratio."

BS...........WHERE

[john61ct]

Originally Posted by Dave_S

BS...........WHERE

First page of the PDF instruction sheet for 105 hardener

[Cadence]

Originally Posted by chris95040

Nothing in the instructions about thinning the ratio, either, yet you went ahead with that experiment! In fact I'm quite sure they caution you against it for obvious reasons.

Admit it, you didn't actually read the instructions, did you?

You mean you're resorting to, "When all else fails read the instructions.".

[Dave_S]

Originally Posted by valhalla360

So did you grind out the 8-1 mix. If it's any kind of structural use, I wouldn't trust it.

West System has great online documentation that really gives you good insight into how to use their product for a host of projects. Read up before wasting a lot of expensive epoxy.

Originally Posted by Dave_S

Thanks all

It worked a treat. I bought the cheap baking trays and mixed in that. The shape on the bottom of the tray makes it hard to mix thoroughly but you just flatten it first. Mixed at 5-1 and had plenty of time. And it was hotter today.

I mixed the 411 filler, maybe a bit thicker than peanut butter but it went on and smoothed out ok.

Before I did put the filler on I removed the old epoxy layer with 40grit on and orbital sander. It sands easily. Then replaced the glass mat and put the filler on when that coat was still tacky.

I'll go back tomorrow and sand it but it looks pretty good so far, so went from pretty messy to looking pretty professional.

Thanks :-)

It seemed as hard and as strong as the 5-1 sections and it came off the same as the 5-1 underneath but I took it all off. I then put another coat of glass and epoxy over the top then a layer of the filler. I'll sand it back tomorrow but it came up really well.