I've worked with System Three regular resin for more than twenty years and I'm very confortable
with flawless application of that resin.

So, silly me, I decided to try some MAS epoxy when someone here posted, it was on sale, last year.

The System Three regular resin with slow hardener has a slight yellow cast and the MAS is supposed to be clear
so, I wanted to try MAS with some of the clear Captain's Varnish on a light colored boat.

I found little bubbles flying out of the mixing cup when I mixed the MAS epoxy. Odd.
And there seemed to be much more foam and bubbles in the mixed resin than I was accustomed to.
Plus the weird smell. Smells like those deodorizer pucks they throw in urinals!
Is this why it was on sale?

I did a seal coat with slow hardener and then wet-out my glass with resin and slow hardener and was somewhat
surprised that MAS with slow hardener, set-up in about half the time of System Three regular resin with slow.
Everything seemed fine.

It was when I came to my fill coats I noticed an increased tendency for the MAS to hold onto bubbles.
Again, the MAS with medium hardener set-up in about half the time of System Three. I applied a fill
coat to my deck with a foam brush and tipped it off and I thought it looked good and smooth.
I came back a couple hours later to find the deck covered with hundreds of tiny holes where bubbles
had burst as the resin set! Ouch!!!

Next I worked in cooler temperatures hoping that might allow more time for any bubbles to rise and break.
I rolled on thin fill coats on the hull and found huge amounts of very ting bubbles even after tipping off with
a brush. Then I remembered Nick talking about using a heat gun to get rid of bubbles with MAS, so I did that.

Is this what other users of MAS are experiencing?

Now I'm wondering if I will see tiny bubbles trapped in the glass too.

Wow. I can't believe what a difference there is in the resins/hardeners between the brands.

The slower set-up of the System Three regular resin allows any bubbles or foam to totally dissipate and leave
a smooth surface. No I'm not paid by System Three, wish they would though.

Most of all, I want to let people reading this BB to know just how different materials can be from brand to brand.
This makes it very difficult to know, if when people ask about problems on this BB, are the problems because of inexperience,
or because a brand has qualities which are different from the experience of people suggesting help.

Probably few people will notice the difference unless they have worked with various brands.

So, be aware that different brands of epoxy may handle and act very differently. Read the directions carefully
and do a few test panels.

This falls under the heading of "The Devil is in the Details" because very small differences in how a material
handles can make a big difference in success or failure.

When I searched for a varnish or finish for my boats I tried everything, and when I finally tried Captain's varnish
it seemed so much easier than other finishes.

I don't think I will use MAS again.

Rob