Hi Spidey,

I am thinking of building a mould from my next boat and produce a couple glass boats. Do you think this would be a good tough surface instead of a gel coat. I just don't want to spent the money on spray equipment and this sounds like a good alternative to a gel coat.

Hafte

: Fellow Polyester Resin Experimenters: If you're thinking of finishing your
: epoxy-glassed kayak with polyester resin, I'll pass along how I was told
: to do it by the folks who do it every day.

: Make sure the resin you buy has UV protectant. If you can only get the
: laminating resin with UV protectant as one poster reported today, you will
: need to add a wax/styrene mix. It is sold separately by resin suppliers.
: Laminating resin does not cure hard enough to polish, it is designed to
: bond properly with additional coats of resin. Clear, or finishing resin
: contains a wax/styrene mixture that comes to the surface and prevents the
: air from coming in contact with the surface (similar to the amine blush we
: see with some epoxies) - This allows the polyester resin to cure very
: hard, able to be buffed & polished. The resins are otherwise identical
: except for this addition of wax for the finish coat.

: Before you start mixing resin and MEK, you MUST stir the resin/wax mixture
: thoroughly - the wax tends to separate from the resin, and you must mix it
: VERY thoroughly before pouring some off. I was told I could not mix it too
: much 8-)

: For a finish coat, you want to mix a "cold" mix, meaning about 0.5%
: MEK by volume (200:1). You want it to remain thin and not "kick"
: too early, as it levels like a dream given enough time. No "tipping
: off" will be required either, as any bubbles you create will rise and
: pop in short order. This would be about 2cc to 16oz of resin if I did my
: math properly. I think most resin mfrs recommend a 1% mix ratio, we want
: to halve that.

: Mask the boat into 2 halves, hull & deck. The proper way to apply and get
: great results will drip, so keep it off the side you are not working on.

: Mix about 16oz, pour it down the centerline, spreading it with a brush as you
: go. You don't want to play with small batches and lots of delicate
: brushing, as you're bound to get brushmarks and bubbles that won't go away
: as it thickens. You want to spread it freely all around, letting it flow
: and self-level (and drip off the sides :-). The brush is there primarily
: to spread, and make sure the resin is wetting the surface. This reminds me
: of the way they taught me to glass the hull, which I found to be quick and
: efficient - albeit with a squeegee instead of a brush.

: Unmask while the resin is green. When the coating has cured, wet sand
: starting with #400 (using a sanding block!) and then up to wherever your
: buffing method requires (i.e., #1200). Here's my favorite finishing page:
: http://www.taunton.com/fw/features/techniques/finish/1.htm

: That's it, one coat should do it IF you allowed it to flow out properly. I
: figure about half will end up on the floor, and you'll sand off a few oz.,
: leaving about 4-6oz per side of the kayak. Not bad for a liquid glass-like
: finish that will preserve the color of your wood grain . . . I can't tell
: you how "impressed" I was by the finish on their surfboards.

: Hope this helps, Spidey