: Hi, new to the forum, although I've been snooping for a few months.
: About to start my first boat, Rob Mack's Fire Star, and had some
: questions about fiberglass selection. I'm leaning towards
: s-glass, 6oz for the hull and 4 oz for the deck, with another
: strip of 4oz on the outside hull for abrasion resistance. As
: I've never worked with fiberglass should I just stick to the
: standard 6oz E-glass for the first boat? Is S-glass inherently
: harder to achieve a transparent wetout? If I was to choose
: S-glass, looking at the Sweet Composites site they have a plain
: weave (6533) and 8-harness satin weave (6580) - both 6oz. Are
: the two weave types equal in terms of strength? I understand a
: tighter weave is more challenging to work with to get a clear
: finish. In other words I'm looking for advice on balancing my
: lack of fiberglass experience with what I should look to achieve
: with this first boat. Thanks to all for this great resource.

: Mark

6 oz. S-glass is overkill.

I'd suggest using 4 oz. S-glass plain weave.

4 oz. S-glass is actually easier to wet-out than 6 oz. E-glass.

The 4 oz. S-glass will also conform to sharper curves / edges such as
my recessed coaming in your plans.

One layer of 4 oz. S-glass on the hull and deck are enough. If you wish
you can put a second layer of 4 oz. S-glass below the waterline on the hull.

And, you must add extra reinforcement under the deck around the cockpit.

S-glass plain wets-out well but there will be a visible weave pattern on CLOSE inspection.
Few if anyone will notice.

Please note as I state in your plans, you must take the same steps for a transparent lay-up on your
exterior seams and stem reinforcement as you do for the hull / deck lay-up. Cold thick resin applied
to a cold boat will not allow your seam / stem glass to totally wet-out to a transparent level.

I emphasize this because it took me years to realize this. It is oh too tempting to wet-out the glass on the
seams and stems without taking the time to warm the shop and resin so it will be as thin as possible.

All the best,
Rob