To fiberglass or not ??

[Archie1979]

Hi Everyone,
I am just about to start my epoxy work on the Qualia which was the mercury you can see it on a thread from a couple of days ago. My question is the hull will be clear coated so do i really need to use fiberglass matt from the chines to the sheer.
The material is Honduras Mohogany and is 6mm thick and beneath that is another 4mm of marine ply so there is no doubt of the strength,

Any thoughts suggestions would be great

Archie

[marshmat]

Hi Archie,

I take it this is the boat? http://www.boatdesign.net/forums/wooden-boat-building-restoration/mercury-22-footer-coming-along-nicely-23239.html

Strips laminated over plywood can provide plenty of strength, and the glass skin on such a hull is often more for abrasion resistance and to protect the wood from changes in moisture level that would cause it to swell, shrink and crack.

Using glass mat for this kind of topsides layup would be unusual. It would be more common, for a protective glass skin, to use a layer of light cloth in epoxy, then do your clear finish coat over that. With the right resin, this is transparent enough that it just looks like a thick varnish coat. If the design is for just a very thin glass skin, it's probably for abrasion resistance- you could skip it, but you'd regret doing so in a few seasons.

If the glass skin is a structural part of the design, that would be a different matter, but in this case I doubt that it is.

[Archie1979]

Thanks for the info Matt, you are right in suggesting that the glass skin is not part of the structural desiign, when you mention light cloth how light do you mean ??

Thanks for the help

[DMAN1968]

Having used 6 oz. and 4 oz. cloth on the boat i am currently building, 4 oz. wets out clear/transparent...6 oz. and above can be seen without to much difficulty.