fiberglassing plywood hulls

[tarrat68]

I'm trying to decide if I should fiberglass a glen-l classic runabout plywood hull with fiberglass. I know the strength adds value but I've heard that it can cause the hull to rot faster. Is there any truth to this rumor? what would you do? Is it alright to epoxy and paint only? Isn't this the more traditional approach?

[the1much]

it will only rot if you dont glass it right. do "shody" work,,and ya it will rot. and i've never done it,,(the epoxy dudes will ring in soonz),but i think i read another epoxy thread and they said it can be done,,but just epoxy and paint is better then just paint,,and just paint is better then no paint or anything.

[PAR]

This is a well debated subject and you serve yourself well if you did a few searches on the subject.

As a rule, epoxy on wood (painted or varnished of course) doesn't add any significant strength. It does seal the wood, but only if total encapsulation techniques are employed.

Epoxy bonding fabric to wood doesn't impart substantial strength either, unless you use a pretty fair thickness of fabrics. In other words, a single sheathing of moderate weight fabric over wood, will provide little more then abrasion resistance (and the most common reason for doing so), very little noticeable strength, unless you use some of the high tech fabrics (bring you first born to the supply house).

If you haven't epoxy encapsulated your planking, I would strongly urge you to not 'glass the exterior. Just paint her and keep after the maintenance when the needs arise.

If you feel you must add cloth to the outside of your boat, but haven't encapsulated the planking, then use one of the fancy fabrics, such as Dynel or better yet Xynole. They absorb much more epoxy, but will dramatically improve the abrasion resistance compared to regular cloth. Dynel is about 3 times better and Xynole is about 6 times better then similar weights of S cloth (the regular stuff).

If you have embalmed the planking with at least two (much better if three) coats of unthickened epoxy , then you have a good prospect for fabric sheathing. This will increase you abrasion resistance and water proofness a substantial amount.