Recommended fiberglass cloth

[cghubbell]

Are there any guidelines for correct / incorrect fiberglass cloth weights / materials for repairing decks? I was about to start a repair with 6oz cloth just because it's what I had on hand from my last shopping trip. Then I did some poking around and noticed the Don Casey recommends 10oz, and another site I saw spoke of biaxial cloth. Haven't heard of that before. I plan to use epoxy for this project.

I'm not racing. I don't intend to cross the ocean (although Lake Ontario can be pretty tough at times!). I just need a structurally sound repair for the deck of my 30 year old Good Old Boat. Would appreciate any wisdom that could be shared on material selection.

And while I have the attention of the experts, bonus question is, does your answer apply to repairing transducer holes in a hull as well, or would that be a unique situation.

Thanks in advance,
Chris

[sailingdog]

Generally, the lighter weight cloth is necessary for more complex shapes and such, since it will follow the curves and drape better than heavier weight cloth. If you have 6 oz. cloth, it should be fine... but you'll need to use more layers than if you had 10 oz. cloth.

BTW, cloth is typically biaxial... it has fibers running in two directions. Triaxial cloth has it running in three...

[mitiempo]

I would use 1708 biax which is a stitched (not woven) roving with epoxy compatible mat on one side. Excellent strength and less layers required. Tim Lackey of Northern Yacht Restoration | Tim Lackey:* One Man, One Boat at a Time uses this for both recoring decks and glassing in through hull holes. You can peruse his site for step by step how-to with pics.

[sailingdog]

The 1708 Biax w/ mat is great stuff but not as versatile as 6 oz. or 10 oz. cloth. Also, a lot more expensive.

Originally Posted by mitiempo

I would use 1708 biax which is a stitched (not woven) roving with epoxy compatible mat on one side. Excellent strength and less layers required. Tim Lackey of Northern Yacht Restoration | Tim Lackey:* One Man, One Boat at a Time uses this for both recoring decks and glassing in through hull holes. You can peruse his site for step by step how-to with pics.

[mitiempo]

More expensive but it does build up thickness faster. 2 or possibly 3 layers of biax can replace 6 or 7 layers of thin cloth. Stronger as well. For a deck recore which has no compound shapes it works well.

[Gary M]

It would depend on what he is repairing. If it is not in a structural spot cloth should work fine. Apparently there are some types of glass cloth/matte or what ever that does not work well with epoxy. Anyone know the details?

What are you doing? Being a past CS27 owner I know that they had pretty thick skins on either side of the coring, what happened to them?

[sailingdog]

very true...but if he already has the cloth...

Originally Posted by mitiempo

More expensive but it does build up thickness faster. 2 or possibly 3 layers of biax can replace 6 or 7 layers of thin cloth. Stronger as well. For a deck recore which has no compound shapes it works well.

[mitiempo]

It is for deck repair, I believe the top skin being replaced after recoring some areas. The CS 27 does have thick skins, where I've measured 1/4" for both inner and outer layers. To build up this thickness with cloth alone will take many layers. Biax would be a lot less labor intensive as well as probably stronger.

[sailingdog]

That would take quite a bit of cloth... and 1708 biaxial roving with mat might be faster.

[scottyt]

i can lay 10 layers of glass in 30 mins or less. i just use a table, lay the glass down pour some epoxy on squeege the epoxy around, lay the next layer etc etc, then move the whole thing to the boat where i need it. now this assumes i have it all precut. i have used the heavy stuff, its a pain in the butt to get the resin to completely saturate the glass. i would say to build a 1/4 inch thickness the 7 oz glass might take just a few mins longer, mostly due to getting the thick glass completely wetted out