fiberglass resin vs epoxy

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Pat McD
Bottom Sanding Grunt
Posts: 8
Joined: Sat Jul 05, 2008 11:20 am
Location: Sault Ste Marie, ON

fiberglass resin vs epoxy

Post by Pat McD »

I am getting ready to tab in new companionway bulkheads and berths on my Seasprite. This will be my first glassing work on a sailboat this size. Over the years I used fiberglass and resin to repair small sailing dinghies and canoes with good success.

So the question is, will fiberglass tape with resin do the job or should I use epoxy?

Thanks

Pat McD
Captain of the project boat Azul
CharlieJ
Wood Whisperer
Posts: 649
Joined: Fri Aug 19, 2005 7:42 pm
Location: South coast of Texas, Matagorda Bay

Post by CharlieJ »

either will work, provided you grind the surface well.

Lets clear something up here. There really is no such thing as "fiberglass resin"

Fiberglass is the glass strands that make up either the matt, or cloth, or roving that you apply resin to.

Resin can be one of several things, the most common being polyester resins in various forms, including Vinylesters. And then you have epoxy resins, again in various types.

So you are really asking "can I use Polyester resin or would epoxy resin be better?"

So yes, either will work- after all the boat was most likely built using a common polyester resin in matrix with the fiberglass. But yes, epoxy resin would be better- you'll get a stronger bond, again provided you grind the surface well where you will be adhering the fiberglass tapes.

Another question might be- "what is the best tape?" And for that, in my opinion, the best is bi-axial tape, because none of the strands parallel the joint- they all cross at an angle, therefore all contribute to the strength. However, many many boats are out there happily sailing with plain old woven tape or a tape/matt matrix tabbing the joints. And yes, you can use matt with epoxy, quite well in fact.

So in the end, it's up to you.
Pat McD
Bottom Sanding Grunt
Posts: 8
Joined: Sat Jul 05, 2008 11:20 am
Location: Sault Ste Marie, ON

resin or epoxy

Post by Pat McD »

Charlie,

Thanks for the advise and for understanding what I really should have said re resin.

You folks are a great resource for newcomers.

This might be another stupid question, but here goes. The weather is getting cooler up here in Sault Ste Marie, Ontario and one of the many things remaining on my to do list will be to sand the hull and apply new antifouling. Is there any reason why I should not sand my hull now in the cool weather and then apply the antifouling next spring in warmer weather?

Pat McD
Hirilondë
Master of the Arcane
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Boat Name: Hirilondë
Boat Type: 1967 Pearson Renegade
Location: Charlestown, RI

Re: resin or epoxy

Post by Hirilondë »

Pat McD wrote: Is there any reason why I should not sand my hull now in the cool weather and then apply the antifouling next spring in warmer weather?

Pat McD
Unless you sand through to bare fiberglass I see no reason at all. And depending on how/where you store your boat that may not even be an issue. You will need to clean the bottom again in the spring before painting, but that's easy.
Dave Finnegan
builder of Spindrift 9N #521 'Wingë'
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CharlieJ
Wood Whisperer
Posts: 649
Joined: Fri Aug 19, 2005 7:42 pm
Location: South coast of Texas, Matagorda Bay

Post by CharlieJ »

ROFL- Glad Hirilondë answered you. Look at my name and location. What do I know about cold weather-grin
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