Fiberglass question

[Vinnys]

I am making new hatches for the bait box and fish well.

I want to do one layer of roving on it to protect the wood.

Can I use Cetol on the wood so it matches the rest of the boat or will the resins not work and not bond to the wood.
I am using furniture grade 1/2 " oak veneered ply doubled up.

Vinny

 

[azmav]

Re: Fiberglass question

To get a good bond, you want to coat the wood with resin before applying any glass, then while it is tacky, you apply fresh resin, lay the glass and coat the top with more resin. Some guys skip the first coat but I believe it gets more penetration into the wood that way. Remember, wood is porous and from all I have read on all these guys posts, I would not use the Cetol as it will reduce the porous nature of the wood, the fiberglass done right will waterproof well enough. That being said, you cannot just lay down roving by itself. Roving needs a layer of CSM laid down first, otherwise you end up with a resin rich layer between the roving and wood that is weak, if you are using poly. Epoxy could be used that way with roving I think. If you only want to do one layer of glass, you might consider 1708 biaxial. It is cloth with a layer of CSM stitched to it. Good strength to weight ratio.

 

[DeepBlue2010]

Re: Fiberglass question

I agree with 1708 being a good alternative to roving. Saturating the wood with resin first is a good insurance that the wood will not absorb the resin out of the glass leading to weak glass to wood bond. But, your choice of wood is not suitable for this application. Furniture grade ply is not suitable for marine environment since its glue is not water resistant, it will rot if moisture finds its way to it. Use exterior grade or marine grade. I am not sure what line of Cetol you want to use, you did not specify if you want to use it at the end after glassing (as top coat) or as an alternative to glassing or in combination with glass?! Please add more details.

 

[Vinnys]

Re: Fiberglass question

I have been using Sikens cetol marine varnish.
I feel if I cover all the wood with fiberglass the hatches will last longer that the garbage already breaking down since they were not taken care of.

Can I use the Cetol over fiberglass and come out with a finish similar to the rest Of the wood on the boat?

 

[Woodonglass]

Re: Fiberglass question

So I take it you want the Natural look of the wood to show through. If so you will need to alter your plans just a bit, IMHO. Since these are hatches and not pieces of wood that will be constantly immersed in water then cabinet grade wood, while not being the best choice, can be acceptible. IF the wood is encapsulated properly. The wood should be stained with a water based dye not oil based stain. Once dry then, I would highly recommend using Epoxy for this application. Precoating the wood first with epoxy followed by 2 layers of 4 oz cloth embedded in epoxy. The weave of the cloth will disappear when the coats of epoxy are applied followed by 4 coats of Epiphanes Marine varnish. This will give you a Glass like finish with the beauty of the natural wood showing thru, UV protection and the wood totally encapsulated and waterproofed.

 

[Vinnys]

Re: Fiberglass question

Woodonglass

That sounds doable.

I will try your method.

Thanks

 

[Yacht Dr.]

Re: Fiberglass question

You could also glass the wood .. then put on some veneer .. then coat the veneer with your cetol.

Just another suggestion ..

YD.