New floor question - sealing both sides or one side

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geedubcpa

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This is for my 1981 starcraft aluminum boat - I am replacing the wood floor with marine grade - I am planning on sealing the wood with fiberglass resin and then following up with a vinyl floor.

My question has to do with sealing the floor - when you paint wood you generally only paint one side so the other side can breath out moisture - is this the same for boat floors made of wood - Would you only do the top and exposed edges or would you do both sides.

Thanks in advance for your ideas.

gw
 
Bob_VT

Bob_VT

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Re: New floor question - sealing both sides or one side

Seal all edges of the deck...... if you are using fiberglass resin be sure to use CSM or it will not work properly
 
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geedubcpa

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Re: New floor question - sealing both sides or one side

do you do both sides top and bottom? Its an aluminum boat and the deck sits upon the stringers screwed or rivited in.
 
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Chuck Gibson

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Re: New floor question - sealing both sides or one side

I believe I read somewhere on this forum that you should put one coat of just fiberglass resin on wood, let it kick, and then put on a coat with CSM. If I remember right it said to do this to keep the wood from soaking up major resin while you are trying to wet out your CSM. Would someone please confirm if I understood this right? It won't be long until I am at that stage.
 
tdrudd87

tdrudd87

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Re: New floor question - sealing both sides or one side

Chuck, you are correct. A seal coat is needed on bare wood to prevent the wood from drawing redin from the laminate and leaving a dry layup.

I would put glass on both sides of the deck, poly on its own will crack and let water into your wood.

Terry
 
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Chuck Gibson

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Re: New floor question - sealing both sides or one side

Thank you tdrudd87,
I have another question for you guys. I also read on this forum somewhere that if you really want your wood pieces to last for decades that you cannot expose wood in any shape, form or manner. It seemed like overkill but it actually said that when you placed your deck down to the stringers, you drill 1/2" holes through the deck and into the stringer everywhere you want to put a screw. Then you fill those holes with fiberglass putty or whatever you would use to make fillets on your stringers, let it kick and then drill small holes through the spots you just filled so the only thing you are penetrating with screws would be fiberglass...not wood. Does this make sense or do I need to explain myself better?
 
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wallybme

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Re: New floor question - sealing both sides or one side

What is CSM???
 
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Chuck Gibson

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Re: New floor question - sealing both sides or one side

CSM= Chopped Strand Mat.
 
ezmobee

ezmobee

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Re: New floor question - sealing both sides or one side

Chuck Gibson said:
I have another question for you guys. I also read on this forum somewhere that if you really want your wood pieces to last for decades that you cannot expose wood in any shape, form or manner. It seemed like overkill but it actually said that when you placed your deck down to the stringers, you drill 1/2" holes through the deck and into the stringer everywhere you want to put a screw. Then you fill those holes with fiberglass putty or whatever you would use to make fillets on your stringers, let it kick and then drill small holes through the spots you just filled so the only thing you are penetrating with screws would be fiberglass...not wood. Does this make sense or do I need to explain myself better?
Click to expand...

That's one way to do it but I prefer to just predrill, fill with some 5200 and screw.
 
Mark42

Mark42

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Re: New floor question - sealing both sides or one side

Chuck Gibson said:
What is....5200?
Click to expand...

3M makes two popular marine grade sealants, 4200 and 5200. 4200 is used when the parts will eventually need to be separated or disassembled. Like the mounting bolts for an outboard. 5200 is best used where parts are not intended to be disassembled, because it is more of an adhesive than a sealer (in my opinion).

4200 works great for all applications, as far as I am concerned. I have seen fiberglass ripped off of transom when 5200 was used to seal the outboard mounting bracket. Its a dangerous product when used for the wrong purpose. I have struggled to get screws out of engine block because of it.

Just something to keep in mind. When in doubt, use 4200. Or use the Boatlife brand of sealer. It works great and comes apart without too much swearing!
 
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