Can carpet be used to separate Aluminum from PT Plywood?

rpm6100

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Jun 6, 2012
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Hi guys, I'm looking for a little advise here. I have a 16' duranautic boat that is an aluminum hull. It appears that there were some panels of the boat made out of PT plywood. The panels have been wrapped in carpet and there is no actual wood in contact with the aluminum of the boat. I was curious if this was ok and would prevent corrosion or if these panels need to be removed and constructed from standard plywood. The carpet on these panels is wrapped over the wood by about 8-10" in most areas on the rear of the panels. I was not sure and couldn't find any answers on if the metal needs to be in direct contact with the wood to create corrosion or if the treatment would basically transfer through something like carpet and still create problems. Any advise on this would be great. Thank you.
 

lckstckn2smknbrls

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Re: Can carpet be used to separate Aluminum from PT Plywood?

When the wood gets wet the copper will leach out. The carpet will keep the wood wet.
 

Woodonglass

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Re: Can carpet be used to separate Aluminum from PT Plywood?

Yep, the above^^^ is my understanding too. I would remove and either seal the wood with epoxy or replace with non PT wood
 

rpm6100

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Re: Can carpet be used to separate Aluminum from PT Plywood?

Thanks for the info I didn't think of that. My next question is can I use a latex or oil primer to seal the pt wood?
 

jigngrub

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Re: Can carpet be used to separate Aluminum from PT Plywood?

Thanks for the info I didn't think of that. My next question is can I use a latex or oil primer to seal the pt wood?

A penetrating sealer would be best, like exterior grade Spar urethane... and it's the same price as paint.

Make sure your plywood is very dry before you seal it, this will ensure maximum penetration of the sealer.

Use at least 3 coats of sealer for maximum protection, I use 4 coats for exterior applications but 3 is ok.
 

rpm6100

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Re: Can carpet be used to separate Aluminum from PT Plywood?

The spar urethane can be used over pt wood? I just want to make sure that this will be an acceptable finish. I plan on drying the wood very well and using atleast 4 coats. Thanks for the info, extremely informative.
 

rpm6100

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Re: Can carpet be used to separate Aluminum from PT Plywood?

Thanks for the info. I didn't know there was an alternative to epoxy sealing pt wood from aluminum. I am glad to find something that will prevent corrosion between the two. Thanks again for the info.
 

Bob_VT

Moderator & Unofficial iBoats Historian
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Re: Can carpet be used to separate Aluminum from PT Plywood?

Water is going to get to the wood and corrosion is going to get to the hull. It is a well known document many times here on iboats with pictures that PT and aluminum do not mix.

Good luck but it sounds like you are determined to do it your way anyway.:facepalm:
 

rpm6100

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Re: Can carpet be used to separate Aluminum from PT Plywood?

Its not that I am determined to do it my way, I am actually going to tear it down to the bare hull and replace everything with exterior grade ply. I was questions the advise that the person above me gave regarding using spar urethane with skeptism. I didn't think that it was on par with the other responses. This is why I questioned it so much.
 
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