Aluminum Boat Floor

Joined
Jan 25, 2015
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Just bought my first boat last fall a 18' Alumacraft Trophy 175. Had it out a about a dozen times last year. Need some tips on redoing the floor. I am looking a redoing the floor all new deck and carpet (outdoor marine grade rubber backed). Have read some post on floors and most I found are putting multiple coats of resin down. Wanted to know if there is a less expensive alternitive to resin? Could you just use a sealer? I am plaing on keeping it cover or keeping it in the garage when not using it. Any tips would be great.
 

GA_Boater

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May 24, 2011
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Welcome aboard, brando.

Plenty of us use urethane spar varnish in our tin boats. With care it will last much, much longer than the original wood flooring from the factory. I use the Helmsman brand from a Big Box store.
 

Jeep Man

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Oct 17, 2008
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I'm refitting an aluminum 15.5" and replacing the floor. Doing it on the cheap, and like you, not leaving it on the lake. Used ACX 3/4" plywood with good primer and 2 coats of marine oil base paint. Doing the deck with marine vinyl. Easier to clean up fish residue. Hopefully there will be some.
 

dozerII

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As GA_Boater mentioned quite few of us use Helmsman Spar Varnish, 2 to 3 coats on the flats and hit the edges 5 to 6 times and the wood will last a long time.
 

jigngrub

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Mar 19, 2011
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As a rule, cheaper won't last as long as the better material. Going cheaper won't hurt anything, you'll just have to redo it sooner than you would if you use the better materials.

I've used the spar urethane in some marine applications and it works for a while, but it failed over time and I ended up redoing it sooner than I would've liked.

I haven't used the paint but I wouldn't expect it to last any longer than the spar.

Going cheap the first time is a good learning tool and it'll make you appreciate the better material the second time you do it. The epoxy resin may seem expensive now, but on the second go-round it'll be a bargain.
 

gm280

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Jun 26, 2011
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I often thought that if I have to replace a floor in a aluminum boat that I would beef up the under-support with aluminum supports and then sheet the floor with aluminum sheet. And never ever have a rotted floor issue ever again. However, I'll admit I never looked into that cost of doing that. It just seemed a great way to forever fix a rotted floor situation in an aluminum boat to me....
 

Woodonglass

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I'm NOT a "Tinner" but, I've seen this ^^^ discussed here on the forum, and I believe the general consensus is an aluminum deck/floor would get kinda "Toasty" in the sun. I guess if you were to carpet it or put vinyl on it that might be different. :noidea:
 

gm280

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I'm NOT a "Tinner" but, I've seen this ^^^ discussed here on the forum, and I believe the general consensus is an aluminum deck/floor would get kinda "Toasty" in the sun. I guess if you were to carpet it or put vinyl on it that might be different. :noidea:

Yea but if you were fishing, and actually catching fish, you could have your fish fry onboard then... :facepalm:

I most certainly cover it with quality marine carpet... :)
 

Woodonglass

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Now THAT"S an idea!!!! And the more I think about it, JON boats have aluminum seats and decks. And I think some Pontoon boats have aluminum decks but I'm not sure about that. Oh well, like I said,I am NOT a Tinner so NOT my expertise by a LOOOOOOONG shot!!! But I do KNOW it would NEVER ROT!!!!!:lol:

To the OP, I've been doing a LOT of research lately on Exterior Wood Preservatives and during my perusing, I came across this product...http://onetimewood.com/ Never used it, Have NO experience with it $85 per gal and if covers 300 sq. ft. with a 7 yr. guarantee not to peel crack etc.., sooo You'll have to read and decide just like me. It is sold in my city (check for location) so I plan on buying some and trying it out on my Fence. I figure it get's about the most abuse that wood can get and if it works on that It should work on Plywood in a boat. But then again, That's just me!!!
 
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jigngrub

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I often thought that if I have to replace a floor in a aluminum boat that I would beef up the under-support with aluminum supports and then sheet the floor with aluminum sheet. And never ever have a rotted floor issue ever again. However, I'll admit I never looked into that cost of doing that. It just seemed a great way to forever fix a rotted floor situation in an aluminum boat to me....

If you ever price sheet aluminum you'll see that you can put in 2 marine grade CCA plywood decks for the cost of one aluminum sheet deck. Sheet aluminum is very expensive compared to plywood. Aluminum angle for additional framing is also expensive, but most of the tinny restore I see on this forum need more framing.
 
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hadaveha

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Mar 17, 2009
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389
A friend of mine used 3/4 treated ply and painted it both side with about 4 coats of rust oleum to keep the cooper in. I know you are not supposed to use the treated with aluminum, but had allready bought and dreid it. He should be set for as long as hell be using the boat
 
Joined
Jan 25, 2015
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OK it has final warmed up here and I have take the floor out of my boat. Now I am going to have to take the foam out as mice had at one time made a home in it. I was going to us a 1.75-25fs class 1 foam density as a replacement has anyone ever used this type of foam before in a boat?
 

Watermann

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Jan 12, 2013
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:welcome: aboard Brando.

Most of us use the 4x8 sheets of rigid foam board found at home depot or lowes.

So the floor in a boat is called a deck. I've rebuilt a couple boats and I've used spar for sealing the decking and transom wood. Just remember nothing is perfect at sealing up wood because you go drilling and running screws into it but taking care of your investment by covering it will make the boat deck last for decades.
 

jbcurt00

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I was going to us a 1.75-25fs class 1 foam density as a replacement has anyone ever used this type of foam before in a boat?
I'm not familiar w/ that foam. I think DozerII did a DIY spray foam on 1 of his projects, but I don't think he still owns it, so not sure you'd get good long term opinions about it's worth as a replacement foam in an aluminum boat.
 

jigngrub

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I'm not familiar w/ that foam.

I'm not familiar with it either and wasn't aware it was a spray foam kit... so I googled it. I couldn't find a price for that exact kit, but found a similar one at Grainger. A 17 cu. ft. kit of 1.41 lb. density for $734.

While I'm a big fan of the expanding urethane foam, I don't feel that this particular material is suitable for a boat build. Foams with less than a 2 lb. density are much less water resistant than foams of 2 lb. density or higher. And the price of $734 for 17 cu. ft. is very expensive, especially when you consider you can get 20 cu. ft. of the sheet foam for $160.
 
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