Replacing floor in boat

[Lost]

I've got an old fixer-upper runabout. I need to do something with the floor because it's weak. I'm wondering if I should replace what's already on there or just put some marine-grade plywood over the top of the current stuff. Any suggestions?

Also, how do I cut the new boards so they follow the curve of the boat?

I was also playing with the idea of using vynil docking material instead of wood so that I wouldn't have to deal with wood rot in the long run.

Anybody want to do the job for me?

[This message has been edited by Lost (edited 04-22-2004).]

[bwtrout]

i would tear out the old decking. the old stuff is probably water logged and adding another layer on top is adding alot of extra weight. take measurements across every foot and freehand the curve? i did it to my boat a couple years ago, it was a big job and for awhile i thought i had a real disaster on my hands, but it turned out looking brand new.

[Steve Bakken]

If you want to have someone do it for you, give us a call and we can help you out. If you feel up to tackling the job yourself, check out the threads in this site's archives about plywood floors and what to use. They'll be very helpful.

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com

[Surface Tension]

Don't go over the old floor, remove the rotted wood. If this is a fiberglass boat you'll probably have to replace the stringers as well as the floor which will be a big project.
To cut the profile in the floor you use a basic setup using a Reference Line. This line will be the height of the floor.
In this case the R/L will go down the center of the boat, bow to stern. Now find and mark the height of the floor where it meets the side of the boat. This line once placed doesn't MOVE and all your measurements are in relation to that line.
If you can't make the line on a stationary object like a stringer then use a masons line. Start at the bow and measure down the R/L, from that point measure over using a square to the line you've drawn along the side of the boat. In curved areas the more measurements you have the better the profile will be.

[PaulB]

I just took the floor out of my boat (16 ft., fairly flat bottomed aluminum hull). There are pieces of foam under there that have disintegrated and will need to be replaced. I know you can buy expanding foam that you mix and pour, but how do you keep it out of the drain channels in the ribs? And has anyone ever thought of using that fake wood planking for decks for a floor? Might get expensive, but should hold up well, I'd think.

[musky hunter]

Matching the contour is a real issue. You can cut cardboard templates, but transfering curves is a job that takes skill. If you can remove the existing floor either in tack or in carefully cut pieces you might use that as a template. I've used 3/4" green treat and it has held up. Good luck with you're project.

[Lost]

Stringers? What are those and what do they do?

[Surface Tension]

Stringers are the wood members your floor sits on. They're probably glassed in. Thats if you have a fiberglass boat.

[Surface Tension]

Paul, you can use a closed cell foam in sheet form. Easily obtained from Menard's.

[Lost]

Yup! It's a fiberglass boat. The guy that gave me the boat (yup, free boat... turning out to be expensive) says he'll help me with any fiberglass work that's needed. Thanks for your help guys!

Found a book at the library that'll help out. Just wish it had more pictures and less words.

[Surface Tension]

HeHe. Free boat
Before you pour time and money into it take a rubber mallet and check the hull for soft spots. As you tap tap tap you'll know when you hit a bad spot. Give the transom a good look over too for rotten wood. It'll be sandwiched in glass also.

[Lost]

Yeah yeah, free things usually cost more than new in the long run. I've got the transom taken care of. No problems there. Just gotta get a new floor in and decide what I wanna do with the windshield. Probably just remove it.

Where can I find some Rhino spray-on bed liner to coat my new floor?

[Surface Tension]

I don't know how well a spray on liner adheres to wood. If the bedliner doesn't seep into the wood it won't take long before it comes off in chips. Some how I think you'd a have a big mess in a short time.

Theres a couple methods of sealing the floor by using a polyurethane or resin. These penetrate the wood fibers. Once sealed glue your carpet down and wrap the edges and staple the under side.

[This message has been edited by Surface Tension (edited 04-29-2004).]

[Steve Bakken]

That adhesion question has been plaguing me as well. As a test mule, we sprayed some test panels of plywood with our line of coating and have been abusing the living heck out of them. One sat submerged at the bottom of a tank of water for three weeks straight. The wood swelled and warped but we can't get the stuff to let loose from any of the panels. It's passed the test to my satisfaction and we haven't had any customers come back with any problems. So, hope that helps you feel a little more comfortable with your decision if you decide to put it on.

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com

[Surface Tension]

Steve thats good to hear. I can see a few more applications where the bedliner might be just the ticket.

[PaulB]

Steve, do you use some kind of sealant under the bedliner coat? Maybe a combination of the resin previously mentioned, over all the plywood, then the bedliner just on the exposed surfaces? I was thinking about running it right up the sides of the boat too, for a little sound absorbtion. Thanks to all you guys for your advice.

[Steve Bakken]

We apply it directly over bare wood. The purpose of those test panels was to test the limits of the product and we could not get it to let loose from the wood. In fact, any kind of resin or sealant may actually inhibit adhesion. The main ingredient for adhesion is physical "bite" to a rough surface. By pre-applying any sort of other chemical, in theory, you would reduce this effect. Also, the bedliner wasn't designed to have any sort of chemical bond with any other product. The only exception to this is when applying it to bare aluminum. In this case, for warranty and proper adhesion, we first apply a phospheric acid etch primer to create that "bite" that the material needs in order to stick. If you wanted to, though, I still don't think that it would be a bad idea to apply a sealant to the back side of the plywood before you install it in the floor. One more step to add protection.

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com

[analyzer]

Wood under water doesn't rot. It's the repeated wet and dry that gets it.

[Steve Bakken]

Analyzer hit the nail right on the head. The best thing that you can do to keep anything attatched to wood- whether it's carpet, resin, paint or bedliner, is to keep the wood protected. The bedliner- like any other material, WILL let loose if the wood is subjected to an environment which causes it to rot. Then the outermost layer which is attached to whatever material has been put on it will begin to seperate. The first step is good protection which we have already covered in this thread, and the next step is just common sense care.

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com