How to seal cabin sole against mold, etc.

[SailorMcCruise]

Hello,
i will soon replace the cabin sole veneer on my old deep bilge long keeler with hard wood planks. Due to the slightly shaped nature of the floor and the rather thick ( 3/4“ ) planks, there will be some hollow space.
In order to avoid any mold and gunk build up, I‘d like to seal that space properly against moisture.
Now of course I could use some sealant like sika or 3m 4200 and such but that will get unessecarily expensive.
So I was thinking that maybe pu-foam might work?
Any suggestions welcome.
Thanks!

[s/v Jedi]

I wouldn’t do that. I think you mean you need a gap filling adhesive?

I recommend you use penetrating epoxy on the surface that you glue onto, then regular thickened epoxy on the planks that you put on top.

You can buy TotalBoat Thixo (if I spell that right) but I lrefer to simply mix it myself with microfiber and colloidal silica fillers, then uses a notched spreader to apply it.

Alternatively, for the boards you can also use the construction adhesive from the big box stores; I think I used Locktite Premium PL which is a polyurethane.

[Searles]

Go with Jedi ,if possible increase ventilation.⛵️⚓️

[SailorMcCruise]

Hello and thanks for the replies.
So, ventilation of the boat is pretty good. But for the area under the planks it would probably not be good enough.
The old Teak veneer was pretty rotten at the edges where the
occasional sea water drips could accumulate over the years.
The area I will install the planks onto is already some sort of polyester with thickener to which the veneer was glued to ( see image )

I am a bit reluctant to use something like thickened epox and such as it is very hard to remove if so desired or needed in the future.
Also in some areas the gap would be pretty large so a lot of expensive epoxy would be needed.
This is why I was looking into options.
What argument are held against the closed cell pu-foam?

Thanks again

[Kello]

Years ago a friend told me that if everyone put their problems in a pile, that once you saw other people's problems you would quickly reach in that pile and get your own problems back out.

And that is exactly what I thought when I saw your photo. 8-0 (big eyes and screaming mouth, CF doesn't have such a necessary emoticon.)

What about using starboard? It comes in many thicknesses, is easy to cut and router, has a non-skid texture, and can't mold. If the price of it nudges you to thinner product then you might have to put in extra joists so it doesn't sag. It can't break, but it can sag. Whether or not the PO likes that Idea, I'm interested in any experienced feedback.

[JimsCAL]

I am assuming this was teak veneer plywood. Sounds like you are removing just the veneer and then will attach the 3/4" wood planks to the old plywood core. Why not remove it all? Do you really want to attach the new planks to an old damaged plywood core?

[s/v Jedi]

Yes, remove the rotten plywood.

[Pandor]

But if it isn’t rotten, I’d sand it smooth, put two coats of epoxy over it and the go to the flooring shop for some cheaper laminate. The modern stuff is a breeze to install and will hold up quite well.

[s/v Jedi]

Originally Posted by Pandor

But if it isn’t rotten, I’d sand it smooth, put two coats of epoxy over it and the go to the flooring shop for some cheaper laminate. The modern stuff is a breeze to install and will hold up quite well.

You can also fill the voids before gluing something on top using a product like TotalFair or mix it yourself with regular epoxy and micro balloons.

[SailorMcCruise]

Hello again, yes, I am removing the veneer with the plywood base completely.
The new floor will be hardwood planks.
I need to fill the few hollow spaces in between these planks snd the bare cabin sole.
Of course I can use thickened epoxy or polyester ( the latter be much cheaper )
but I would like something which is easier to remove in case I need to access the original beams and planks ( which are
constructing the actual floor.)
Hence my question about the PU-foam.

[scherzoja]

If you have floors (what you call beams) under your plywood sole, why not remove the plywood and install sole directly to the floors? You won't have to worry about rot, except for the sole/floor contact.

Not sure what kind of planks you are using, but if they are 3/4" thick, they might easily span your floor spacing. If not, add a few floor beam to shorten the spacing.

I replaced the rotten veneer plywood with hardwood (teak/white oak strips). Unfortunately (or not?), I have a fiberglass pan (molded fiberglass sole) under the plywood. To reduce chance of rot, I drilled 3" holes in all the low spots and backfilled the core with epoxy to seal it. Any water that gets under the wood sole, will move to the low spots and drip into the bilge.

The white oak stirps are tongue an grooved into the teak. No special tools, just a table saw with dado blades and a sharp thin kerf blade to create the tongue and grooves.

Attached are pics during install
More pics here: https://bodylens.com/sailboat/index....bum=Cabin-Sole

[pbmaise]

SailorMcCruise

I suggest you forget about considering the difficulty in the future. If you do this repair correctly, you will not need to remove the boards again in your lifetime. You have access to materials the original builders didn't and will be able to make a far longer lasting repair. Further you will be sealing the ends of your planks.

There is a really simple way to do this.

1. Seal the wood that will be buried...and yes make sure all rot is gone.

2. Proma Self Leveling Underlayment Pro Flowlever 40 Fiber Reinforced 40 lb (6138). Can be used on critical substrates when used in conjunction with PROMA’s fiberglass woven mesh PRO FLOWLEVEL FIBER MESH You will need to make sure boat is in calm water during this step and level in all directions.

3.Seal the self-leveling compound. If you are really nice...I would next do a layer of fiberglass on top of the leveling compound and lap it up the side. This will help prevent the leveling compound from cracking as the vessel moves.


Note: Expect immediate screams that absolutely don't do this...However, again I bet this repair down correctly will last far longer than you continue to own the vessel. Further, you will be over and done with the task with level solid floors far stronger than if you filled the area with closed cell foam.

This will add some weight to your vessel, however, based upon the type of vessel you have it is already a heavy vessel. Further, it is all weight down low. To minimize the weight gain you could you some strips of ply that are glued down and sealed. The goal would be to make sure the thickness of the concrete leveler is no more than about 1/4"

[Icarus]

Sand it smooth, stabilise the plywood with Everdure or a similar epoxy based product, after that cover the floor with a commercial type of floor covering..gluing wooden slats is expensive and time consuming...I installed a number of laid wooden cabin soles in boats, planks 2"x ¼ with a ¼" gap for a spline inlay or polyurethane adhesive..like a laid teak deck.