advice - replace balsa core with ?????

[arch007]

My deck is soggy since water got in it.

It is balsa cored.

I want to replace with foam core of some sort.

What do people recommend ?

arch

[skipmac]

Don't know if there are new and better options for foam cores but back in the olden days when foam cores were first used they were found to also have serious but different problems.

With the original foam cores the foam could break down over time, especially in areas of high loads so you ended up with more or less the same problem as you have with balsa, just a different cause. Maybe some who are more experienced with foams may comment on new versions that could be better.

That being said, I have a 30 year old boat with foam cored decks. The only problems were areas where leaks developed, otherwise the core is great. I would tend to go with balsa again BUT keep the water out. Very doable and very reliable by proper mounting and bedding of stanchions, deck hardware and any other place you penetrate the glass layer.

[Adelie]

End grain balsa is what I’d use.

[JohnT]

Watch the YT videos of the replacing of Athena's deck from around this video https://youtu.be/Y7lC6KNWr1c

[skipmac]

Sorry. Just noticed I said my 30 year old boat is foam cored. That is a mistake. Decks and hull are all balsa core.

[Suijin]

Divinycell. Some complain that it's expensive, but in the grand scheme of a recoring project it's cheap.

[billknny]

Originally Posted by arch007

My deck is soggy since water got in it.

It is balsa cored.

I want to replace with foam core of some sort.

What do people recommend ?

arch

Doesn't matter one bit if you use balsa or foam--if you don't fix the leaks that caused the problem, it will be back. Foam might last a bit longer wet, but certainly not forever.

If you (really) fix the leaks, balsa core will last as long as the boat.

[Reefmagnet]

How old's the boat and how long to you intend to keep it? No use repairing it so it will last forever if you don't intend to keep it that long. As has been mentioned ^^, better to spend additional time and effort fixing leaks. Especially check the oft overlooked hull to deck joint.

[Moosemiester]

Marine Plywood is cheap relative to balsa or foam, easily found, and easy to work with.

Like other posters have already said fix the leaks first...

[thinwater]

Originally Posted by Moosemiester

Marine Plywood is cheap relative to balsa or foam, easily found, and easy to work with.

Like other posters have already said fix the leaks first...

• Heavy.
• Wicks water faster (not end grain).
• Rots faster.

[Hasbeen]

When based in Rabaul New Guinea I bought a very decrepit fireball dinghy to race with the local sailing/yacht club. The deck was a foam core fiberglass structure, & much of the foam had disintegrated, leaving 2 skins of about 3 Oz fiberglass, with little between them, not strong enough to sit on.


After drilling some large holes, & getting as much of the old foam out, & blowing out with compressed air, I used mix & pour polyurethane foam to replace the old.


This stuff applies considerable force when expanding after pouring, so I had to support each section with plywood clamped above & below while foaming.


It was only an old sailing dinghy, but I then raced it a couple of times a month, & loaned it for club use when I was out of town. It was still going strong a couple of years later when I left the area.

[carlheintz]

My 2 cents: use marine plywood, but before you install it, soak it with penetrating epoxy, especially on the ends. I would cut all pieces to size, get them ready to install, then apply a liberal amount of penetrating epoxy all around. You will end up with something that is incredibly stiff and will last as long as the boat, if not longer. Love the stuff!

[dietervoegeli]

Divinicel.

[DerekKelsall]

Originally Posted by arch007

My deck is soggy since water got in it.

It is balsa cored.

I want to replace with foam core of some sort.

What do people recommend ?

arch

I am amazed at the number of boaties who are unaware of the fact that cross linked PVC, Airex and Corecell do not rot or take up water. 70-80 Kg density will do most jobs. Use with polyester or vinylester. Epoxy works but beware the toxicity - do not breath the fumes or dust and do not get it on your skin. I have recently been in touch with the new owner of tri Trifle, which i built in 1967. Still sailing, still sound and I have dozens of other incidents. PU foam is another kettle of fish - a few boats were built using low density PU and gave foam a bad name. Boats built to my spec will almost certainly be free of structural issues going back to 1965 and all kinds up to 100ft. GB 11, 78ft., Alan Gurney design, I built - first to finish in the first Whitbread Round the World. Still sailing and probably the most travelled yacht of all time. PVC foam, unidirectional E-Glass and polyester resin.

Happy boating,

Derek.

[Aaarrgh]

Originally Posted by carlheintz

My 2 cents: use marine plywood, but before you install it, soak it with penetrating epoxy, especially on the ends. I would cut all pieces to size, get them ready to install, then apply a liberal amount of penetrating epoxy all around. You will end up with something that is incredibly stiff and will last as long as the boat, if not longer. Love the stuff!

Could you please offer a preferred source for the penetrating epoxy that you recommend, and maybe a preferred brand name?

Thankfully,
Aarrrgh!