Boltec?

[John]

Boatech?

Is anybody familiar with Boatech? I think that's the spelling, although I can't find anything online for this that is directly relevant. It is a 4'X8' sheet of some sort of fiber glass with balsa wood sandwiched in between. I am told it is stronger than plywood and also very light. it's also expensive - about $250-$300 per sheet. It was recommended to me to use instead of marine plywood for the bulkhead I'll have to replace. The same guy who recommended this to me, however, insisted that I should fiber glass the bulkhead into the hull, which would mean a whole lot of extra work. My suspicion is that this guy is really into high-end boats, racing, etc. Our boat (a C36) is a good production boat, but not more than that in my opinion. If I did everything he said, then I'd end up with one bulkhead that is stronger than the whole rest of the boat. Not sure it's worth it.

What do you think?

 

[Dan H]

Re: Boatech?

You might be talking about Coosa Composites. Google it and see if that's it.

 

[Don12364]

John,
I believe that soft cored laminates such as fiberglass/balsa/fiberglass are not good in compression, either along the laminate or through the laminate. Both aspects vital for bulkheads to resist compression loads of the mast, deck and hull and also to resist compression loads of fittings screwed to or through the material.
Laminates are only as strong as their outer skins (almost as if there was no core) in these two directions.
What they are excellent for is resisting bending loads across the thickness where their light weight can justify the additional expense.
On the other hand, good old fashioned plywood is excellent for the above-mentioned loadings.

 

[Ron20324]

It is "Baltek" , the ContourKore product most likely. 3/4 inch 24x48 is 55.99. See the 2008 Defender catalog, page 210

 

[sailingdog]

On very high end racing boats, the bulkheads are often made of laminated foam or end-grain balsa with glass or carbon-fiber laminate on either side, often with a veener of wood. This is done to save the weight of the equivalent strength of plywood. Properly glassed into the hull, these can make a very stiff and lightweight bulkhead.

 

[Jim]

John,
I would never want to do this project again. If this product would be more maintenance free I would consider it. I would be more likely to spend extra money replacing the carpy Catalina chainplates that caused the probem.

 

[John]

Jim
The way I see it, it's not the chain plate that is the problem; it was (originally) the wrong type of sealant (not flexible enough) used for the deck penetration and then the fact that the previous owner allowed this condition to continue for years. If I rebed these chain plates every other year, I figure I won't have to replace the bulkhead again. It seems to me that no matter what material I use, if it's allowed to leak year after year, then eventually the same problem would arise.

As far as replacing the chain plate - what would I replace it with? And the main problem is not the chain plate itself, as far as I can figure it out, but the fact that leak around the chain plate caused the bulkhead to deteriorate. Maybe the chainplate shouldn't have been attached to the bulkhead, but changing that is a larger task that I feel like taking on.

On the Baltec vs. plywood: What I have is a decent production boat, not a high end cruising or racing boat. I could end up with a bulkhead that is far superior to everything else about the boat. I don't see a lot of sense in that.