Isn't all balsa these days used in boats treated to resist rot?
It's not like early 90's stuff used I'm sure.

Like I said before problems with water in the balsa core would be shop related issues! Now to qualify above statement that’s assuming the resin and laminate schedule were even halfway in touch with reality.

We had a lot of gunboats on the gulf all of them with balsa core I never found a core related problem, That whole experience changed my outlook on balsa core.

Water intrusion from the inside then look to see if the last lamination was top coated with an inhibitor.

I have heard the weight gain/age thing before and it was traceable to the two-part foam around the tanks

Bottom pressure ??? What are you talking about in psi? , In “testing” I have cut thru the outside laminate exposing bare core making changes in the bottom geometry and never had a hydraulic/delaminating problem in those days we ran 115-120 these were Airex boats but water pressure is water pressure , That said on return to the shop for modification/race prep no evidence of any damage was to be found and that is pushing the point!

Personal experience.

In the old days balsa came in blocks that you placed one by one into the wet glass one of Harry Schoells guys figured out the scrim system as legend has it..

Its all in the name "End grain Balsa". Water intrusion if it spreads is going to follow the grain.Planks of balsa are likely to spread water intrusion but end grain blocks are vertical to the outer laminate so the water tends to stay in the area of the damage.

essentially the answer is yes.

especially when considering YOU, will be paying for the rxpense.

I would think Skater of all companies would be at the leading edge on this.

Baltek has been claiming their product won't wick water since the late 70's.

You have two issues, rot and water absorbtion. If it fills up with water, your light layup hull can gain alot of weight.

I would think the people who build large yachts and commercial boats (ABS specifications, Lloyds standards) would be "Leading edge" also the point being if the material is installed --- Properly (Key word) moisture is a NON issue.

I don't know what products are available what I do know is that my boat is loaded with this product. http://www.baltek.com/alcan/acsites....&m=3&type=.htm

It looks like a checker board and was explained to me if one square gets wet it can't migrate since the end grain is going in a different direction.

You mean like Bertram, Hatteras, Broward and such? That's funny because rotten cored decks are really common in those boats.

How can so many people be doing it wrong?

The grain doesn't alternate. The grain is oriented at a right angle to the sheet. The face of the sheet is the end grain. Balsa (supposedly) won't absorb water because if its cellular structure. Here's a pic-