Balsacore

[dwaynec]

I have a couple soft spots in my cockpit deck near the fuel tank sight glasses that need to be taken care of. I assume that the best choice would be to use balsacore for replacing the rotted wood except for around the site glasses which would be FRP. I have also seen where some of you have used marine plywood for this purpose. Which is better? Here in western Illinois I don't know of any suppliers of either balsacore or marine plywood. Do any of you know of a source reasonably close by? Thanks.
Dwayne

[Genesis]

Marine plywood is stronger but WAY heavier.

I used plywood for the pulpit area replacement when I did that area, mostly because I didn't care about the weight but DID want it VERY strong - that's a potential risk area if you ever need to anchor out for a serious blow, and the last thing you want is the front of the boat coming off during a hurricane - wrecking you when you would otherwise successfully survive it!

I ordered the marine plywood I used and had it sent to me. Expensive (the freight was almost as much as the wood!) but in the grand scheme of things not all that bad. Two sheets cost me something like $200, all-up and delivered, and I've still got one complete sheet left in my garage if someone needs it and can come get it....

[34Hatt]

Like Karl said for a pulpit or area near by Plywood is what you want. But if you are just replacing a deck I use Nida core instead of balsa nice to work with and will never break down like balsa go to http://www.nida-core.com/english/index.htm You may find someone near you just call them they will help you out.

[Maynard Rupp]

The reason they use balsa is the end grained blocks soak up the resin and the bond is awesome. The deck of my racing sailboat is closed cell foam. I spend lots of time re-bonding it by drilling a line of holes and injecting epoxy. While closed cell foam won't rot or let water in, it also doesn't bond well. End grained balsa is light and bonds well. Just keep the water out. I don't think plywood is a good material for a core as it has its own lamination problems and the resin can't penetrate the plywood as well as balsa.

[rtrafford]

I don't think plywood is a good material for a core as it has its own lamination problems and the resin can't penetrate the plywood as well as balsa.

if you use plywood it's a very good idea to drill many small holes in the wood and vaccuum bag it down in order to properly saturate and bond the surfaces. reality, you should vaccuum down the balso as well, or any substance that you use.

nida core is extremely nice to work with and makes an exceptional choice. however if you're not into bagging and the area for repair is small you might simply consider using a chopped fiber paste to fill the area being repaired.

[dwaynec]

Thanks guys. I will probably go with the balsacore again. I think that once I get the core replaced and the point(s) of intrusion sealed that it should be ok. I liked the comments about the end grain balsa absorbing the epoxy and laminating to the frp better as opposed to problems with other core materials.

[34Hatt]

I liked the comments about the end grain balsa absorbing the epoxy and laminating to the frp better as opposed to problems with other core materials.

Well its your choice but I don't understand the problems with other cores such as the Nida core. It absorb very nicely and is far superior then balsa. I don't know anyone that has used Nida core and then gone back to balsa. Also there is another product that I am using for the cockpit deck of a 34C another gas boat with new tanks thanks to Ethanol. It is Coosa Bluewater 26 nice stuff and can be screw done like plywood and absorb nicely. But it your choice back when I did my cockpit I used balsa did not know about Nidacore and I wish someone had told me about it!

While closed cell foam won't rot or let water in, it also doesn't bond well.

As for that, My hard top was done with that and has held up GREAT but then again I vacuum bagged it that is usally a layup mistake when people use it, or take shortcuts such as not vacuum bagging it. Which also is much easier then it sounds if anyone is willing to give it a shot!