Getting Ready to Place the Core - Questions

[CatBuilder]

Originally Posted by AndrewK

If you dont mind flat decks then vacuum bagging the block balsa on a flat melamine table is an option, plywood is another.

If you want camber you can still do your decks in balsa as intended, get sheet balsa.

I prefer foam.

I'd like to keep the camber. The balsa supplier said the sheet balsa won't bend enough to do the deck camber without breaking. He thought it would split.

I am leaning toward foam, but maybe the supplier was just telling me it would crack because he didn't want to exchange it?

Sure wish I had first hand experience to know... there's always so much conflicting information when building a boat.

[waikikin]

Originally Posted by CatBuilder

Hmmmm.... so a regular mold of melamine. Could work.

What do you all think is easier?

1) Use the balsa core by making a melamine mold, then seal and tape the core off with plastic bags using a dessicant

or...

2) Use foam and just deal with replacing the core where I have hardware.

Which would you pick? I am not out any money by not using the balsa because I can use it up on my deckhouse roof and hard bimini.

Using foam in your deck will be easier esp as your pretty well set up for that at present, how ever the use of a contact mold surface greatly speeds up your finishing process as if nicely detailed your pretty close to painting stage, use of melamine mold surfaces for hard tops, cabins, underwing, bulkheads, other flattish surfaces etc is the go.Proper Bedding of the core to the first skin is a vital step. Replaceing the foam or balsa in way of fastenings is no major deal- just another step in building.
I see you have some drama with moving large stuff, I include some pics of my trailer- I built it for about $3400 Aus, its purpose is multiple- to store my tooling on when I had no shed- then as the basis of a laminating table for large flat sheet molding, teamed up with table frames & melamine sheet pictured on top- then also for the stongback basis of underwing melamine sheet mold, then for the support cradle to underwing for transport to water. this trailer measures 11M x 1.8M (37' x 6') + the guards/wheels, its been very handy for other moves too.
All the best with your building from Jeff.

[AndrewK]

Balsa sheet is not the ideal material for your type of build. But if it is your preference it can be done, provided the camber is slight and constant right up to your deck radius. In a lot of cases the camber increases as it transitions into the deck radius this is the zone you could have splitting in, if this is what you have.

In a typical fine catamaran hull last two feet at the bow will give you problems, but even in foam you will need kerf cuts there.

[CatBuilder]

Thanks, guys.

I think I'll go with easy. Foam it is!

I'll worry about replacing core on the deck when I get to bedding hardware. Cross that bridge later on.

Does anyone have any suggestions for a good deck foam? I'm thinking of the following priorities:

1) Closed cell
2) Stays bonded
3) Low Cost
4) Not Friable
5) Handles compression loads well (for smaller things)

What core would you suggest, knowing I'm not buying any more Core Cell at $5.++ per square foot?

The Core Cell I did get was bought at $3/sqft or so. I'm looking for something cheap like that.