something better than balsa?

[ssanzone]

my brilliant master plan to pull the original (crappy plastic) port lights, glass over and replaces them with awesome pre-vietnam era bronze ports has hit a snag...

cabin top is glassed and faired and ready for paint and i am starting to sort out the port installation.

introduce the wrinkle: the ports are 1.5" wide and the cabin top fiberglass is 1/4".

a 1/4" lip is fine and i will be laying up 1/4" mahogany so... what material do i use to pad the internal cabin top 3/4"?

balsa see like a good option since it is light and simple to work with and fit to form. i can epoxy it to the hull, sand down the high spots when mix up some resin with 407 or 410 and get a pretty water resistant layer. after i cut in the ports, i can epoxy the opening and, combined with the silicone, should have a pretty good solution.

any ideas on a better product than balsa? light and easy to fit to form?

lil help?

-steve

[zeehag]

why not make a pretty hardwood plate for them to mount into--something that wont rot in sea water, like teak if you can find it..

[DeepFrz]

The only other product I would use would be foam. Don't use plywood. Foam or balsa will give you some nice insulation as well. Whatever you use make sure all the seams are filled with bedding putty of some sort.

Edit: Something like this.
http://www.bluewatersupply.com/struc...foam_core.aspx

[ssanzone]

zee, teak would cost a fortune and be really heavy.

deep, i considered foam but didnt know how i would be able to attach the mahogany.

-steve

[roverhi]

If you want to insulate the cabin sides, epoxy (ply)wood strips around the port area, fill in the surrounding area with insulation like styrofoam or other insulating foam glued to the cabin side. Face the cabin side with a suitable material like plywood, T&G wood, Formica faced plywood.

You can have the port spigots milled to whatever depth you want. Had to do that with the ports when I build our Westsail 32. Used plywood and foam insulation on the cabin sides with T&G 3/8" finish material but the spigots were still too long and had to be milled.

[ssanzone]

i have the mahogany so it isnt about how the cabin is finished.

i did consider having the ports milled but it seems a crime to mess with 70 yr old bronze and these ports angle downward to make sure water dosent pool which would be removed if milled.

what if i actually glass the balsa instead of rely on resin and / or resin with 407 or 410?

-s

[roverhi]

The wood around the ports will be held in place by the ports. Just using thickened epoxy should be fine. IIRC, used 1/2" furring strips and the same thickness styrofoam insulation. Pre drilled the holes for fastening the ports and temporarily used the fasteners to hold the furring in place while the resin kicked. Used polyester resin thickened with asbestos fibers and has held up for going on 40 years. Amazing that asbestos was the standard thickening agent in those days and sold without any precautions. Would use epoxy today, however. The ports were close enough together that it didn't need intermediate furring strips between the ports. Never sailed the boat to really cold climates but the boat was a lot more comfy in the 50ish winter chills of SoCal than other boats I've been on there. Also was comfortable in the tropics though that probably had more to do with our full coverage awning.

Really like the Newport 41. Used to be one in Hawaii called Anuenue (rainbow in Hawaiian). The memory of that boat bearing down on me with their rainbow spinnaker still sticks in my mind. Every once in a while, when I get a bit crazy, think about selling the Pearson and buying an N41. They are a bargain at the listed prices. Do you have the Mark II variety or the original C&C version??

[ssanzone]

i have the original c&c and really like it. i am not sure what it is... but fast for sure.

clearly i am not going to use asbestos (idk if i could even get any)... what replaced it as the sound dampening / insulation material?

home is boston and i plan on sailing home in 18 months and it is certainly a lot colder there than san fran.

-steve

[roverhi]

Check the West System website for their thickening agents. I use 404 a lot but it's a high strength agent that is probably overkill for what is essentially glue. Know they have other thickeners that they recommend for their adhesive qualities.

The asbestos was just a thickening agent. Wouldn't reccomend using any asbestos these days. The asbestos was powdered which is the really dangerous form that is easily ingested into the lungs. Amazing how available and poorly controlled it was back in the '70s.

Would make the cabin sides as thick as I could for insulating properties. Figure out what insulation you want to use and fur out the hull to match. Sailing in the NE isn't the warmest even in the summer. You'll probably love all the insulation you can add to the boat. If you are redoing the head liner, would also insulate that as well unless you need max head room.

[ssanzone]

yeah... i will epoxy the balsa direct to the inside of the cabin top and then inlay 3/8" inch strapping to be used later for affixing the mahogany and then saturate the balsa with a wet slurry of lam res and 407.

under the mahogany i will use that 1/4" insulating (bubble style) foil. the same bubble foil will go under the headliner.

i worry a bit about over insulating as i will spend a lot of time in warm climates (flab blue hull too) but well... AC if it becomes unbearable.

-steve

[barnakiel]

Check if foam might be an option for your application. Depends all on how the member is loaded.

b.

[minaret]

Coosa board, already. Why do people persist in using organic materials that rot on a boat in the 21st century?

[ssanzone]

minaret... idk about anyone else, but in my case.. because i didnt know what alternatives exist... hence the post.

how pliable is Coosa? cuts with a knife or or jig saw or what? how light is it compared to balsa / marine ply?

a lot more expensive than balsa too which isnt a big deal if it is the right product and meets the criteria.

more info?