1/4" balsa core construction (relocated)

[JimT]

Does anyone have experience using thin balsa end-grain sheets ripped to strips as an alternative to cedar in strip construction?
I'm hoping that a sandwich of 6 oz. s-glass or kevlar, 1/4" balsa core, and 4 oz. surfacing fiberglass would be light and stiff enough to be used for a tripping canoe, yet be adaptable to conventional strip construction. I have no idea if the assembly would be ugly enough to require an opaque finish but this isn't intended to be a work of art.
Any thoughts on the practicality, strength, fairing of balsa, etc. would be appreciated.
Jim Traugott

[Ssor]

Jimt, I am about to start building a dinghy using CoreCell in the manner that you discribe. I have been making and testing samples and have determined that 1/2 inch Corecell faced both sides with 2 plys of 4.35 ounce fiberglass that I got on Ebay.The result is 10% lighter than 5/16" northern white cedar and just as strong and 18 % lighter than Corecell faced both sides with 6 ounce glass. Corecell is sold in 4x8 sheets and I think that it weighs in at about 5 pounds per cu.ft. Check out the fiber glass on Ebay. I bought 35 yards for 40 bucks including shipping (.89/yard). It conforms nicely, I covered the bottom of a rounded bottom plastic bucket with a piece just to see if I could do it without any wrinkles. Until I bought this batch I thought that all fiber glass was woven like burlap but this is like heavy backpack fabric. The large expanses won't need much, if any, sanding befor painting.

[JimT]

Ssor -
I considered trying the A500 Core-Cell, but read somewhere that balsa would be better suited to inpact areas. This will be my first canoe project and I'm comfortable working with wood. I've been re-reading my strip canoe books and I think most of the techniques will transfer directly to balsa. Foam core construction is another study that I would prefer to avoid. If the balsa turns out to be a bust, I intend to go with the traditional cedar. Heavier, but probably better looking.
Also, I couldn't find a local supplier for any of the ATC or Diab products and their foams come in 4'x8' sheets. The shipping costs for (2) sheets would be out of line. The 2'x4' balsa sheets can be sent UPS.
Good luck on your project. A good alternative to Seinfeld reruns.
Jim

[60minmacd]

I have been playing around with a combination of 1/16 balsa sheets, fiberglas cloth and epoxy. I find that with 3 sheets, the center at crossgrain to the outer ones and 5 ounce cloth between each, and the outer surfaces covered with 10 ounce cloth and epoxy, the combination produces a lightweight, strong hull. Perhaps with the grain at 45 degrees and using 5 oz. cloth on the outer surfaces would suffice for a canoe.

[BOATMIK]

Originally Posted by JimT

Does anyone have experience using thin balsa end-grain sheets ripped to strips as an alternative to cedar in strip construction?
I'm hoping that a sandwich of 6 oz. s-glass or kevlar, 1/4" balsa core, and 4 oz. surfacing fiberglass would be light and stiff enough to be used for a tripping canoe, yet be adaptable to conventional strip construction. I have no idea if the assembly would be ugly enough to require an opaque finish but this isn't intended to be a work of art.
Any thoughts on the practicality, strength, fairing of balsa, etc. would be appreciated.
Jim Traugott

Hi Jim,

It seems like a strange thing to do - to cut planks into blocks, glue the blocks together to make sheets, then cut the sheets to make planks.

What about using balsa strips the same way you use cedar strips

See my page on the balsa strip canoe it includes scantlings and some useful handling tips
http://members.ozemail.com.au/~store...alsacanoe.html



Best Regards
Michael

[rturbett]

Jim T,
I am building a catamaran with 1/4 balsa endgrain. I have made some test panels, and I am very impressed with it's strength and light weight when sandwiched between 6 oz glass. I may increase the glass thickness.
Let me know how it works for you. I am especially interested in hoy you end up applying the balsa. I plan on doing it one block at a time .
Rob T