Hi Guys,

I have a simple question for you all. Hopefully, you have a simple answer… I’m going to build a new 10-rater. My last one was made using the foam-between-the-lineforms-method.

This works well but form my new boat I want to use balsa to make the plug. I think that the result will be better. The main problem is that the boat will be approx. 150 cm (+/- 60 inch) long and the only balsa I can find is 100cm (of 39.3 inch) long.

How do you guys handle this sort of problem ? I can’t imagine that you would use 2 seperate balsa-parts …



Look at the US1M builders guide on the AMYA site. There is an article on how to seam balsa.

Vancouver Island

simply glue it together with pva dont use epoxy dew to the fact that it is a hell of a lot harder to fair than balsa and if not very carefull you will get a high point around the glue line

When the Apprentice knows more than the Mentor its time to quit!

I used to do wood trim in houses, and we could splice wood by cutting the ends at an angle (lik an outside corner), then you could glue those together and hide the joint. Strong joint too.

Does anyone know what “hard balsa” is?


balsa normaly false into 3 catagories.

  1. contest grade balsa 4 to 7 lbs/ft^3
  2. normal hobby store stuff 7 to 12 or 13 lbs/ft^3 depending on who you talk to
  3. “hard balsa” 13 up to like 20 lbs/ft^3 if memory serves.

for reference high quality western red cedar is 21 lbs/ft^3


what is the best way to seal balsa wood?

Anybody have any info about sealing wood? I’m going to scratch build a boat from wood, but don’t want to go through the trouble of glassing. Would paint followed by several coats of polyurethane seal the hull?

I wouldn’t worry about the pieces being too short. What you do is lay out a plank and at the very last bulkhead cut your plank halfway across the bulkhead. Then butt joint your next plank and continue to the end of the hull. Then the next plank, go in the reverse direction. Be sure to stagger your butt joints and be sure to end your planks at a bulkhead.

Best way to seal balsa wood is to glass it with 1/2 oz fiberglass and resin.

BUT since I hate epoxy or polyester resin, I have sucessfully glassed using polyurethane. It is a litte tricky to do since the glass will not lay down as flat as it would if you used resin. After you fill in your balsa hull, give it a coat or two of polyurethane, sand it and then glass it with 1/2 oz glass using polyurethane instead of resin. Test on a sample first.