Cold moulded hull,seams showing

[Tactic]

Hi all,
I have a hull built from 3 skins of New Zealand Kauri,cold moulded all on the diagional,the glue used was Areolite 306.
After 30 years there are a few seams showing through the paint work.
The hull is not glassed and has a single pot type paint finnish.
What is the recomended procedure for dealing with these types of seams?

[frosh]

Aerolite 306 being a Urea Formaldehyde product has been around since about 1940. While being a good product in its day it has been easily surpassed by the epoxy based glues. Also using one pot paint (less water resistant than two pot) I suspect that some of the glue between wood layers has now starting breaking down.
The best repair method is clean up problem by sanding, assuming the hull has been fully dried out, and removing the paint. Fill any visible cracks or eneven areas with an epoxy microballoon mixture. Sand again until the surface is fair and no cracks are visible.
Sheath the hull with fibreglass /epoxy, and then paint, preferably with two pot polyurethane.

[Tactic]

Thanks Frosh,Pretty much what I thought.Any other opinions?

[Tactic]

6 oz cloth or 3 oz? I want to add as little weight as possible.

[frosh]

Hi Tactic, what is the size and approx weight of the hull?
3 oz. is very thin and is not going to have much mechanical strength. If there has been some slight movement of wood strips you want some strength to prevent further movement. Is the boat for racing?

[Tactic]

yes a racing hull.22 foot trailer yacht.
plank movement is very minor at this stage.
See my "stern extension " thread in the sailboats forum for pictures of the hull.

[frosh]

Hi Tactic, I have seen the pics. The boat is substantial. I wouldnt consider less than 6 oz. fibreglass. The weight gain in percentage terms of all up sailing weight will be very tiny!