View Full Version : tight seam garboard plank repair

01-10-2006, 01:39 PM

My co-owner and I have a 1962 Bjarne Aas built (to a Herman "Swede" Whiton design) 5.5 meter mahogany-on-oak racer that has some leaks. We are looking for a comprehensive instruction set for how to go about replacing planks on this tight-seamed hull, but aren't able to find any. There doesn't seem to be much about tight seamed hulls out there and hot to maintain them. Does anyone have any ideas?

Also, we are trying to research the vessel of this vessel as much as possible, and possibly find her original drawings too. Any ideas there?

Thanks very much,

Brett Putney

01-11-2006, 09:45 AM
Tight seamed boats always turn into loose seamed boats.
Edge compression over time opens up leaky gaps.
I would think a little common sense here would go a long way.

This is what I think of as far as tight seam construction
When new plank edges but tightly together producing a very tight almost waterproof seam,
1 or 2 cotton threads stuck between planks into a small caulking bevel which is then filled up red lead putty, etc..., no oakum used. Over time wood swelling and plank rubbing compresses and wears the edges and leaks start, etc...

So you need to restore the plank edges or use bigger 'oakum caulking' and or refastening.

01-11-2006, 10:18 AM
You could always paint a waterproof coating on the bottom.
Rotdoctor and Sanitred sell liquid polyurethane coatings.
www.rotdoctor.com/poly/polymain.html (http://www.rotdoctor.com/poly/polymain.html)
www.sanitred.com (http://www.sanitred.com)

Rotdoctor is coating the hull of a large tug with his product.

01-11-2006, 07:11 PM
The Concordia yawl built at A&R was planked with a tight seam-a rolled groove that was planed off, later to swell and compress. It was standard practice at Concordia , when an individual plank had to be replaced, they relied on a caulking seam.

01-11-2006, 08:19 PM
"tight seam construction". Is there such a thing? I also have a 16ft sailboat, perhaps oak on oak, with seams so very tight and no sign of any caulking or anything ever, not even some paint, between the 6/8"x 3" planks. The boat is probably 80 years old or more and has been upside down in a field for 20 years and then in a shed for 15 years-still very little gap and certainly no "v' of any kind between the very hard, brass screwed, planks. I can't figure it out!-so I don't know what to do. :confused: qmBob