Paul Gartside's cautions about strip planking

[rbgarr]

http://www.gartsideboats.com/faq2.php#strip

Other items in his FAQ are worth reading, too.

[MiddleAgesMan]

His concerns about the cumulative swelling are why I've never considered it. And I'm not so sure his suggestion to overlay it with multiple diagonal "cold molded" layers eases my mind enough to change it.

On the other hand, strip planking a small area of a hull such as the Rescue Minor's weird bottom shape seems like it could work. In the latest thread about a R. M., recently launched, it seems to have been successful. As I imagine how that strip planked bottom might respond to expansion it doesn't appear that it would be catastrophic.

[James McMullen]

Paul Gartside really, really knows his stuff! He draws carefully thought out and very purty boats too--one of my favorite living designers.

[Paul Pless]

And I'm not so sure his suggestion to overlay it with multiple diagonal "cold molded" layers eases my mind enough to change it.'Strip diagonal' - cold molding, seems to be a pretty well established technique that eliminates the 'strip swelling issue.

[davidagage]

He does make a valid point. I refer to the building Susan threads and the 72' schooner in Vietnam as examples of proper strip/encapsulating. Black Spirit will be encapsulated when we are done. I think alot has to do with the wood choosen for the strips, their size, and using the more rot resistant and stable woods I think might make a difference.

[JimD]

With strip planking the fibre orientation is in one direction only and the expansion is cumulative. Ah hah, you say, but that was before the miracle of epoxy resin. Now there is no transfer of moisture and hence no movement. Well I am afraid that is where we run smack onto the shoals that lie between the sales literature and real life. My experience is that a strip planked hull will shrink and crack in a most distressing manner if it is hauled out in the sun for too long, and I have seen everything from broken frames to the decks pushed up off the clamp as a result of swelling. Sure, epoxy resin is a wonderful coating and applied in sufficient thickness drastically slows the changes in moisture content, but I have plenty of evidence that it cannot prevent movement taking place in the wood entirely. I would certainly not rely on it to overcome the colossal tensions this form of construction engenders.

I'm sticking to plywood.

[outofthenorm]

I hesitate to disagree with someone of PG's experience, but I submit that there are exceptions.:)

Traditional strip plank, 50 years old. Planks are 1 inch square, glued, nailed and screwed to frames. All fastenings galvanized. No sheathing 'cept paint. Always been painted blue. Always hauled out in the Winter. I've owned her for almost 30 years.

I'm now in the closing stages of a re-fit and the area that has needed the least care is the topside planking. I've only had to deal with about 20 feet of open seam above the waterline and maybe 40-50 ft below during the re-fit. I'd done that much already over the years, and repairs I did twenty years ago are still invisible. BTW, I calculate that there is at least 4,000 feet of seam, so a few failures are to be expected with time. ;)

None of the issues she had were caused by the strip planking - just the wear and tear of 40-odd years of real use.

- Norm

http://pic90.picturetrail.com/VOL2330/11517070/22665443/376932844.jpg
http://pic90.picturetrail.com/VOL2330/11517070/22665443/376932840.jpg
http://pic90.picturetrail.com/VOL2330/11517070/22665443/376932839.jpg

[HarryH]

That is a sweet lookin' vessel, Norm..

Mr. Gartside does not hold back in his aversion to strip planking, and perhaps that has been his experience. But there are way too many successful and long lasting builds via this method to merit a sweeping condemnation. Norm's example is far from unique.

Paladin? You lurkin' about? Do I remember correctly that you built a
blue water vessel this way, and did some serious cruising with it? What's your take?

[KMacDonald]

I recently inquired via e-mail with Paul about his plan "Jessie # 113". I asked if strip planking would be suitable for the design and he responded it would be and has been built many times with that method. He also stated he has never seen a strip planked boat fail. If the boat lives on a trailer, I dont think you can go wrong with strip planking covered with glass inside and out.

[Paul Pless]

Norm, what are the specifics of the seams that need to be repaired on your boat? And how are you gonna repair them? She's a beauty by the way.:)

[outofthenorm]

Thanks Paul and Harry.

Paul, there were seams where there was obvious glue failure. A few feet here and there. Never a full seam. Some were probably stress accumulations, but I think just as many were simply wide glue joints in the first place and the glue didn't hold up. The glue is Aerolite.

The open seams behave just like carvel plank. They open up in the winter and most close again within a few hours of launch. There was one longer one under the water that was always a real gusher, however. I learned to fill it with slickseam before launch and it would squeeze it all out within 24 hours, then stay tight all season. The interesting thing was that that seam was open when I got the boat in 1980 and never changed. Overall, not a serious problem at all.

I repaired them all by cutting a shallow groove into the open part of the seam. I use a circular saw with a carbide blade set to cut about 3/8 or 1/2 inch deep. I used to use battens as guides but now I go freehand. The saw cuts a trench of clean wood and reveals the inner portion of the seam. At that depth, the saw only occasionally makes contact with a nail. The blade cuts right through them, but only maybe 2 out of a dozen - not enough to worry about because each nail goes through 3 planks, and anyway, the builder used about triple the nails a sensible person would. :D

I then plane up a sort of spline to fit the groove and set it in slightly thickened epoxy. A tight fit ensures that the epoxy is driven into the inner part of the seam. When it's dry I plane or sand off the excess. As I said, I did some of these up to 20 years ago and they're still invisible today. I just finished doing all the ones I haven't bothered with over the years, so it will be interesting to see if any more show up when she goes through another cycle. Planking is white cedar, edge grain. I use the same or DF for splines

- Norm