Rotten Deadwood Plank - repair ideas?

[Roach1948]

During my fairing adventures on the hull last weekend and found a soft patch in the deadwood. I poked around and quickly discovered that I was dealing with a rotten Elm deadwood plank. Aft of the keel, one plank from the bottom.

What I would like to know is how to go about replacing this part of the plank without taking my boat apart as she is pretty much repaired everywhere else and I was hoping to get her launched soon.

I have gone down the plank with a prodder and then a chisel to see how far along it has gone. Well it is not the whole plank, but pretty much. About a metre and a half long and 10cm high. It has not spread to other planks (Roach is splined).

As it is deadwood, my idea for a non intrusive fix is to cut only half the thickness of plank out (Around 10cm). Then I could make a template of the replacement shape in softwood. Then I would drill through at the corners of the shape so that I could position the mirror image of the repair on the other side of the hull. The repair being done in two halves of English Oak (allowing recesses for deadwood bolts) and epoxying the two sides together. This way I would not need to remove bolts etc. etc. (and I am not in a boatyard for a lift in order to drop bolts). Is there a better idea?

[Andrew Craig-Bennett]

We take it that:

" Knock out the aft keel bolts, drop the rudder, remove the rotten elm, make and fit new lump of iroko or epi or similar, refit keelbolts" is not the answer that you were looking for?

[Roach1948]

I think I am still in shock/denial... and I reckon this will really test the limits of my practical nature. So far I have approached the problem by working out how much it would cost a boatbuilder to do, and then put that money towards chartering a Classic Sailing Club Yacht!

[S.V. Airlie]

Roach.. I hope that you are not going to discover a can of worms.
I see images of Uncas when I read your post.
I have no idea how best to approach this although your idea(s) seem the most logical.
Good luck..
jamj

[Roach1948]

Sorry, I did not take photos last weekend as it was too depressing to look at... And you can't seemuch anyway - as the hull is primed and the prick holes dont show much. I'll get to the extent of the poblem this weekend. I might need some Dutch courage!

As for the location, the rotten part of plank is not above the keel nor does it butt up against the rudder. The keel bolts have been replaced by a boat builder and I note that the part above the keel is new wood - so maybe there was porblem back then. Rainwater seeping in must have been the culprit.

So the rotten bit is one plank up from the bottom - with three or four good deadwood planks above it that all butt up against the sternpost(transom hung rudder - no rudder fittings extend beyond the sternpost). Small yacht, so the thickness of deadwood at this point is 20cm. No means of lifting the yacht at present to drop bolts as I am not in a boatyard - some bolts will require removing engine!

Ugghhhhh. Friday - where's that G&T

[Andrew Craig-Bennett]

Am I seeing this right? We are talking solid deadwood, not planked down, here?

I'd say that with rotten elm you want the entire member out and replaced, but I cannot for the moment see why a replacement member could not be made up in two halves and glued and screwed together.

[Roach1948]

My mistake for calling it a plank. It is a solid bit of wood 30cm wide tapering to 20cm wide at the aft end. Looking at the plans I am sure there are 3 mild steel drifts running through this section, so that might be a concern, but I suppose I could cut these out in sections and replace from top down. The splines have been epoxy glued, thus stopping rot moving up or down - I am hoping this will create a clean "hole".

[Andrew Craig-Bennett]

There will be a means of keeping it attached to, and in line with, the sternpost, also. Judicious exploratory chiselling will reveal what it is. The drifts can be hacksawed through and replaced.

[Roach1948]

Judicious exploratory chiselling will reveal what it is

I told Moray at Classic Marine about my discovery and mentioned that he might be needing to make some new drifts for me sometime soon at which point he said "It's always worse than you think" - I left the shop chearfully and shuddered when I realised I miss heard him when driving back home!

[Andrew Craig-Bennett]

See PM

[Tom Robb]

Rot is like an out-of-work brother-in-law. You've got to get him out of your life or you'll live to regret it. Half measures now mean lots more problems later.

[Roach1948]

Don't worry, my unemployed brother-in-law will be out of the boat in no time. Its putting a wealthy uncle in his place that I am not so good at!