Lifting the foredeck

[EastCoastChris]

Having the repairs below the waterline sorted much earlier than I expected (See this thread), I'm turning my attention to the one other soft area I have found on Athaena. Unfortunately, my budget for boatbuilders is now spent so I will have to do this work myself.

A previous owner had applied a bead of bathroom sealant in the forecabin to stop water coming into the cabin down the sides of the samson post. Unfortunately that sealant did exactly what you would expect and trapped water in the gap between the post and deck.

I've explored round the samson post and having poked through the surface, there's pretty much a void where the plywood should have been.

Outside the area is covered by the bowsprit and samson post. Here's an overview of the foredeck taken when I was buying the boat...

Poking around today revealed the void comes right through...

Everything other than the ply and the immediate area of the samson post seems sound. Obviously the samson post is rather important, so I plan to replace it. It is stepped on the keel/stem. The thinking at the moment is to take out the post and cut back to good wood all round.

The deck teak seems fine so I had planned to do this from below and epoxy in new wood. Then fit a new oak samson post. However, I now think I'm only going to be sure of cleaning out all the bad wood by attacking it from above, that means the foredeck needs to come off. Aside from a couple of pieces I will need to cut, there seems to be a convenient join in most of the teak deck strips so lifting it is simplified a little. Once the deck is up I hope I will be able to remove all of the bad ply.

Any comments or advice as always gratefully received

Chris

 

[Seanick]

I think you have come to the correct conclusion. Take up the foredeck, make good the structure underneath-you may need a new beam and king plank-then relay the ply. You may struggle to get the laid deck up in one piece, and to be honest if I was doing the job I would not bother, just drill some holes up from underneath, then come up with a jigsaw and slice the lot up. The laid decks seams are very inconsistant and there is no king planl or margin boards-its a bit DIY to be honest. I would sheath the deck with 300g woven rovings and epoxy, which will give a good deck for anchor work. Finish in two pack and non slip for a durable and easy clean non-slip finish.

 

[EastCoastChris]

I would sheath the deck with 300g woven rovings and epoxy, which will give a good deck for anchor work.

Sorry Nick, not sure I followed you on this bit. Are you suggesting not replacing the teak and just using epoxy and glass over the new ply, applying epoxy and glass over the ply and then laying the teak on top, or laying the teak and then applying epoxy and glass over the top of that?

I was going to use glass and epoxy over the ply to prevent leaks and then relay (or replace) the teak on top of that, finally recovering with coelan to keep a matching finish.

The internal king plank feels very sound (don't know what it is) but the beam does have soft wood so a good portion of that will be replaced to be sure.

Chris

 

[Seanick]

I would just sheath it. If you really must triple the job, then sheath, then lay new teak, but with a proper king plank and margins please!

 

[EastCoastChris]

I would just sheath it. If you really must triple the job, then sheath, then lay new teak, but with a proper king plank and margins please!

I like the idea of having a robust foredeck for anchor work, mind you I also like the teak (even without a proper king plank and margins ). I'm on quite a wooden boat learning curve at the moment, so it's one step at a time and try not to scare myself too much! I'll start lifting the deck this coming weekend and see what nasties are lurking beneath.

Thanks for the advice, it's very much appreciated

Chris

 

[Tranona]

You don't say how the teak is laid on the ply. There do not seem to be any fastenings so it is probably glued. Suspect it will be impossible to remove only part, repair the rot underneath and relay.

The key issue will be how far the rot has spread into the ply and to a lesser extent whether it has spread into the sampson post and the main king plank. I think I would start by cutting a margin (about 60mm wide) around the sampson post from the top - at least taking the teak off. This will allow you to see how much rot there is below. The sampson post itself is probably sound although may be soft around the deck. If the teak is sound and reasonable thickness, I would take the rotten ply away from underneath, dry it all completely, inject epoxy and relay laminates of ply and glass from underneath and finish with a doubler about 100mm all round on the sound ply. You may also have to do some repair work on the king plank - hopefully it is solid wood rather than ply. Beacause of the curve in the deck at this point you will have to use thin ply - up to 4mm to take the curve.

When you have made it all good from underneath, lay some teak in the margin you have made on the top leaving seams to caulk with Sika. If all this work is carried out with epoxy it will be watertight. Paint all the new wood underneath and you won't know it is there.

As Nick says, the alternative is to strip all the teak off and replace the ply then sheath it all in glass epoxy. That, however is a major job which will make your hull repairs look simple!

 

[EastCoastChris]

I've got plenty of time, now that I've had the hull done professionally this is my main winter project, so maybe some more investigation is in order. I'll see how much bad ply I can take out from underneath. I want to be confident I have got it all.

The samson post is definitely soft around that area so I really think it needs replacing to avoid me having unpleasant thoughts whilst trying to sleep at anchor.

Adding a king plank to the teak deck may provide some options when it comes to making good, or there might be the option of adding a pad for a potential future windlass install or similar (like the one where the deck pipe is mounted) that would potentially cover the repair area.

Strangely I'm much more confident above the waterline, having watched the progress of the hull repairs has helped my confidence too. My plan is to take my time and try not to do anything too drastic too quickly.

It's very helpful to talk through the options, thanks.

Chris

 

[Tranona]

You may well find that although the sampson post is soft it is a very substantial section and you may be able to remove the soft bits and laminate new wood on it to bring it back to the original. It looks very well anchored in and a shame to take it out.

The same in a way about taking the teak deck up. Not normally a lover of teak, but this looks well laid - even without the king plank. However, once you start taking it up you may find it very difficult to replace it and look good.

BTW I was referring to potential rot in the under deck king plank where it buts the sampson post and the ply deck is attached.

As I think I mentioned before I have had great success using composite type repairs on decks and coachroofs. The biggest problem is always getting wood or ply to follow the curves when you are only doing small areas - hence the use of thin ply and veneers to build back the thickness.

Good luck with it and feel free to ask if you need any comments as you go.

 

[EastCoastChris]

You may well find that although the sampson post is soft it is a very substantial section and you may be able to remove the soft bits and laminate new wood on it to bring it back to the original.

BTW I was referring to potential rot in the under deck king plank where it buts the sampson post and the ply deck is attached.

I had wondered about the possibility of doing a dutchman repair on the samson post, but assumed it wouldn't be strong enough. I'll pop it back onto the list of options.

The internal king plank feels very sound, not soft at all, but the beam supporting the deck is definitely in trouble. It was that in the main that left me thinking the deck has to be lifted.

With regard to the teak, I think it is sat on some sort of brown sealant rather than being epoxied or whatever. Where I have been burrowing away inside (after the photos above were taken) the ply has come away very easily from the teak (which is only about 10mm thick).

I would prefer to do an internal repair, but the post, king plank, beam and partition for the anchor locker are all in the way. Fitting laminates of ply in from underneath would be very fiddly, possibly more so that lifting the teak and doing it from above.

I think Nick is right that the work, although it was done by a "professional" seems a bit DIY. The deck doesn't seem to be laid conventionally and I'm hoping this brown sealant doesn't have the same holding power as expoxy/sika.

Roll on Sunday!

Chris

 

[EastCoastChris]

So far, so good.

Had to do some work relocating the frame supporting my winter cover so I could get clear access to the foredeck from above. So I didn't get as far as I'd hoped today, but I'm also taking my time and trying not to do anything rash.

Started lifting the teak, which is a 6mm veneer layed on the ply. I don't know what it's stuck down with but it definitely wasn't epoxy or the sealant I was expecting. Seems to have very hit and miss adhesion with only a few spots solidly stuck down, most seemed to be easily parted by a little persuasion with a mallet and scraper.

Some of the teak split, which was no great surprise, so I will need to find a source for some replacement to match the exisiting.

The plywood underneath that I've seen so far is mostly sound won't know the full picture until next weekend.

Chris

 

[Seanick]

Don't compromise on the sampson post, or every time it blows a gale you will have a sleepless night, weather on board or at home, Its just a bit of oak. Just fit a nice new one.

 

[EastCoastChris]

Don't compromise on the sampson post, or every time it blows a gale you will have a sleepless night

That's pretty much my thinking, it has to come out whatever and if I have even the slightest doubt (and at the moment I do) I'll make a new one.

Chris

 

[EastCoastChris]

Thought I'd post an update, I'm taking things quite carefully as I'm new to this and don't want to do anything daft in haste.

It's a bit hard to pick out the detail in the piccy, for those who are interested, so I've linked it to the original (just click on the photo to get the full size version)




Mostly cut back to sound wood except towards the bow above the anchor locker where I need to go further forward. Most of the rot has been under the bowsprit and along the central seam that ran aft from there. The central seam in the removed teak was directly over the central seam in the ply deck so a teak king pank will definitely be going over that when it comes to making good.

You can see the rot in the forward deck beam, fortunately this seems quite limited. Other than this beam all the rot has so far fortunately been restricted to the ply.

I'm wondering whether it would be prudent to remove the bowsprit, but other than the two bolts (the holes for which can be seen on the top surface) I have no idea how it might be attached. I'm loathe to do this unless it's really necessary.

As always any observations or comments gratefully received!

Chris

 

[EastCoastChris]

Well it took a little time and care, but I've removed the bowsprit without damaging anything around it.

I'm glad I did, it definitely needed to come off having seen below Plus the whole repair looks easier for me to manage with the improved access.

What was under the bowsprit...

(Apologies for the poorer quality Blackberry photos) You can make out where I have probed with a scraper to find the bad wood.

The damage to the samson post (now removed for replacement)...

As always, I could do with a little advice. I'm going to need to remove the metal plate that the innner stay (cutter rig) attaches to. This is screwed to the stem. Obviously this attachment point is quite important to the rig.

Before I remove it I want to be sure I can put it back! What is the best way to re-attach it later. If I fill the holes with epoxy (plus filler) and then drill new pilot holes for the replacement screws will that be OK and avoid chewing up the wood of the stem?

Many thanks,

Chris

 

[DownWest]

If it were me,
Remove the fitting, see how the holes were; good wood or rot. Drill them out to good wood and fill with thickened epoxy. Position the fitting and drill pilot holes for corse thread machine screws. Tap the threads and screw the fitting back.With just enough thin epoxy on the threads to make them grip. (ie do not squirt lots into the hole before fitting the screw as it will 'hydraulic lock' and stop you tightening them home)
There is something in the WEST book on this, I don't have a copy to hand.
A

Even if the wood is perfect, I would go this route, as it is much stronger. In good wood I the holes should be about 2x the screw dia. Others might comment on this.

Putting wood screws into hard epoxy is not going to work. But the quick method if the wood is good would be to set them in uncured epoxy.

 

[EastCoastChris]

Thanks DW, I'm going to watch out for a bargain (hopefully) copy of the West book at the boat show. But I was interested to read your comments on the strength of your suggested method as that is my primary concern.

Chris

 

[Seanick]

The more usual way of dealing ith older fastening holes is to drive in a 'sprig' of timber. Machine up a foot length of 1/2" square timber, sharpen a long point on it and dip it in your fave glue. Drive it deep into the hole. It will push away any soft wood. When its driven in, use its position as a 'holder' to sharpen up the timber for the next hole. Snap of and go again.
Quick and easy, and stays away from 'epoxy everything'.

That fitting needs to come off. Looks like the heads are corroded from being under a soggy bowsprit.

From the pics I think you will end up removing more than you hope, ie pulpit,'covering boards', stem head fitting, sampson post etc in order to replace the deck ply to a satisfactory standard.

 

[EastCoastChris]

That fitting needs to come off. ...

From the pics I think you will end up removing more than you hope

Thanks Nick. I was pretty sure the fitting would have to come off, but I didn't want to go ahead and do it and then find out I'd done something silly.

I still have a little hope left (the joy of being a novice), but I suspect you're right. I had a look at what would be involved yesterday and fortunately the toe rail boards have joints about level with the aft of the foredeck so I wouldn't have too much to lift.

Chris

 

[DownWest]

I was hoping Nick would chip in, my builds are more new ply/composite. But I feel uncomfortable about screwing into end grain, as in the plug style repair. The pox/thread/machine screw system is probably over kill, but I don't have to cost my time. The bits are cheap but it takes longer.
My thoughts might be influenced because I have used epoxy fastenings in stone/concrete for the last 15yrs. They are vastly better than rawlbolts or any plastic bushes.
A

 

[Tranona]

Thats a way overengineered fitting with far too many tastenings! Anyway you need to re-use all of them if you are reusing the fitting.

I would use a compromise of the two solutions offered. Bore the screw holes out, probably 10mm will be enough to clear fibres chewed up by threads. Actual size needs to be big enough for the length and gauge of the screw. Fill with a dowel plug - ramin from B&Q, well soaked in epoxy. short enough to go 6 mm below the surface then cap with a normal plug cut with a plug cutter, again set in epoxy. That way the thread has good solid wood to screw into and no exposed end grain. Drill your pilot holes in the usual way.

DownWests machine screws set in epoxy is an excellent method but way OTT for this application.