Thread: Caulking instructions required - step by step

Hi Lea,

I have been a boat bum, and builder for over 40 years now. Started when I was about 12 years of age.

Caulking as I know it.
Underwater, use oakum, above the water line cotton is O K .

Pre paint your seams with redlead paint. (the real stuff, make your own if you have to. )

Using your caulking irons and mallet, set the oakum or cotton, so it is firm, but not too hard, especially on a dry hull.

This takes a bit of practice and comes from a little bit of experience to get it right.

When you finnish caulking, then you can paint (redlead) over your work. Then apply a good quality putty. Linseed oil based of course.

I have never heard of mixing antifoul with putty, but if it works then O K do it..

Remember, when the boat goes on the slip next, a lot of your putty filler will need to be levelled off, due to the expansion of the planking.

Hope my raving helps.

Paul.

Thank you Paul.

I did think the caulking had to be as firm as possible. So good to have the added knowledge for a dry hull. Our old girl (1949) is definitely wet at this stage.

Im going to ring a boat yard today and ask if anyone, that might be doing some caulking work, wants free labour, to get some hands on experience. Im near Newcastle/Port Stephens so keep your fingers crossed for me. We will be bringing the boat we have just bought, out of the water the weekend after Easter as her bilge pump is going off each hour.

Do you know anything about Creosote? Whether it is for underwater use? Copper sheeting for corners? We were told oregon for the planking, but is it a particular kind of oregon that I should try and find?

There are old old "brass?' fixtures, that are now unused coming through the bottom of hull. These are seeping small amounts of water around them. Is a wooden "plug" used if we remove these? I would have replaced the plank but wanted to make sure.

So many questions...lol ... I so wish that I had your years of experience.

Like Red Lead ,, I think the move has been away from such items because of toxicity and unintended consequences (someone down the line powersands the red lead without dust extraction or some other scenario). Which is why you can't buy the stuff anywhere in the Western world ... there are reasons for this happening.

Most of the major paint companies have safer alternatives these days. For the lead, not the creosote! Not all boats used creosote even in the old days, but red lead was pretty invaluable back then.

I will give PAR (Paul) a yell .. he probably has something useful to say about the alternatives from a serious boat repair background.

Best wishes
Michael

Michael, is right about, how hard it is to get red lead.

That is why i suggested you make your own.

Red lead powder should still be available. Then you need linseed oil and dryers.
If you have a local paint manufacturer, the can advise you.

The modern world has become so safe for us it is getting harder to find the good products we grew up with. I have never known anyone to suffer problems using red lead primer. I do acknowledge the possibility. But if you step out into traffic it is also possible to be hit by a car.

I have never used creosote in a boat. Other than to help worm proof big timbers like keels etc. before the building actually started.
Creosote is pretty dangerous stuff. If you use it at all make sure to wear gloves a mask and eye protection.
Do not get any on you at all. With some people it can take the skin off. Do not get any in your eyes.
I can't see why you would want to use it at all on a boat restoration.

As for those old fittings. Remove them and clean out the holes to clean wood. Then cut a bung for the hole. If you can, glue the bung in. (epoxy).
The next part is up to you, you can eithe put a small piece of timber on the inside of the hull to completely cover the bung, or do the same on the outside of the hull. Putting your patch on the inside will keep your hull looking good.

I don't understand your question about "COPPER SHEETING FOR CORNERS". You should not need to sheet anything. If there is severe damage then that should be replaces. If it is only cosmetic damage, sanding and filling should suffice.

I don't know about the oregon planking either. There are very few boats here in Tas that use oregon for planking. The main use here has been for masts. Also some framing work in more modern designs.

You will need to check this question locally.

Paul.

Howdy,

In the end we all have to make a decision about how to do something for ourselves.

I've spent too much time working around the waterfront in the era before all these restrictions to know that most of them are vast improvements over practices that were there before.

I get annoyed at some of them too ... but by and large they do take care of the workers much better than the old system.

For example ... we used to have a big bin of solvent for first washing all our brushes. Later I realised that one of the paints we used was about 20% lead and we were getting at least some over ourselves with the splatter from the brushes as they were progressively cleaned. I had been working there for 5 years on and off when I realised. And the row it caused when I said it wasn't good enough (in a nice way) ... from both co-workers and managers... most people hate change more than anything else.

That's why the stuff is not available now ... people don't read the labels and follow the safety instructions or just don't know it is there somewhere down the line.

Think of all the toys that China exported a couple of years ago with lead and cadmium heavy paints.

Quite different from crossing the street. I think that was one of the examples my manager used.

In the end ... people can make choices whichever way seems right to them and the way we work we are much more individually responsible ... If Paul uses Red Lead in the privacy of his own boatshed ... I am not likely to complain at all. His decision.

This is my feeling about it ... I don't say it is any better than what Paul (hooked up) is suggesting, just another way of looking at it.

What I would like is PAR to drop in. (I have PMed him). He does a lot of traditional stuff but has adapted his approach to the current regulatory system and has been doing it for years. So he may have something useful to say about how well the modern stuff works over the long term and what direction to go in.

Best wishes
MIK

I happened to drop in and haven't received a PM from Michael yet, so it must have been mental projection or something.

A couple of thoughts. One, I'd strongly recommend you have the boat caulked by a person with considerable experience. You can ruin a boat's planking, fastenings and framing from a bad caulking job. It's an art form that requires a considerable amount of practice to get it right.

When I caulk a hull, which doesn't happen all that often any more, I always start at the sheer. This way I can get a "feel" for the iron and mallet, before I get down to critical watertight seams, below the LWL.

You can still get red lead in this country, I'm not sure about yours, but it's increasingly more difficult each year. Yes, you can make your own. I'm not convinced it's the best material for priming a seam. I've seen and used shellac and thick varnish for the same task.

The condition of the hull, the seams and the structure has to be sound or you're wasting time, money and materials caulking her. Caulking a dry boat is very difficult to do properly. There's just no way of knowing how much she'll "take up". The usual result is she spits out some of her caulk.

I've used a garden sprinkler to wet down a dry boat for a few days before beginning a caulk job.

I see very few uses for Creosote in a boat and wouldn't recommend it.

Copper has many uses. Common locations would be on the hull above a prop, so the wash doesn't toss stuff into the planking and rip out wood, transom corners, chines corners, stems, etc. These are almost always bedded in tar and nailed in position. I don't like the idea of a metal plate anywhere on the outside of a wooden hull, below the LWL, except above the prop or as a proper anti fouling treatment. It's just a place where you get something growing behind it eventually. The benefits of having it over the prop out weigh it's draw backs.

Okay the PM thing just popped up, so maybe I should finish up.

Red lead in the seams works very well, but what it does is protect the caulk, which can be done with other materials. A coat of light shellac (3 pound), followed by a heavy coat (9 pound), then the caulk will work just as well. If you have a well used can of varnish, you also have a perfect seam sealer. The thick, usually no longer useable goo at the bottom of the can is just right for this task.

There are new "modern" products available, but I've seen mixed results. I've yet to see a better product for covering the finished seam. We call it "Slick Seam" here in the states. It's been around for generations and I haven't seen a polyurethane or polysulfide that can hold up as well. The new formulations of polysulfide probably will, but I haven't tried it yet.

I know of several that mix anti foul with the seam compound, but I wouldn't recommend this tactic as it has no chemical relevance to warrant it. A good paint job will protect the seams.

A tip, always fill the seams slightly proud of the surface, let dry then scrape or sand smooth (scraping is much better). The wood will swell and push the seam compound out a little. On the following season's annual haul out, knock the seams flush again, which will stay that way (for years) until the caulk begins to fail.

The keys to a good caulk job other then really clean and good condition seams are the boat structure and planking. It has to have a good solid structure, tight fasteners and non-work hardened plank edges (a common problem on old planking) or you're just pissing into the wind and no caulk job will last long.

I would go with the first paul (hooked up) about some antifoul in the putty ... if going that way. I once helped with a caulking job ... just puttying the seams .. a long time ago under instruction.

Boat ended up having to be slipped again and there were worms in the putty. I guess that is a regional variation - the warmer waters of Sydney and the wildlife therein.

But Paul number 2 (PAR) ... starting from scratch with none of the above conversation ... if you started with shellac, would you finish with putty ... or would you go another way altegether .... polysulphide mastics etc.

I know you have covered this before on this forum for little jobs, but for a substantial vessel like this ... what way would you go?

Also Paul (Hooked up) what is your opinion of the modern seam fillers/sealers? I imagine it is not too positive ... but interesting nonetheless.

May as well make it a comprehensive thread for those that come later if you chaps think it is a good idea.

Call me a troublemaker (with a service orientation)

MIK

If you make your own seam compound (not a good idea) the anti foul will help, considering what the usual recipes are. I don't recommend these home brews unless you have a good bit of experience with them. I have to admit I have several home brews, but they've been passed to me by old timers who got them from old timers and their track record is documented.

Slick Seam will not be eaten by marine beasties. With a fresh bottom paint, few worries.

On fresh seams I'd use shellac and traditional seam compound (Slick Seam).




The latest formulations of polysulfide will work and the marine buggers don't eat it. It's much more flexible then the traditional rosin and wax formulations (like Slick Seam), but they are also more likely to pull up bits of wood when it comes time to recaulk the boat (polysulfide is far superior to polyurethane in this regard, as it's much less "grippy").

I've seen many a carvel's seams ruined with polyurethanes, but polysulfide not so much.

On a boat with really big seams, tight fasteners, good planking, etc. I'd be tempted to use polysulfide, but on regular width seams, Slick Seam is the way to go. In other words, the polysulfide can span larger gaps and remain elastic.