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[mikegreaves]

I'm completely new to model boat-building but fairly skilled in woodwork and other practical skills. I've recently acquired a 4' carvel-built boat that was built by my great-uncle as a steam yacht or steam launch (not quite sure of the difference). I remember it as a child 50 years ago with a steam engine and vertical boiler, but since then it was badly converted to sail (and all the original fittings lost). The hull was covered in layers of paint and the inside filled with Stockholm tar.

I have started to restore the hull and have carefully stripped off the paint to bare wood, and have started removing the Stockholm tar - after this length of time it has become very brittle and chips away quite easily. This reveals that several of the boards (are they called strakes?) have sprung in places so that gaps have opened up between them and the ribs, one of which is broken. They are nailed to the ribs with brass nails and bent over inside. The screw was removed leaving the shaft and a seized universal joint in situ. Obviously water had penetrated under the tar, causing swelling and movement, but there is no sign of rot although the boards are discoloured in a few patches. There is also a hole through the keel where some hefty ballast was bolted. A couple of photos will give some idea.

Has anyone had any experience of this type of restoration and can give me some pointers? Ideally I would like to restore to a fully working steam model again with a watertight hull, preferably sealed and varnished to show off the construction detail. I can splice in a new section of rib, but I'm not sure of the best way to caulk the joints and set the boards tight to the ribs. If it's not feasible I will restore it to a shelf model.

I'm not sure where this topic should go so please move it to the right place. Thanks in anticipation.

Mike

[tobyker]

Interesting boat. The hull is planked, hence made of planks; nowadays the term strake is used only for the top one, called the sheer strake, and I think the one nearest the keel called the garboard strake. The hull should have been built over formers and the ribs steamed and bent in before the formers (shadows?) were removed. However if only one or two are broken they can be removed and carefully replaced. If you want to waterproof and preserve the outside you could give it a coat or two of two-part epoxy finishing resin, maybe using some kind of filler in the resin to fill larger gaps first. You could paint a narrow white strip (boot topping) at the waterline or paint the hull below the waterline green or whatever - quite a lot of steam launches were varnished above and painted below the w/l. A steam yacht is a small ship that millionaires could cross oceans in or take their chums for a Mediterranean cruise- a launch is a day boat more suitable for the Lakes or the Thames. Good luck - you've come to the right place for advice from people who know a lot more than me.

[barryfoote]

Welcome Mike,

A very interesting project and one that I am sure will be made much easier by the experts on the forum. Personally I would try to keep the outside looking as natural as possible, depending on condition and concentrate on waterproofing the inside with fibreglass matting or similar. The outside could be well sanded and prepared before painting below waterline and varnishing above to leave that beautiful wooden finish.

Now over to real experts to help and don't forget to keep the photos coming.

All the best,

Barry

[Bunkerbarge]

I think you have a superb project there and you should try to preserve as much as possible the original beauty of the wood.

After a clean up and careful repair of any ribs and internal structure I agree with tobyker and would seal the outside with a resin.  This will bring out the beauty of the wood just as a varnish would but it will also greatly strengthen the hull and seal imperfections considerably better.  You will have to carefully sand down the surface first to remove old dirt and coatings and prepare the surface back to good wood.  You will have to be careful though to not sand it back so much that it looses it's character and charm.  i.e I wouldn't rub it back to a perfect, all over new wood surface, but that is really up to personal taste.

If you are going to put a steam plant in it again I would do a similar process on the insides as well as the presence of steam, condensate and oil is always going to give to a challenge with a wooden surface so a good sound sealed coating will protect the wood.

By the way tobyker is quite correct that the top strake is called the Sheer Strake but basically a strake is a strip of planking in a wooden vessel or of plating in a metal one, running longitudinally along the vessel's side, bottom or the turn of the bilge, usually from one end of the vessel to the other.   The top one is known as the Sheer Strake and the one adjacent to the keel is known as the Garboard Strake but there are also Rubbing Strakes.  A rubbing strake was fitted below a sheer strake in a carvel construction. It was not as wide as the other strakes but thicker so that it was proud of the surface and took any rubbing against obstacles or other boats when the boat was in service. In clinker built boats, the rubbing strake was usually applied to the outside of the sheer strake for just the same reasons.

The remaining strakes could well be identified as Bottom Strakes, along the bottom of the hull, Bilge Strakes, at the turn of the hull and Side Strakes, obviously up the sides of the hull.  These distinctions are, as with a lot of things, being lost in time and they may all be simply referred to as Strakes.

[John W E]

Hi ya there Mike

I think you have the gist of the terminology of the builds of a carvel & klinker built boat - as far as planks are concerned.

Going back to your restoration, Stockholme Tar on the inside; eee the last I heard of that was on the Spinners record; before you do anything with the outside of the hull (personally I would remove as much of the left over of the tar as possible) - I am not sure what today's thinners/acetones would do to remove this, but, this type of chemical may be worth a try to wash the inside of the hull out with.  Once we have this back to a reasonable state - though I very much doubt you will remove all traces of the tar from the grain of the timber - the next procedure would be to replace the broken rib/s.    If it is going to cause too much structural damage to remove the rib, you could lay a new rib alongside the broken one - and refasten it in to the planks.   Use the same method as was used for  fixing the old rib in.   

I would recommend using epoxy resin to coat the outside with.   However, the first coat of epoxy would need to be thinned down as to soak into the grain of the planks, as far as possible.  Then, after the epoxy has dried, 2 coats of normal epoxy over the top.    First of all before I epoxied the outside, I would have the hull the right way up and, over the top of all the open plank seams, where you have gaps - put cellotape - this will prevent epoxy running all the way through.

Once you have finished the outside to the standard you require, & I do tend to agree with what has been said on the previous postings about not trying to achieve a perfect finish on the planks, on the inside I would give it a coating of epoxy resin, followed by a layer of lightweight, chopped strand matt, cut into strips to fit between your ribs.    Once this has been done, the whole area being given a top coat of epoxy resin.

Good luck, a very challenging and interesting restoration.   Keep us informed. 

aye
john e
bluebird

[Bunkerbarge]

Bluebird, what would you recommend for thinning down resin for the first coat?

[John W E]

Hi there,

Denatured alcohol - this is supposed to be good for thinning down Epoxy.

I originally suggested thinning down Epoxy resins, to try and ease the method of working the thick epoxy into the grain of timber.    Some people just paint it on and think it will naturally soak into the timber.   In many cases it just lies on the surface without very little penetration into the timber.   You have to actually stipple hard with the brush to ensure that the resin is getting into ever nook and cranny of the material.

aye
john e

[Bee]

With regard removing the tar. You may be better off keeping it cool and chipping it off as dissolving it in thinners will make it run more into cracks and perhaps interfere with the paint/coatings.
Where has it been stored? A change in conditions might lead to additional problems, or been the cause of the present ones.
It is interesting that it is 50+ years old and surviving. Anyone got a 50 year old epoxied boat? So would coating this actually be a good idea? Would you put an epoxy varnish on your chippendale cabinet because it resists staining better than french polish?
I don't know what is best myself, I just wonder at what point a model becomes 'historic' and perhaps merits less modern treatment.

[John W E]

hi there

Bee - If one keeps chipping the tar away - from inside of the hull - one may cause more damage.   This is due to the fact that parts of the plank would be coming away with the tar - just my thoughts of course.    But I would err on caution at chipping at it - experience tells me it isnt a good idea.   

Ever tried chipping epoxy out of the bottom of a hull; when you have epoxied either ballast or an item in the wrong place    .  If truth were only known, I am sure there may be a few who would say they have gone through the hull chipping at it?    Again, just my thoughts mind.

I do think the paint must have been doing a good job of sealing the outside - I would suspect if the water had penetrated the paint to the outside of the hull, you would see evidence of rot on the inside of the hull; underneath the tar; would you not?

aye
john e
bluebird

[mikegreaves]

Fantastic forum - thanks for all the advice and encouragement!

History - the hull is probably 80-100 years old (I'm not that old but it was already long in the tooth when I first knew it.) It was only sailed a few times after conversion (because it kept capsizing/sinking!) and has been stored dry since then - I think this may explain why water penetration hadn't caused more damage. I have been keeping it in my workshop-cellar - dry and cool, with air humidity 60-70%.

So, as several people suggested, I very much want to keep the character of the wood just as in restoring old furniture - celebrating rather than disguising its history. I'd originally thought of using varnish, but I don't see anything wrong with using a modern material like epoxy, if it doesn't alter the character. It's got to be better than Stockholm tar!

By the way, Bee is right - the tar does chip out quite easily. I was really worried about this because it's up to 1" thick in places. I have removed 2/3rds of it (you can see in the top picture where the ribs and planks are exposed on the right), using a blunt chisel and a fine screwdriver. I started very carefully but I found that the tar has become very brittle and breaks up easily, whereas the timber is hard yet flexible, and fine-grained. Where the planks have moved, there is a gap between the tar and the wood, which makes it even easier. I will finish off using fine wire wool and white spirit which seems to dissolve the last stains on the wood surface,

When that's finished ...

1   I need to fill the larger gaps between the planks (visible in the second photo), and there are some holes that need filling too. I was thinking of using a wood filler like Brummer Stopping, but I would welcome better ideas. I guess it needs to be slightly flexible, as well as matching the colour of the existing wood.

2   I need to seal the wood and the fine gaps. I prefer the idea of sealing the outside, not the inside as I guess this could just make a water-trap. The wood seems pretty sound, but it wouldn't surprise me if it was a bit porous in places. Thinned epoxy resin sounds promising. How does the appearance of transparent epoxy compare with varnish - is it obviously different? Does it produce a similar colour-change? Is there any brand which is recommended?

3   Another idea I was wondering about... I'm a garden designer/landscape architect and we sometimes specify a compound called G4 which is absorbed by concrete and doesn't need to be bone dry as it is water cured. Is there something similar for wood, I wonder? And would it be compatible with epoxy (or varnish)?

4   Then I want to thing about the next stages when the hull is ready. The first decision is what scale to use. I was thinking of 1:10 - many of the steam engines available seem to be that scale. Or is 1:12 more common (I used that for making a dolls house when my daughters were little). Which fittings are more readily available?

5   Then after getting the steam plant I need to design the deck, superstructure etc. Can anyone suggest a good source for plans or other info on Edwardian and similar period steam launches? I've downloaded as many photos as I can find.

6   And I'm sure there will be more! Is it customary to keep a single thread per project or better to start new threads for new problems.

Sorry for so many questions!

[dreadnought72]

G4 is perfect on wood. And paper, card...all sorts. I'm using it under the paint on my Dreadnought.

Waterproof, runny enough to soak into porous surfaces - I think it'd be ideal for a project like this.

Andy #1963#

[Bunkerbarge]

Mike, The resin will give a finish that looks very similar to varnished, depending on how much you put on.  As Bluebird suggests a thin coat followed by two normal coats will look like a well varnished wood.  The wood should take on colour just as it does with a normal clear varnish and the real beauty and character will come through.

There are lot's of 1/12th fittings and accesories around so aiming for that may be a bit easier.  Lots of dolls house stuff can be used, especially figures.

Just a thought, instead of trying for a pristine Edwardian type of model what about going for something completely open, more like a work boat.  The character and finish of the wood would lend itself to that much better than a perfect lake launch.

Have a look at Bernards here:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=10364.0

which I think is one of the nicest launches I have ever come across.  The attention to detail is what really makes it stand out and I think something like this with your hull has the potential to look equally eye catching and different.

I'm sure if you were interested in such a direction Bernard would be happy to help out with what plans and drawings he used.

Also in a similar vein have a look at this seen on eBay a couple of years ago:

[mikegreaves]

Some inspiring pictures and wonderful detail. I like the open launch idea, but I wonder if  it would work at 1:12 - i.e. 48' length.

I'm going to do more research on steam launches while working on the hull. I will post again when I've made siginificant progress.

Thanks again - Mike

[mikegreaves]

Sorry it's been such a long time since I posted - it's time for an update.

Cleaning the hull took a LOT of time and patience, especially removing the Stockholm tar [see Picture 1], which I did with chisels, chipping out the thick stuff and holding them nearly vertical like a scraper to remove most of the rest [2]. A wire brush in the Dremel flexible shaft took out the last hard-to-get-at bits (but I left the area where the saloon is going to go). I then sanded the outside with a Dremel flap-wheel sander.

There were gaps (up to 3mm) between the planks and the planks on either side of the keel had warped out of line with the rest of the hull. I tried soaking and steaming the wood to see if I could get it back into shape but in the end I profiled some 1" pieces of timber to fit across the bottom, screwed them to the keel and then screwed the planks to them from the outside with small brass screws sunk below the surface [3]. This will also support the floor and replace the broken rib. Then I filled all the gaps and screwholes with Brummer waterproof stopping, mixing a couple of colours together to get the best match that I could. I discovered that the hull is made of two different timbers - some sort of pine above the waterline, and oak below [4]. Has anyone come across this before? I wonder if there's any advantage over all oak planking (other than price!).

Then I fitted a sealed propellor shaft and a propellor. Finally I treated the inside and out with one thin and one thick coat of epoxy [5]. I'm not too displeased with the result - it has really brought out the wood tones (although it is a bit shiny!).

During this (lengthy) process I thought it over and decided to recreate a saloon launch - as near as possible to the original that I remember. But rather than being a pristine new build, I will aim to make something that looks as though it has a history (as indeed it does) - an elderly well-cared-for but slightly scruffy launch that has perhaps seen better days but has acquired some character in the process.

The next task was to re-fit the original rudder. It had previously had a tiller and the rudder tube came to the top of the deck, but I wanted a wheel so the shaft had to be shortened and made waterproof. So I filed grooves in the shaft and fitted O-rings [6], with plenty of silicone grease between them in the tube, and it seems to be waterproof (the bottom of the rudder tube is above the waterline anyway). Then I fitted the shaft with horns for the servo, and more horns for cables to the wheel (which will be side-mounted).

Then I acquired a steam plant Research showed it was from a Krick launch and was made by Wilesco. I restored it and fitted it to the hull, really to get a bit of experience with steam. It ran well and the valve gear looked great.

   See http://www.flickr.com/photos/42425168@N07/3913514498/

I found it could propel the hull through the water quite well (though my pond is very small so it couldn't go far!). However I decided to sell it and put the money towards a better boiler and engine (it had no pressure gauge and a very clunky water gauge, and I think it would be better treated as a toy). It sold on Ebay for MUCH more than I expected. Now I have a very nice Maccsteam boiler, which I've clad and painted [7].

I've just taken delivery of a Graham TVR1A kit from the USA which I now have to build. I'll post again when I've made more progress.

Queston - Could this thread be moved to the Steam section which will be more relevant?

[kno3]

Nice work, and the boiler seems to suit the hull very well.

[barryfoote]

A beautiful old lady!!! 

[dreadnought72]

That's a lovely piece of restoration. Top marks for perseverance!

Andy