Wooden Coach Roof

[noswellplease]

My boat is 40 years old, GRP hull still in good condition and coachroof made of wood in good condition but needing TLC, Winter protection from elements, which have caused some hairline cracks where a few sections of the structure join together. The deck then to complicate matters slightly is made of teak and in quite good condition.
It was suggested to me that I might look at the possibility of removing the paint from coachroof and epoxy the lot using a fine roving mat. I plan to lower the mast to do some other jobs this winter and think I can get the boat into a shed where the work could be done mainly by myself say next Spring.
What I'm really wondering is?

Is it worthwhile, will the end product be a relatively maintenance free coachroof?
Would it all look a bit of a dogs dinner, epoxy on wood?
Is it a major undertaking that requires high levely of skill to do properly?

I realise some purists will detest the idea of using epoxy on wood but I am open to all suggestions regardless. Thanking again in advace the forumits that are so helpful so much of the time. Russ

 

[Tranona]

There are many ways of dealing with repairs of wooden coachroofs. Complete sheathing with epoxy and glass cloth is one of them - but is an extreme method and probably more useful when the boat is new than as a repair.

Might I suggest you get onto the Wessex Resins website as they publish extensive material on using eopxies in maintenance and repair of wooden boats.

It is almost impossible to give definitive advice without seeing the boat, how it was built and assessing the extent of the required repairs - and even then different people will have different views on the most appropriate method. Personally I would lean towards repairs that keep as much of the existing structure as possible and make full use of the properties of epoxy. Others would not touch epoxy and recommend use of traditional methods.

Difficult choice if you do not have the knowledge and experience to do it yourself.

 

[oldsaltoz]

G'day Noswellplease,

Just a few notes,

Epoxy is not UV stable, so will need some sort of protection and most use a paint.

Before you even consider epoxy know that "all" varnish and other materials must be completely removed before any epoxy is applied.

The timber must also be very dry and oil free, as least on the surface re oil.

So, having stripped, cleaned and coated the area you still have to sand, fill and re sand to a reasonable finish then add some form of UV protection.

2 pack polyurethane with long chain polymers are considered on the better materials, for a really good finish this sprayed on.

As you can see the above is going to take a lot of time and a lot of money, even more of both if you get it wrong at any of the several stages involved.

So what am I trying to tell you here?

Simple, If this is your first foray into the use of epoxy and 2 pack paints feel free to dive in head first.

Or, get hold of some people who know what they are doing and do all the work you can like preparation, sanding, cleaning, setting up, etc etc.
But a pro to do the expensive the application.

This will most likely save you heaps but also teach you what to look for next time.

I'm up to my armpits in glass and resin almost every day, but I like nothing more than showing some poor sole how to do it and do it properly, safely and economically.

I hope this helps.

Good luck.

If you need any advice I'm sure this forum will come through for you.

 

[noswellplease]

Thanks Tranona and Oldsaltoz for your advice. I think I will have a chat with my local yard and see what they say. I'm quite happy to do the donkey work removing paint varnish and whatever if that keeps the labour costs down. I will also check out Wessex Resins to see what they have to offer. The coachroom was extremely well built by Dutch carpenters 40 years ago so basically I would like to just add a further layer of protection against the elements which would last for a good few years to come.
Again many thanks for advice. Russ

 

[chippysmith]

We have just finished exactly that! Difference being our teak was shot and it was a structural part of the build. We removed both teak and sub-deck, used two layers of ply to replace that removed.

All timber was sheathed in epoxy then epoxy bonded, this was all sanded flat, filled then faired off. All paint was removed from coachroof and cockpit then we had a professional (friend), completely sheath using a heavy roven mat all over, decks first, then coachroof sides followed by the coachroof, we also did the seat tops and the cockpit sole.

Once the roven is wetted they use a fabric called peel ply over the top and wet this onto the roven, once its set the peel ply is removed to leave a lovely flat finish. Joints need fairing but it certainly makes it easier.

The top was then finished in two pack paint

We were blessed with good weather, and as a part diy/pro project it has still taken 4 months. Biggest issue was the moisture, we used west systems fast hardener but still got caught once or twice.. The paint was the most difficult for the same reason, you have to get it down early on a relatively hot day, yes it's two pack but it takes an age to cure, if you get it wrong it just blooms by the morning. If it rains, well then you sand it off and start again!

Very pleased with it though, lots of nightmares over and it looks just great

 

[chippysmith]

This is hours before her maiden trip, to Cherbourg :/

 

[Tranona]

Thanks Tranona and Oldsaltoz for your advice. I think I will have a chat with my local yard and see what they say. I'm quite happy to do the donkey work removing paint varnish and whatever if that keeps the labour costs down. I will also check out Wessex Resins to see what they have to offer. The coachroom was extremely well built by Dutch carpenters 40 years ago so basically I would like to just add a further layer of protection against the elements which would last for a good few years to come.
Again many thanks for advice. Russ

Would I be right in thinking that you have posted the same (or similar) question about your Trintella before? I seem to remember responding at length.

Anyhow it bears repeating. The method of construction of your boat is probably one of the worst ever devised. It was in fashion for a short period in the transition from wood to GRP. Builders thought customers would not accept the bland nature of GRP decks and coachroofs - and still of course had skilled shipwrigyts to keep employed. Moulds for GRP superstructures are much more complex and expensive to build and volumes often did not justify it. So you ended up with the worst of both worlds. Hulls that did not take advantage of the properties of the new materials in either design or construction and superstructures that retained the major weaknesses of wood construction - multiplicity of joints exposed to fresh water. To compound the problem the two materials had to be joined together at one of the most vulnerable and weakest point - and economies were often made on material quality to keep costs down.

It is a tribute to the quality of construction of your coachroof that it has lasted so long - many wooden coachroofs (on GRP hulls as well as all wood) have fallen apart in that length of time.

First thing to recognise is that the wood part will always need maintenance. How much will depend on how sound it is and the quality of repairs if needed. Once watertight and well fastened, the use of modern finishes can substantially reduce annual maintenance - but any failures must be dealt with swiftly.

Epoxy is one of those materials that can be used effectively, but it is not a magic cure. Complete sheathing is a possibility, but perhaps not a sensible option. It is enormously time consuming and potentially expensive to do properly as you would have to remove every fitting and your teak deck, make good any rot in the wooden structure, dry it all out and then sheath as described by chippysmith. Effectively your current superstructre becomes a male mould for a composite structure - but you retain the wood feel to the interior. A number of boats have been built like this - Golden Hinds are a good example, but I think it would destroy any value your boat has.

I think you have to accept that if you are going to keep your boat you cannot avoid an ongoing maintenance schedule that is greater than an all GRP boat - but arguably less than an all wood one. Expensive if you have to pay somebody to do it, and time consuming if you do it yourself.

I think I may have said before, I have owned the same boat for 30 years - not dissimilar to yours except the hull is sheathed wood. I have spent more time on keeping the wood coachroof and deck up to scratch than the whole of the rest of the boat!

 

[whiteshythe]

Hi noswellplease,
I own a 40 year old Trintella 1A with a wooden coachroof similar to yours.
A year ago I also had to rectify a similar problem caused by water penetrating the join between the white painted coachroof top and the varnished coachroof sides.The water ingress started to cause a hairline crack and slight delamination in places of the plywood roof.
I am only moderately skilled in dealing with such repairs, but I have restored the coachroof to its original pristine condition as follows without resorting to glassfibre:-

1. I stripped all paint and varnish back to the bare wood, which is mahogany veneered ply.
I used paint stripper and a good quality scraper. Wear gloves and goggles!
2. I allow any moisture to dry out completely, and used a hair dryer and heat lamp to speed the process up,( don't let the wood get too hot! Having your boat in a shed is a great help as it may take a number of weeks to dry completely).
3.I then sanded the surface of the coachroof to get rid of any imperfections and traces of paint and varnish.
4. I Filled the cracks with a two part epoxy filler,and when dry sanded again finishing off with 240 grade paper.
5.I masked off the coachroof top, and applied 5 coats of Epifanes clear rapid varnish followed by one coat of Epifanes high closs varnish to the coachroof sides.(You should be able to get two coats per day on of the rapid, using a foam brush)
6. I then masked off the coachroof sides and brush painted a white epoxy wood primer to the coachroof top followed by two coats of white non slip Interdeck paint.

I expect this to last at least five years before having to repaint. The thought of covering in fibreglass appalls me, as it would ruin the appearance of these very pretty Dutch built boats.
Tyler made a version of my Trintella, called the '29' with a moulded glass fibre coachroof well into the 80's, but to me it does not have the same appeal.
Hope this is of help.

Regards,

Steve.

 

[noswellplease]

Many thanks Tranona and Whiteshythe for your detailed and comprehensive replies to my query and indeed Tranona I did post something similar a while back but unfortunately after the replies I was still quite unsure as to the course of action best suited to my needs. To encapsulate the whole coachroof in roving and epoxy seemed like a good solution at the time but I did not want the end result to look like a DIY dogs dinner and I'm thinking that it would need a very skilled craftsman to avoid such an outcome!
Whiteshythe you experienced the very same problems I have with your Trintella 1a (hairline cracks in paintwork where two surfaces are bonded together) and your course of action seems the way to go. I hope to get the benefit of my local boat yard shed for a time over the Winter or Spring when I could undertake such a project and as I live only a few miles away the labour and general donkey work I can do myself. I think for the time being I will read up on resins and the Wessex catalogue and see what they have to offer.
For the record Tranona although the coachroof is wood the deck is GRP with teak laid on top which I will be leaving well alone having replaced some 60 odd teak screw plug inserts where they had popped out and all now appears to be normal.
If by any chance Whiteshythe you think of anything tips or otherwise that might help in this repair project I would be most grateful and perhaps you could PM same. Again thanks to all who offered advice on this subject much appreciated....Russ

 

[noswellplease]

Thanks Chippysmith for your detailed account of work done to your boat. I take it that your profession helped you a great deal in sorting out timber issues though thankfully in my case I don't have to deal with the deck also (at least at this stage I don't think I have to).
I will have to get up to speed with the various epoxy resins available and how to apply them properly. I take it that your comprehensive job must have cost a small fortune but if you were happy with the results, then thats all that counts. I think in my case using a heavy roven mat to encapsulate the coachroof would surely distort the timber effect, but perhaps I'm wrong or were you able to keep the shape of your coachroof as before?
Again thanks for you help and advice ....Russ

 

[Tranona]

For the record Tranona although the coachroof is wood the deck is GRP with teak laid on top which I will be leaving well alone having replaced some 60 odd teak screw plug inserts where they had popped out and all now appears to be normal.

The GRP deck does remove the potential weakness of a timber deck onto a GRP hull. However then puncturing a monolithic watertight deck with hundreds of holes to screw wood onto it does not (indeed is not) a good idea, particularly if the deck is sandwich construction. Again you are lucky it has lasted so long, probably because it is a relatively small area and stiff. On many boats with that method of construction decks are needing replacing in less than 15 years and remedial action such as your plug replacement exercise in less than 10 years.

Without wanting to depress you too much, you are probably well into the second half of the life of the deck. I hope your re-plugging is successful, because water ingress through plugs and screws is one of the causes of failure. Others are seams failing because of differential expansion of the wood and GRP and wear of the teak itself. To illustrate how important it is to keep on top of maintenance, materials for a deck your size will be £4-5k and professional labour anything up to twice that amount!

It is for some a DIY job. My neighbour in the club replaced the deck on a 32ft Vindo a couple of years ago. It took him a year of weekend and evening work. New deck is stuck on with not a fastening in sight. This is more difficult to do but removes the issue of leaks.

I hope you continue to enjoy your boat, but as I observed earlier it will be high maintenance compared with an all GRP boat, and once let go will deteriorate rapidly. Plenty of examples of boats where this has happened sitting in the corners of boatyards!

 

[noswellplease]

Chippysmith, just seen the pic of your boat and you certainly did a fantastic job there. Maybe on to you again with a PM just to gleam a bit of info at a later stage when I get started myself. Didn't think you could get such a good result using that method! Well done...Russ

 

[Bobobolinsky]

I did the two coach roofs on my boat with traditional cloth and paint, which looks fine. It is relatively easy to do is not too moisture and temperature intolerant and the cloth finish is pleasing to the eye as well as being non slip. I must say that it used far more paint than you might expect, and in total, over two 6' x 6' roofs used 5 litres of primer and 3 litres of top coat.. I used more topcoat than I should have because I used a dark primer and it took some covering.
Total cost
Sanding £2.00
Cloth £20.00
Oil based Primer £12.00
International Alkyd top coat £34
Mahogany trim £10
Total £78.00
In epoxy I would expect twice that at least