Deck Canvas - application tips requested

[lesweeks]

Following the advice from renown forumites, I have decided to treat my 100 year old deck to a ply lid and an epoxy/glass covering to help strengthen her up and keep the deck as waterproof as possible. However, to try and maintain some traditional aspect to the top I have decided to cover the new cabin roof (see picture) with canvas.
I'm interested to hear from any forum members who have undertaken this sort of job before with any hints, tips, advice or pictures.
Questions:
1. Are there any other sources of cotton canvas other than John at Traditional Boat Supplies?
2. Should all gaps etc. between the T&G be filled before covering? - I'm assuming that they do to avoid the voids.
3. Will any type of oil base paint be suitable for bedding the canvas down?
4. I'm intending adding a hardwood trim over the turned and nailed canvas edge. Would sikaflex or similar be sufficient under the screwed trim.
5. Do I use an oil based undercoat over the canvas before painting top coat(s)?
6. Best type of paint to finish?
Thanks in anticipation.
Les

[andygc]

I can't answer most of your questions, but I have a cloth-covered deck and coachroof.

If you are fitting a ply deck why do you want to sheath it as well? My boat's deck was relaid in 1970 using plywood and was covered with canvas. It is repainted when it looks scruffy and it does not leak. I have just stripped the 39 years of paint from the coachroof with a hot air gun and the canvas is in perfect condition.

4. If you use Sikaflex you create trim that is very difficult to remove. Why not use putty? It still works as well as it ever did.
5. Use a normal primer/undercoat.
6. Deck paint! You are bound to stand on it at some time, and don't want to slip.

[lesweeks]

Thanks for the reply - I was beginning to think that nobody could help me with my lack of knowledge!
Your comments are very useful, and reassuring - A canvas top lasting 39 years; I'd like to think that I'll last that long!
I'd not thought of using putty under the trim; I expect that I'll have some, mixed with white lead powder, left over after caulking the hull - an obvious solution.
Les

[Seanick]

Originally Posted by lesweeks

Following the advice from renown forumites, I have decided to treat my 100 year old deck to a ply lid and an epoxy/glass covering to help strengthen her up and keep the deck as waterproof as possible. However, to try and maintain some traditional aspect to the top I have decided to cover the new cabin roof (see picture) with canvas.
I'm interested to hear from any forum members who have undertaken this sort of job before with any hints, tips, advice or pictures.
Questions:
1. Are there any other sources of cotton canvas other than John at Traditional Boat Supplies?
2. Should all gaps etc. between the T&G be filled before covering? - I'm assuming that they do to avoid the voids.
3. Will any type of oil base paint be suitable for bedding the canvas down?
4. I'm intending adding a hardwood trim over the turned and nailed canvas edge. Would sikaflex or similar be sufficient under the screwed trim.
5. Do I use an oil based undercoat over the canvas before painting top coat(s)?
6. Best type of paint to finish?
Thanks in anticipation.
Les

Twenty odd years ago I did a few canvas decks with my then foreman who was in 60's, so I presume this method is about right. However I also knowm that those decks have since been stripped back, a thin ply interface added and then epoxy sheathed. In one case the boat was never used but laid up and well coverd. The canvas still rotted around the edges!
Don't forget that you can make glass cloth and epoxy look just like canvas if you lay it well and squeegee off excess resin. If you want a pic or two I will post one.

In answer to you questions:

1) a quick goolgle for 'cotton canvas supplies' brings up a couple of suppliers.
2) no
3) yes
4) Never sika. Arbomast Buytl rubber, or 'Door and window sealant', but not oil based, or silicon, or putty-always leaks after a knock.
5)No
6)Gloss in the first few years, then Blakes deck paint in later years as it beccomes smooth and looks like an epoxy sheathed deck.

This is the method I was taught..........

Do a dry run with your canvas
If you have an apperture eg forehatch run the canvas over it and cut out when finished.
Prime the deck with metaliic primer or red lead primer and let it dry
Try not to fill the gaps between TnG, to allow for expansion
Mix up all old paint ends, should make a brown colour and brush on to first section.
Using cut copper tacks every inch, pull the canvas smooth but not too tight
Move on to the next section. When you have done a side, and whilst the paint underneath is still wet, get a bucket of water and a hand dusting brush and soak the canvas.
This may sound wrong but it makes the canvas shrink and go tight.
Finish the deck and soak that section too.
When its dry, say 2 days, paint with primer and gloss. It will be so fluffy you wont need non slip for years. Matt finishes hold the dirt.


Remember years ago most boats wintered under cover, so their decks lasted longer, so,
after 10 years or so, remove all deck fittings and trim and repeat the process!

[lesweeks]

Thanks Nick,
This is just the sort of complete answer that I had hoped for.
You may have remembered that it was you who advised me against canvassing the decks in favour of ply plus epoxy/glass and that remains my intention for the rather scruffy decks; I may even try your squeegee off the surplus technique for making them look canvassed. However, I really do want to canvas the cabin top partly for the experience and partly for some attempt at authenticity. Hopefully it'll last a bit more than 10 years if I do it and maintain it well and, frankly, after that it'll probably be someone else's problem!
Fair winds, Les