Restoring marine ply

[Guest]

Having removed all the old paint from the coachhouse exterior I have now decided to try varnish rather than paint. (You can always paint over varnish but not easy to do the other way round!). But some of the wood has been discoloured with dampness. What type of cleaner should I use. The ply seems to be veneered in mahogony (International do a teak cleaner, would this work?)

I'd also like to darken the wood but which stain should I use? I want one that penetrates and that won't smear when the varnish is applied. A friend in the USA uses a standard woold stain available in DIY shops over there, then he coats in a very thin epoxy to penetrate and then varnishes over that. It certainly looks good. Would in work in the dampness of Ireland??


Joe

Joe & Nicki
http://www.exchangeyourboat.com
http://come.to/feakle

 

[miket]

Best way to bring out the "natural" colour of the wood is hard preparation. Just be careful with veneered ply not to rub through the ply. I hate stains. They rarely seem to look right. Do your preparation and keep rubbing in a smear of white spirit every so often. This will give you the colour test for when you put on the varnish.

Might be worth a call to West Epoxy Systems, to see if they have anything that will give a varnish like finish, but resin based?

 

[Guest]

West Epoxy can be brushed on as a very good "epoxy varnish". However it will only stay put if the wood is really dry and the piece needs to be sealed on all edges (difficult on a section that is already in place). Any damp inside and the pressure will build up in the sun and blow the finnish off.

Works really well on new wood but I've never managed to keep it in place for any length of time on existing wood.

You've really got the choice of microporus finishes or regular rubbing and re-varnishing.

Classic Boat have been running a long term test on the new high build varnish / stains. Nova Tech etc. Interesting, but nothing looks as good as real varnish, just depends how much time you have and what you need to cover up.

 

[Robin2]

West System say that epoxy must be protected from UV rays either with paint or varnish.

Having used enough to keep the company in business while building my boat (which is still very new so no ageing tests) it is hard to see how it can come off simply because it is hard to keep it off everything you don't want it to get onto.

 

[Guest]

Hi there
I just did up an old plywood Broom speedboat and found that even the bits that looked really badly stained (by mildew as opposed to actually being wet) came up well with an enthusiastic sanding, taking off no more than the top .5mm. Couldn't go too deep of course or she would have started to look like an Ordnance Survey map of a valley.
If you decide that it is worth trying stain remover, I was recommended - but never had to use - Oxalic Acid for dark stains. Your chandlers will have various potions such as Deks Rens or Teak Brightener which probably contain it in a diluted form.
Hope this helps. What boat is she?
Mine, should you be interested is visible at http://www.arweb.co.uk/towpath/discus/messages/11/11.html
should you be interested.

Nick Dalton

Nick

 

[Guest]

Just what I had hoped Robin. I've still got plenty of it stuck on all sorts of things but if was coming off the boat inside a year. It has been fantastic on new wood. I'm convinced the problem is getting a low enough moisture content in the wood before applying it and keeping it low by sealing all surfaces. As I said in my earlier post you just can't always get to all the edges of a fixed panel / timber.

So it's not my choice as an everlasting varnish on an old boat but it's wonderful stuff. Used 3 gallons last summer on various repairs!

 

[Guest]

Nick

Just got your message and visited your site to see the photos. She looks lovely (The Broom).

Our is a Rampart 32 and she is lying on the Shannon here in Ireland. There is a photo of her on the news pages of www.ExchangeYourBoat.com

All the best for now and thanks for the information

Joe

Joe & Nicki
http://www.exchangeyourboat.com
http://come.to/feakle

 

[Guest]

Hi

Andrew - we spoke on the phone last year when I was thinking of buying an Osborne Kestrel in Windsor. Unfortunately that boat had some bad rot and we decided not to get her. Instead we ended up with a Rampart 32 bought in Poole and now back on the Shannon. There's a photo on the news page of www.ExchangeYourBoat.com

Epoxy would be great if I could get the wood dry enough. I believe it should have between 8-12% moisture content. As our boat is not in a shed but in the water - in Ireland (even though under a tarp) the moisteure content is more likely to be above 30% and all the epoxy manufacutrers say that is just too wet. So it looks like regular varnishing and maintenance. As she is 35 yers old with the original surperstructure and is still in good nick, I guess I'll just have to go the hard way and stain, prime and coat with varnish (lots of coats!!)

Thanks for the advice.

Joe


Joe & Nicki
http://www.exchangeyourboat.com
http://come.to/feakle

 

[ccscott49]

I would be tempted to try coelans, it cures with moisture and is breathable, it lets the timber breath and isn't pushed off. I know I go on about this stuff, but it really is good, but a little expensive. With a 30% moisture rating, you can forget anything conventional, it just wont stick in the first place, so it doesn't matter how many coats you put on it will start coming off as soon as it's applied. The coelans is flexible aswell.

 

[Guest]

Coelan is incredible stuff. Seals all sorts of leaks, likes being put on damp wood, expands 300% etc etc. It has one major drawback: It looks very "plasticy". Which is hardly strange as that is what it is, a thick coating of plastic stuff! So it's never doing to look like proper varnish.

I stripped back the superstructure on my 46 footer last summer. Looks great but leaks like a sieve. Guess what she is going to be finnished with this year?

So it'll look "plasticy" but it won't leak!

 

[ccscott49]

Well Andrew I disagree, it looks plasticky if you put it on like plastic, it is in fact polyurethane, like the polyurethane varnishes or rather clear sikaflex. But moisture curing, if you put it on in thinner coats, you will not need as much inside anyway, it will look fine. I have just finished my masts with it and it looks like a high class varnish job. You can flat between coats to get a glass like finish, its all in the application and preperation, same as any finish. The two things I really like about it, is its longevity and repairability, in the meddy. My brother is about to put it on the tyeak laid cabin top of his morcambe bay prawner/racer, in glasson, if its good enoufgh for the classic festivals.........

 

[Guest]

I'll reserve judgement until after I've done my superstructure. Perhaps I've only seen it badly applied. I've only used it for leak sealing so far, no large flat areas.

So my boat might not look to plasticy after all. I'll report back in about £800 worth!