Which varnish?

[meow2222]

Hi

What varnish should I use for (treated softwood) wood that stays wet more or less all day? The first stuff I tried failed very quickly

Thanks.

[Andy Dingley]

Use the right timber species.

The right timber doesn't need to be treated. Treated timbers won't be the right species, QED.

Varnish won't make a blind bit of difference.

If it really is continuously wet, that's a let better than alternating wet and dry.

[meow2222]

there wasnt enough time, so its treated softwood

It does to the apearance, very much so.

if only... :)

NT

[Chris]

The 'standard' approach for modern wooden boats is a couple of coats of epoxy (either West or SP Systems):

'd go for the SP Systems because it comes with the dispenser pumps that makes life a lot easier.

Followed by a few coats of International two pack polyurethane varnish:

you do go down this route, make sure you have LOTS of ventilation and the room is well sealed off from the rest of the house. The varnish in particular is very unpleasant stuff.

Cheers

Chris

[meow2222]

b-gger, that would really be a problem. Thanks!

NT

[Pete C]

Where did the varnish fail, along edges, round knots or all over?

Is the wood exposed to sun, or temperature cycling?

How many coats on the wood were there, and was it coated 100% all over including any hidden faces?

It sounds like you've varnished some planed tanalised timber, for use in a shower or bathroom.

cheers, Pete.

[Weatherlawyer]

Get a tin of Cuprinol or something similar. You can get water based stuff but oil based is superior. But that will mean you need a run of nice weather which means holding off until 9th July.

You might get away with varnish then too, especially if the first week is also dry.

[meow2222]

Its under cover, no sun, no big temp cycles, but gets soaked daily. The first varnish just turned white and came off all over where it gets wet. It was only coated on top, but the stuff came off after a day or 2, it just isnt water tolerant at all.

Its treated softwood, but not tanalised.

The main reason for varnishing is to keep it looking decent. Just need a varnish that will hold up to near constant wetness.

NT

[Pete C]

I see. Normal varnish won't stay on wood if it gets wet underneath the varnish. Epoxy would be more forgiving, but a a good solvent based woodstain like Sikkens etc in a light shade would be ideal, it's microporous so would allow the wood to dry out when it can.

I'd give wood stain on exposed faces a go first, easy to put on and can be sanded off if need be.

cheers, Pete.

[meow2222]

yabbut I dont want it darker...

whine, moan

NT

[Chris George]

Dear Meow2 In such an environment, it would have been better to have used Tanalised timber - a water-borne process that provides a chemical combination with the wood (the hydroxl groups) and which cannot leach out under water cyles. Too late for that now? So you are stuck with what appears to be Aquavac or Double vac treated softwood which will most likely be Scots Pine. (aka deal, redwood etc)- the only suitable commonly available softwood that has the porosity to accept the treatment process for D/vac. I agree with the post suggesting Sikkens and the like. It is a no- brainer and the right answer. If you want to retain the look use the lightest type you can that is the least opaque. Make sure there are no sharp arrises. Round them off if you have to. Get it as dry as possible before applying. Be prepared to repaint every 18 months. Chris