Varnishing over old Varnish

[STATUE]

I have varnished one of my washboards, that I had previously varnished.

But, some of the old varnish had worn away back to bare wood, these patches had black marks, no doubt from water ingress.

I then gave a cursory rub down and varnished - doesn't look nice, because the bare patches retain the ingress marks.

So I got what I deserved, - without rubbing down the whole area back to original wood, WHAT should I have done?

 

[Poignard]

Treated the blackened areas with oxalic acid, I'd say.

 

[PlankWalker]

You should have re varnished them 2 years ago

 

[Pye_End]

A few years ago I stripped off all the varnish, cleaned as best I could (the black bits are very stubborn) and then coated with several coats epoxy, followed by yet more varnish. Never looked back. Much easier to maintain, and looks good.

 

[RJJ]

A few years ago I stripped off all the varnish, cleaned as best I could (the black bits are very stubborn) and then coated with several coats epoxy, followed by yet more varnish. Never looked back. Much easier to maintain, and looks good.

Epoxy as in epoxy, or epoxy varnish. Thanks! Thinking of doing companion way later this year.

 

[johnalison]

Epoxy as in epoxy, or epoxy varnish. Thanks! Thinking of doing companion way later this year.

I did something similar on the edges of the washboards on my last boat because they got scuffed. I understand that epoxy degrades in UV and so needs to be varnished over for protection.

Although oxalic acid is quite effective, bad stains are often impossible to remove and you have to either live with them or sand right down.

 

[Wansworth]

Although varnish looks nice a well painted surface with a chosen color breaks up the varnish and glassfibre

 

[Pye_End]

Epoxy as in epoxy, or epoxy varnish. Thanks! Thinking of doing companion way later this year.

I used West epoxy junior pack. There are instructions on their website on how to use it as a coating.

One point - the varnish took a very long time to harden. If you do this, don't panic, just put it in the airing cupboard for a whilse and it will eventually harden.

 

[V1701]

If it gets to the stage where the veneer has worn through they'll look better painted. Zinsser shellac-based paints go on over hard, shiny surfaces like varnish as an undercoat...

 

[philld]

This guy is interesting if you are looking at epoxy and getting good finishes:-

, especially when he shows how he sorts out his mistakes.

 

[Lucy52]

What happens when the water gets under the epoxy? Surely it will eventually.

 

[Pye_End]

What happens when the water gets under the epoxy? Surely it will eventually.

I have had to patch up a couple of places that got bashed, but it does not seem to suffer the same problems of just varnish. Perhaps its adhesion is rather better.

 

[Spirit (of Glenans)]

Time to change over to perspex/acrylic?

 

[Daydream believer]

Remove the existing varnish using a Wickes heat gun & a tungsten tipped scraper .
Lightly sand with 180 grit abrasive paper.
Apply 1 coat stain ie Sikkens Cetol HLS plus. 2 if necessary but unlikely.
Apply 2 coats Sikkens Cetol Filter 7
the bow of this boat was a real mess & had been left outside with peeled epoxy varnish for some time, but has been burned off as described & still needs a coat of Filter 7 to complete. It was done outside in the last few days. so conditions were far from ideal.