Varnish not drying

Presumably you stirred it thoroughly before starting?

David

I had a similar problem when using some varnish I'd bought from B&Q. I'd painstakingly stripped a framed and many paneled bureau with paint stripper and various scrapers. After washing, drying and rubbing over with wire wool, I applied the varnish. A month later it was still slightly tacky to the touch. I was quite miffed to get this result after all the work I'd put in. I covered it with a dust sheet for a couple of months more , after which it became serviceable. I don't know what the cause was. I wanted to blame B&Q but never became sufficiently convinced.

I did this - painted a table with yacht varnish and it never dried. I was told that proper yacht varnish doesn't dry properly, so that the deck of the boat doesn't get slippy. I've no idea whether that was true. I ended up stripping it and starting again with a proper interior varnish.

ROSIE

Probably "trapped" solvents. If too much is applied in one coat, the surface dries prematurely and stops the solvents evaporating from the rest of the film.

Nearly dry... I'll give it another few days...

Colin

Sometimes wiping over with appropriate thinners will cure this problem.

just give it a week or 2, and use more suitable varnish next time.

Ultraviolet light will accelerate the 'drying' (really polmerisation) of varnish. Sunlight is a free source of ultraviolet, but it's absorbed by glass.

Not much chance of sunlight here over the next few days :-)

Thanks for the tip.

Colin

No, yacht varnish should always dry properly. The main reasons why varnish doesn't dry are:

- Failing to stir it properly

- applying it too thick - varnish needs lots of thin layers and time to dry in between

- applying it over an incompatible substrate - a previous coating that it reacts to

- wrong temperature - too cold or too hot. Too hot sets the skin too quickly and slows down evaporation of the solvent

- too much humidity (which sometimes causes a white bloom to appear)

Roland Mann Jenny Painting Systems

Don't want to depress you but we have some stairs with varnish which has not dried fully and we've waited a year. Vim taking it back to bare wood was the remedy. We found the tin in the shed with the lid off - the surface of the varnish had not even skinned. I suspect a bad batch or, more likely, the previous owner contaminated the tin with cooking oil or something! Phil

diffused skylight contains just as much UV. Glass windows block it though.

NT

I've never had much luck sunbathing under a parasol, let alone sunbathing on a cloudy day :)))

cheers, Pete.

uv photosensitive pcb works fine on cloudy days. NO suntan doesnt mean no uv, just means not as much as in summer.

NT

Spar varnish (the real stuff anyway, which most isn't) is intended to remain flexible in service. It does "dry", but dry isn't especially hard and it's much less than glossy.