unclear clear satin varnish

[Adam Funk]

I recently repainted a wooden panel in the bathroom that had (over some years) developed mildew stains under the hand-towel hook. We still want to keep the hand-towel in the same place, so as a preventive measure I decided to varnish it after painting.

Previously the panel had light white woodstain on it (well actually, diluted emulsion paint), covered with acrylic varnish. Now it has white satin paint for wood on it.

I found a tin of "clear satin outdoor varnish" in the shed & thought "this must be tough stuff". I started slapping some on the panel today --- it was yellowish or light brownish, not clear. So I stopped to see if it cleared on drying. Nope.

Is it likely to be discoloured (well, coloured at all) because it's old? (It looked to be in good condition when I opened it.) Or do I need a particular kind of "really clear" varnish to put on top of white paint?

[fred]

IME very few varnishes are completely clear. The clearest would be one of the water based ones. Easy to use and easy to clean up but a real bugger to get a top class finish from but then I am very fussy.

[Martin Brown]

Most wood varnishes are not pure enough to be water clear - they don't normally need to be as a slight yellow tint isn't noticeable on wood.

Yes. You want a more refined one that is truly water clear. The sorts of overcoating varnish used in the automotive industry base coat clear paint technology are an example.

TBH I prefer a slight yellow tint in my wood varnish it makes it easier to see where it has already been brushed out. My yatch varnish has a slightly evil green colour cast from the (nasty) antifungal components.

[stuart noble]

The only clear varnish I know of is the 2 part stuff from Rustins (Liquid Plastic?). Most urethanes are yellow and d-i-y acrylics are dull and cloudy. Automotive finishes are applied in a temperature controlled environment, which makes truly clear finishes possible.

[Adam Funk]

Hmm. The acrylic varnish we used last time was clear, but not mildew resistant in the long term. I guess I could try that again, & just expect to recoat & sometimes repaint periodically.

[Adam Funk]

OK. I wondered if the problem was using varnish that might be a bit old. I'll try another test patch with acrylic varnish (that worked before on white-stained wood).

[Gordon Freeman]

I recently got some clear gloss varnish from Wilkinsons and was surprised to find that it was completely clear when dry, I had expected it to be a bit yellowy. It's called "Wilko Quick Dry Varnish (for internal wood)"

[fredsmithdc]

That is a. Water based varnish. As I said before water based varnishes are amongst the clearest available

[polygonum]

Oil-based varnishes tend to become yellower over time even if they start out pretty clear. Don't think I would expect any to remain water-clear even if they started out that way.