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keju
6th February 2009, 01:17 PM
Is there such a thing as UV protective additive for finishes?
Or are there finishes on the market that already have UV protection?

I was mainly thinking of pyrography as it tends to fade when exposed to light.

Thanks
Juvy

durwood
9th February 2009, 10:58 AM
yes there is such a thing as a UV additive but the science needed to use it properly means that the manufacturer adds it to his product as it needs to be done accurately.

So if you want a clear with such material added to it then those which are sold as suitable for external use should have it in the can. You could always double check by contacting the manufacturer and asking.

Don't see how it would help Pyrography though all the clear does is seal the surface off from the air any fading of the actual timber or burn marks will happen anyway.

echnidna
9th February 2009, 11:35 AM
Look at some of the photography finishes, which you can get in spray cans or brush on.

rsser
18th February 2009, 10:08 PM
Marine varnish is sposed to have a UV inhibitor but that's to protect the finish, not the wood, and the only test of its effectiveness in reducing fading (which was pretty crappy) wasn't promising.

durwood
19th February 2009, 07:37 PM
rsser, you have missed the point, The varnish is applied to protect the wood. Oherwise it would be left bare and would look like a paling fence after a while.

All an UV inhibitor does is extend the life of the material it is added to. Its discovery meant that any clear finishes life was extended as UV light is the main destroyer of paint finishes. Clears are the same as their coloured brothers except they don't have the protection pigment has in replelling the UV rays. Where white will reflect most of the light clear lets it penetrate straight through. Have you even noticed how metallic colours on cars collapse quicker than ordinary colours the metalic flake reflect it back so they get a double dose of UV.

Depending on the colour, a paint will last only a certain time. Reds and maroons will fade quickly, where other colours depending what it is and the pigment used will last longer in varying degrees.

Clear outside in the harsh sun especially that which we get here in Australia is really tough on all paints. UV inhibitor is a type of sun screen. Depending on how good it is or how much you use or who puts it on there skin will depend how long it will be before they get sunburnt. Same with the paint, poor clear shorter life, good clear even better with the inhibitor.

Pick a poor clear even with an inhibitor in it will just mean you are going to get a bit more time before it breaks down. You have to go to a far better material than a varnish even if it is a marine version.

If you get 2 years out of a turps thinned enamel or varnish out in the sun on a boat etc you are lucky. The best you can expect from any type is 10 years maybe a few more but none are guarenteed more than that. If you lived in England your varnish may last a lot longer but not here or in any tropical sunny region.

Ian Wells
22nd February 2009, 10:28 PM
these are artist grade varnishes(they get used on paintings wort millions!) with UltraViolet Light Stabilizers,
http://www.goldenpaints.com/products/varnish/index.php

Available at good Art shops only

Ian Wells
22nd February 2009, 10:31 PM
rsser, you have missed the point, The varnish is applied to protect the wood. Oherwise it would be left bare and would look like a paling fence after a while.

All an UV inhibitor does is extend the life of the material it is added to. Its discovery meant that any clear finishes life was extended as UV light is the main destroyer of paint finishes. Clears are the same as their coloured brothers except they don't have the protection pigment has in replelling the UV rays. Where white will reflect most of the light clear lets it penetrate straight through. Have you even noticed how metallic colours on cars collapse quicker than ordinary colours the metalic flake reflect it back so they get a double dose of UV.

Depending on the colour, a paint will last only a certain time. Reds and maroons will fade quickly, where other colours depending what it is and the pigment used will last longer in varying degrees.

Clear outside in the harsh sun especially that which we get here in Australia is really tough on all paints. UV inhibitor is a type of sun screen. Depending on how good it is or how much you use or who puts it on there skin will depend how long it will be before they get sunburnt. Same with the paint, poor clear shorter life, good clear even better with the inhibitor.

Pick a poor clear even with an inhibitor in it will just mean you are going to get a bit more time before it breaks down. You have to go to a far better material than a varnish even if it is a marine version.

If you get 2 years out of a turps thinned enamel or varnish out in the sun on a boat etc you are lucky. The best you can expect from any type is 10 years maybe a few more but none are guarenteed more than that. If you lived in England your varnish may last a lot longer but not here or in any tropical sunny region.

"Reds and maroons will fade quickly" not if they are cadmiums, pyrols they don't