Safe, Effective Turpentine Substitutes

[Richard Bingham]

Not to leap-frog a reply from Virgil, Michele, but a "final varnish" has a function above whatever integrity the paint films that comprise the painting may have, and that is to be a removable barrier between the painting and subsequent wear and tear.

As for the question of whether alkyds yellow, you can quite easily test the materials you are using. Apply a film of alkyd medium to a small piece of glass . . . make a few. Place one outside in full weather, another where it gets a lot of sun in an interior setting, and a third someplace where it's dark and damp. Within a few weeks, differences will begin to show if the material is "fragile". If it's tough stuff, it may take a few months to see changes.

[Michele Rushworth]

Thanks, Richard!

[Virgil Elliott]

Originally Posted by Richard Bingham

Not to leap-frog a reply from Virgil, Michele, but a "final varnish" has a function above whatever integrity the paint films that comprise the painting may have, and that is to be a removable barrier between the painting and subsequent wear and tear.

As for the question of whether alkyds yellow, you can quite easily test the materials you are using. Apply a film of alkyd medium to a small piece of glass . . . make a few. Place one outside in full weather, another where it gets a lot of sun in an interior setting, and a third someplace where it's dark and damp. Within a few weeks, differences will begin to show if the material is "fragile". If it's tough stuff, it may take a few months to see changes.

Richard,

That's good advice. I'd suggest extending the test over a period of at least a year, preferably longer. Some of my tests have involved as much as 23 years. That gives me a pretty good idea which materials will outlast which over the long term.

Virgil

[Michele Rushworth]

Thanks, Virgil!

[Richard Bingham]

Exactly, Virgil. You're definitely right about the length of time involved. Good stuff can take a long, long time for failure modes to appear, and it's really instructive in the meantime.

Testing is something of a necessity, if one truly wishes to know the nature of materials As with so many other things, a wide range of quality often exists, but our tendency is to accept simply identifying materials as species and leaving it at that. That's as naive as identifying a liquid as "wine", ignoring the gulf that separates stuff some homeless guy under a bridge is guzzling from the fine vintages offered in a four-star restaurant.

[SB Wang]

Memorable quotes for
Dreams (1990) More at IMDb Pro

[SB Wang]

Original text: Translation: Chinese

[Dianne Gardner]

Science has a lot of faith in itself.

[Richard Bingham]

How is this relevant to a thread titled "Safe, effective turpentine substitutes" ? . . .