Oil Paint Mediums - Recipes

[Ron Francis]

Thanks Sid, Gigalot.

I was kinda thinking the same thing
that it is one thing while in solution, but different story when evaporated.

Same here. If turpentine does make the paint film more porous after evaporation, then that would account for the paint drying faster.

If turpentine really does act as an antioxidant while in solution, then it makes a lot of sense that I have to reduce the amount of cobalt when using OMS.
I doubt that the wax could play much of a part as it is such an inactive substance.

[Anwar]

Anyone try silica as a matting agent. Apparently, it is used in industry. I expect the resulting film to be more durable than one with wax as an additive since wax is permanently soluble. I've mixed up a gel with walnut oil and drier and will give it a try tonight with some black and as a clear. I am such a freaking genius.

[Anwar]

Hmm... well maybe not such a genius... I get the idea that solvent is required. Now if solvent required it seems overly complicated.... why not just use solvent?

[amanda]

What would liquin be made from then? Is it a combination of some of these. Does wax medium dry very slowly?

What is its purpose (I have a tube but don't know what to do with it!).

[Gigalot]

Liquin is an alkyd resin (which is made from vegetable oil and phthalic acid) and slow drying synthetic solvent.

[fxoflight]

Originally Posted by Ron Francis

Anwar,
Thanks.
Here is the recipe that I'm using at the moment if it helps.
I used to use turpentine as the solvent, and after changing it to OMS I found that it had more tendency to gum up in the palette cup after a few days, so I've added a portion turpentine which seems to stop it happening.
Note that the solvent amount is quite small so the medium is fairly syrupy, but this can be adjusted to taste.

Stand Oil 1 fl oz 30 ml
Linseed Oil 4 fl oz 120 ml
OMS 1.7 fl oz 50 ml
Gum Turpentine .35 fl oz 10 ml
Wax .26 oz 7.5 g
Cobalt drier 15 drops

I melt the wax into the mix in a double boiler.
Also, the amount of drier is dependent on the concentration of the brand, so I would suggest slowly adding it until you get the desired drying time.
(Oddly enough, your 3 drops per ounce of oil is what mine ended up being.)
Mine takes overnight to a couple of days to dry enough to overpaint depending on the pigment and weather, and I paint very thin layers.

Let us know what you end up with and how it works for you.

Hi Ron,

Is this your current recipe? It seems that you're adding more than 3-4 drops of drier per 500ml, which you had suggested to me in another thread. Is that because you have higher oil to solvent ratio in your recipe than I do?

Cheers,
-fxoflight

[Ron Francis]

Originally Posted by fxoflight

Hi Ron,
Is this your current recipe? It seems that you're adding more than 3-4 drops of drier per 500ml, which you had suggested to me in another thread. Is that because you have higher oil to solvent ratio in your recipe than I do?

Yes, it is the current recipe, but I am still playing around with different mixtures.
I use more drops because the cobalt solution is weaker in the brand that I'm using.
It's only 1.5% cobalt whereas the Grumbacher is 5%.
If I was using the Grumbacher, I would be adding 3-4 drops (3.33333) in my solution.
I would possibly not use any if I didn't have stand oil in it.
Did I really say 3-4 drops in 500ml?

But your right in thinking that the cobalt should be in proportion to the oil in the mix rather than the solvent/oil mix.
If I decided to add more or less solvent for example, (while keeping the oil content the same), I wouldn't change the amount of cobalt I used.

[fxoflight]

Awesome, thanks Ron.

I mean Mr. Francis