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Anoxia
06-04-2005, 04:03 PM
Does Linseed oil make oils dry faster at all?

I'm trying to avoid having to use turpentine.

Keith Russell
06-04-2005, 04:21 PM
Does Linseed oil make oils dry faster at all?

I'm trying to avoid having to use turpentine.

What I've heard is that using linseed oil (by itself) as your medium, will keep your paints wet, longer.

A medium of 1/2 linseed oil and 1/2 turpentine (or, what I use, odourless mineral spirits--OMS) will make them dry slightly more quickly.

There are other oils (walnut, safflower) that also affect drying time.

In any case, I certainly recommend OMS over turpentine...

Keith.

WFMartin
06-04-2005, 05:25 PM
Of the oils, Linseed Oil seems to dry the fastest, while making the most archival paint film.

Walnut oil and Safflower tend to dry slower than Linseed Oil.

Solvents (turpentine, or mineral spirits) are the elements that speed up drying. That's their purpose in a medium--to evaporate, thereby speeding the drying. It makes little difference whether you use turpentine or mineral spirits.

So, the basic equation is: More oil than solvent = slower drying.
More solvent than oil = faster drying.

Bill

Einion
06-04-2005, 06:09 PM
Does Linseed oil make oils dry faster at all?

I'm trying to avoid having to use turpentine.I think you'd benefit from having a look at some introductory oil-painting books which cover questions like this.

Don't forget to do a search for "drying" "speed" and other terms like this, you'll get rather a lot of threads ;)


A medium of 1/2 linseed oil and 1/2 turpentine (or, what I use, odourless mineral spirits--OMS) will make them dry slightly more quickly.No it won't - compare and see. Fundamentally you're adding more oil to the paint, if you apply the same coat thickness the oil proportion is higher and hence the drying will be slower (the OMS is essentially irrelevant).

In any case, I certainly recommend OMS over turpentine...Turps evaporates faster so paint layers made with it will set up faster than those made with low-odour solvents and most mineral spirits.

Einion

Einion
06-04-2005, 06:12 PM
Solvents (turpentine, or mineral spirits) are the elements that speed up drying. That's their purpose in a medium--to evaporate, thereby speeding the drying.Not quite Bill - check up the siccative properties of various diluents.

It makes little difference whether you use turpentine or mineral spirits.It can make a great deal of difference which you use as mineral spirits vary enormously, some are very slow evaporators compared to turpentine.

Einion

Anoxia
06-04-2005, 06:59 PM
Thanks, everyone. That answers my question.

I did searches, but I didn't try "drying speed", I bet that would have done it. The beginner oil painting books I have weren't straight forward enough. They were too vague or something.

I'm still trying to decide if I want to paint with oils or acrylics. I really want to make oils work (without using the solvents).

Simon Bland
06-04-2005, 08:33 PM
If you don't like solvents, try some water soluble oils. Grumbacher has a range that's equivalent to their regular paints.

Simon

Anoxia
06-04-2005, 08:46 PM
If you don't like solvents, try some water soluble oils. Grumbacher has a range that's equivalent to their regular paints.

Simon

Do those have an odor like regular oils?

Simon Bland
06-04-2005, 09:45 PM
They still smell a bit, but not so bad that you can't use them inside your home.

Simon

Keith Russell
06-04-2005, 11:21 PM
No it won't - compare and see. Fundamentally you're adding more oil to the paint, if you apply the same coat thickness the oil proportion is higher and hence the drying will be slower (the OMS is essentially irrelevant).

Interesting, I'll definitely keep this in mind--as my interest is in making my paints dry slower. (As far as I'm concerned, if you want fast-drying paints, use acrylics!)

Turps evaporates faster so paint layers made with it will set up faster than those made with low-odour solvents and most mineral spirits.

Interesting. Do you know how this works, exaclty? It seems counter-intuitive, given the ways oils dry--by absorbing oxygen, I would have guessed that it doesn't make any difference... (Not that guessing would give me the right answer, of course! LOL.)

Thanks for the clarifiction...

Keith.

WFMartin
06-04-2005, 11:38 PM
Studio Products "Spray Medium" is (according to the manufacturer) made with 2 Linseed Oils, 2 resins, in a solvent of white spirits.

So, perhaps "white spirits" are very different from the usual "mineral spirits". If they're not, all I have further to offer is that THIS medium, made with THIS "white spirits" represents probably the fastest drying medium I've ever encountered. And, its solvent is "white spirit"--not turpentine (at least, if one can believe the manufacturer).

Bill

WFMartin
06-05-2005, 12:10 AM
Not quite Bill - check up the siccative properties of various diluents.

It can make a great deal of difference which you use as mineral spirits vary enormously, some are very slow evaporators compared to turpentine.

Einion

I'm not sure how to "read" your answer, here. First, you claim (judging from your "Not quite, Bill" statement) that solvents are not the material which aids in the drying of oil paint.

But, then, you claim that there is a great deal of difference among the various mineral spirits, compared to that of turpentine. Differences in WHAT, if not about that which we are discussing--drying times?

I suggest that you make up two simple mediums--one containing a higher ratio of linseed oil to that of solvent--ANY solvent. Then mix up a medium containing a higher ratio of that same solvent to that of linseed oil. Mix each with oil paint, apply each to a canvas, and decide which dries the fastest--the one with more oil, or the one with more solvent.

Bill

Ben Sones
06-05-2005, 02:13 AM
It can make a great deal of difference which you use as mineral spirits vary enormously, some are very slow evaporators compared to turpentine.

But both are very fast evaporators compared to, say, the oxidation rate of linseed oil. I don't doubt that turps evaporate faster, but either will significantly speed drying if you mix a bit into your paint.

If you really need faster drying sans solvents, your best bet (IMHO) is to check out some of the alkyd mediums like Liquin.

Anoxia
06-05-2005, 09:19 AM
If you really need faster drying sans solvents, your best bet (IMHO) is to check out some of the alkyd mediums like Liquin.

Is liquin noxious?

dcorc
06-05-2005, 09:41 AM
Liquin contains mineral spirits, among other ingredients, so it's not "solvent-free".

Some people don't like the smell of it.

Dave

Baroque01
06-05-2005, 11:42 AM
Anoxia,

I can't think of anything more noxious to add to your paint than liquin. From my experience using it, it actually surpassed the mineral spirits in odor and made me really sick. However, if you want to avoid using solvents, but need a faster drying time, I'd still recommend adding some type of resin or drying agent to the paint. Liquin is very smelly, so I use MGraham's alkyd medium. At the risk of sounding like an advertisement, I'll just say that I use it very sparingly to speed drying time and have not experienced any side effects like a nasty smell, etc..

Ben Sones
06-05-2005, 01:07 PM
Liquin contains MS? I didn't realize that, although I knew that it did contain some sort of additional drying agent.

The smell is an individual thing, though. I know some folks who just can't stand the smell of Liquin (to the point of feeling ill), and others who don't think it has a very strong smell at all (like myself). Try opening a bottle in the store before you buy it, and take a whiff. If it smells bad to you, avoid it.

There are other alkyd mediums, though, like Gamblin's Galkyd, which I also use sometimes. It doesn't accelerate drying as much as Liquin (and I have no idea whether or not it contains solvent), but it does have less of a smell (most of the folks that I know who can't stand Liquin seem to do fine with Galkyd), and it looks and handles more like a traditional oil medium.

dcorc
06-05-2005, 01:22 PM
Liquin contains MS?

http://www.wetcanvas.com/forums/showthread.php?t=75303

Dave

Einion
06-05-2005, 07:32 PM
Interesting, I'll definitely keep this in mind--as my interest is in making my paints dry slower. (As far as I'm concerned, if you want fast-drying paints, use acrylics!) I'm sure you'll find that the natural drying speed of most oil paints is more than adequate. If you buy linseed-based paints I wouldn't suggest you try to extend the drying time as this is usually a bad idea from an artistic point of view - leads too easily to overworking - and from a technical perspective the slower drying can lead to some problems.


Studio Products "Spray Medium" is (according to the manufacturer) made with 2 Linseed Oils, 2 resins, in a solvent of white spirits.

So, perhaps "white spirits" are very different from the usual "mineral spirits". If they're not, all I have further to offer is that THIS medium, made with THIS "white spirits" represents probably the fastest drying medium I've ever encountered. And, its solvent is "white spirit"--not turpentine (at least, if one can believe the manufacturer). Did you consider it might be the resins? :D

First, you claim (judging from your "Not quite, Bill" statement) that solvents are not the material which aids in the drying of oil paint... But, then, you claim that there is a great deal of difference among the various mineral spirits, compared to that of turpentine. Differences in WHAT, if not about that which we are discussing--drying times? Sorry I muddled things up a bit here but hey, I was answering quickly waddya want? :) With the very slow evaporation of some mineral spirits the initial drying can be much slower; you see this mentioned a lot if someone has switched from doing their underpainting in turpentine straight to OMS where the contrast is most obvious. Then proper drying starts and here most mineral spirits have zero effect.

Turps on the other hand is completely different in how it works inside an oil paint film compared to the average mineral spirits which is why I consistently recommend its use if someone doesn't mind the smell. Turpentine plays an active role in drying; in one of the few cases of concordance on an issue like this Rob Howard and more traditional sources of technical info agree on this point so that's pretty sure to make it gospel!

I suggest that you make up two simple mediums--one containing a higher ratio of linseed oil to that of solvent--ANY solvent... It is coat thickness that is the critical issue here, one that is generally overlooked in this sort of comparison; people tend to forget that by thinning their paint they are tending to then apply a thinner coat (as you should of course) which automatically dries faster. Thinning with mineral spirits has no effect on the rate of oxidation per se; this is in general, they vary so much some might have. Try a comparison by brushing out a layer of straight oil paint as close as you can to the equivalent of a washy coat made with the same paint thinned with mineral spirits, the former can actually dry faster.

Einion

dcorc
06-05-2005, 07:41 PM
Turps on the other hand is completely different in how it works inside an oil paint film compared to the average mineral spirits which is why I consistently recommend its use if someone doesn't mind the smell. Turpentine plays an active role in drying; in one of the few cases of concordance on an issue like this Rob Howard and more traditional sources of technical info agree on this point so that's pretty sure to make it gospel!

And I, meanwhile, keep asking for the data on which the oft-expressed opinion is based ;)

I'm well aware of Knut Nicolaus' assertions in regard to this (which is what, after much invective :rolleyes: , RH quoted to me)

Turpentine oil is not a binding material -- in other words, it has no adhesive power as far as pigments arc concerned. Nevertheless, it is far more effective than a mere dilutant, such as white spirit. In oil or oil and resin retouching, its ability to absorb acids swiftly (forming hydroxides) has a positive effect. Turpentine oil transfers acids to the oil, thereby helping the retouching to dry more quickly. Since turpentine oil is strongly represented in retouching paint, the processes of acid transfer and drying can take place uniformly and not merely on the surface. If one adds small quantities of turpentine oil to the retouching paint, its luster will increase, though if it is added in large quantities the retouched surface will star to look gaunt and dull.

I can't help feeling that lost something in translation (like plausible chemical mechanism, for a start!)

Dave

WFMartin
06-05-2005, 09:17 PM
Einion,

Well, I do agree with you regarding the benefits of turpentine compared to ANY mineral spirits, even if drying time were excluded. My "comparisons" were simply based upon solvent-laden mixes vs. oil-laden mediums. But, in comparing solvent vs. solvent, I, too, believe that turpentine would probably win out over mineral spirits, in the race of drying times.

And, I'm willing to accept (without testing) that you may also be correct regarding the thickness of the paint film being the more important factor toward the drying. That makes sense, to me.

And I, too, realize that some artists such as Rob Howard actually feel that turpentine truly imparts some mystical, chemical (or shall we say, "alchemical"),force, or "bond", to the Linseed Oil, that simply cannot be accomplished with other solvents. I tend to agree with that idea, although, I have absolutely no proof of it, other than the way mineral spirits tends to "curdle" the paint residue in a washup can, compared to that of turpentine, when used in the same washup can.

I am aware that many scoff at my observation of that phenomenon, but that's honestly why I came around to using turpentine as an ingredient in oil painting mediums, rather than mineral spirits which is what I first began using. For that reason I will probably not use mineral spirits as a medium ingredient in the future. I believe turpentine to be a bit friendlier to linseed oil-based paints than any mineral spirits. And, when you use the high quality spirits of turpentine, there is actually very little smell, and what there is, is quite pleasant. When mixed into a medium the smell dissipates to a minimum.

Bill

Keith Russell
06-06-2005, 12:27 AM
I'm sure you'll find that the natural drying speed of most oil paints is more than adequate. If you buy linseed-based paints I wouldn't suggest you try to extend the drying time as this is usually a bad idea from an artistic point of view - leads too easily to overworking - and from a technical perspective the slower drying can lead to some problems.

Well, 'overworking' is a matter of taste, but I'm definitely trying to avoid technical problems; I'm trying to develop archival working habits.

Thanks!

Keith.

Anoxia
06-06-2005, 11:23 PM
I feel so lucky to be part of such a knowledgable community. Thanks so much to all of you for giving such great feedback!