Cleaning Varnish Brushes - Mineral Spirits? Turpentine? Exotic cleaners?

[PaulGrun]

Like many here, I am on a lifelong quest to improve my varnishing skills. At the moment I am wrestling with the problem of cleaning my brush after a varnishing session. For the record, I use Schooner 96 - no complaints, and fairly high quality brushes.

The issue is that it is very, very difficult to get the brush clean using standard Home Depot grade mineral spirits. I use a 'four coffee can system' for cleaning brushes comprising one can that is kept clean and three cans labelled Dirtiest, Dirty, Clean. The used solvent is allowed to decant in each of the three cans, with the gunk scraped out of the bottom of each of the cans. I re-fill the 'Clean' can with new solvent, and move used solvent progressively from the clean can to the dirty can to the dirtiest can. You get the idea. Anyway, it's a pretty rigorous process.

Regardless of how anal I am about the cleaning process, at the end there are still little bits of varnish balls stuck to the bristles. The next time I use the brush, sure enough the finish is rough with the embedded specks of varnish left in the brush. Back to the cleaning station we go. After two or three go-rounds over the course of a couple of days the brush is again clean enough to use. Gd help me if I leave the brush hanging in the solvent (even the clean solvent!)...it comes out looking fuzzy like the bitter end of a mooring line that's been allowed to dangle overboard.

Here are my questions:
1. Are there different grades of Mineral Spirits, some more potent than others? Maybe my problem is that the Home Depot solvent simply isn't very good at dissolving the varnish?
2. Is there a better choice of a solvent for cleaning brushes? Would turpentine be more effective? What about one of the hideously expensive proprietary solvents like Interlux 216?

I've read all the discussions about storing brushes in diesel and so forth. All interesting discussions, but right now I am focused on cleaning brushes after use.

Insights and Wisdom from others eagerly sought.

[Peerie Maa]

If it is cleaning before storage I do as you do, then massage washing up liquid into the bristles. I work plenty right in to dissolve any oil based residue, then rinse the soap out with copious water. I spin the brush dry between every rinsing with the white spirit, and again between every rinsing with water. I then wrap the bristles in a roll of newspaper, taped or tied and store them wrapped.
Have you checked that the varnish you are using will actually dissolve in white spirit? Some don't, it should tell you on the tin.

[Jay Greer]

I have written about brush cleaning before on this forum. So, you might wish to research the older postings. I always use a five or six thinner wash on my very old Linzer varnish brushes, which incidently, at 55 years of age are still just fine! The trick that works for me, during the thinner rinsing process, is to first masage and squeeze the body of the brush under the thinner and then invert and squeeze the thinner out till it runs clear and clean out of the heel near the ferrul. This gets most of the varnish residue out of the heel. Even so, it always takes a lot of fussing to really clean a brush well. Eventualy the heel will get a build up of residue that causes the brush to become less flexible. Every few years I soak my brushes in Star 10 part B paint remover. This is the remover that has no jell in it. The brush is then masaged and flipped until dry and combed out with a steel brush comb. It often takes five or six soakings to restore the brush to the original flex pattern. Afterwards I open the shop door a crack to allow a sun light shaft to beam in as I flip the bristles till no varnish nerds can be seen coming out of the brush. I always store my varnish and paint brushes on end and under thinner wrapped in a jacket of thin absorbant blotting paper that comes from scrap book pages. The absorbant paper draws any residual resin from the brushes and maintains the chisle edge of the brush that is so important for cutting in. For this reason I never spin my brushes as it splays the fibers turning the tool into a usless mop! I never never, wash my boar hair brushes with soap and water which while it softens the brush it also takes the life out of a top quality tool making it feel dead in the hand while being used. The only exception of this is for brushes that are made of synthetic fibers or some treated boar hair Hamelton's that the mfg. designates can be washed with soap and water. While others will advocate the use, I really find no advantage to the use of soap and water on a brush used for varnish or oil based paint.
Jay

[PaulGrun]

Nick and Jay, thank you both for your helpful and insightful answers.
Jay, I did a search on various combinations of clean / brush / varnish and a few other keywords but with no success, although I did find an interesting (and very looooong) thread on long-lived varnish. Yikes. Any place else I should search for more insight?
Thanks again...

[Jay Greer]

Paul, Sorry you couldn't find the thread. The long lived varnish I spoke of was Behr Spar Varnish, a product that has been pulled from the market due to EPA regulations. Fortunatly I bought enough to last me a long long time.
Jay

[CundysHarbor]

I have a trick for keeping varnish brushes that are not going to be used for a week or so. A sign painter showed me his collection of artist brushes (quills) kept in a paint roller tray with a little engine oil. I was amazed; he said some have been in the tray for years. I tried it on a favorite varnish brush (I prefer to use sash brushes, but that's another story). After nine months in the oil, I cleaned it in paint thinner to remove the oil and it is like new. My spring varnishing done, the brush is now slumbering in 5W30.

[David G]

CH - Many folks keep their brushes in kerosene. Very similar effect, but not as hard to clean out before using again.

[CundysHarbor]

Yes, but oil does not evaporate!

[Wayne Jeffers]

I hired a professional painter to varnish a lot of woodwork in our West Virginia house, a 5-week project. He washed his brushes only at the end of the workweek. I asked him why, and he said that was because washing shortened the life of his expensive brushes. At the end of each workday, he wrapped his brushes in plastic wrap (Glad Wrap) and put them in my freezer until the next morning. I asked him if things didn't get gummed up at the root of the bristles after a while. He said that he uses a wire brush to knock out whatever may be a problem.

I can't vouch for this method, as I stayed at the house in Ohio most of the time he was working, but I assume he knows what he was doing. His varnishing skills, at least, are incredible. Simply stunning depth of finish in 3 coats, and the man did not use masking tape -- he cut in all the lines at the edge of the woodwork (the day I was here watching, he was cutting-in on baseboards using a 3-inch brush) and got not a speck of varnish on adjoining painted walls, etc.

When I build my next boat, I may hire him to come do the varnishing.

Wayne

[Seneca]

If I recollect, Epifanes makes a 'brush keeper' (Jamestown used to sell it; I think and may still), where you fill it with your choice of solvent and hang the brushes in there when not in use. It cost about $40 or less. I have to be honest; I've given up trying to keep them soft and chisel-edged and use disposable brushes for the first coats (each brush lasts a while) and then a foam roller/foam brush to tip for the final coat. I'm sure it's heresy.

[Draketail]

The Jamestown brush keeper is just a Tupperware loaf of bread widget with a rack for brushes. I built the same thing (same exact plastic contianer) with a block of wood and cup hooks screwed to the lid. A loop of string on the brush handle and you're done. I had a good laugh when I saw the Jamestown version in their catalog. I think I spent $10 at WalMart and 20 min of my time as opposed to $40 and shipping.

I've been suspending my brushes in gum turpentine now for the 4 years of the draketail build. It's working like a charm. Every year or so I do have to decant and scrape the goo from the bottom of the container.

[Mrleft8]

I use turpentine, not "paint thinner" or "clean air solvent"...... I just think it seems to work better, and it certainly smells a hell of a lot better.... After the turpentine wash, I wash them in warm sudsy water using dish soap, and shake them dry..... But if I'm going to be using them again w/in a week, I just soak them briefly in turpentine and seal them in a zip-lok bag in the fridge.

[lesharo]

Schooner Varnish Brush Cleaning:

You can't clean Schooner varnish brushes with paint thinner. I've experienced this at various times over the years, but I proved it again the other day. I dunked and cleaned the brush in lacquer thinner one time and then put it to soak in paint thinner. Later on, it had little bits of congealed or gelled varnish in the thinner and a little on the brush. If you take a used brush with Schooner varnish on it and stick it in paint thinner, it will gell almost instantly. I don't know what's in that varnish, but I know it does that. I'm even leery of presoaking a brush in standard thinner and then using it in Schooner. Once I think I got gelled bits in the varnish.

Clean the brushes in lacquer thinner till they are virtually clean and then you can finish them in paint thinner. But they have to be pretty clean first. And to put them in to soak also. Try it and you will see. A Schooner brush left in paint thinner makes a hell of a mess. And it takes a lot to get it clean.

[PaulGrun]

Yes! Thank you Lesharo, that has been my exact experience, and is the problem I am specifically trying to solve! So the answer seems to be to clean the brush in lacquer thinner first?

What you describe is exactly the problem I am wrestling with. I rinse the brush in mineral spirits (which, btw, is the procedure recommended by Interlux!), and I get this kind of sticky mess on the bristles. If you look at the bristles of the brush with a magnifying glass, they are clearly coated with residue, which is very tough to get off. If I go through enough rinse cycles using mineral spirits I can eventually get most of it off, but it's a struggle.

I will try the lacquer thinner approach. My other thought was to try Interlux 333 solvent, but at some some exorbitant price per quart, it's not economically feasible to use it as a brush cleaner.

I will report back on my findings. It's remarkable to me how little information there is out there in the world on best strategies for cleaning brushes. I've looked high and low and can find very little written documentation. Heck, even going to the Interlux website I had to dig deep to find a data sheet on 'best practices for varnishing' which included only a sentence or two on how to clean a brush that had been used for Schooner, and I could find nothing stating the appropriate solvent to use for brush cleaning. It's enough to make one want to go to a workboat finish. :-)

[Jay Greer]

I found when I tried to buy paint thinner last week that, during my absence, California no longer is allowing it to be sold within the State. My only remedy is that, just like during prohibition, I will be forced to bring it in from out of state. Since I do not use synthetic varnishes in my work, I can't comment on the new, weird concoctions, called varnish, that are now being forced upon us. But I do know, from past experience, that a brush that is hung in thinner that develops globs and curds in the bristles has not been thoroughly washed out.
Jay

[PaulGrun]

But I do know, from past experience, that a brush that is hung in thinner that develops globs and curds in the bristles has not been thoroughly washed out.
Jay

I am positively, absolutely, completely and entirely sure that you are 100% right. The question is, "how to get the brush thoroughly washed out in the first place?"

I am in the middle of experimenting with Lacquer thinner (remember, this is specific to Interlux Schooner #96), and so far judging by the junk that is now flooding off the brush, the results are encouraging. Hallelujah! (celebration may be a bit premature, but so far the results are encouraging).

Just to follow up, Lesharo and I seemed to be seeing the same behavior: If you take a brush used for Schooner and dunk it in clean/clear mineral spirits, the varnish remaining in the brush instantly develops globs and curds. Or as someone called them earlier, "varnish nerds".

[Peerie Maa]

I use turpentine, not "paint thinner" or "clean air solvent"...... I just think it seems to work better, and it certainly smells a hell of a lot better.... After the turpentine wash, I wash them in warm sudsy water using dish soap, and shake them dry..... But if I'm going to be using them again w/in a week, I just soak them briefly in turpentine and seal them in a zip-lok bag in the fridge.

If you do use soap and water, massage the soap in first, so the soap molecules dissolve in the organics before letting water near it, it will work better.

[PaulGrun]

Okay, here are my results so far: Again, this is specific to cleaning a brush that has been used for Interlux Schooner 96. YMMV...

1. Paint thinner - I did not try this, since my understanding is that it is the weakest of the four solvents,

2. Mineral Spirits - poor results. Using a 'three can system' results in globs and sticky bristles and a great deal of frustration. Not good. Long soaking produced no appreciable difference. Multiple cycles through the three cans worked somewhat better but still resulted in a brush that was carrying lots of little dried clumps to the next varnishing session, producing a wonderful non-skid surface. Not what I want in a varnished surface.

3. Turpentine - better than mineral spirits, but not much better. Much more crud came out of the brush, but still left the bristles feeling sticky.

4. Lacquer Thinner - very good results. Using the same sort of graduated 'three can system' there is all kinds of crud coming out of the brush, which is rapidly approaching a usable state (i.e. a final rinse leaves the lacquer thinner still clear and not cloudy.

Clearly, petroleum-based products ain't cuttin' it, but Acetone-based products seem to be the ticket. I wonder why Interlux doesn't mention this on their website or in the product literature?

I won't comment on the on-going debate on whether or not to rinse a brush in soapy water afterwards except to say that I've been doing this (even before embarking on my current adventures in high tech varnish brush cleaning) and found the results positive but that may be because the soap rinse partially compensates for the failure of the traditional mineral spirits-based cleaning methods. That being said, I do not have the long, long, long experience of others who have graciously commented on this thread and who report brush lifetimes measured in decades. I have a lot of respect for that.

With the new lacquer thinner-based cleaning regimen, it is entirely possible that a soap and water rinse just isn't needed - it will depend on how the brush feels once it's been through the lacquer thinner process and dried. If the bristles are smooth and supple but not soft (you know what I mean), I will be inclined to leave well enough alone.

Thanks to all for your willingness to share your experiences. Collectively you have contributed to saving me about two decades of time working out what works and what doesn't.

[PaulGrun]

If you do use soap and water, massage the soap in first, so the soap molecules dissolve in the organics before letting water near it, it will work better.

When using a soap rinse, this is exactly what I've been doing. Squirt a liberal dose of detergent on the brush and work it in. As Nick says, this allows the soap to 'encapsulate' the clumps of crud in the brush and carry them off during the water rinse.

[Jay Greer]

The new age varnish products on the market today, react differently than do tung oil based varnishes. Lacquer thinner would deffinatly be a no no when working with real varnish as it can cause curdling. If you can get your paws on NAPTHA, you will find it will clean out most all oil based products. For those of you keen on using oil in your brushes, I use it for keeping my sign writing quills, greyhounds and striping daggers soft. The sign writers's oil of choice is LARD OIL. Turpentine will also clean brushes but, if not, thorougly rinsed out, it can turn to goo and ruin a brush as it contains distilled resins. AGAIN, I HAVE NEVER SEEN A PRO BOAT PAINTER USE SOAP AND WATER OR A SPINNER AFTER USING HIS OR HER BRUSHES! It WILL F--NG RUIN THEM! We had a three seperate rinse tub of thinner set up at one of the yards where I worked. It held about thirty gallons which was enough to last the paint crew a week. We used it for five days and then refilled the tubs on every Monday morning. Even three rinses with judicious massaging of the bristles is not enough to get a brush clean, we always follow up with three more, seperate, rinses of clean thinners. Again, if you are getting curds or nerds in your work, you are not cleaning your brushes enough, using the wrong thinner or, you are not tacking the surface off well enough. My son and I are, just now, putting two fresh up coats on our H28 "Bright Star". Our brushes have been wrapped in absorbant paper and standing on end in that same one gallon plastic salad dressing jars, we liberated from Zerkelbach's Market trash can twenty five years ago. Our brushes have been stored under thinner all winter long just as we always have done. After flipping out the excess thinner, we found them to be just as chisel edged and pristine as they were when we put them away last November. My varnish brushes are now fifty five years old and Jaime's are thirty. I think we must be doing, something, ok so far.
Jay

[jonboy]

Clarification needed please....! I find the generalisations like 'paint thinnner' confusing...water is paint thinner if it's waterbased paint....

'thinners' here and in uk usually means cellulose thinners as in car type paint, but as cellulose varnish is not common except as a 1st coat grain filler that's probably not what is meant...?

Mineral spirits...Is that what we call Methylated or denatured alcohol? Meths has pyridine in it to make you puke and purple dye so as you don't drink it by mistake,
Ethyl alcohol (Ethanol)is otherwise pure alcohol and the 'alcohol' content in all our drinks at varying percentages...methyl alcohol (Methanol)is almost the same, but usually made from wood rather than edible fruits or cereals.
Turpentine...is that as in the pure pine resin derivative terebine used by artists as an oilpaint thinner....?
or Turpentine substitute, turps, white spirit, rectified paraffin, Stoddart's solvent and other synonyms...in USA I think Naptha Safety Solvent, Varnoline, ....

Lacquer thinner --? here that would be pure alcohol as above or to save money on shellac, just meths, as above. When using shellac I make it with pure ethyl alcohol but clean brushes etc with meths. In Portugal pure alcohol isn't much more expensive than meths, but in UK it is really hard to find pure alcohol, you need a customs and excise licence for more than a litre or so, and its the same price as brandy.

British Standards classification and TuV in Germany usually helps clear up confusion, but it is not uncommon for the product makers not to say what the base is so you buy their usually very expensive repackaged otherwise common product. Google and Wiki are good too, but sometimes unverified...

The bottomline has to be that the thinner or cleaner or solvent has to be the same as the paint or varnish base or the coagulation will happen or nothing at all.


There has also been much discussion on other posts as to the simple cost factor of cleaning brushhes versus buying new ones, always a good topic!

[lesharo]

I've never tried 333 to clean brushes, it's outrageously expensive. A couple or so dunks in lacquer thinner should get you going and then you can finish off in paint thinner. "Paint thinner" is not denatured alchohol. It is thinner or solvent for "oil based" paint. If you clean in soap and water, obviously the brush has to be completely clean first. And try Dr Bronners or any castille soap, it works good.

[lesharo]

Have you ever heard of "Robin Hood's barn"?

[PhaseLockedLoop]

Clarification needed please....! I find the generalisations like 'paint thinnner' confusing...water is paint thinner if it's waterbased paint....

From Wikipedia:
A paint thinner is a solvent used to thin oil-based paints or clean up after their use, although all such solvents have other uses. Commercially, "paint thinner" is usually a name for mineral spirits.

Products used as paint thinners include:

• Mineral spirits
• Acetone
• Mineral turpentine (turps)
• True turpentine
• Naphtha
• White spirit
• Methyl ethyl ketone (MEK)
• Dimethylformamide (DMF)
• 2-Butoxyethanol, or any of the other glycol ethers

Solvents generally used in the production of paint thinners include:^[1]

• Ethylbenzene
• Xylene
• n-butyl acetate
• Butan-1-ol

Not much in the way of clarification, I'm afraid.

[Clinton B Chase]

My students are currently learning about brushes and cleaning them, so this thread should thoroughly confuse them, but it will get them thinking. Thanks.

We have a lot of Thin-X here for cleaning. That is a mineral spirit. Anybody have comments about this product with respect to cleaning brushes.

Cheers,
Clint

[PaulGrun]

Clarification needed please....! I find the generalisations like 'paint thinnner' confusing...water is paint thinner if it's waterbased paint....

'thinners' here and in uk usually means cellulose thinners as in car type paint, but as cellulose varnish is not common except as a 1st coat grain filler that's probably not what is meant...?

Mineral spirits...Is that what we call Methylated or denatured alcohol? Meths has pyridine in it to make you puke and purple dye so as you don't drink it by mistake,
Ethyl alcohol (Ethanol)is otherwise pure alcohol and the 'alcohol' content in all our drinks at varying percentages...methyl alcohol (Methanol)is almost the same, but usually made from wood rather than edible fruits or cereals.
Turpentine...is that as in the pure pine resin derivative terebine used by artists as an oilpaint thinner....?
or Turpentine substitute, turps, white spirit, rectified paraffin, Stoddart's solvent and other synonyms...in USA I think Naptha Safety Solvent, Varnoline, ....

Lacquer thinner --? here that would be pure alcohol as above or to save money on shellac, just meths, as above. When using shellac I make it with pure ethyl alcohol but clean brushes etc with meths. In Portugal pure alcohol isn't much more expensive than meths, but in UK it is really hard to find pure alcohol, you need a customs and excise licence for more than a litre or so, and its the same price as brandy.

British Standards classification and TuV in Germany usually helps clear up confusion, but it is not uncommon for the product makers not to say what the base is so you buy their usually very expensive repackaged otherwise common product. Google and Wiki are good too, but sometimes unverified...

The bottomline has to be that the thinner or cleaner or solvent has to be the same as the paint or varnish base or the coagulation will happen or nothing at all.


There has also been much discussion on other posts as to the simple cost factor of cleaning brushhes versus buying new ones, always a good topic!

Oh my...I'm afraid my sloppy use of the language is at least partly to blame. When I said "Paint Thinner" (note the caps), I was referring to a product available for purchase in a hardware or paint store labelled as "Paint Thinner". I crudely group "Paint Thinner", "Mineral Spirits", and "Turpentine" together as products described as being based on a petroleum distillate. (that's as much as you can learn from reading the can).

There is also another category of "solvents" which in my simple mind I think of as alcohol based (I'm not a chemist, and did not enjoy High School chemistry) which tend to contain substances like Acetone, MEK, Toluene and so on. "Lacquer Thinner" (again, note the caps as denoting the label on the can in the store) falls into this category, as does Denatured Alcohol (I think). These products tend to evaporate very quickly in open air, in contrast to the "Petroleum Distillate" products described earlier, which, although volatile, are less so then these solvents. I am sure that an organic chemist in our midst will set me straight.

You are exactly correct on your bottom line. My quest has been to experimentally discover the "base" for Interlux Schooner 96 varnish, such that I can quickly and thoroughly clean my brush. So far, "Lacquer Thinner" seems to be the right answer. My experience, and Lesharo's, seems to suggest that the combination of resins and oils comprising Interlux Schooner is not especially soluble in Petroleum distillate-type products. Cleaning a brush used for Interlux Schooner varnish using Mineral Spirits (as recommended by Interlux) is a lengthy, tedious and not very effective process requiring many, many turns through the mineral spirits bath and at least a measure of mechanical cleaning. And it still doesn't produce a satisfactory result. I again wonder why Interlux doesn't provide more guidance. I dunno. Maybe when I have some time I'll pursue it with Interlux.

[Jay Greer]

I have to agree that experimentation with todays products for thinning and brush washing is about all a guy, who wants to use a compatable product, can do.
This week I was shocked to find that "mineral spirtits" AKA petrolium based paint thinner, is priced at sixteen dollars a gallon here in CA! My first impression was that it, deffinatly, has a different smell. However, it did the job when it came to cleaning out our brushes after using them for tung oil based varnish.
Jay