stupid newbie question: used rags?

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Forum topic by DragonLady posted 01-01-2011 08:21 PM 30553 views 0 times favorited 28 replies Add to Favorites Watch
View DragonLady's profile


298 posts in 4257 days

01-01-2011 08:21 PM

I’ve never worked with oil-based stuff before. Is it possible to wash and reuse rags that have had mineral spirits, polyurethane, or paste wax on them? Or do I just toss them?

-- A woman's work is never done-but power tools help!

28 replies so far

View Howie's profile


2656 posts in 4173 days

#1 posted 01-01-2011 08:28 PM

Toss. Not worth the trouble.

-- Life is good.

View ajosephg's profile


1898 posts in 4811 days

#2 posted 01-01-2011 08:34 PM

Make sure you put them in a suitable container to prevent spontaneous combustion or dry them safely before putting them in the trash.

-- Joe

View JJohnston's profile


1622 posts in 4541 days

#3 posted 01-01-2011 08:35 PM

The mineral spirits will evaporate, so those can be wrung out, hung up, and reused. The wax will dry out, so those can probably be “snapped” or beaten to get most of it out, then reused. Poly will cure, so those should be tossed.

-- "A man may conduct himself well in both adversity and good fortune, but if you want to test his character, give him power." - Abraham Lincoln

View lew's profile


13431 posts in 5005 days

#4 posted 01-01-2011 09:17 PM

I tried washing my rags that had mineral spirits on them. Let’s just say Mimi was not in favor of me using her washing machine again.

Looking on the bright side, it did get me out of doing the laundry.


-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View hObOmOnk's profile


1381 posts in 5377 days

#5 posted 01-01-2011 09:35 PM

Used rags aplenty: I put out a request to my temple for used tee shirts and cotton bed spreads.
Now I have more than a year’s supply for my professional studio.

-- 温故知新

View Dan Lyke's profile

Dan Lyke

1530 posts in 5375 days

#6 posted 01-01-2011 11:06 PM

I just want to reiterate Joe’s warning to “dry them safely”: Lay them out somewhere so that the volatile spirits can completely evaporate before you put them in a bag to throw them out. Wet (with mineral spirits and other petroleum distillates) rags in an enclosed space can spontaneously combust and ruin your day.

-- Dan Lyke, Petaluma California,

View AaronK's profile


1512 posts in 4714 days

#7 posted 01-01-2011 11:24 PM

you guys have had rags with just mineral spirits on them spontaneously ignite? that seems odd. ignition comes about by the oxidation process that hardens/cures stuff like polyurethane. non-curing things like solvents and waxes shouldnt get warm in the least bit. if they are, something else must be going on.

i reuse rags that have been used for waxing. they’re good for either more wax, or just general cleanup in the shop.

View Scott's profile


153 posts in 4222 days

#8 posted 01-01-2011 11:27 PM

This is timely; I just took an old metal popcorn tin that my wife dug out with the Holiday decorations and painted it red to use for soiled rags and towels.

View Chris Pond's profile

Chris Pond

63 posts in 4297 days

#9 posted 01-01-2011 11:31 PM

Polyurethane rags can’t be reused they just get hard. How ever all other rags can be used even one with “dry” stained can be used, for thing like checking the oil in the car…

By the way I always hang my rags and my rags that are done I through outside.

-- Chris, Fernie, BC

View dfdye's profile


372 posts in 4287 days

#10 posted 01-01-2011 11:34 PM

I use paste wax on tools as rust prevention and to make them slick for the next use. I keep a rag for wiping/buffing them off beside the tin of wax, and I rarely change it out. I have never had a problem, but I would never think of trying to clean it!

As others have said, if you have a curing oil like BLO or tung oil, then you really need to ensure they are spread out to dry, but for solvents, there isn’t nearly the danger. Still, good practice dictates that you should probably lay all of your rags out flat to dry just to be on the safe side.

The one thing that KILLS me is seeing people drape the oil-soaked rags on the edge of their trash can full of saw dust! If a rag does decide to catch on fire, you want it NOWHERE NEAR a bunch of highly combustible material! I know the risk is low as long as the rags are flat, but it scares me nonetheless!

-- David from Indiana --

View PhineasWhipsnake's profile


77 posts in 4298 days

#11 posted 01-01-2011 11:35 PM

I don’t think mineral spirits are a problem with washing, but boiled linseed oil will surely combust if wadded up & left in a pile. I wouldn’t try to reuse polyurethane or other film-type finishes.

-- Gene T

View ajosephg's profile


1898 posts in 4811 days

#12 posted 01-02-2011 12:44 AM


I have personally observed rags soaked with toluene (aka toluol) catch on fire at a company I worked at. The rags were used to clean up a paint spill. SOP was to put them in a sealed container, butleft on a table top for no longer than several minutes and vioila – smoke followed by flames! I haven’t seen mineral spirits soaked rags ignite, but I’m confident that if the conditions are right, they would.

You could argue that “pure solvents” won’t ignite, but in the real world rags that get soaked with solvents are not pure anymore, and whatever they were used to clean up could initiate the chemical reaction leading to a fire.

So rather than debate and figure out the chemical reactions involved, it’s just good practice to follow a protocol that won’t lead to a disaster.

-- Joe

View Don's profile


517 posts in 4323 days

#13 posted 01-02-2011 12:48 AM

I just seel them in a metal paint can filled with water. I won’t take even the small risk of hanging them up to dry. I’ve seen people do that only to have them fall on the floor into a pile that goes unoticed. I also use the rags in a box from Home Depot that are cheap, more absorbant, and have less lint than cotton T-Shirts

-- Don - I wood work if I could. Redmond WA.

View AaronK's profile


1512 posts in 4714 days

#14 posted 01-02-2011 12:57 AM

thats exactly the point: the solvent was mixed with paint, which has in it an additive to accelerate drying/curing. the solvent was just more food for the flames, so its not surprising that this solvent-rich mixture ignited faster than just a poly-soaked rag.

so: I’ll maintain that a rag soaked with solvents is fine to bunch up and throw out. but if that rag or solvents have seen the slightest bit of curing resin, then they should be dealt with carefully. I’m not just trying to make a point for the hell of it – just like other types of safety (like table saw kickback) it’s important to understand why the problems arise and to know how to take the right precautions… not just be over cautious all the time.

View Don's profile


517 posts in 4323 days

#15 posted 01-02-2011 01:04 AM

To be clear, the paint cans I use never had paint in them. I buy empty paint cans that are intended for mixing paints. The only thing that goes into them is the oily rags and water.

-- Don - I wood work if I could. Redmond WA.

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