Rant: Today's Oil Paints

[Willa]

I have been using a lot of oil based "Direct to Metal" paint to paint pickets, sash windows and storm windows.

I have been decanting small amounts into a plastic cup for brushing, always close the gallon of paint promptly - but still there is a skin that forms on the paint that must be dug out (or it lurks, creating GLOP). Like this is a can of paint that has been in use within a one month period - not a can from 10 years ago in the basement.

I have been adding Penetrol to assist with the paint performance, which it does.

I am so frustrated with the apparently short shelf life of today's paint though. What have they done to it to make it behave so poorly ?

[awomanwithahammer]

I use the BIN oil-based primer for my sashes and trimwork, and I've noticed the same thing. I just thought it was a thing, though, because I've never used oil paint before. Well, not that kind of oil paint. Tubes, yes.

[Sow's Ear Mal]

That last bit of atmosphere trapped by the closing of the can will do that. You can buy aerosol sprays that will vacate the gasses in a can just before you close it. I know the frustration, trust me. Every time I close up my gold size (adhesive) I get the skin. I have paint strainers to remedy it. You can always keep the can on it's head in storage. Then the skin won't be in the way.

[heartwood]

the skin is just a characteristic of oil paint...I use a utility knife to cut a clean line around the perimeter then pinch and lift at the center of the skin folding it in half then in quarters while I gently squeeze the liquid paint out...it happens in the original container and in the smaller plastic container...

sarco putty has a skin over issue as well...we pour water or a wet paper towel to keep the drying/skin over to a minimum but it's just the nature of an oil product...

my suggestion is to just expect to remove the skin each time and know it's not a failure issue...

there you have it.....
...jade

[awomanwithahammer]

That's good to know, Jade!

[phil]

working in printing, its the same thing. ink skins so Ive done that a million times. use a knife with a blade about half the width of the can. use a corner of the blade to cut around the very edge and leave the skin where it is. Then stab it down through the skin but not deep. then turn the can holding the blade parallel with the surface, or go in a circle, andkeep the blade just a teeny bit below the surface. the object is to pick off the skin while taking as little of the paint as possible and to get every bit of skin the first go. the top of the skin will remain dry. stir it in and you'll have lumps and make curse words. Paint re-levels, ink is similar but thicker so with ink you take off the top and never dig down or if you do you leave the can level. If you dont; leave the top level it will make it hard to remove.
if you want you can find stones, wash them then drop them in to fill the can or transfer to a smaller can. I think flipping the can and creating a skin under the surface lends to risking paint and skin getting mixed. I guess it seals better so long as it doesn't leak.

how you keep the rim clean is another story. some punch holes to let the paint drip back in the can, it doesn't affect the seal. you can use the plastic pouring things. I usually just use masking tape in an effort to make it so I can pour without filling the rim but usually I end up with a rag and screwdriver cleaning the rim and pushing a spoonful of paint in circles