Film on paint, why?

[Auldfart2010]

This is a problem I've had several times over the years. I will open a previously opened tin of enamel type paint and find a film of dried paint that I have to remove. I always replace the lid as securely and tightly as possible before storing it away it away. Any proven suggestions would be welcome.

 

[Droogs]

The oxygen in the tin reacts with the paint. 2 ways to beat it either, once closed properly place tin away upside down. This way you still get a thin film but it is under the paint when you open it or replace the air in the tin with a heavier inert gas (you can get aerosols for this) good for very long term storage of paint.


edit typo

 

[Cabinetman]

The oxygen in the tin reacts with the paint. 2 ways to beat it either, once closed properly place tin away upside down. This way you still get a thin film but it is under the paint when you open it or replace the air in the time with a heavier inert gas (you can get aerosols for this) good for very long term storage of paint.

Very similar to what I was always taught, after putting the lid on a tin turn it upside down for a couple of minutes the paint goes into any slight voids and fills them. Then store the correct way up, very little if at all skin on the paint.
CO2 would do it, that’s a good idea I hadn’t thought of that and didn’t know you could get aerosols. Ian

 

[Droogs]

Just updated the other pebble based thread with this

 

[islayhawk]

I find that after putting on the lid give the tin a shake this also seals any gaps

 

[Auldfart2010]

If CO2 would do it I might try blowing into the tin to replace the oxygenated air. Thanks every one.

 

[carpenteire2009]

A few other tips when resealing tins of oil paint, I always make sure the mating surfaces of the lid and rim of the tin are clean- usually clean these with a rag and some white spirit. If I know I won't use the paint for some time I'll usually dip my finger in some linseed oil and rub it around the mating surfaces- I find this gives a great seal. I also write on the tin with a marker when last opened and how much is left in the can- very useful for odball paints or colours that arent used too often.

 

[John Brown]

If CO2 would do it I might try blowing into the tin to replace the oxygenated air. Thanks every one.

I think you'll find there's still a fair bit of oxygen in your exhalation.
Maybe farting into the tin would work?

 

[JobandKnock]

Just out of interest I looked it up. One reference stated that, "Farts are primarily made of odorless vapors like carbon dioxide, oxygen, nitrogen, hydrogen, and sometimes methane.". So maybe not the perfect solution. Good attempt at self-sufficiency, though

Of course when dealing with any flamable gasses safe handling is a must. After all you wouldn't want this to happen, even by accident: