Could you just buy some smaller empty tins?

Jim

For primers I use plastic tubs with self sealing tops and take up the air by means of glass marbles…..works very well. Just getting to the end of my 'Ardenbright' alluminium primer from 1957…keeping the air out worked well.

Air leaks? If properly sealed, they will not deteriorate until quite a low level.

I agree with this method have done it for years and find it does help a great deal as it is the build up of paint that make the replacing and removal of lids a pain.

To address OP's question I look for good metal screw top jam jars with the rubber seal still in good condition. I find plastic screw tops less effective. I also try plastic sheet under the lid but it never as good.

On the separate subject of paint skinning. Even a totally sealed half full tin will skin if in the wrong conditions. If the top cools the body of the paint being warm evaporates thinner which condenses on the lid and allows a skin to start. Repeated temperature cycling makes it build up a skin even if the solvent is dripping back. I try to minimise this by stacking tins and bunching them up so only the lid of the top one gets cold.

After replacing the lid my father always inverted the tin briefly, never had issues with drying out.

Beware of old paint when top performance is needed – even unopened tins have a limited shelf-life.

Paint doesn't just dry, it also hardens. Some types rely on evaporation of solvent, others harden by a chemical reaction triggered by exposure to air. Many do both.

Taking the lid off immediately causes most paints to deteriorate slightly, some seriously. Symptoms include difficulty cleaning brushes, poor adhesion, lumps, poor coverage, poor finish, streaking and reduced resistance to weathering. The older the tin, the worse the problem. If you get disappointing results, try new paint.

Dave

.

How about something collapsible to remove the air (or most of it).

**LINK**

Ed.

Never tried it but perhaps a layer of clingfilm pushed onto the surface of the paint before closing the tin would work?

I remember a round plastic film layer on something I opened years ago, had to peel it off

Chucked it away in my ignorance, probably shouldn't have

Edited By Ady1 on 27/08/2018 14:09:09

Unfortunately Brickies advice is not good, although it is seems a popular belief. All it will achieve is to form the skin on the surface of the paint which is in contact with the air-space i.e. halfway down the tin, where it is almost impossible to remove without getting bits of skin in the paint.

As S.O.D. says, there are many types of paint but talking only about the oil-based household and hobby paints: The last thing the paint manufacturer does before sealing the tin is to add a small amount of methyl ethyl ketoxime which is an anti-oxidant. This does not interfere with the drying because it is highly volatile and quickly leaves the drying film. The ketoxime is sufficient, together with the small air-space in an unopened tin to stop the paint drying (aka skinning). If you open the tin, use half of the contents then reseal the tin, you will have lost the ketoxime while the can was open, and there will be enough air above the paint to cause skinning.

There is only one way to avoid this, and that is to open the full tin and decant the contents immediately into smaller, well-sealed containers until they are required. Or buy smaller tins of paint

Chas

Try searching online stores for ‘plastic paint pots with lids’ they come in various sizes, might just find the sort of thing you are after.

Edited By V8Eng on 28/08/2018 21:25:11