How long does paint last?

[orangetrader]

I have several cans of paint that I used to paint the rooms (interior latex paint). I turned them upside down and stored them in the garage. It has been I think 20 months ago. Today I opened them so I can do some light touch up work on a few patched up screw holes, I noticed the paint has turned into hardened cottage cheese. How long are they supposed to last? a few months? On the other hand, I have the same brand (Benjamin Moore) latex primer Fresh Start which I bought around the same time, and that was fine. Am I not storing them right or do these paint have a shorted life span? Yes I made sure I close the lid tight, and tapped with a mullet and turned them upside down when I store them.

If I just need to make some light touch up, what is the smallest size they will sell (if I have to add colorant)?

Thanks,

O

[Roger]

Depends on the paint type, the temperature in garage, quality of seal, etc etc. Latex will not tolerate freezing, and turns to a cheesy mess. My exterior latex paints last about 5-7 years, but garage does not get near freezing here. Towards the end of the paint's life it may get sour smelling, but still sets properly. When I have less than 1/2 gallon unused, I pour into quart or pint glass jars w/ paper or rubber gaskets, so that there is almost no air. Be sure to clean threads well - paint is a wonderful adhesive...The newer plastic paint cans will also preserve paint, as there is no rust - a real prob. for acrylics. Nomally they will mix a quart as a minimum, but some lines of paint are now selling premixed sample bags that hold just a thimbleful of custom color.

No wonder you have probs - try a mallet.

[George E. Cawthon]

That's your problem you tapped with a mullet. Too soft, should have used a mallet. Seriously, primer seems to harden slower than regular paint. I've had paint 3/4 of a gallon last for 5 or 6 years and only 1 year with a quart remaining in the 1 gallon can. Part of that is air space but part is just the changes in paint formulation. You can usually buy 1 quart, but it will cost nearly 1/2 of a gallon. Turning the can upside down probably did nothing. Adding a 1/8 -1/4 inch layer of water on the surface of the paint or breathing CO2 into the can before putting the lid on can help sometimes.

[Doug Kanter]

Store at any temperature you're comfortable at. Your garage may not offer those conditions, especially in winter. And, there's a cheap little tool made for opening paint cans - it hooks under the rim and opens the lid without deforming it, as a screwdriver might. Some paint/hardware stores will give you one for free if you ask. When closing, put a piece of 2x4 on top and tap on THAT with a mullet, squid, smallmouth bass, or a hammer. The hammer works fastest, but the first three are quieter.

[m Ransley]

I probably froze to turn thick like that. Good brands can last 20 yrs

[John Grabowski]

I once asked my Benjamin Moore dealer that very same question. He said that it would last a long time at room temperature with no air in the can. As I was carrying several cans of paint out the door he made a point of telling me to always keep the cans right side up. I assumed it was to avoid accidental spillage.

I don't know what the reasoning is for storing cans of paint upside down.

[curmudgeon]

No air in contact with the "top" of the paint...at least it will be the top when you re-invert the can to open it. Avoids hard crusty film....but not applicable when you've let the paint freeze!

[Doug Kanter]

The reason comes from the same school of thought which says that an unopened container of cottage cheese will last longer if placed upside down in the refrigerator. This idea, in turn, is perpetuated by the same people who think you should hold your breath when you pass by a cemetery.

[Roger]

Storing paint upside down has some pretty credible adherents, including lots of self help sites, university extensions, and painters. It also works for me. Turns out paint is a much better seal, when in contact with the lid, than an ill-fitting metal-to-metal can lid exposed to the air.. Just check on google under phrase : paint lasts longer "upside down"

[Bob]

upside down.

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the lid,

Just check

I've stored paint "upside down" and found when I opened it that the paint was suspended from the bottom of the can by a thin layer of dried paint. If it's rightside up, you can remove the extra layer and get to good paint. Stored upside down, when the dried layer breaks, you've got paint with broken dried paint mixed in.

Bob

[orangetrader]

No, no freezing at all. Location is Miami, Florida so I am sure no freezing was involved!

O

[orangetrader]

Located in Miami so no freezing here.

O

[m Ransley]

To much air in can cured the paint

[Norminn]

I think paint lasts longer than the container - can gets rusty and crumbles into the paint when opened. I have transferred paint to jars, but that runs rish of it breaking. Have heard DIY tips to lay plastic wrap over the surface of the paint before closing the can to prevent drying of surface.

[Doug Kanter]

Oh well. It harms nobody to do it. I've used the neat little "key" tools to open the lids, so they seem to reseal perfectly.

[SJF]

With a microscopic gap in the rim seal there is air exchange with internal expansion and contraction due to temperature changes. This will permit continued oxidation of an oil based paint forming that familiar skin on the top of the contents. In an upside-down position, the viscous paint prohibits the expulsion of air, stopping the air exchange.

Latex paints don't oxidize to set up. There would seem to be little advantage to inverted storage. My experience is that they store better unless the can starts to rust because of the water ------ SJF

[Choise76Smu]

"Doug Kanter" in news:bO37d.5446$rs5.841 @news01.roc.ny:

i thought the advice is to hold your breath if *buried* in a cemetery.

[Choise76Smu]

Norminn in news: [e-mail]:

i've dealt with cans that had been 'sealed' with plastc. polyethylene-bag plastic seems to allow faster gas transfer than just the lid alone.

[Bob Joesting]

I have used both latex and oil that was more than 20 years old with no problem. I had several cans of latex go bad when it got too cold when we went about a week without power in a winter storm a few years ago. I have also had both oil and latex go bad in a few cases when it sat for a year or so in a can that was way less than half full.

Bob