Tips to store paint once it is opened!
Tips to store paint once it is opened!
(OP)
Hi Everyone,
We use aerospace grade paint(2 part) and primer (2 part). Some times the batch sizes are really small that the paint and primer is not completely utilised. According to the supplier we cannot use the cans after 8-10 hours of opening. Fair enough because you have oxygen entering the can. I was thinking of filling the can with nitrogen and close it (hopefully the can is not damaged) and store it at recommended temperature. Does any one have any better suggestions to preserve and reuse the paint.
Thanks for any help, its much appreciated.
V.
We use aerospace grade paint(2 part) and primer (2 part). Some times the batch sizes are really small that the paint and primer is not completely utilised. According to the supplier we cannot use the cans after 8-10 hours of opening. Fair enough because you have oxygen entering the can. I was thinking of filling the can with nitrogen and close it (hopefully the can is not damaged) and store it at recommended temperature. Does any one have any better suggestions to preserve and reuse the paint.
Thanks for any help, its much appreciated.
V.





RE: Tips to store paint once it is opened!
I suggest that you open the can only long enough to transfer out what you need. There are cans of nitrogen or argon that a sold specifically for purging air out of cans to preserve the contents. I've considered using readily available freeze spray which is R-134 but I not sure how nonreactive that is. I store cans in a freezer, opened or not, as cold will slow down all reactions. Some paints may not tolerate freezing.
Alkyd paints cure by reacting with oxygen in the air. There are anti-skinning agents that are ingredients of these paints, which are also available as preservatives, where you add a drop or two to the can before resealing it. This prevents the paint from forming a cured skin on the surface of the paint remaining in the can.
RE: Tips to store paint once it is opened!
Oxygen-cured systems such as alkyds (drying oils) are frequently stored under N2 or argon- argon being more effective because it's denser than air.
RE: Tips to store paint once it is opened!
RE: Tips to store paint once it is opened!
RE: Tips to store paint once it is opened!
RE: Tips to store paint once it is opened!
You don't; you displace the gas in the paint can with the gas you dispense from the dispenser. Assuming that their sales pitch isn't totally bogus, a heavy, inert gas would tend to settle into the paint can and push out other, lighter, gases.
This comment: http://homefixated.com/keep-paint-and-stains-fresh... might also be feasible.
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RE: Tips to store paint once it is opened!
If you must buy in gallon cans and cannot find another supplier for smaller cans then repackage the paint yourself into smaller cans the first time you open the gallon can. But, repackaging is troublesome. That's why many companies have a business model based on buying drums and selling small cans at a huge mark-up.
RE: Tips to store paint once it is opened!
RE: Tips to store paint once it is opened!
Note also that the isocyanates are moisture rather than oxygen-sensitive. What you don't want to do is to entrain a bunch of moist air in with your dry nitrogen or argon or you'll be doing more harm than good. You need to introduce it slowly and flow just enough to displace the air completely before replacing the lid, assuming that these materials are stored in metal cans with press-fit lids. Transferring the contents to other containers for storage is likely to do more harm than good.
RE: Tips to store paint once it is opened!
RE: Tips to store paint once it is opened!
Paint msds:
https://buyat.ppg.com/ehsdocumentmanagerpublic/kit...
Primer msds:
https://buyat.ppg.com/ehsdocumentmanagerpublic/kit...
RE: Tips to store paint once it is opened!
There are polyurethane formulations which involve pre-reacted isocyanates, i.e. short polymers of isocyanate and polyol with live isocyanate functionality available to form crosslinks. These materials are very durable and hazardous than the old formulations which had free isocyanates like TDI or HMDI etc., but they do still contain reactive isocyanate functionality.
There are likely many others.
You'll notice that your MSDS does contain the language related to respiratory distress, sensitization etc. even for the base material which should contain no isocyanate. I suggest you speak with PPG's applications staff and find out what you're really working with.
RE: Tips to store paint once it is opened!
Argon and nitrogen are inert gasses, so how and why do you think they may react? I noticed that you didn't use the word react, so may be previous question is irrelevant? But how will they be harmful if there was no reaction?