To prevent the curing of certian finishes, can I use the canned air used for dusting camera lenses and electronics in stead of Bloxygen? I’ve read on the label that it’s an inert gas (type of alcohol) and is heavier than oxygen. So it would make sense that it would work.
I’ve tried it and after a week I’ve noticed no curing on the top of the poly, but this may not be long enough. Also, it changes the pressure which causes it to compress the can.
It’s also 3 bucks at wal-mart for a bigger can than that of 13 dollar bloxygen.
Can any chemists out there help out with this one? Am I creating any potential hazards?
Replies
A supplier of wiping varnish suggested I forget the expense of canned air and pour water in the varnish until the can is full. Since water and oil don't mix, the finish is at the top which I later remove with a turkey baster.
Jeff
Re: water in varnish
That's a very interesting idea ...... have you tried it yet? The only problem I see is getting all (or most) of the water from the can.
It's probably inevitable that some of the water will remain, and will get mixed in with the varnish as you brush it on. And I wonder if that might create a problem?
Somebody here a while ago suggested that propane would work for this application.
I tried it with a can of oil based paint (1 qt, 2/3 full). After a week, the top was completely skinned over. A complete failure.
Sorry I don't have a positive answer, but I sure would like an alternative to the Bloxygen too.
We have found that MIG gas works well .One of the guys at the shop has Argon for welding.Nitrogen would be fine ,Propane is a bit dangerous and smelly.It needs to be heavy and inert.
Oxygen is what causes finishes to start curing. Once the finish is exposed to the oxygen it will begin the process. Resealing the container as quickly as possible and doing something to remove the oxygen will help the finish longevity, but once opened, the process starts.
Rather than water, I would add marbles to raise the level of the liquid in the can or decant to smaller containers. However, all finish deteriorates over time. I date all my finishes when opened and discard them within 3-4 months. In the grand scheme of things, finishes are a small cost in the overall project. It's not a place I look to be frugal.
As to using the "canned air", it's effectiveness is dependent on what is being blown out. If it is just compressed air, then oxygen is being blown out and using it to displace the oxygen in the can makes no sense. If however, it is some other inert gas, then it can be used to displace the oxygen. Remember, it's the displacement of oxygen that is the objective.
A second to Howie's suggestion of marbles. They work great (until you loose them, LOL).
Yes, I haven't been able to find my marbles in a long, long time. If they turn up in the bottom of anybody's varnish cans, please send them to me.
That's a good tip. Seems kind of messy, but using a small ladel can keep the messyness down.
It sounds like the "canned air" you have it's probably fine (though I doubt it's an alcohol, and if it really were canned air, it would not be fine). A someone said, the idea is not so much to put something into the can as to prevent air from being there. That means you probably want to put the top on to close the opening as much as possible, then use a thin tube to spray into the can to flush out the air, and then to get the tube out of the way and seal the can without lifting off the top.
Lots of things ought to work, but I would think carbon dioxide would be a good bet: it's cheap, won't burn, and is a bit denser than air. Either a little cartridge as used in a soda siphon, or a bit of dry ice should work fine. Another option would be a flexible bottle so you could squeeze out the air before you sealed it.
I was going to Walmart anyway, so I picked up a can of the air duster being discussed. They had three different varieties, two of which didn't identify the gas and which also contained additives such as scent and a "bitterant" to discourage those who get their kicks sniffing solvents.
The third version was made by Fellowes, an office product supplier, and it gave the chemical name as 1,1,1,2-tetrafluoroethane with no additives mentioned. This is one of the low impact substitutes for the older Freon gasses and it is used as a refrigerant under the name of Freon 114. It is virtually non toxic and like most of the Freons it is non reactive with most other materials. I believe that it is heavier than air but I didn't look this up.
It should work well as an oxygen excluder, I'll give it a try with some Waterlox which has a very low shelf life once air gets in the can.
John W.
Yes, tetrafluoroethane is about 3 times as dense as air, and will certainly not react with anything in the finish. How well it works will depend on how thoroughly the air is flushed out. But it's not just storage: if the whole can is exposed to air and light for a long time as you use it, it could then cure even in the absence of air. To make it last longest, expose it to air as little as possible: take out what you will use, flush the can with something to replace the air and seal the can, then use the finish you took out.
Edited 11/4/2004 5:20 pm ET by AlanS
You make an excellent point. Never work from the original can unless you intend to use all the finish right away. Always pour out what you will immediately use and seal the original can. And, don't later dump leftover finish back into the original can. Pouring, stirring, brushing all introduce oxygen. Plus the finish is contaminated with dust while you use it so you don't want to pour that back into the fresh finish.Howie.........
John,
How did it work with the Waterlox?
A trick used by photographers to preserve developing chemicals is to add marbles to bring the liquid to the top of the container.
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