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Thread: What not to use instead of Bloxygen

  1. #1
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    What not to use instead of Bloxygen

    I tend to go through finishes, and especially paint fairly slowly, so I lose a lot to the finish skinning over in the can, and then have to either filter (losing more material) or be really careful to avoid the leftover bits and blobs. This wasn't so bad back when a gallon of good paint was $15, but now it's pushing $80, and I'm a cheapskate. Hence Bloxygen. But being a cheapskate it was hard to swallow the price of bloxygen, even if a $1-2 puff worked to preserve $30 of paint for the next time.

    It was argued on the interweb that "any heavier than air gas will work", so I tried an experiment using 1, 1-difluroethane (aka HFC-152a) an allegedly ozone-friendly refrigerant sold inexpensively as an "air" duster. It's about twice the density of nitrogen or oxygen, so should work nicely, right?

    IMG_1897.jpg

    Not so fast. I had a can of polyurethane, about 80% full. Used it for a small project, then used a short blast of 1,1-difluroethane prior to closing the can. When I came back the next day, what to my wondering eyes should appear?

    IMG_1895.jpg IMG_1896.jpg

    But a can, collapsed, as if a good vacuum had been applied. When I pried it open there was an inrush of air, indicating a pretty good vacuum inside. OK, what then is going on?

    Hypothesis 1: the 1,1-difluroethane reverted back to liquid state in the can. (Unlikely, I think, given a boiling point of -25C)
    Hypothesis 2: the 1,1-difluroethane was reactive with something in the finish, making a solid or liquid product, leaving a vacuum behind (Looking at the molecule it's hard for me to posit a reaction, but I'm a biologist, not a chemist)
    Hypothesis 3: 1,1-difluroethane is very soluble in oil-based poly, and simply preferred to be in the liquid phase rather than the gas phase.

    It doesn't speak to the utility of the solution (unless it's reacting, which would presumably be a Bad Thing), but this was a curious, unexpected result I thought I'd share. I'd appreciate input from the chemists as to mechanism. Vacuum packing finish would be fine for preservation (works great for wine), but I'd worry about a large, mostly empty can, collapsing to the point of leakage.

    For those of you who do use "canned air" (not actually air) for preserving finishes, which product do you use?

    Meanwhile the search for a cheap argon tank and regulator goes on.

  2. #2
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    Quote Originally Posted by roger wiegand View Post
    For those of you who do use "canned air" (not actually air) for preserving finishes, which product do you use?

    Meanwhile the search for a cheap argon tank and regulator goes on.
    I would use argon but I use nitrogen instead since had a spare tank I filled with nitrogen to have on hand for various other uses. I know nitrogen is not heavier than air but it is very close since air is largely nitrogen. I keep a 100 cu ft (I think) tank in the wood shop with a regulator and use a piece of plastic tubing to flow it under the lid for a few seconds to displace the air. I use a gentle flow rate so the pressure doesn't splash the liquid around in the can/bottle. It works well, as well as Bloxygen as far as I can tell.

    I think the tanks I buy are $150 or so and are the largest I can buy from my gas distributor - larger are rent/lease only. I use it quite a bit and it will still probably last for a bunch of years. Note that the regulator is not exactly cheap. Maybe look for a used tank/regulator. You can buy a smaller tank than what I use for not much.

    Note that if you buy any tank, say with oxygen, you can swap it out at a gas supplier for a different tank such as for argon (as long as it's not damaged). The company here doesn't charge for swapping a tank - just for the gas which is cheap.

    Note also that Bloxygen is now pure argon but it used to be an argon/nitrogen/co2 mix:

    bloxygen_contents.jpg

    JKJ

  3. #3
    Well if you want to have a cheapskate competition, you're in the right place. Here's what I do. Get a $10 Vac-U-Vin off Amazon (this is the little plunger device for extending the life of wine). It will come with a couple of the rubber stoppers, and you can buy an additional set or more if you need them. You can also get them at BevMo, Wal-Mart, lots of places.

    Then take a few bottles of wine or beer, and once you're done drinking, use the clean bottles to store your finish and use the Vac-U-Vin to pump out all the air and create a vacuum, which you will verify by sound each time you remove the stopper. Store the bottles of finish in a dark place or cabinet because light is not a friend to stored finishes (must be why they're always sold in tins).

  4. #4
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    I'm cheap, too, Roger, and also tried a can of air duster. Same result; the can collapsed like someone had pulled a hard vacuum on it. I'm back using Bloxygen - cheaper when you buy several cans at once. I think I paid about $11/can. If I get 50 shots out of it that's $0.22/shot. A can of Epifanes is almost $50/qt. If I can use the whole can for an extra $1 of Bloxygen that's still a good deal to me.

    John

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    Quote Originally Posted by roger wiegand View Post
    ... Hence Bloxygen. But being a cheapskate it was hard to swallow the price of bloxygen, even if a $1-2 puff worked to preserve $30 of paint for the next time.
    Bloxygen goes for about $12 for a single can. If you are only getting 6 or so applications per can, you are using way too much.

    The ad copy says 75 quart-sized applications per can (half as many for gallon-sized containers). That's probably over-optimistic. But even figuring a pessimistic 25 quart-sized applications per can, that's less than $0.50 per shot. How cheap do you need to get?
    -- Jim

    Use the right tool for the job.

  6. #6
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    Good to know I'm in good company imploding cans. I thought it may have happened because of the change in temperature inside the can. I had used the canned air because there's no place close to buy Bloxygen.
    Confidence: The feeling you experience before you fully understand the situation

  7. #7
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    Quote Originally Posted by Jerry Bruette View Post
    Good to know I'm in good company imploding cans. I thought it may have happened because of the change in temperature inside the can. I had used the canned air because there's no place close to buy Bloxygen.

    $11.95 + free shipping on several sites on the web. Google "bloxygen".
    -- Jim

    Use the right tool for the job.

  8. #8
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    I find the bloxygen cans go empty sitting on the shelf once they've been used (that's with n=2, not a statistically meaningful sample). That drives the cost up quite a bit.

    Any insights about what's going on? I favored the solubility hypothesis, but with a logp of -0.75 that's not a very greasy molecule.

  9. #9
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    Quote Originally Posted by roger wiegand View Post
    I find the bloxygen cans go empty sitting on the shelf once they've been used (that's with n=2, not a statistically meaningful sample). That drives the cost up quite a bit.

    Any insights about what's going on? I favored the solubility hypothesis, but with a logp of -0.75 that's not a very greasy molecule.
    Odd,

    The one that I last used about 5 years ago still has gas. Does the shop get hot and cold? Maybe leaky valves? If you can document the issue with usage records (seconds of use) and dates perhaps the company would send you new cans.

    JKJ

  10. #10
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    Cans are long since thrown away. While I may be bored enough to write long rambling posts on the disappearance of a gas inside a can, I can't see keeping use records at that level of detail. Shop temp varies from 40-45 in the winter to 85-90 in the summer; nothing super extreme. It's well insulated and I heat continuously but only AC when I'm out there. I've only turned the AC on once this summer. They could certainly have had a batch with bad valves, both cans were bought at the same time and the second had little left in it when I used it a year later. (Now that I have retired I don't expect shop supplies to sit around so long!)

    I just ordered a new can of bloxygen on Amazon, we'll see how it goes. I'm going to be using some pricey moisture catalyzed urethane paint and it apparently polymerizes in the can with little provocation.

  11. #11
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    Quote Originally Posted by John K Jordan View Post
    Odd,

    The one that I last used about 5 years ago still has gas. Does the shop get hot and cold? Maybe leaky valves? If you can document the issue with usage records (seconds of use) and dates perhaps the company would send you new cans.

    JKJ
    My impression is that the manufacturer is usually pretty good about replacing defective cans - apparently they have gone through one or more bad batches.
    -- Jim

    Use the right tool for the job.

  12. #12
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    Much of the problem with finishes going off is difficulty in reseating the lid tightly on the can. The solution is to use a small screw driver and punch a neat hole in the bottom of the groove that the lid seats in. This breaks the hydraulic/pneumatic pressure in that groove that stops your lid sealing properly. Any paint left in the groove drips back into the can. This technique has been used by polishers for way longer than I have been around.

    Also remember that finishes do have a shelf life and cheap skatery can end up costing longer term performance. Cheers

  13. #13
    Very interesting thread. The collapsing can is very impressive. It also says something about cheesy cans. I vote for hypothesis 3. (Too bad science isn't democratic.)

    But my reason for posting is to object to such wild profligacy as Bloxygen. (The best word I can come up with as the opposite of cheap skatery.) Noble gasses and nitrogen? Bah, humbug. Gently dribble a layer of mineral spirit on top of the remaining oil based finish. Then seal the can and put it back on the shelf without disturbing it. I think that turpentine might be better than MS for this purpose but I have not tried it because the MS seems to work just fine. My father used to store the cans upside down, without the MS. He was even more frugal than I am. Of course, paint and varnish took more than 20 minutes to dry back then, but his method, like (ahem) my method worked fine.

    Doug

  14. #14
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    PROPANE is heavier than air

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