Removing air from cans of finish

[Lyle]

As I dumped another can of finish that has gone off. I was wondering if it would benefit if I could expel the air in the can and replace it with carbon dioxide. Along with keeping the can as cool as possible I was thinking this might increase the opened can shelf life.
Any coments or other suggestions.
Lyle.

[artful bodger]

Perhaps you could put some other inert material in the can to raise the level of the fluid to where it was when it was a new can.

[dai sensei]

Marbles work well, even help with mixing, but you can also get collapsable containers to expand air (like these http://www.ebay.com.au/itm/5L-Collapsible-Water-Container-Camping-Festival-Carrier-1-Gallon-Collapsable-/191588211724?hash=item2c9b8c1c0c but there are black ones too for protections from light)

[KBs PensNmore]

One way that I've been told, is to put Glad wrap on top of paint/finish/? So that majority of air is expelled, with the Glad wrap sitting like a bag, coming outside of the can and sealed with the lid on.
A friend told me this and has cans sitting for about 3 years.
Kryn

[mike100jobstodo]

I heard that you could use a product called "Bloxygen" to revive your finishes that has gone off.

[RoyG]

I heard that you could use a product called "Bloxygen" to revive your finishes that has gone off.

Bloxygen does not revive a finish that has gone off.

Bloxygen is used to replace the air above the remaining finish in a can with a heavier than air gas that prevents the remaining finish from going off. I used to use it when I was living in Canada a few years ago. It's not a cheap solution, and the degree of success that you'll have is very dependant on your technique when you inject the gas into the can, and on the quality of the seal on the finish container. I managed to keep part used cans of Oil Based PolyU that had been treated with Bloxygen for at least two years, when a half tin of the same PolyU without Bloxygen would go off in less than a year.

I haven't bothered to continue using Bloxygen since I returned to Australia, mainly because now that I'm retired, I tend to use up cans of finish much quicker than when I was a weekend only woodworker.

Bloxgen is available in Australia from two outlets that I am aware of. I think that ALS Speciality Marine is the Australian importer, so they should be able to tell you who the other stockists are.



ALS Speciality Marine Products (http://www.alsmarineproducts.com.au/) at Oxley, Qld, and
P Square Agencies (http://www.psquareagencies.com.au/index.php?productID=1125) at 25 Vale Court, Wandi, WA, 6167.


Regards,

RoyG

[Wongo]

I normally put the finish in a plastic bottle and squeeze it to the top. This will help a little but I think the best way is buy the smallest quantity possible for the job. You pay more for a smaller tin but waste less.

OR use MinWax wipe-on poly. It lasts 2-3 years. It's amazing.

[Christos]

I have seen on youtube a fellow crush the can to expel the air. I can see some merit to this logic but I don't like the idea of crushing a can.

My reasoning behind this comes from cans of food. One thing that I was told, if a can of food is dented in anyway then do not buy or use it as the integrity of the can has been compromised. I might be over reacting with cans of finish. :shrug:

[Lyle]

It is the Minwax WOP that I have in the rectangular tins. I keep opened tins in an old esky deep under the bench (coolest and darkest place I can).
I was thinking of the soda syphon CO2 bulbs and using a modified 'injector' or even an empty whipped creamer to expel the air from the tin.
Would keeping the tin in a cool dark place with the air expelled with CO2 prolong the shelf life?

Lyle.

[groeneaj]

I purchased half a dozen of these earlier this year: http://www.leevalley.com/US/Wood/page.aspx?p=72867&cat=1,190,44133&ap=1

They are cheap and work quite well.

[Lyle]

Thanks groenai.
Are theyreuaeable. I couldn't see on the site.

[Master Splinter]

If you have a TIG or MIG welder and argon cylinder handy, you can use the argon to displace the air in the can. Bloxygen in industrial size cylinders, if you will.

[Lyle]

Bloxygen = argon. Great. I'mm gunna get some and try it out. It would work better than the CO2 I was thinking about.
Cost will be the equaliser.
Half a tin of WOP is about $15. If the cost of the Bloxygen is about equal than the savings will be good.
I have sent an email to the Aust distributor asking for cost and delivery.

[Vernonv]

How about LPG ... it's heavier than air and should displace the air in the tin without too much trouble.

Just put out your cigarette before opening the tin next time you go to use it. :)

[Lyle]

Aust distributor for Bloxygen returned with $30 delivered to PC 2318.
Lee Valley has the Finish Storage bags (qty 6) for $US26.50 posted. Approximately $Aus 6.00 each.
Now I need to decide which to try.

I can possibly clean out the Finish Storage bags and re-use them. So that will reduce their intial cost over time.

The Bloxygen is capable of PROVIDES ABOUT 75 USES IN LITRE CANS. So I suspect that will be enough for many tins.

So I will have a think before buying either.

Thanks for the inputs so far.
Lyle.

[steamjunkprops]

You can pick up dry air blanket from barnes. It is an aerosol purging gas. Used it for years on resins and polyurethane with success.

[steamjunkprops]

http://www.amcsupplies.com.au/index.php?main_page=product_info&products_id=5982

Most molding/casting places sell it.

[groeneaj]

Thanks groenai.
Are theyreuaeable. I couldn't see on the site.

Yep, they can be used again.

http://www.stoplossbags.com/about.html

[soundman]

there have been all sorts of ideas like this going round for years ....... I've come to the conclusion that mostly they are a waste of time and money. ........ or a money make for those selling them.

For a lot of finish products the air in the top of the can is the least of your worries.

#1 is the effectivness of the seal ..... so often once you have opened a can and been using it ..... putting the lid back on makes a poor seal. ..... paint tins are a package not a storage container.

#2 is product ages regardless, even in full tins a large proportion of finish product has a finite shelf life ..... the product will react with its self or otherwise degrade

#3 tins rust and the bottms fall out.

#4 some products simply opening the tin signs the death warrant .... as soon at the top is off the product starts rapidly absorbing air and water ....... If you happen to be dipping the brush directly into the tin ..... you are contaminating the product with every dip.

#5 certain finish products are not reactive and it does not matter what is in the vacant space in the top of the tin ..... add more of the correct thinner and the product is good as it ever was.


so ..... there is a very small proportion where this whole problem is the problem at all ...... in that case the best choice is to get fresh clean paint tins .... and pour the contents of the part used container into a fresh clean tin that has an unmolested virgin seal.

cheers

[Christos]

From the Lee Valley web site in regards to their bags,

Effective with oil-, water- and alcohol-based finishes (not for use with finishes containing methyl ethyl ketone, lacquer thinner or acetone).

http://www.leevalley.com/US/Wood/page.aspx?p=72867&cat=1,190,44133&ap=1