Finish storage bags.

Re: There is science behind your procedure

AZ in Colorado Springs

Not exactly a parallel example, but I buy titebond glue by the gallon (about every 18 months). I have a couple of applicator squeeze bottles. After I fill those, I decant the remainder into smaller bottles. Mustard squeeze bottles, BBQ sauce bottles, and Powerade bottles (about quart size, I think). Fill to the brim, and put the cap on (ensure clean threads on both cap & bottle) and they open easily. I store them in a dark, temp controlled space -- a kitchen cabinet.

As the level goes down in the applicator bottle, I keep it topped up (quicker to apply glue and minimizes air space). I replenish from only one of the "decanted" bottles at time. I've not had cured or jelled glue in any of these containers.

Re: I face the same problem. Solutions? *LINK*

John in NM

Ok, didn't know if you were familiar with gas suppliers, a lot of woodworkers aren't and I don't recall you ever mentioning doing any welding.

Bottles are expensive to buy retail, but cheaper to lease or buy used, around $100 for a small one like in the link. I don't remember lease prices specifically, maybe that costs more than I recollect - my impression is that gas suppliers charge enough to make you want the deposit back but not so much that you buy your own bottle. They like captured customers who can't shop around, just like the propane guys do.

Maybe $100 is too much, but it doesn't seem that way to me, given how much mileage this discussion always gets. You could also look into CO2 for food use, seltzer and whipped cream machines that use little cylinders. I bet those will run more than $100 though.


https://www.usaweld.com/Gas-Bottle-Refurbished-p/99900.htm

The problem with CO2

Bill Tindall, E.Tn.

It is soluble in organic solvents and will create a vacuum in the can. Not as soluble as propane and Freon DustOFF though. I would like to try it but never had a source to try.

glue cure is different chemistry

Bill Tindall, E.Tn.

Titebond regular glue cures by water leaving the glue. It is stable for years so long as it doesn't loose water. Titebond II and III? have an additional cross linking chemical cure. I don't know the chemistry so I don't know how to prevent this cure in storage. Refrigeration will likely be beneficial. I do not know if oxygen participates in this cure.

Store Titebond regular to minimize loss of water through the container walls(yes, water does diffuse through polyethylene, slowly). Minimize surface to volume ratio. But, the process is so slow (years) that practically you can just leave it in the gallon bottle.

Re: The problem with CO2

John in NM

I can try it here, what kind of can are you thinking? Round paint can or rectangular oil can? I'll put about 1/3 linseed oil in the can and add some CO2.

The CO2 I have available is for cleaning optics, but I figure a little dry ice won't hurt the oil too much.

Re: The problem with CO2

Bill Tindall, E.Tn.

typical would be a quart cylinder paint can 1/3 to 1/2 full of any organic solvent. I would choose mineral spirits as that is the typical varnish solvent. After the experiment you can reuse the mineral spirits.

Pressurized CO2 that becomes liquid is a good solvent for hydrocarbons. It is used as an extraction solvent to decaffeinate and other uses. Can't predict what it will do at atmospheric pressure. I think some will certainly dissolve, but I think not enough to create a strong vacuum leading to can collapse.

As they say, "Theory guides; experiment decides".

Re: The problem with CO2

John in NM

The pressure drop as the liquid comes out causes it to change to solid that then sublimes at atmospheric pressure. Usually there's a few moments of cold gas first, that's how I was planning to displace the air and test the vacuum theory. Might get a little dry ice in too.

CO2-Argon mix

John K Jordan

>>>I have a MIG welder so keep a tank with 25% CO2 / 75% Argon mix on hand. Will this mixture work as an inhibitor or will the carbon dioxide defeat the purpose.

Larry,

The Bloxygen people quit using CO2 in their product at some point. From their web site:

We use ultra pure Argon because it's totally inert. CO2 is okay, but it's not totally inert and will react with water to form carbonic acid.

http://www.bloxygen.com/frequently-asked-questions.html

Carbonic acid is H2CO3. I can't find anything that tells what carbonic acid does to finishes. But on the other hand, I don't think there is much water is typically in a can of oil, shellac, or varnish. I suspect the relative small amount of CO2 in the argon mixture would be better than leaving the oxygen. I'd use it if I didn't have the nitrogen. BTW, I use a small plastic hose to direct a gentle stream from the regulator under the lip of the can lid for 5-10 seconds - too much pressure and it will splatter the finish.

Bloxygen did in fact used to contain CO2 and it worked for me just fine until I switched to pure nitrogen. Argon might be a touch better, since it's a tiny bit heavier than air, but I don't find that a problem. I like having nitrogen in the shop since I use it for other things as well, such as extending the life of vanilla beans for making extract.

Some people use propane, but as they point out in the FAQ it is highly flammable and.

JKJ

Re: Marbles

Sgian Dubh

Steve, I have used the marble trick a limited number of times, primarily because I use a relatively large volumes of finishes, so long term storage (more than three or four weeks) generally isn't a significant issue for me. And I also take the attitude that I'm not going to take a chance on any finish I've stored for a while and I'm not sure about, i.e., If I think the stuff's too old, dodgy, whatever, even if it's several litres it's dumped and replaced with new product.

However, I don't recall there being a problem stirring up the flattening agents of non-gloss varnish when I have added marbles to the can. I wonder now, in fact, if the marbles actually aided the mixing through their tendency to rub and bounce off each other as they're agitated, but it's been a few years since I did the marble thing and really can't remember. Slainte.

don't confound the experiment

Bill Tindall, E.Tn.

If you include solid, it will become gas that will add pressure. Just wait for it to sublime before sealing.

Bloxygen misleading information

Bill Tindall, E.Tn.

There are lots of chemical reactions that carbon dioxide could participate in. None are relevant to using it to inert the head space of a can of varnish. The acid worry is baloney.

The problem with propane is not flammability. The diddly amount of propane in the head space is hardly a hazard. And in fact little of it will be in the head space. As I have explained many times, it is solubility and vacuum formation leading to can collapse.

There is about 1 cent of argon in a can of Bloxygen. Why not use it when it enables bogus marketing claims?

Re: don't confound the experiment

John in NM

Good point, two things I can do to make sure - either blow the CO2 into a bag or other vessel as a solids trap with a hose from the top of it to the can, or I can just wait until we have an empty cylinder and use the remaining gas from it. There's always full pressure for a little while once we've used up the liquid.

Re: mistaken Bloxgen folklore

Don Evans

Theory and reality are not always the same.

Perhaps you can explain how my 2 jars of tung oil finish after bloxygen added are still good as new after 5 years with not one smiggen of skimming?

Don

Re: mistaken Bloxgen folklore

John K Jordan

>>>Then there is the issue of adding this gas. There is no way to add it from a pressurized container without turbulence in the head space. It will be largely mixed to begin with.

What I do is insert a small tube to nearly the surface of the liquid then add gas for a long enough time to have a chance of displacing most of the air. I'm sure it's not perfect but it works well.

mistaken understanding of what I reported

Bill Tindall, E.Tn.

I am not questioning the fact that blowing this stuff, or any inert gas, into the headspace can work to prevent premature cure. It is the explanation of how it works that is flawed. Blowing the inert gas into the container displaces the air in the headspace. Because there will be mixing when the Bloxgen is blown into the headspace, several headspace volumes of Bloxgen will need to be added to displace most of the original air. Promptly seal before air diffuses back in and the container is largely oxygen-free.

The procedure is a classic dilution problem. With perfect mixing when one volume of inert gas is added what remains is now 1/2 air and 1/2 inert gas. Add one more volume of inert gas and what remains is 1/4 air and 3/4 inert gas. Etc. I expect about 4 volumes of inert gas will need to be added to achieve a low enough concentration of oxygen to prevent premature cure.

If the inert gas could be added at the surface of the varnish, and without mixing, now we have a displacement problem. Only one volume of inert gas would need to be added and all the air would be displaced. Because of the rapid diffusion of gas molecules ,and inevitable mixing, perfect displacement will never be achieved.

Careful adding as John describe will result in some situation between perfect displacement and perfect mixing. Whether what is added is a "heavy" gas like argon or carbon dioxide, or simply nitrogen, is largely irrelevant for inerting oxygen curing finishing material in a small container.

Re: Bloxygen misleading information

John K Jordan

Don't hold back, Bill. Tell us what you really think of Bloxygen.

summary

Bill Tindall, E.Tn.

It is an expensive, effective way to preserve partial containers of oxygen curing finish. So, maybe to some it is not expensive. However, the company literature contains flawed science. That's what I think

I wish I could find a small inexpensive tank Air Products would fill. I have a regulator.

tanks

John K Jordan

>>>I wish I could find a small inexpensive tank Air Products would fill. I have a regulator.

If Air Products is like other gas suppliers they will fill privately owned tanks Q and smaller. Occasionally I'll see one on Craigslist. The gas companies sell them too.

I've bought several new and had them refilled but I eventually saw the advantage of simply trading the tank in for a filled one - the supplier (Holston Gas for me) will take the tank without inspection and immediately give me a full one with the inspections and hydro test up to date. If I want to keep the same tank I have to leave it for them to fill, drive back to get it, and am responsible for the inspections.

I had a small tank I gave to a friend who wanted some nitrogen in his shop. I can check if I have another, might trade for something. I used to keep small oxygen and acetylene tanks for a portable torch but I don't use that torch any more. (The gas company doesn't care if the tank is painted for oxygen - they'll trade any tank for any other tank the same size for the cost of the gas, or for a larger tank for the difference in price.)

JKJ