I use a drip tube system which requires filling the tube prior to every coat of mow spar.  The one-gallon plastic bottle I use for storage is also used for catching the varnish below the tube.  This system works with my limited garage ceiling height.  The problem is that with all the pouring and filling and open space in the storage bottle, the varnish gets put in contact with a lot of fresh air.  Living in Phoenix doesn't help matters.  My bamboo is provably dryer than most and in the summer I can varnish wraps in a day, but keeping my varnish in good shape is tough.  Because I've have to replace a fair bit of it this issue is a real concern.

Now... with that said, I've received a lot of good info from the list.  Thank you all.  I really liked the idea a few of you had about home made CO2.  I have decided however, based on my system and circumstances that it will be most effective to get a small bottle of nitrogen and fit it with a regulator as suggested by Troy Miller off list.  Nitrogen is dry, clean, inert and safe.  It's only slightly lighter than air and will effectively purge air with the insertion of a tube near the bottom of  the container.  It's a cheap common gas used in numerous other purging processes.  Several list members also expressed concern about tediously regulating  the flow from Bloxygen and other products.  An accidental blast into the varnish with the resulting spray is not something I want to contend with.  The regulator will eliminate this potential. 

The down side here is the initial investment.   A filled, 25 cubic foot bottle, (about 4" X 18") with a low pressure regulator costs about $120.00.  That equates to 10 or 11 cans of Bloxygen and that's provably enough to last most of  us the rest of our rod making days.  However, with a little help from my friends, I've manage to scrounge up everything I need for next to nothing.  I do think though, that even if I had to buy everything over the counter, for me, it's a cost effective addition to my shop.

This is my own personal conclusion and may not be the best choice for many.  (Jim Harris)

Instead of draining your varnish from your drip tube into an empty plastic gallon jug, why not drain it through a tube into a collapsible plastic water bottle (that could swell on filling)?  The drip tube could fill with CO2, stored in an inflated plastic bag, using the vacuum created by the varnish outflow.   By using a couple of bags, a couple of valves and some tubing wouldn't you be able to minimize the exposure of your varnish to air for only a few bucks?

Just a thought.  (David Smith)

You may not be aware that there are accordion-like opaque brown bottles made for darkroom use which would do exactly what David is suggesting. They come in quarts, half gals and gals.  (Art Port)

That would work, or just drain the varnish into a container and drop marbles into the container to fill the space.  (Tony Young)

When I was storing the varnish in a plastic container I had a lot of problems with the varnish jelling. I was told that plastic breaths. Since I started draining back in the original can and add a little bit if thinner on top of the varnish before closing the can, it more than tripled the life of the varnish over keeping it in a plastic jug. The plastic jug may be a big part of the problem.  (Tony Spezio)

If that's correct it's most certainly a big part of the equation!  I will change it regardless. Thanks,  (Jim Harris)

My answer to this may sound stupid but it works for me. I dip my rods in my bathroom (no jokes please), I have a second one so it's not a problem. I take everything (except the blank) in I run the hot shower for a couple minutes (the steam holds down any dust) left after the thorough cleaning I give the bathroom, dip tube and heated drying cabinet. I have a sheep wool glove that I rub the Plexiglas on my drying cabinet with to build a static charge with to attract any left over dust to the outside of the door. When all that is done I bring in the cleaned rod sections and dip them then put them immediately into my drying cabinet.

Not the most scientific method but, works well for me.  (Shawn Pineo)

In addition to use nitrogen, as James suggests, I use bottled CO2 in my home brewing.  The two most common types are the gas container and regulator that James has described - and you can also get a smaller  sized one that uses the pellet gun sized CO2 bottles.  I think these are used to pressurize growlers and so forth.  Same thing you see in old movies for creating and dispensing soda water.

Take a look in the yellow pages for home brewing supplies.  (Claude Freaner)

If you store the varnish in the original tin after firmly closing the lid, store the tin upside down so the film forms on what will be the bottom when you open the tin up again, or add marbles to fill the space.  (Tony Young)

Does anybody know of a common, readily available gas that could be used to evacuate the air out of a varnish container. (for the purpose of keeping the varnish fresh during storage)  I was thinking about looking for the aerosol version of the varnish I use and just spraying it into the container to drive out the air.  I'm not sure if this would screw up the chemistry or if it would even work.  I know there is an existing aerosol product made especially for this purpose, but its expensive, and as I recall, the gas is not a common one.

Any ideas on this one?  (Jim Harris)

The commercial product is known as Bloxygen. I believe I have seen another one too. How about CO2? A bit of baking powder and vinegar in a container, and then "pour" the gas into your varnish container.

The Bloxygen really is economical, it doesn't take that much of a squirt into a container, especially a dip tube.  (Larry Blan)

I was wandering how long a can of Bloxygen would last.  You certainly don't get a feel for it's quantity/volume by hefting the can.  I'll take your word for it's economy though.  (Jim Harris)

I have been using the same can for the past two years.  That tops the dip tube for about 25 rods each dipped three times.  I think the can is getting nearly empty, but have been thinking that for a little over a year!  (Bill Lamberson)

Here is one that does not work. The stuff that you buy at office supply stores to blow dust out of cameras and computer keyboards.

I do not use Bloxygen, but if I am not going to be dipping, I drip about twenty drops of mineral spirits on top of the varnish. Seems to keep it from drying out fairly well.  (Jeff Schaeffer)

I have two tubes filled all the time, one with MOW Spar, and one with P&L Varmor. Both have been stable and do not film over or congeal after more than a year. I keep them fairly full and cap with a neoprene cap That has a steel hose clamp screwed tight. I got the cap from Home Depot. Since I warm the varnish before dipping, I cap and seal the still-warm tube. I think that creates a partial vacuum in the tube and tends to lessen oxidation.  (Steve Weiss)

I tried this with a gallon jug, baking soda and vinegar to generate the CO2. I tried to do a thorough job by overdoing everything (length of pour, etc). It did not work for me.  (Jon McAnulty)

I've been using the product from Office Depot for several years, the current can does not have the specific formulation, but I recall its that same stuff as Bloxygen. I punch 2 nail holes in the varnish can lid on opposite sides.  Insert the tube in one and very, very gently add gas for about 15-20 seconds.  I also have similar holes in the screw top of my dip tube.  Cover with strips of duct tape.  Probably cheaper than Bloxygen at 2 cans for $7.95 on sale - also works for cleaning the mouse and CPU.  (Carey Mitchell)

If anyone happens to have any contacts in the paint manufacturing game, you might hit them up for a few ounces of an item called MEKO (Methyl Ethyl Ketoxime) This is the product that is in all oil based varnishes, added just before it is packed off in the original tin to stop skinning. It has several commercial names, but your mate will know what you are talking about.

The problem is it evaporates when you take the lid off the varnish, hence the skinning. If you make up a 5% solution in mineral turpentine, and then add about a tablespoonful to the varnish (float it on top of the surface) when you put it away, it won't skin.

Remember to shake up or stir the varnish before you use it next time.  If you add too much, it will slow down the dry of the varnish next time you use it, so don't go overboard.  (Dave Kennedy)

Don't shake any varnish as you will only make bubbles in it.  Only stir it so this doesn't happen.  (Bret Reiter)

To prevent finishes from skinning over in the container I have used Bloxygen and more recently have simply used the cans of stuff from Office Depot sold to blow dust from computers, etc., which works just fine.  I  invert the can lift the lid slightly and gently blow it in liquid form.  This evaporates instantly, insuring ample volume to force air out.  Went to the garage for a can of enamel tonight (still remodeling, will get to start on the new shop in a couple of weeks) and found the lid loose and a thick skin on the surface.  Removed the skin carefully, filtered and realized what had happened.  When the duster can is inverted and the contents exit as liquid, it becomes very cold.  If the can is sealed immediately and the liquid warms, pressure builds and off pops the lid.  I watched it happen on the new can.  The lesson here is to allow the pressure to escape a bit before final sealing of the lid.  Almost lost a gallon of  of the wife's custom color by failing to think ahead.

BTW, I have also used it to prolong the shelf life of Gorilla Glue, by gently squeezing the air out of the plastic bottle, inserting the the little tube into the spout and gently releasing the grip, allowing the gas to fill the bottle.  It has worked for a year, which is about 4 times longer than ever before.  (Carey Mitchell)

Some time back I remember someone saying that you can mix baking soda or baking powder with something else, possibly vinegar to make a substitute for Bloxygen.  I tried to find this in the archives unsuccessfully.  Can anyone help me with this?  (Hal Bacon)

You can bet that vinegar and baking soda will make a lot of CO2. But just how you control it to make use of it in a varnish can or tube is a different problem. I have heard stories about some of my hillbilly/redneck relatives filling a gallon glass jug 1/2 full of sand and adding 2 cups of baking soda and 2 cups of vinegar, screwing the cap on very quickly and chucking it into a deep hole full of fish and getting behind a tree before it exploded. So be careful in your attempt to capture the gas. (Don Greife)

I was the guilty party! I read the formula in a Wood Magazine issue a couple years back. I don't think the ratios are critical. I believe it was about a tablespoon of Baking SODA to a 1/4 cup of vinegar. Do it in something big like a half gal or gal milk container and make believe you're pouring a liquid (after it fizzes awhile)  which you can't see, out of the jug and into your dip tube. Obviously you don't want the "mixin's "to escort the CO2 into the varnish. <BSEG>

I've since tried Bloxygen and I think the old way worked better! I can't be sure as the old tank had a rigid cap and the new one has a flexible rubber one. But it seems to sink in from oxidation whether I use the Bloxygen or not!!!! And I AIN'T real pleased about maybe losing a couple of quarts of Man o' War when I paid an additional 10 bucks for the Bloxygen!  (Art Port)

If you can find a rubber stopper to fit the top of your tube, it is an easy matter to pour a teaspoon of turpentine on top of the varnish in the tube, then squeeze the sides of the stopper as you put it in the tube to let out any air, the turpentine vapors will keep your varnish good as well as anything else. turps works better for this for some reason than mineral spirits do, though I have used both. I currently have some L&L varnish in one tube that is well over a year old and some old formula MOW in another that is around 4 years old.  (John Channer)

I have struggled with this issue since I have been making rods (a little over one year) and have tried the commercial Bloxygen, and the homemade stuff using vinegar and baking soda. Neither of these had given me satisfactory results as I was still skinning over. Someone on the list (I believe Mark Wendt) turned me on to the computer air duster sold in a spray can. The brand I use is FELLOWES and can be found at Walmart. You spray the stuff from the can holding it upside down, just a little squirt or 2, and shut the lid quick. I use this on the quart size can of varnish and not the varnish tube since I use a drip system and do store my varnish in the tube (no skinning since I went to this). I will add that if you read the cautions on the can it says not to spray upside down or to inhale the stuff so proceed at your own risk.  (Bill Bixler)

The stuff in the computer duster cans is the new supposedly environmentally safe air conditioner refrigerant. It says not to spray upside down because the liquid can freeze things that it gets on as it evaporates so quickly. It's the same stuff that powers the hand held air horns. So if you have one of those and don't mind the noise spray a blast in to your varnish. The gas is a lot heavier than air, I filled a party balloon with it once and it dropped like the proverbial lead balloon.  (Darryl Hayashida)

I have a piece of interesting news! I just got my Wood magazine today and there's a question on varnish and paint skinning over. The "finish expert" (Bob Flexner) says the skin does absolutely nothing adverse to the underlying finish and if removed carefully and after straining, the varnish may be used with abandon! He says "It can skin over 5 times in 5 years and the varnish underneath will still be usable."  (Art Port)

That's been my personal experience with paint.  I have some my grandfather left in his shed at the cottage, must be 60 or 70 years old by now (my first real memory of him is his retirement party at age 70, March 1946).  Some of it is a little thick, but works fine if thinned to proper consistency.  Never tried it with varnish though.  (Neil Savage)

I just had to throw away a quart of Last N Last Spar this morning because it had globbed up (hardened).  I had always used Bloxygen when closing it up and am confused as to why it has done this.

Has anyone come up with a way to store varnish that has been opened up and closed for long terms without this happening?  (Joe Byrd)

I have six cans of Helmsman that have gelled. I have used it one day just fine and a couple of days later it is a gelled mass. Can't tell you why. I feel if I got five or six rods out of it, I am still ahead. My problem is disposing of the stuff, the dump will not take it, the pickup center told me to burn it out of the cans before taking the cans to them. Anyone wants six cans of gelled Helmsman.  (Tony Spezio)

I think you can leave the lid off and let the varnish harden into one solid mass. Then they will take it. An old painter told me about that trick.  (David Dziadosz)

Varnish in my dip tube is pretty old, (measured in years) and all I've done is spray in Bloxygen and thin with mineral spirits.  I guess I've filtered it a time or two as well.  Old painters I've talked to tell me to dribble a couple of tablespoons of mineral spirits on top of the varnish before sealing it, and make sure that the mating surfaces of the can and the lid are clean.  I also turn the can upside down when storing, figuring that'll heal over any holes.  Don't know if it's scientifically sound, but it has worked for me.

My Sutherland Wells Tung Oil (the thick stuff) gelled on me no matter what I tried.  I'm guessing that the tendency of a varnish to gel is directly proportional to it's price.  The costlier the finish, the shorter the shelf life!   (Brian Creek)

Here is another idea.  When I was in university, the photo students would store there chemicals in brown plastic accordion bottles with a screw top lid. As the chemical was used they would just make the bottle smaller by pushing down on the jar, screw on the lid and bobs your uncle. No need for Bloxygen.

Good photo supply shops may still sell this type of bottle.  (Daniel Durocher)

I leave the varnish in the container it came in. As I use it up, I drop in the container large glass marbles (1" in diameter) to take over the space used. As you add the marbles the level will come up. I now have about 25 marbles in my container right now. Like this the level is always near the top of the container  and it never, never goes hard of make a crust on top.  (Michel Lajoie)

It seems to help a bit to keep the interface between the can and lid scrupulously when resealing, and to store cans upside down.   (Bill Fink)

I have far too many flammable substances in my basement.  Will freezing ruin stains and varnish?  Would love to move that stuff out to the garage.  (Lee Orr)

I wouldn't want to say for sure, but I know I have old oil base PAINT in the Upper Peninsula (of Michigan) that's still good after 20 years.  Anything water base shouldn't be allowed to freeze.  I'd start by reading the labels and not put anything outside that specifically says not to store below xx degrees.  Then, try a few and see how they weather the temps.  Also, if your garage is attached, I don't know that you would gain much. 

Fine Woodworking has an article about shop fire safety, including flammable storage, in the Winter 2004-2005 issue.  I think that's the latest one, Issue #174.  (Neil Savage)

I thought some of you might find this interesting. Especially if you can't get Bloxygen in your area.

"For only a few dollars more than a can of Bloxygen, the truly obsessive compulsive can buy a several lifetimes' supply of oxygen displacer in the form of a small bottle of Argon from a welding supplies vendor. Argon is totally nonreactive and heavier than air, and probably what's in Bloxygen anyway. If you happen to have a MIG welder, it's already available. Just crack the valve through a piece of poly hose to the paint can."  (Wayne Kifer)

I was given 3 previously opened gallons of Last-n-Last varnish by a Rodmaker that was discontinuing his rod making.  What I'm wondering is would this varnish be OK if it had been stored in a barn that with below freezing temperatures? Is there a way  how to determine if the varnish should be used or if I should chuck it and by fresh vanish?  If anyone else uses Last-n-Last vanish, I'd be interested to here their pros and cons about it?  (Wayne Daley)

A couple of things;  1) is it oil base?  2) does the can say "protect from freezing?"  3) has it scummed over, or worse is there a solid layer on top?  I have oil base paint that my grandfather left in the woodshed up north that's 60 or 70 years old and still good.  I'd guess that varnish is ok too.  I'd take a throwaway foam brush and put some on a scrap board and see what happens.  If it dries OK and looks good it's probably OK.  Water base is another story, I'd probably throw it out.  FWIW (you get what you pay for!)  (Neil Savage)

Well... It's called Last n' Last..."-)

As long as it's not snotty, it's probably fine...(Dave Collyer)

"Opened gallons." That's not good. At a minimum I would buy some of that canned Nitrogen to spray in on the top of the varnish. It displaces the oxygen with an (inert?) gas so that the air can't dry it (or react with the varnish) out. I have no idea about the temperature question. All I know is "cool is good", I don't know anything about "below freezing" temperatures on varnish though I would think it wouldn't be good. I will be curious to see if anyone has done that with varnish too.  (Martin Jensen)

In case anyone else was interested here is the response I received from the Last-n-Last varnish manufacturer.

Hi Mr. Daley,

Yes the Last n Last Marine & Door Spar Varnish should still be good. The low temperature should not effect the finish.  It is also a good idea to test it first.

Robert Mendello

Absolute Coatings, Inc.

(Wayne Daley)

Someone on the list suggested that you could use propane to top off your dip tank to keep the varnish from scumming over.  I have now switched to Ace Hardware Spar Varnish that was suggested on the list.  I tried this and it seemed to keep the varnish clear on top but when I started dipping my rods in the varnish, it seemed to cause runs and streaks in the varnish on the rod.  I thought maybe that I put too much propane on the top of the varnish and this was causing the problem.  I am in the process now of sanding out the runs and streaks on a couple of new rods.

Has anyone else had this problem and what am I doing wrong.  (Tom Peters)

Considering how much time and effort it takes to build a rod why do folks insist on experimenting with stuff like this when Bloxygen is cheap and readily available and is made specifically for this purpose?  (Larry Puckett)

Propane, as used in our gas grills,  torches, and other useful tools, has additives like the propane "stink" which are oils.  Even when the propane is in a gaseous state, that oil is still present in some form.  That's probably what contaminated your finish, and has contaminated the finish in your tank.  It would probably be better to home-brew some CO2, (and probably a lot safer - less flammable) using vinegar and baking soda and letting the gas dribble into your tank.  No additives to contaminate your finish.  (Mark Wendt)

Here's a list of various common propane contaminants from an industry publication. I sent it to the list last week when the topic first arose but for some reason it appears to have only gotten back to Al. At any rate there are a number of things in commercial grade propane that could cause problems with your varnish.

Appendix A. Contaminants

There are a number of potential contaminants in propane that when present in sufficient quantities have been shown to cause problems. This appendix provides a brief overview of just a few common contaminants, including:

. Water

. Oil residues and heavy hydrocarbons

. Solid particulates

. Air and nitrogen

. Ammonia

.High butane, propylene, sulfur, hydrogen sulfide, or sodium hydroxide content  (Larry Puckett)

I got one word to say on this. Bloxygen (it's a brand and these words don't count against me)  (Martin Jensen)

I’m the guy who suggested propane over varnish.  I’m using Helmsman varnish, flooded with propane then tightly capped.  My varnish has stayed skin-free as serviceable for over two years, now.  I’ve never had run or streak problem except when I have not paused long enough at a guide.

One thing I do to ensure highest propane concentration is to put tape on the air holes in the nozzle.  Otherwise you get more air than propane.  (Al Baldauski)

I have a propane torch. I keep my leftover MOW in these snap cap pill containers put out by CVS. The varnish don't skin over until I empty out a quarter of an inch or so, so are you telling me if I spray a little propane into that space and put the lid on the container, that the propane has replaced the air  and the varnish won't skin over?

Have I got it right or am I some kind of dummy?

And then when I open the lid the propane being heavier than air stays right on top of the varnish until I blow it out?  I then use what varnish I want and replace the  lid after putting in some more propane?

Would that work with any oil based paint as well?  (Dick Steinbach)

Have you ever lit your gas grill after waiting too long before hitting your igniter?  I just goes whump.  The small amount of propane in the top of a dip tube is unlikely to do anything but a brief  flare if ignited since it is NOT well mixed with air which it needs to burn.  (Al Baldauski)

There were a lot of post last week and I might have missed an answer to someone’s question so here’s my final answer:

I haven’t conducted a test to “prove” the effectiveness other than to say that my dip tube hasn’t skimmed for two years.  Granted the air space is small in proportion to the volume, so maybe the propane isn’t doing that much.  But in theory, it should work.  You could satisfy yourself by placing a small amount of varnish in a large container, say three time the volume of the varnish, cover it with propane and seal the container.  After some time, if it hasn’t skimmed, you got it!

Small plastic containers are more likely to be a storage problem since, believe it or not, oxygen does permeate plastic, although slowly.  So propane may be more of a benefit here.

Larry brought up some information about potential contaminants in propane. In theory they could cause problems, but is my belief that the levels are so small as to be insignificant.

I wouldn’t recommend this technique for large cans, say 1 quart of varnish in a gallon can, since that volume of propane could be dangerous IF touched off.  The air space over my dip tube is only about a half a cup.  (Al Baldauski)

I was just thinking absent-mindedly and thought that this might be a good storage container for varnish. What do you think?

Let me know, I used to keep some pretty caustic chemicals in the ones I had as a photographer.  (Ren Monllor)

I bought a couple of these several years ago from Woodworkers Supply. My varnish gelled pretty well in one. I think Woodcraft also sells them. The one  that I have left is collecting dust somewhere in a cabinet in my shop.  (Steve Weiss)

I know a lot of people use a diluted varnish for their first couple of coats on the wraps.  I would like to know what you all store the mix in or if you just mix a couple cc’s for each application.  Right now, I use a drip tube for varnishing the blank or the rod and store that varnish in a one gallon can.  Instead of taking from that can every time I want to coat my wraps, I would like to have a smaller container that I can mix and leave in the container in between coats.  I have heard that leaving it in glass jars or small glass tubes like head cement containers allows the varnish to thicken or cure some.  Enough rambling, how do all of you do it?  (Greg Reeves)

I get a quart of phenol/alkyd varnish just for wraps and general purpose.  I break the fresh quart into smallest baby food containers (8) filled to the brim and open one at a time.  No problem jelling.   They are cheap even if you throw away the baby food -  or get jars free from new parents.  I happen to like the baby chocolate pudding - but detest any but fresh, stone ground grits. No, Cracker Barrel doesn't count.  (Darrol Groth)

Ah ha, Darrol – That’s why I use empty marinated artichoke jars. I love those things. And besides the jars are hex shape, easy to grab without slipping!  (Tom Vagell)

I found some ¾ oz. glass jars in the painting department of Michael’s Crafts. Put in a little Bloxygen or use the breath deep, blow into jar and shut lid quickly method. I haven’t had any problem yet.  (Gary Jones)

I use polyurethane and use 1 oz glass bottles and put them in the freezer. Keeps for a very long time. I do not know how long since I have never had one go bad.  (Steve Kiley)

Well, I thought I'd give everyone a good laugh this morning.  I had mixed up a batch of varnish in a gallon glass jar a week ago in preparation for dipping before I found the bubbles in the wraps. 2 quarts of varnish. I also added 15% mineral spirits and 10% Penetrol. Mixed up just fine. Even added some of the heavier than air gas to keep it from forming a skim and put the lid on. The gas worked just fine. When I opened the jar and stirred it this morning it hadn't formed a skin on the surface, but I discovered that at least half had congealed into a large mass of rubbery goo. I could actually lift it out of the jar in one large drooping mass with a stick. Total loss. Understand the jar has been inside out of the cold the whole time. I've seen varnish and paint form a surface skim but never seen anything do this.  (Wayne Kifer)

Yes, things thinned with mineral spirits will do that.  when I was in the trades we used to recycle our mineral spirits by dumping it in a 5 gallon bucket & letting it sit for some time.  There was always a mass of gunk in the bottom from the mineral spirits settling out. this is the last time I am going to say it. Thin with good turpentine!!!!!!!!!  (Bret Reiter)

You know, I purposely bought a small bottle of artists turps to thin the varnish for my wraps. Then, of course, I went ahead and used the mineral spirits when I mixed up the larger batch for the dip tube. Brain fart. That seems to happen more often these days. The rod making gods have to be laughing. (Wayne Kifer)

The ONLY things I use Mineral Sprits for is to thin oil base paint and clean out the brushes or remove "road tar" from my car. Never with mix it with varnish. You're just asking for trouble.  (Don Schneider)

For those of you that may be interested about the differences in varnish, check out this page.  (Don Schneider)

Long live Tung oil.  (Ren Monllor)

This is the reason that I not longer use thinners or Penetrol. Had the same thing happen a couple of times. Lucky enough, I caught it before it had set and I could clean my dip tube.

Prior to thinners/Penetrol - no problem. After stopping their use - no problem. Some of my varnish is in the dip tank for 3>4 years. All you need is a good valve.  (Don Anderson)

I wonder if there is any evidence that direct sunlight causes varnish to go bad. I'm relatively new to this but noticed that a sealed canning jar of thinned spar varnish that I was using on wraps kept well for several months out of the sunlight, but when I used it this summer and left it for several days near the window it gelled up. I have read in this forum that there seems to be a difference between clear and opaque dip tubes; could their exposure to sunlight also be a factor?  (Ray Wright)

That looks like it could be an experiment for someone to try.

Put equal amounts of varnish into two canning jars. One seal as is. The other, introduce some Bloxygen or CO2 (Made by combining Baking soda and Vinegar) and seal the jar. Place both jars in the sunlight. After a week check both jars by tipping them to see if either is jelled. Keep checking them this way and note which one jells first and how long it took. Keep checking until both are jelled. Report back to the list.

Sorry, but I am traveling right now or I would do it.  (Dick Fuhrman)

Did you use some sort of gas to displace the air in the jar? If you didn't I'd think that the gelling was due to having been opened for longer and that as the amount of air increased due to using some of the varnish there was more oxygen in the jar to promote gelling. (Henry Mitchell)

Remember that clear glass does not give you protection from Ultra Violet Light, this is exactly why they used to put stuff (anything that needs UV protection) in brown bottles or some other color that does protect from UV.  (Joe Arguello)

If UV exposure but also air affects varnish, would it then be a good idea to do this?

1.) Buy a couple of bottles of good red wine, enjoy them over a nice dinner, and thoroughly wash out and dry the dark green bottles;

2.) Get some of those wine bottle rubber stoppers with the air pump that draws out oxygen and creates a vacuum in the bottle;

3.) Pour varnish in the bottle and use those stoppers and the pump to seal your varnish.

This works for a 1962 Chateau Margaux.  It might work for spar varnish.   (Alan Boehm)

Excellent suggestion.  (Hal Manas)

What a WONDERFUL idea.

I shall be supplying bottles to all, at a modest fee of course, and probably be able to address the labels correctly, as long as not too many requests come in per day!

Send your requests, with $10 each, to Art Pooor  whatver,

   37 Ardssssssel
    Static Islllllllld
    Nuevo yo....
    10020003000000something  (Art Port)