I purchased a bottle of Japan dryer about 12 - 15 years ago. Just now I am trying it in a solution of linseed oil, spar varnish and turpentine. The solution will not set and harden properly. Its taken over a month for the last coat to set and it is still a bit sticky to the touch.

I overdosed a solution to see if I could get it to solidify and it is still liquid after a few days.

The question is does Japan dryer degrade over time? Based on the way the chemical reaction is supposed to act I hadn't thought so.

https://www.sherwin-williams.com/homeowners/products/crown-japan-drier

Use this product with oil-based paints, oil-based enamels and varnishes

https://www.tinboats.net/varnish-vs-polyurethane/

Japan Drier is a common drying agent that can be mixed with other oils such as boiled linseed oil and alkyd resin paints and varnishes to speed up the “drying” or “curing” process. It’s also used by professionals to speed up controlled drying when they need to apply several coats on the same day. Japan Drier is a special blend of lead-free drying agents that accelerate the drying ability of oil-based paint, enamels, varnish, and polyurethane. It is especially effective in highly humid or cool weather conditions. Although Japan Drier may appear purple, it will not affect the color of your coating. (varnish or paint). Normally, one ounce of Japan Dryer per quart of paint or varnish and mix thoroughly. Do not exceed 4 ounces per gallon.

Try using mineral spirits instead of turpentine. These combinations don't always work out the way they should. And you are using boiled linseed, not raw?
JR

Use boiled linseed, as Roberts suggested. If you want a slightly hotter mix, substitute some VM&P Naptha for the mineral spirits. I always have at least a little turps in my mix, because the smell makes me think I’m doing a better job.

Also, be careful which spar var you use. The low VOC enviro friendly products are mostly crap. Example: McCloskey Spar Var in the brown can used to be my favorite, but when they switched to the new formulation in the green can, I had to stop using it. Would not polymerize properly.

The bottle says Alkali Refined Linseed Oil purchased from a fine arts store and doesn't mentioned boiled so that may be the problem. If I were to substitute tung oil for linseed oil do I need to pay attention to how the tung oil is processed? The spar varnish I used is Old Masters exterior oil based spar-marine-varnish, so should be fine there. I mixed my Japan dryer as per instructions on the bottle which was 28ml per 4 litre which reduced down to 1/4 tsp per 4 tsp of solution.

If the finish is still tacky after a month, the first thing to do is strip the finish off to start over, something is really wrong.

The thinner you use shouldn't matter, it should have flashed off in a day or less, wiping varnishes are thin.

The oil could be a problem, but I doubt it, call the artist store and ask them how quickly the oil should dry. I suspect that stuff is pretty expensive, personally, I wouldn't spend the money on it, or the hardware store oil either. The best linseed oil I've used is Tried and True, there are no driers in it and its put through a heating/polymerization process.

I suspect the problem is the varnish. Brush some varnish on some scrap wood and see how long it takes to dry, the label will tell you what to expect, if its taking longer, buy a new can, and check the date.

Tim

I only use Linspeed, which has been around gun work a long time. Pure linseed oil and never a drying problem. Perfect finishes, fast drying, and thin as desired with mineral spirits. Nothing better.

I've wondered about GB Linspeed. The SDS suggests that it's about 50% petroluem distillates. Does that just mean that it's thinned in mineral spirits?

On the Japan Drier, I bought some from an art store. It was very viscous and the same color as linseed oil. It is cobalt based. Sounds very different than what is bought at the hardware store. Anyone have experience using this type of drier?

It's something like this.
Link to product

IMO You have too much oil (linseed) in the mix for it to dry in a reasonable time.
You may have applied it too heavily also.

Linseed coatings need to be ultra thin to get them to set-up.

Smear a coating of the same thickness as you put on the stock onto a clean glass jar surface when you are doing a stock.
Leave the stock alone to 'dry'. Check the smear on the glass jar surface to see when it's hardened.
If it isn't set up on the glass surface,,it won't be in or on the wood either.

The Spar Varnish is already a linseed based varnish with a + amt of oil in it to keep the final set finish somewhat flexible to withstand outside weather. That's where the name Spar comes from,,boating use. But it's been used pretty loosely over the years to market as some sort or extra special varnish.

Then you've added more linseed oil to it.

All that oil in the mix with what little resin in the SparVarnish orig make up is what you have made as your Varnish finish.

The turp or or paint thinner is nothing more than to mix and thin the above components. It evaporates from the mix as it sets on/in the wood. It does help with some penetration into the wood due to thinning.

Linseed does take a while to harden. It oxidizes to harden, it doesn't just air dry like we think of most paint products doing.

I'd skip the extra linseed oil. Use the Spar Varnish or any decent varnish by itself. Thin it with min spirits if you like for easier handling like sanded in finish.

Thinned with min spirits (petroleum distillates!) and you have what about what is sold as Wiping Varnishes in the DIY finishing depts of Home Depot ect.
They are around 75% min spirits, 25% varnish.
The varnish portion will be the oil (linseed, tung, or perhaps another plant oil) and an resin,,either natural or man-made.

The different ratio of oil content in the varnish makes them more or less suitible for outdoor use over indoor use.
That's were you get into the differences in Long Oil Varnishes and Short Oil Varnishes,

Linspeed Oil and Tru-Oil are nothing more than Linseed oil based varnished using synthetic resins (alkyds) instead of natural resins.
Along with that there are dryers in them, synthetic also as the old Japan Dryers were lead compounds and taken off the market.

I just looked up the Old Masters spar on their website, and they show max VOC of 350 gpl. That’s pretty low and could be part of your problem. The old school spars were about 575 gpl, but that stuff is getting hard to find. If you must work with low VOC product, plan on thinner coats and more of them, wiping off almost everything you apply. Get some naptha.

Thinned spar varnish wants to dry too quickly, which gives very little working time to properly apply without getting tacky and "grabby". The boiled linseed slows things down a lot and allows plenty of working time to level everything out and cover every little place on the stock. Cannot over-emphasize very thin coats either. The first couple need to be wiped off, leaving nothing but what has penetrated.

I agree the finish you have applied should be removed with lacquer thinner and allowed to totally dry out for a couple of days before starting over. I would stay away from tung oil in the mix.

I've tried all of these concoctions and more over the years, but I've quit that and now use Timberluxe No. 2, which is their thinner version. It's easy to apply because it doesn't become tacky too quickly, dries/cures fast, and is as durable as any of these kinds of classic, hand applied finishes can be, and it is easy to repair.

Nothing is as durable as the conversion epoxies like those on some target guns, but they just don't look right on a classic gun.
JR

And to further complicate things, the Old Masters spar comes in gloss, semi, and satin finishes. Don’t ever use anything other than gloss in your mix, because the satin and semi contain flatting agents that obscure the figure in the wood. Properly applied, the gloss should look correct on a vintage gun, and you can always knock down the sheen later if desired.

I had a slacum type finish that would not dry, even in my dry climate. A friend recommended dampening a cloth with Japan Dryer and lightly rubbing down the reluctant finish. The result was a dry finish in a very short time. No guarantees, but it worked for me.

One of the things your fighting right now is the summer weather conditions. Any oil based finish takes longer to cure out in hot humid conditions.

Look up Timberlux's web site and watch some of the videos Brian has posted, in at least one of them he mentions the drying time issues in the summer.

Well, after some testing on all the components it turns out to be the spar varnish. It sets up with a very sticky, rubbery feel to it and not a hard finish. I bought some Armor Coat spar varnish, a Canadian product and it works as it should. Problem in Canada is we've banned a lot of the nasty chemicals and spar varnish is hard to find. What's on the shelf may have been there for a while.

Then look up Timberlux MSDS for the ingredients. It is a vastly over-priced teeny little bottle of 25% sunflower oil, 25% linseed oil, and 48% naptha, with a little dryer added. There are much better stock finishes available that do not cost over $1900.00 per gallon.

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=561390&page=1

He's not doing bulk refinishing, Keith. Price isn't that big of a deal @ $12.95/1/2 oz. if it serves the purpose. I've done 3 buttstocks and fore ends with that smallest bottle of Timberluxe and still have half the bottle. Doesn't take much, looks great, and very easy to use. I like it better than anything I've tried, and I've tried a lot.

Of course, if you want something you can slop on in quantity, you may want to concoct a quart of something...
JR

It isn't the price alone John, although paying $12.95 for 1/2 ounce of those sub-standard ingredients is not my cup of tea. You can get an attractive finish on a gunstock with BLO alone, or with a little dryer added. But the ingredients in Timberluxe (or BLO) are very poor at protecting a gunstock from moisture or UV light, and they actually support the growth of micro-organisms that cause mold and rot.

I do not want to slop any finish on in quantity. I just want something effective and attractive that actually does a great job of protecting my stocks. I hope you will read the thread in the link I provided. It was intended to help, not to disparage those who use other products. When doing a period correct restoration, sometimes an inferior product is exactly the right thing to use. But most people restoring a Model A won't use lead based straight enamel for the finish... especially if it cost as much as Timberluxe.

Problem is not the age of the varnish, it’s the ingredients. Sounds like it’s the enviro friendly crap, and that is how it cures. Totally useless for serious work.

Yes totally useless and being environmentally friendly it ended up in my refuse bin along with all the other recyclable garbage

When buying varnish, as you've learned, it goes bad, always buy fresh, or test it first, if it doesn't cure correctly, take it back. I don't know what thinners/solvents Canada allows, but there are excellent varnishes that are thinned with only mineral spirits and maybe naptha. Normally, theres no need for any of the more unfriendly solvents in varnishes.

When you buy varnish for a wiping mixture, like you are using, make sure it is thinned with petroleum thinners, that way you will be assured they are compatible with linseed oil and mineral spirits. Not all modern varnishes are thinned the same, use the wrong varnish and you probably won't like the results. As an aside, turpentine is an excellent thinner for any oil based product. for some applications there is probably no benefit, but for example, thinning varnish to brush, it is much better than petroleum thinners.

Tim

I don't know about the low V.O.C. environmentally friendly varnishes, but the old stuff does not go bad in a sealed can. I have used old varnish that was heavily crusted over, and I used an unopened quart of Sherwin Williams Spar Varnish that was at least 40 years old, and they set up perfectly.

I have yet to see an expiration date on any paint, stain, or varnish product. But I am not impressed with any of the newer low V.O.C. finishes, and prefer to stock up on the old stuff when I can find it.

Some may be confusing varnish with shellac. Shellac does go stale when it sits too long, but old fashioned spar var is like Hostess Twinkies. If you don’t open it, it will last for hundreds of years.

Are there any particular brands of Japan dryer that are preferred? Where would they be sourced?

I'm aware of the difference between shellac and varnish, although technically, shellac is also a varnish. In the 1800's, resins such as shellac, lacquer, copal and some others that were solvent in alcohol were called spirit varnishes. Resins that were combined with oil and thinned with petroleum or turpentine were called oil varnishes. Over time, terminology changed. Just like today, polyurethane is a varnish, but who calls it varnish?

Yes, varnish should last a while, but that doesn't mean it will. 20 years ago I bought a can of varnish, within one year I opened it to finish a table top, and had the same experience as Tamid, it refused to cure. With the exception of lacquer, it never hurts to test your finish before you use it, poor
batches do slip out and some are adversely affected by time.

Tim

The second time I bought a bottle of GB Linspeed, it didn't set up. It was fresh and new, but remained sticky even after a couple weeks on my stock.

I'll agree that bad batches can slip out during production. I always assumed that batch of bad Linspeed simply didn't have the correct amount of dryer. In a way, I'm glad it happened because it prompted me to move on to better stock finishes, and to learn more about them. But I agree with Replacement that the older oil based varnish does not go bad in a sealed can, even after decades of normal storage. I'd be interested to hear what component might even possibly degrade under normal storage in a sealed can. I wouldn't advise anyone to throw out old varnish based upon conjecture.

Yeah, don't throw something out because its old, but definitely try it first. I seem to recall industry recommendations of shelf life of 5 to 20 or so years for varnish, but I'm going from a slightly faulty memory. But it can last longer, but I wouldn't bet stale bread on hundred year old varnish being any good.

As far as what goes bad, when it comes to petroleum, gasoline goes bad but I think mineral spirits is pretty stable. I would guess the resins are relatively stable too. On the other hand, linseed oil is a vegetable product. It might have a long shelf life, but I don't see it lasting forever. How long do canned vegetables last? The other question, do petroleum products affect its stability? I don't know.

Tim

Gasoline does not go bad if kept in a sealed container. Emphasis on “sealed.” That means zero exposure to atmospheric oxygen and atmospheric or other moisture, and zero chance of evaporation. Under those conditions, there should be no phase change. Although such storage conditions are difficult to achieve, it is possible.
More info than you probably want:
https://www.intechopen.com/books/storage...rage-conditions
This is one paper. There are, of course, conflicting opinions.
Under typical storage conditions, gas will go bad.

Something is still amiss. I changed out the varnish and now it is not drying at all after 4 days. I'm strongly suspecting the Japan dryer since I have added more than the recommended dosage and it won't harden up the solution on the stock or in the bottle. I've set up two solutions of 1 to 1 linseed and dryer and 1 to 1 to 1 solution of turpentine, varnish and dryer. Will need to wait a day or so to see what happens.

Here are the ingredients I am using at 1 part turpentine, 1 part varnish, 2 parts linseed oil and Japan Dryer at ratio of 1/4 tsp to 3 tsp solution.

It’s gotta be the linseed oil. That looks like the art supply stuff. Go to a paint store and get BOILED linseed oil. You don’ t need a lot of dryer. Remember that your spar var and linseed oil mix does not dry the way paint dries. Once the solvents flash off, the oil polymerizes. It’s a chemical reaction. On unfinished wood, your first application should be 60-70% solvent. Apply liberally, let it soak in, wipe everything off, and walk away until tomorrow. Repeat daily until finish starts to build. You can also wet sand the mixture into the pores after the first few applications. Start with 600 grit and work up to 1500-3000 grit, depending on how you want the finish to look. You can get the WD paper at any auto body supply or on Amazon. Wipe the surface dry after each application. Final finish should be IN the wood, not ON the wood.

And I just looked up the Armor Coat spar var. Not a lot of detail found on first pass with Google, but Canadian Tire says it creates a “tough plastic finish.” That is absolutely what you DON’T want, and implies that it is a polyurethane spar var, which you also don’t want. CT also brags that it is low VOC, which means that it is, by definition, complete crap. Order some old school spar var from a marine distributor like Jamestown Distributors or Fisheries Supply. Don’t screw around with DIY crap from a tire store.

When you get the proper ingredients together, try this blend:
15% high VOC spar var (no polyurethane)
15% BOILED linseed oil
10% turps (because it smells good and it works)
60% quality mineral spirits (NOT the low odor or low VOC crap); substitute some VM&P naptha if weather is cold or humidity is high

Replacement,

You don't put a dryer in the solution?

By the way the Armor varnish is not polyurethane and I'm surprised they say low VOC because is has a very strong chemical smell. It smells like to old school varnish I used a good many years ago.

Non-the-less it is time to stop playing with sub-standard ingredients.

Depending on conditions, you don’t need dryer. It just speeds up the chemical process. Mix small batches of your blend, and add no more than a couple drops of dryer. If you add dryer, discard any excess batch that has dryer. If you skip the dryer, you can keep using the batch of finish for a few days, IF you keep air away from it and replenish a little of the solvent. I wouldn’t go more than three days before blending a fresh batch.

Something is definitely amiss. First, if it's a 1 to 1 to 1 mixture, it should dry just fine by itself. I'm not sure I would trust that linseed oil, get oil intended for woodworking. Second, and this isn't personal experience, but what I've been told, you shouldn't need more than a capful per quart of finish, remember, a lot of your finish is thinner. I just re-read your post, you are using too much linseed oil. Another thing with Japan drier, too much can screw up the curing process, meaning it may not cure.

If I were you, I would scuttle the drier, and get a good wood finish linseed oil, you should be fine with the turpentine. You want equal parts of all components in the finish, don't load it up with oil. It should be a 1 - 1 - 1 mixture. And last, it needs to go on really thin. Your first coat can go on a little wet, give it 15 or 20 minutes to soak in, and then wipe it off with a barely damp rag. You can do the second coat the same, see if any soaks in and then wipe it off. If you're sealing the pores, each coat can be wet sanded till the pores are filled, but don't leave it on the stock heavy, with all the oil, if its too thick, the resins can skin over and slow down the oxidation of the oil underneath, thin coats are your friend.

good luck, Tim