Thinning Tru Oil

[longcruise]

Does anybody have any ideas on what to use to thin out some tru oil that has grown thick in the bottle?

[California Kid]

Get a fresh bottle.

[Jerry V Lape]

Tru oil gets thick quickly when exposed to air, even the air trapped in the bottle once it is opened.  This can be some what mitigated when using  Tru Oil by quickly taking a small amount from the bottle, replacing that volumn with a marble or two to limit the air left in the container and reclosing the container quickly.  It is almost pointless to save part of a bottle for another project. 

[D. Taylor Sapergia]

TruOil definitely has a shelf life, and not a long one.  I don't know if I've ever got to the bottom of the bottle before it went thick.  I've tried turning it up-side-down, filling the gap with marbles, squirting propane into the opened bottle before capping...nothing works.

TruOil is not a very tough finish.  It wears quickly in wrist, and forearm areas and likes to be touched up from time to time.  But it's easy to do...strip the gun of its parts, lightly steel wool it, and reapply a couple of coats of the finish.

In short...buy a new bottle!

[longcruise]

Thanks for the suggestions.  Guess it's time to go out in the rain for a fresh bottle.  Seems to explain why they don't offer a large "economy" sized bottle!

[FG1]

I have thinned it with Ronson lighter fluid about 25% with no ill results . It still cured out fine . I also do this for 'wet' sanding and filling grain on open grained walnut .

[D. Taylor Sapergia]

That's interesting!

[bgf]

If Tru-Oil is what I think it is, paint thinner, mineral spirits, etc. should work fine depending on how much working time you want, if it is still liquid and just thick, not chunky .  Probably some thinner is evaporating. 

[shortbarrel]

I do it like the above post, but I use mineral spirits to thin it for sealing, and a little less when wet sanding to fill the grain. This only works with a bottle that has thin liquid,not like molasses. There are a couple of stock coatings listed in the vendors catalogs that work better.

[wmrike]

Are we talking about two different things here, the first being the effective shelf life and the second being the thinning of an unexpired product?

As to simple thinning, one part paint thinner to two parts oil.  That's thin enough to be sprayable.

As some of the other fellows have indicated, Tru and other oils seems to have an internal clock that's running once the bottle is open.  I notice this mostly as an extended cure time after application.

[Dphariss]

Does anybody have any ideas on what to use to thin out some tru oil that has grown thick in the bottle?

Throw it away and buy new is the best course.
You can try turpentine, the real stuff as a thinner. It actually adds something to the finish in addition to thinning it.
Mineral spirits really has no place in a stock finish.

Dan

[Kermit]

"Bloxygen." It's canned argon gas. Inert and heavier than air. The stuff works. If you buy a new jug of Tru-Oil, get some of this at the same time, for next time.

http://www.bloxygen.com/

[longcruise]

Well, I'm going to get a new bottle for the project(s) on the bench but am giving Dan's idea a try by adding a bit of turpentine to the problem bottle.  I'll post the results here on that.

On another note, I visited the Birchwood Casey site and discovered that there is indeed a large econonmy size jug of Tru Oil!  Don't know who uses enough to buy it that way but it is sold.

[smart dog]

Hi Longcruise,
Tru-Oil is a polymerized oil made I believe from linseed oil.  During the polymerization process it is either cooked or drying agents are added to start the polymerization (hardening) process.  That is why it dries quickly on your stock.  It will gel in the bottle over time and there is almost nothing you can do about it.  Although others mentioned some agents that thin out the gel, it is probably going to compromise the quality of the finish unless you simply use the thick oil as a glaze or stock filler. 

dave 

[Dave K]

I have tried both mineral spirits and turpentine. Both work, but I really like the turpentine better. Also, while you are at the store picking that up, get some "Japan" drier as well. I really like a drop or two in my Tru-Oil that is mixed up in an old ash tray when I rub it in.

I have tried the marbles in the bottle also. It works and just makes a mess as far as I am concerned. Buy the small bottles and just use them as you need them.

 On another project I am doing right now, I am using a varnish that has a tung oil base. I got from some of the other finishers using this varnish that to help it keep better, just use some propane to displace the air in the bottle to keep it fresh longer. So that is what I am doing and it works. Of course the torch is not lit (read that again!) and I just let it blow into the bottle to displace the air and allow it to continue to blow as I put the cap on. But, don't say I didn't tell you to be careful. Before other freak out on this, I doubt if this is more flammable than the wet varnish and thinners we use as well. Just don't light the torch!

[bgf]

Hi Longcruise,
Tru-Oil is a polymerized oil made I believe from linseed oil.  During the polymerization process it is either cooked or drying agents are added to start the polymerization (hardening) process.  That is why it dries quickly on your stock.  It will gel in the bottle over time and there is almost nothing you can do about it.  Although others mentioned some agents that thin out the gel, it is probably going to compromise the quality of the finish unless you simply use the thick oil as a glaze or stock filler. 

dave 

I believe it is a highly thinned oil and varnish mix; don't know how the oil varnish ("modified oil" in MSDS) portion is modified, likely added resins; definitely has a large percentage of Mineral Spirits.  Here is the MSDS:
http://sport.birchwoodcasey.com/files/MSDS/%282010%2923123-23035-23132Tru-OilFinish.pdf
The "highlights":
Mineral Spirits 56% by weight
Modified Oil 33% by weight
Linseed Oil 11% by weight

One reason it dries quickly and thickens in the bottle is almost certainly the volatility of the Mineral Spirits, which is why I think you can thin it out a bit if desired, at least for some time. 

[Birddog6]

I seldom thin it, because if you do you will be coming back adding 3 times as many coats. What I have thinned, I thinned with turpentine.  However, I buy a new bottle for every stock I finish. Use the old stuff for sealing the ends of blanks, sealing under buttplates & in barrel channels, etc.
I figure $5 a bottle, that is gonna be one of the the cheapest investments in building a rifle.

Keith Lisle

[Dphariss]

Hi Longcruise,
Tru-Oil is a polymerized oil made I believe from linseed oil.  During the polymerization process it is either cooked or drying agents are added to start the polymerization (hardening) process.  That is why it dries quickly on your stock.  It will gel in the bottle over time and there is almost nothing you can do about it.  Although others mentioned some agents that thin out the gel, it is probably going to compromise the quality of the finish unless you simply use the thick oil as a glaze or stock filler. 

dave 

I believe it is a highly thinned oil and varnish mix; don't know how the oil varnish ("modified oil" in MSDS) portion is modified, likely added resins; definitely has a large percentage of Mineral Spirits.  Here is the MSDS:
http://sport.birchwoodcasey.com/files/MSDS/%282010%2923123-23035-23132Tru-OilFinish.pdf
The "highlights":
Mineral Spirits 56% by weight
Modified Oil 33% by weight
Linseed Oil 11% by weight

One reason it dries quickly and thickens in the bottle is almost certainly the volatility of the Mineral Spirits, which is why I think you can thin it out a bit if desired, at least for some time. 

I would have to dig for it but I seem to recall reading that Tru-oil was a cheap phenolic varnish. This bears this out.
To be honest I had never looked up an MSDS on the stuff.
As I stated before mineral spirits has no place in a stock finish.
I bet a drop test on finished wood will show its a brittle finish as produced.
The "skin" that forms in the bottle is glass hard and cracks.

Dan

[longcruise]

I had some old fasioned genuine turpentine on the shelf and went ahead and poured a bit in.  No precise measuremnt and maybe a bit too much, but it did thin the oil out.  At this point it is a bit thinner than a new opened bottle.  A test block with two coats dried up nicely on the first coat and the second began to show a bit of gloss.  Second coat is taking a bit longer to dry than typical for Tru Oil, but it is drying just fine.

I had a recently completed bow and decided to use it on the riser for a test.  Working out just fine.  The riser is walnut but it is not soaking up the oil and showing the end grain the way walnut can.  Probably because I sealed and sanded it three times with a water based wipe on poly finish.  The water based poly raises the grain just like it was water so it makes it easy to seal and whisker all at once.

Still planning on a new bottle for the stock on the bench!