Home Forums Hunting & Shooting Gunsmithing Question for the wood workers...

Rather interesting experience here gents involving tru-oil AND boiled linseed oil.

Im refinishing a rifle stock of mine and decided to use Tru-Oil. Ive done several in the past so I'm not a total rookie...but this last effort i tried something different. After stripping and burnishing etc i applied Tru-Oil as normal. I used about 12 coats, all hand rubbed in and very very thin. The first three or so soaked in and the rest built up the standard high gloss finish. Here is where it gets interesting...after letting the last tru-oil coat dry for 72 hrs i knocked down the shine with a fine scotch bright. I blew it off with a compressor and tack cloth...and then applied boiled linseed oil...rubbed in again by hand. The idea is that i like applying BLO as a maintaining finish as it looks great and isn't as messy and has an easer cleanup than tru-oil. The results are pretty darn good if i do say so myself.

The question is this...will BLO bond sufficiently to Tru-Oil? It seems to be drying ok...but its slow as you all know. The brand I'm using is Klean Strip which is linseed oil and metallic driers.

Sure, Tru Oil is something like half drying oil, linseed or tung.

Well, since most Linseed oils aren't actually true Linseed or plant based, but an oil based finish with polymers to mimic linseed oil it all depends on how well the Truoil polymers and additives are compatible with the Klean Strip additives. You will need at least 30 days for both of them to cure completely to tell how well they are working out. After that, a bit of rubbing out with rotten stone or the like will probably be sufficient to give a nice finish, IMO....

I finished a Kimber 82G with a different method, Tru-Oil and Armor All.. I can not believe the finish. Rock hard and a nice gloss finish. Amour All first and then Tru oil. Only have to wait perhaps 20 minutes between coats, less as you build up. Do a Google search. I was skeptical, but.. Dang did it turn out nice. Better than straight Tru oil or Linseed oil finishes.

The biggest problem with the Armor oil finish is that it has silicone in it and will contaminate the wood and eventually cause the finish to fail....

Was wondering about that, about 6 months now and no issues. They claim the amour all causes some sort of a chemical reaction and makes the Tru Oil harden better. Will see as time passes.

Been reading up on few stock maker books, and a common finish schedule was to use some sort of varnish to seal and fill the grain, then finish with several coats of BLO rubbed in.

Armor-all as in a car detailing product? Never heard of that and not sure that I would want to use a silicone based product on wood. I build custom furniture as a side gig and use a lot of different finishes. Always tell the customers not to use silicone products on the furniture I build. Now back in the old Army days when we waxed and buffed the floors, a trick was to use armor-all with the last buffing pass to produce a higher, longer lasting shine, but that was on linoleum floors.

No idea where that comes from, but it is not factual. Linseed oil is too cheap to need a substitute.

Need to get the details straight first... BLO is simply very low-grade linseed and/or tung oil with a bunch of driers and drying inhibitors. It has no place in stock finishing, period.

What the way-back old timers used was linseed oil which had been boiled so it would cure. Then Japan drier, a heavy-metal catalyst, was discovered and it was added to linseed oil and rubbed in carefully. Fresh oil is far more reliable and as it ages it starts to thicken and gel requiring more pressure and effort to use. Japan drier is no longer a heavy metal compound catalyst.

Really?

By all reports starting with the MSDS and researching forward. Trade secret stuff but it acts like spar varnish mixed with drying oil and Japan dryers though some would say poly varnish. A mixture that had been around before Newell wrote his book. BTW, all BLO is low grade linseed? Where does the high grade stuff go, cheap barn paint? Depends on where you get it. Speaking of Newell he was no fan of paint store linseed. Writes you don't know how long it's been on the shelf. Wrote the stuff begins to degrade after 6 months IIRC.

The high grade stuff goes to art supply houses and, I suspect, the manufacturers of better quality varnishes. Reserve the dusty cans of BLO at the hardware store for mixing into your house paint.

I've always regarded Truoil to be nothing more nor less than a very thin wiping varnish- lots more oil and fewer solids than regular varnish. I kind of chuckle when I hear guys talk about laboriously applying a bazillion coats of Truoil to get a built-up surface barrier. Simply using spar varnish would've achieved the same result faster with the added benefit of more durability, UV protection, and enhanced waterproofing (although no finish is truly waterproof). Said finish can be manipulated (ie: rubbed out) at the end to mimic the look of the vaunted Truoil "oil finish" while producing infinitely better protection of the wood.

Truoil is the darling of the gun world not because of its superior properties but rather because of the marketing genius of Birchwood-Casey. Every gun shop in the land has a pegboard display of B-C products to include little bottles of Truoil. The idea of "hey, there's so much of it everywhere that it must be ok" also applies to we gun loonies. Not that it's bad stuff, just that there's better things out there.

In fact that was Newell's recommendation for a faux hand rubbed oil finish. Spar varnish to get everything level and a couple coats of oil for looks.

Truoil is easy. Have used it to restore truck guns and it's great for that.

Back to the OP. The oil should cure fine but it will be softer than the Tru-Oil. I have had oil over varnish scratch easily even after two years of curing. In that case it was a Slacum mix with wax in so that it has better rubbing properties, but the same can happen with BLO.

If you don't want to wait this long to find out how hard it gets I would recommend mixing some Tru-Oil with linseed to harden it slightly. Shellac is good too and aids in adhering to anything. Use Linseed oil from the health food section of the grocery store, it is refrigerated or get the art store type. Also use turpentine as a thinner instead of mineral spirits. The turps will polymerize with the oils the mineral oil just evaporates and makes the finish more porous.

RE: Armor All one of the main ingredients other than silicon is a polymerizer and plasticizer. I tried it once and am waiting to see how it ages. The only visual difference I could tell is a slight cloudiness. Finish feels hard and is fine after three years.

I forgot to mention that with the food grade oil I add both Japan and Cobalt drier to it. It has all the fats and waxes in it and is the slowest of all to dry. This is an advantage for the initial coats as it has more time to soak in but a disadvantage for the final coats. Another product I am liking is Stand Oil from the art section. This is linseed oil that has had oxygen bubble through which initiates the polymerization process. I add enough turps for rubbing consistency and this type oil dries faster and harder than plain oil.

You want boiled linseed oil, not raw linseed oil which doesn't "dry." Art store, not food store.

It came from a poster on rimfire central who was an executive at a very large paint company that coincidentally made Klean Strip and other oils. George was probably the most expert paint and oil analyst I've ever talked to and he knew all the formulations of all of these so called "oils" on the market. If he said it didn't contain any plant based material, you could take it to the bank. Linseed oil is cheap, but has a relatively short shelf life and also supply chain, IMO...

Bob

Update...it’s now been a couple more days. Added another extremely thin rubbed in BLO...stock is dry and looks fantastic. Seems BLO is fine appearance enhancing top or annual maintenance coat for tru-oil

Exactly right. If you look at the Tru- Oil MSDS( https://birchwoodcasey.com/files/datasheets/23123%252c-23035%252c-23132-Tru-Oil-Saftey-Data-Sheet.pdf) it is fairly easy to see, despite the "technical language", that it is basically an ordinary alkyd( oil based) varnish with about 10% linseed oil added to make it easier to hand rub. Oil-varnish mixtures have been used by wood finishers for at least 100 years. They are easy to apply, and look good, but the oil does nothing for the long term durability. Personally, I have come to rely on Minwax Wipe-on Poly. It dries fast, hard, and does not turn dark with age. It is only 36% solids, so for a pore filling finish, it takes several coats. However, I use the sanded-in system and pore filing happens quickly. Plus, once fully cured, it is very resistant to strong solvents like acetone and MEK.

RAN

+1

Anything you buy marked "BLO" is sold in hardware stores and made of junk oils.

Linseed oil is great oil for finishing, but it is also edible and all the high grade stuff is used either for food, or pharmaceuticals, or other very demanding uses. Tung, for all practical purposes is identical, however many are allergic to the stuff and so it has no use in food and such, therefore the higher grades are available as finish.

Linseed oil has not been boiled to help it cure ever since we discovered the ancient Japanese secret of heavy metal catalysts. There are LOTS of disadvantages to boiling oil to make it cure.

Food store oil is just fine and relatively high grade.

Well, he is either entirely FOS or there was a communication gap somewhere.

http://www.kleanstrip.com/uploads/documents/KS_Boiled_Linseed_Oil_MSDS.pdf

From the MSDS:
CAS # Hazardous Components (Chemical Name)
3. COMPOSITION/INFORMATION ON INGREDIENTS
Concentration
68553-15-1 Linseed oil, cobalt manganese salt {Linseed oil,
manganese and cobalt driers}
100.0 %

Alkyd resins have replaced a lot of linseed oil use, but not in BLO.

Some of the linseed in Tru-Oil and Linspeed is the polymerized type like the stand oil I mentioned. Either oxygenated or cooked or whatever. Alkyds can be added to Linseed to speed the polymerization process. my favorite finishes are a mix of Poly, Alkyd and Oil. I like a little bit of yellowing, the poly adds durability, the alkyd hardness and the oil ease of application and traditional look.

I think all the previous comments were about Tung Oil finish which may not have any Tung Oil whatsoever in it.

The OP is pleased so I will not beat this horse anymore.

Yep, bottom line is if the customer is happy that's all that matters.

One of my earliest experiences in the antique car restoration game was helping my Gramps in his shop where he specialized in turn of the century steam automobiles. One day, 50+ years ago he put me to work on the lathe making walnut handles for use on an 1898 Malden, to a drawing he sketched. The next day he had me standing over a sauce pan of linseed oil on low heat from a hot plate all day, ebonizing those walnut handles. When dried and polished on a muslin wheel they were very black and very elegant looking.

(That car resides in a transportation museum in Istanbul now. Google "1898 Malden steam car" and it'll turn up front and center in "images"- the red horseless carriage.)

Cool

No worries for going off the rails guys...I’m always open to learning. It seems Sitka also found that Klean strip is linseed and metallic driers...which the company confirmed over the phone.

Keep in mind this is only being used as a maintainer coat over the tru-oil. My goal is and has always been reasonable performance and top flight appearance. I’ve been extremely happy with tru-oil in the past...just happy this worked out!

Hardly just found that info. That has been fact for many decades. BLO is unlikely to fully cure...

No offense intended.

How about hemp oil? Every ache and pain commercial seems to tout hemp oil these days. Remembering it was a drying oil I Googled it for fun. Sure enough, it's being sold as a wood finish. Anybody tried it? The woke substitute for safflower oil?

Many oils are or have been used for finish over the years. Walnut oil was considered "the" salad bowl finish by many about 25 years ago. The best choices are usually edible, so it makes it tough to get the best of them for finish.

If you have to use a natural drying oil, at least use a good one. Tung oil is superior to linseed in every respect. Especially in the moisture resistance dept. The 50% polymerized formulation is better than the regular oil. Here is one source: https://www.leevalley.com/en-ca/shop/tools/supplies/finishing/finishes/20050-polymerized-tung-oil Another: http://sutherlandwelles.com/instructions/PTO/GunStocks-PTO.pdf

RAN

Sorry, in use there is absolutely zero difference between tung and linseed oils. They use them interchangeably in the industry and tung oil finishes often have no tung in them at all. No oil finish is truly waterproof.

You need to do a bit of research: https://www.canadianwoodworking.com/get-more/tung-oil-debunking-myths

RAN

This.
Tung is a better oil to use than BLO.

Sorry, but the article posted is ridiculous. She does not even understand enough to cherry pick her facts.

BLO is useless for quality work of any kind. Understanding that BLO is just referring to hardware store grade stuff labeled as such. Linseed oil and tung are equals when they are the same grade oil. When dry they both absorb atmospheric water faster than bare wood.

I mixed my message in my last post...

Gotta differ a little. If you get real tung oil it polymerizes not quite as glossy as good BLO. Also polymerizes a little faster, but not enough to matter.

Both statements are incorrect. Realize too that BLO is a general term for a wide range of products and there are too many variables to make absolute statements like that. Though even general truths do not apply to that.

Linseed oil and tung oil are interchangeable in their pure forms, period.

Gee, I don't know, that's what Newell and I think Dunlap said. So I got some artist quality and did test boards, And that;s what I got. The books said that tung was marginally more water resistant but I didn't test that. In ny case if water resistance was an issue drying oil of any sort would be my second to last choice.

Please, wax on...

Arguments to authority are weak, especially when you look at how rigorous the study was.

Would be happy to entertain your arguments, especially if you provided pictures...

Right, we must disregard experts. Remember that the next time you see your MD. I don't save every test board, more than enough clutter as it is. Moreover none of this really matters to me. I'll use drying oil on period pieces, a modern finish on modern pieces.

As expected...

Who to believe, you or my lying eyes? Notice I said art quality oils, not hardware store which is a crap shoot at best. Even way back Newel said there was a lot of inferior quality oil being sold and to be cautious.

How about the chemists testing under very controlled conditions for a very long time?