Linseed Oil For Metal Protection

Oh damn! The forum is now blue and so am I. That yellow was so soothing...

But I digress. I have been experimenting with boiled linseed oil for protecting old iron artifacts. I have a painted steel sign that had deteriorated to the point where the lettering was practically nonexistent, and could be barely read only with great effort. I painted the surface with boiled linseed oil and it brought the old colors and lettering right out so it can be read easily now. I wonder if that old sign's (probably WWII era) paint wasn't formulated with linseed oil and pigment to begin with.

I am sure this may be an old trick to others but its something new for me. I'm thinking of using the linseed oil to coat other pieces of indoor unpainted steel that I have and want to protect. Are there any downsides that I am not aware of? How long might a linseed oil topcoat last?

Would it be a good topcoat for old varnished wood?

Before the introduction of petroleum based oils linseed was likely used for a lot more than making paint. But, it hardens and becomes gummy. In fact, 18th and 19th century varnish is basicly linseed with hardeners added. Early 19th century firearms .i.e before the Civil War, often have a hard, amber colored coating on internal parts that is probably at least part-linseed. (there may have been tallow or other fats in it also) I wouldn't use it where two surfaces mate as you'll likely be glueing them together. On something like a sign I can't see what it could hurt unless it discolors and is really difficult to remove eventually.

It's often used as spoke/nipple prep when building bike wheels. Lubes as the wheel is built, then gets gummy to 'lock' the spokes but can still be worked later if truing is needed. There are two different kinds.... the types escape me now... maybe 'boiled and 'unboiled'?

Careful when using it... this is the stuff that can catch rags on fire.


bb

Lindseed oil works, but just as a matter of personal preferance I dont like the artificial restored look and feel it leaves on rusty old iron. Its a bitch to get off later. I saw a one lunger where the paint and lindseed oil were peeling and craking and it just looked awful.

I did see how it tends to somewhat restore the paint. I just dont like the look on
old engines or machines though. thats just me. I am sure you alreay know about rust inhibitors as you mentioned cosmoline in you past posts. An old time treatment for rusty iron was wax, no gummy or hard to remove coating. Most of the above, wax, rust inhibitors will enhance the look of old paint and dont sink in and not bond to the finish
the way lindseed oil does.

Anyway, I kinda hate the stuff and maybe its an irational responce to see it slopped on so many nice old tools.

The antique shops sell some expensive cans of finish restoration stuff that does a great job hiding the scratches and putting a nice low luster tone back to old furniture. I think in that case lindseed oil migh be a good choice too. Well, I am just saying I'd advise caution, once applied you pretty much living with it.

This is indeed just an experiment. I am trying a few different things to see what works best. I also want to try the wax that has been mentioned. Probably some museum supply house should have the right stuff as they use it for preserving iron artifacts as well.

rick,

I would think anything that could clean off years of dirt without having much solvent action would bring out the color in just about any old object like that. I bet if you wiped the sign down lightly (and gently) with naptha or mineral spirits you would have a similar effect. alcohol might work well too for cleaning stuff like the sign.

for rust protection, I prefer wax (paste wax), as the buildup is minimal, and the finish doesn't stick out like a sore thumb. linseed oil will yellow with time, and leave you worse off than before with stuff like your sign restoration/experiment, and as stated earlier can be a PITA to remove at a later date.

you might try looking up what art preservation types use to clean old paintings. it is probably something relatively simple to make up, although i doubt it will have any protective qualities. a coat of water-based urethane or the like might be an option for you, as it can be had in gloss to matte finishes. buffing with steel wool will take off a bunch of the annoying shine from the high-gloss.

for finishing wood, linseed oil is usually applied first or as the only finish. you can painstakingly apply layers of oil, let them soak in, and then wipe off the excess and buff with steel wool. makes a nice finish, but needs applying a fair number of times before it is "permanent." wax works best in my experience as a finish on top of old varnish, especially if there is any old poly-urethane involved. There are many, many things that will work with different finishes, and not with others, especially depending on the desired effect. a book on wood finishing techniques would be highly reccommended.

as to the different types of linseed oil, raw linseed oil has no chemical (heavy metal) driers added and takes ages to cure. boiled linseed oil does have driers added (used to be lead and some other nasty stuff, now there are others), and cures relatively fast. I say cures, as it is actually oxidizing, and not drying through evaporation.

Rick, I've used boiled linseed oil for both wood and metal. For me, it works best if thinned slightly with mineral spirits and applied in VERY thin coats, and on warm surfaces. I have not had a problem with it being gummy except in rare cases where I applied it too thickly. It does have a definite yellow tone which may or may not be objectionable depending on what its covering.

If not exposed to sunlight it lasts quite a while, and arrests rust reasonably. The problem is that sunlight breaks it (and most other things) down with time and exposure.

Dark linseed-oil-based paints delay the breakdown because the UV light can't reach all the cross-linked oil. It's blocked by the paint coloring.

It can be hard to get off without damaging underlying paints.

i'll chime in here. i have been using boiled linseed oil for several years now. my application generally is done to old metal that i clean up. the clean up i have done has been performed by, stiff wire wheel on a bench grinder, electrolysis, and acid dipping in vinegar. once the tool or piece has been cleaned, usually to bright white condition i apply the boiled linseed oil as my protective metal coating. the first batch of tools i coated were a 5 gallon pail of hand punches and chisels that i rescued. they have been living in the unheated tool box under constant use for about 4 years now. i have to say while i don't abuse my tools these punches are often on the concrete floor during projects.

the finish has held up well, that is other than in wear spots it is still there in the same manner as applied and no rust has developed. for comparison i have normal use hand tools that i have cleaned the same way and finished with industrial spray paint from a can (hardhat), hand applied oil based paint, and automotive acrylic enamel. i have found that i only get gumminess or wrinkling when the coating is too thick. as with most paint type coatings multiple thin coats are better than one thick coat.

one of the things i most like about the boiled linseed oil is that the tool can generally be completely coated during one application. also the coating has flexibility that other harder coatings do not have and thus in my experience resists chipping and nicking better than all the above coatings i have applied to restored daily use tools. my next test which should take place in a week or so will be to buy paint pigment for oil based paints from the local art store and mix a bit of that in the linseed oil for a tinted look to the tools.

I have to chime in also. I have collected antique (pre-1900) precision measuring tools for eons now. They are ruined by even minor surface rust. I live in very damp and salty Florida, but previously lived in a climate that suffered warm days and cool-cold nights. In other words moisture forms on anything in unheated/AC space.

My tools were stored everywhere - unprotected. They started rusting almost immediately after being brought home. I used everything imaginable to coat the tools. Some things worked, some did not. And that which protected left a heavy, visible and unpleasant to touch coating.

Then, I discovered "Finish Feeder". It is a furniture wax/cleaner comprised of beeswax, solvents and other stuff. I have since coated every bare metal part I own with it and for at least the last 20 years, it has stopped ALL rust.

But, there is a secret to applying it. Here it is. Soak a small paper towel scrap with it and rub it on liberally. Let if flow into every crack, pore and crevice. If the item has moving parts, be sure to disassemble and coat the parts individually. Well, there are some limits as to where I'd coat with it. For, example, the exposed or interior threads of a micrometer are not a candidate for it. But, the bearing surface for a Starrett Protractor head is!

Ok, now that you have it coated liberally, you have waaaaaay to much Finish Feeder on - which is good to ensure protection, but will leave a sticky mess after it dries. And, the residue turns brown if too thick in a few years.

So, take a rag, mechanics towel or something soft and wipe off the excess. Do this wiping to the point where you can't see any liquid left, but can feel it. Wait to assemble the moving parts for about a day so the coating can dry.

You're protected! No rust will form. It is almost like an invisible paint job. And, it can be totally and easily removed with mineral spirits, acetone or other such stuff.

I know, it sounds like a lot of work. It isn't, it is simple and quick to apply, wipe and let dry. It may take you a few tries to get the amounts down just perfect.

Be careful of the cloth wiping material. If left folded or balled, you could have spontaneous combustion. I drape mine over a vice and the heat is never allowed to build. I also hand wash the cloths after they get really full - but never in the SWMBO's (She Who Must Be Obeyed) washing machine.

I get mine from Killians Hardware - use Google to find it.

One ue of linseed oil is to corosion proof the tube frame of light aircraft. After welding, a coule of small holes are drilled in the frame and linseed oil is poured into the tubing. The fuselage is on a rotating frame while this is done. After filling, the fuse is rolled around to various positions to allow the oil to coat the tubing completely. Final step is to go to a position where the original hole is at the bottom to allow excess to run out (no need to carry excess weight), after which, a blind rivet is popped into the hole to seal the framework.

Hello Rick:

Linseed Oil is as old as the hills as a finish & preservative. Farmers used to brush it onto implement parts and tools to preserve them against corrosion. It was also applied to wooden parts and handles.

Blacksmiths sometimes finish their work by wiping it down with linseed oil while the work is still warm. Sometimes, smiths make up a combination of beeswax, turpentine & linseed oil and apply it to hot ironwork. Not having any beeswax at hand, I've used paste floor wax + boiled linseed oil on a rag to coat some of my forge work. It makes a good coating which takes some time to cure.

As a sidelight: "Triple Boiled Linseed Oil" was also used as a sealant. In the 1970's when we'd put the casings together on big G.E. steam turbines, we were directed by the G.E, site engineer to coat the mating surfaces of the the casing joints with triple boiled linseed oil. These were flat surfaces which had a ground finish on them. We stoned the mating surfaces, cleaned them with solvent and put the linseed oil to them. After making up the casing studs (heating them to get the "stretch"), we got on with the job. In service, the joints made up that way stayed steam tight.

If you look in old texts, linseed oil was a staple ingredient of many finishes. It was mixed with pigment & "Japan drier" to create paints. For many years, the standard corrosion inhibiting paint was "red lead". It was mixture of lead oxide and boiled linseed oil. Structural steel used to leave the fabrication plants coated with red lead. It was used on ship's hulls, bridges, and even on water tanks. The linseed oil gave "red lead" the ability to creep or wick into rivetted seams or overlapping courses of steel plates. Great stuff in terms of preventing corrosion, not so good in terms of health hazards. Typically on a lot of water tanks, in ship's bilges and similar, the steel got a first coat of red lead. This was followed by "bitumastic"- another great coating for preventing corrosion but also carcinogenic.

Years ago, also, marine & stationary engineers often made their own pipe dope. For water & air lines, they often mixed Linseed oil with powdered white lead or litharge. This made a pipe dope which stayed halfways live. Screwed joints on steam lines got doped with steam cylinder oil and graphite so they could be taken apart in the future.

Linseed oil was also used in some old veterinary remedies as well as in some cattle feeds to "finish" the animals before they were sent to market.

Linseed oil is one of those things the oldtimers kept around their shops for multiple uses. On top of all else, if they had an axe handle or other tool handle or gunstock, it likely got finished with linseed oil. Nowadays, there are a plethora of preservatives and finishes available. Linseed oil may have faded from common use, but, IMO, it's good stuff to keep around the shop.

Joe Michaels

This old book (1914) has lots of information about linseed oil, starting around page 162:

http://books.google.com/books?id=DI...q=linseed+oil+technical+information#PPA165,M1

I would also like to chime in, I do blacksmithing as another hobbie of mine and an old recipe we use is a 50/50 mixture of boiled linseed oil with beeswax, heat the oil and wax together to form a kinda of paste/ wax(it should be about 50/50 mix of both when done). then heat the part slightly(i know this isn't good for some things but hey its not perfect) then apply the 50/50 mix of boiled linseed oil and wax, thin coats are best, and let dry. forms a hard coating that colors slightly and prevents rusting. If you put too much on or have a thick layer, use a torch or oven and heat the item back up until liquid, then move the piece around to remove the excess by letting it drip off(or just wipe it off). Remember this is a traditional Blacksmith recipe for their ironwork so may not as great for delicate items that can't be heated.

Linseed Oil Finish

I have used linseed oil on forged items for years. It is applied while the metal is still hot, but not hot enough that the oil scorches - a slight smoking is OK. I then wipe the metal with a dry cloth while still quite warm. It will not hold up outdoors but is quite satisfactory for indoor items. There is a mixture of linseed oil - turpentine - and Japan drier that is supposed to work well but I have never tried it. It was pretty much a standard finish used by blacksmiths.
I heard once that linseed oil applied at the proper temperature becomes a polymer - essentially applying a plastic coating to the metal.

Linseed Oil

I left out bees wax as one of the ingredients in the mix in my last post.

Joe M's notes above remind me of the paint area of the iron works in Philadelphia that my family part owned. It is about the middle 1960's until 1985 that i recall, and the period from the mid-1960's until 1970 were in the old building and then, from 1970 until 1985, in a newer steel shed--also in Philadelphia but not 'Center City'--that the Iron Works purchased and moved to. The new shed had been a stone shed and had a 50 ton P & H overhead crane, more than the Iron Works needed so they ran that down to the end of the building and left it there, and installed there own, Cleveland, i think, old one that they ahd brough from the other site, a 20 ton crane I think. Of course they had smaller cranes on the side.

The paint area was always full of red lead overflow and blobs from the primer, continually applied--most of the times I when I recall one fellow worked full time at this, I think--and used shop air from the large compressor and had a five gallon paint pot, that was the first place I saw (and later used) these pots. Though the painter with experience was probably skillful, everything in those areas had a good overspray of that handsome rich red color, including the painter's shoes and goggles.

I believe they may have switched to zinc oxide--kind of neon lemon green--toward the end. And I recall that a small amount of their steel was left unpainted for off-site galvanizing, a hot dip in a big tank, over in New Jersey.

Linseed oil

I thought I'd add my two cents worth. I used to be a glazer and when doing a hackout (replace a broken window pane) on a wood sash frame I used linseed oil to both prime the wood sash and to thin the glazing putty to make it workable. If one doesn't prime the wood sash first, the dry wood would suck all the oil out of the new putty and the putty would not adhere to the wood. When re-glazing steel & aluminum sash we would, again, mix linseed oil into the putty to oth make it workable & adhere to the frames. Linseed oil: good stuff!

I have been reading with great interest, the Linseed oil thread, Many years ago in the foundry i worked in we had a fair number of cast -iron patterns, used for repeat work, on light casting machine details, These "patterns" after being cast using the most carefull workmanship in moulding, (to retain accuracy), were heated up, and allowed to cool in the damp foundry atmosphere, This caused a very slight rusting onthe metal face, giving a virtual negligable change to the dimensional accuracy, of no consequence, The casting was then warmed up ( could be handled ) and then coated with beeswax, and buffed up to a shine with graphite This gave a surface finish on the pattern that lasted for years, and did not rustin use.

About 30 years ago, i had a discussion with one of the port authority crane engineers, The subject of the last big 100 ton steam crane came up,-- Surprise Surprise!, THis massive machine, had as a jib construction two big rivetted steel tubes, cross braced, These big "jib tubes" had manholes near the bottom, The tubes tapered towards the top of the jib, where the big jib head rope wheel was.

This engineer told me that on occasions some "unfortunate serf" had the pleasure? of crawling up the tubes with a long poled brush, and applying boiled linseed oil to the interior surfaces, this gave a skin which after drying and the manhole closed up gave a rust resistant surface This was done after the "serf" crawled out

Linseed oil takes a long time to harden. Doing stocks it would be applied thinly, then whiped off, then allowed to dry a month, and the process repeated until the proper finish was acheived. You can't be in a rush. If you are in a rush then Japane driers work as mentioned.

It adds shine to oil finishes over wood. One popular recipee is Sam Maloof finish which is 1/3rd each of boiled linseed oil (shine and depth), Varathane oil vanish (driers and resitance to water marking), and boiled tung oil (more oil but one that dries harder and clearer. This is a version of traditional "short varnish". That's mostly oil for that in the wood look, with enough varnish to add durability and water resistance.