Rust protection for planes and saws etc

[D_W]

forgot - sewing machine oil is also just stable mineral oil (usually) to make sure it doesn't react with anything (fabric) and to make sure it doesn't oxidize and become gummy in machine parts.

The price for it is the same here as food service mineral oil. I didn't know they sold sewing machine oil by the gallon, but they do.

 

[Sideways]

This was an interesting read following up hydrotreated mineral oil
https://www.machinerylubrication.com/Read/28960/mineral-oil-refining

 

[D_W]

that seems to support the idea of looking for hydrotreated oil. I'm not a chemist - just remember someone telling me that hydrotreating leaves very few volatiles and the oil is very stable. It means, too, that if there's a very thin film on something and you don't touch it, the film won't oxidize and dry and it will protect from rust reasonably.

And while it probably increases the cost of the mineral oil drastically at an industrial level, for our use, a few bucks added to a gallon doesn't matter.

There are other mineral oils here sold for honing (marvel's mystery oil, dan's honing oil, etc) that are either less refined (dans) and really stinky, but still food safe, or strangely colored like MMO.

not sure what's in three in one, but it's also easy to find an SDS of it, I'm sure.

 

[D_W]

people do seem to love MMO.

(stable mineral oil can also be found at vet/equine/ag supply, too - I found a heavier weight of the oil at a horse store years ago for about $12 a gallon. Not a horse person - not sure what it's for. constipation?)

 

[D_W]

three in one is hydrotreated oil plus naptha plus a small percent undisclosed. No clue why it stinks. I wonder if it's on purpose.

marvel mystery oil - stoddard solvent and hydrotreated oil plus a tiny amount of additives.

Are we starting to see a theme here about why the "special" products are a little hokey?

 

[Sideways]

The first place I tracked down is out of stock but £16 / 5 litres plus a bit of shipping looks affordable. They have other useful products so worth keeping an eye on.

Aside. Chopping board oil from the IKEA home store has been pretty successful for protecting some little used table saw blades in my shed. It seems to stay unchanged over time. Sticky and clear. A warmed up honey consistency. That may be a thicker version of the same stuff.

 

[vaj]

It's not totally bullet proof but I've had good luck with a combination of wax (Renaissance puts on a good coating and so far as I know is free of silicones unlike many other types of wax) and then a wipe with a cloth with enough camellia oil to put on a film.

Camellia is nice (it's expensive from some sources but Dictum in Germany do a large volume pack for decent money) because it's easy on the skin and doesn't stain wood or cause finishing problems.

The big problem with rust is when a workshop gets cold for long enough for the heavier chunks of iron about to be brought down to that temperature and is then followed by the arrival of warmer wetter air as a result of a change in the weather.

If the metal (machines, tools etc) is cold enough to drop the wetter air below its dew point the result will be very heavy condensation - as though the items had been hosed down.

There's very little that will reliably prevent rust in this situation, especially if treatments that could cause problems with staining, silicones, finishing, strong smells etc are eliminated.

After that it's matter of either keeping some heat in a workshop when it gets cold (anything less than a few degrees C above zero) or perhaps (haven't tried it) of putting stuff in a storage bag made for this purpose.

A more or less sealed tool cabinet can help too, especially if perforated containers of properly dried out silica gel are also placed in it.

It's in the end short of maintaining quite high temperatures in the workshop advisable to enure a coating of something which acts as a barrier, because unprotected steel will even with light heating otherwise end up rusting a little.

It's a good idea to get set up with an easily accessible kit (tin of wax, brush, wax filled cloth, jar of camellia oil with a brush in the lid, tin with a camellia oil filled rag, fine scouring pad to remove rust traces etc) - that way it's much easier to make it a reliable part of the 'putting away' routine.

It's a good idea to make sure that every new tool is similarly treated when bought - including ordinary stuff like screwdrivers and so on.

If it's really precious bring it into the house over winter...

PS beware of polymerising oils like linseed as they reputedly can (?) if left in rags etc consitute a fire risk...

 

[furnace]

This was an interesting read following up hydrotreated mineral oil
https://www.machinerylubrication.com/Read/28960/mineral-oil-refining

Great article to explain the process. Also introduced me to the term tribologist -
Every day is a school day

 

[tpaul]

I use Renaissance Wax, Light applicatuon and then buff. Won't affect finishes applied to wood

 

[D_W]

The first place I tracked down is out of stock but £16 / 5 litres plus a bit of shipping looks affordable. They have other useful products so worth keeping an eye on.

Aside. Chopping board oil from the IKEA home store has been pretty successful for protecting some little used table saw blades in my shed. It seems to stay unchanged over time. Sticky and clear. A warmed up honey consistency. That may be a thicker version of the same stuff.

chopping board oil should basically be hydrotreated mineral oil.

 

[D_W]

PS beware of polymerising oils like linseed as they reputedly can (?) if left in rags etc consitute a fire risk...

I've never heard of a problem with them unless they are put in a bag or placed in a pile or can so that the center of the blob can build heat to the point that the reaction runs away. I've always laid mine out in the shop flat until they are stiff and then thrown them away, but boiled linseed oil is more suitable for wooden tool conditioning than it is rust prevention. It'll work, on surfaces that you want to be slick, it'll leave a dry film.

Two things about humid shops with still air - a fan is usually enough to prevent a problem, and cheaper than a heater to run (movement with a 75 watt draw isn't a big problem). Second, if something like that is going to rust, putting a cover on the surface would do on large flat tools that won't be used for a while, as would a very light coat of shellac lightly sanded off and then waxed. Especially if the machining of the cast isn't mirror smooth. Clear shellac in a very light cut is fine.

My shop is below grade so temperature is a little more stable but humidity is a lot higher than above grade. I do get rust once in a while, but it is always on bar stock that hasn't been handled much with "oilstone hands" or a new tool/iron that I've made and handled little after tempering other than to test. the really super plain steels that have little alloying in them really do rust a lot faster (1084, 26c3...these being types that have just enough additives to manipulate the iron and carbon but not to float around free).