Cast iron corn sheller

Just so.

Before getting a clue, I tried muriatic (hydrochloric, HCl) acid, battery (weak sulfuric, H2SO4) acid, nitric acid for cleaning ornamental forgings. None of those was good and the HCl was the

*worst* choice. It seemed to endow the workpiece with a permanent ability to rust further despite washing, neutralization and various finish treatments.

Phosphoric acid is the answer. Diluted (I forget just how much, about

50:50 with water) from the syrupy industrial product (68% IIRC) and heated with an immersion heater if your workshop is chilly, it not only removes fire scale and rust but leaves a protective iron phosphate coating that further deters rust. That last feature, the residual protective effect, depends very much on just what you do after you remove the workpiece from the acid. Too much H2PO4 left on the metal will be scummy. Too vigorous washing, scrubbing, abrasives, other chemical treatments will eliminate the protective phosphate effect. Experiment.

Note that if you use shallow trays/containers and immersion heat, the water in the H2PO4 acid bath will gradully evaporate, increasing the concentration of the acid. That will make it work *less* well. Add some water if notice that happening.

Another upside is that phosphoric acid is far less dangerous and/or bothersome to work with than the others. Yes, you *reallY* don't want to splash it in your eyes, you don't want to drink it.[1] But overlooked spatters are unlikely to leave you with burns, disintegrating cotton clothing and other annoyances.

[1] The amount in your favorite carbonated beverage may eat your teeth a bit. Enjoy but *still* don't drink your industrial-strength pickling bath. :-)

If you have strong phosphoric acid and want to dilute it, add the acid to the water rather than the water to the acid. The mixture heats up, and sulfuric acid in particular may spatter violently if a little water hits a lot of strong acid. Chemists learn to dilute all concentrated acids that way as a general safety rule.

  My high school (yes , I can actually remember that far back) said "Always do as you oughter , add the acid to the water." .

  EDIT  (I shouldn't post before my morning coffee .)

I can't complain, I read and post when I'm too sleepy or tired for the real work.

You should wipe food grade mineral oil on kitchen cutting boards. Mineral oil won't go rancid, and it fills all the cut marks in the wood that bacteria might otherwise be thriving in.

Getting into the terminology and formulation of drying oils may be one of the most myth-fraught subjects in old technology. <g>

I don't think the issue is based on misrepresentation; it's more a matter of popular terminology. Looking at what's available on the market today, "raw" linseed is non-food-grade flax seed oil. Stand oil is raw linseed, heat-treated at a pretty high temperature -- like hundreds of degrees C -- in the absence of air, for days -- in closed kettle-like tanks. It's very viscous, much more viscous than any "linseed" most of us have encountered, used by artists in making custom oil paints. My old buddy Rob Howard, author of _The Illustrator's Bible_, gave me a bottle of it around 30 years ago for hand-rubbing on my gun stocks, but it was a sticky mess to use and I don't know how many months I was supposed to leave it to dry. I eventually stripped it off and went back to modern "boiled" linseed. I never figured out a good use for that honey-like glop.

Raw linseed, stand oil, and metallic dryers are mixed and used to make "boiled" linseed oil today This formulation, but using liltharge (lead oxide) rather than coblat or other metallic salts has been used to paint one of my family's houses in NH since 1747. They always called it "boiled linseed oil." They mixed it with white lead (lead carbonate), and that was standard white house paint for hundreds of years. It chalked off pretty fast which made it easy to re-paint year after year.

Aside from artists' supply houses (Rob runs one), I don't recall having seen stand oil for sale to consumers, but there probably are some. Modern "boiled" linseed is what I'd use on old cast iron, but there probably isn't much difference between that and the raw-linseed heated-until-smoking treatment you describe. It probably produces a similar result, quicker.

On the question of buying from McMaster: All I've ever needed was a credit card. They do not require opening any sort of "account."

I get washing soda from the local supermarket. In the laundry detergent aisle.

As an aside, I found Nitric acid to be very good for cleaning up a failed brazing (bronze) repair on some 304 ss before I tigged it. Got it unbelievably clean.

Linseed oil was the base for paint for 100+ years, too.

Seasoning cast iron pans: Never.Use.Soap.On.Cast.Iron because if you do, it takes at least 6 boils to get the crap back out of the pores.

Bring a pan full of water to a heavy boil. Any crap will float to the surface. Toss the water out, rinse, and boil again with fresh water. Now that it's clean and hot, toss out that second load of water. Let it air dry and pour in a teaspoon of vegetable oil (canola,flax), or pure fruit nut oil (almond). Wipe it around the entire interior of the pan with a paper towel or white cloth scrap. Allow the pan to cool, then wipe off any excess. That's it. You're done.

Once you experience food sticking to it, just fill 'er with water, boil it out, and reseason.

Highly acidic foods like tomatoes will eat the finish and ruin your season, so reseason directly after making spaghetti sauce, etc., or use another pan.

Been at least eight years since I have been to their web site. Love the way the search works for springs! Unfortunately did not find one close enough. Went back to where I found the close ones sold in sets of ten and noticed something very odd. The 3" were $80, 3.5" $90 and

4" $93, but the 5" were only $20. (Need 2") Shortening a spring is no big deal so I now have 20 lifetimes worth of springs on the way.

Local Walmart shows it "Available for immediate pickup" which I assume means in stock. On wife's grocery list and can get it within a few days if I have to order it.

Side note: Way too much effort for me, but found you can turn baking soda (sodium bicarbonate) into washing soda (sodium carbonate) by baking it at 400 degrees F.

Once is good enough. Twice if yer anal. But 4x is just plain OCD. ;)

Standard, off-the-shelf Vaseline is not food safe, but they do =make= a food safe Vaseline.

True, but this is not a pan that will be re seasoned from use. Also may need less if the electrolytic works and do not have to sand blast it. Will keep everyone posted when I get to that step.

Will start looking... Years ago worked at Evenflo, noticed the 'grease' they used in the steam presses that made nipples looked exactly like Vaseline. Came in 20 gallon drums labeled White Petrolatum. Yep, same thing different name.

Bueno. Molasses is another good rust remover.

snip

Yup.

Got my de-rusting tank set up last night and it seems to be working great! Plastic tote big enough to hold the two largest pieces. 3/4 cup of washing soda in approximately 7 gallons of water. (You Tube videos were all over the place on how much. From "too much will not work" to "the more the better".) Charger on 6 amp 12 volts. Ran it for a few hours and unplugged it overnight since my charger seemed to be getting slightly hotter than it does charging a battery.

About four more hours this morning and pulled them out. Most of the red rust was gone and /some/ of the black rust scrubbed off with a scrubbing pad in the sink. Back in and bubbling more vigorously than before. Picked up a new wire brush today, sure it will work better Think my goal is all the red rust gone and not worry about any remaining black rust that will not come off easily?

Found some flax seed oil so will try that in a few days after all the parts are done.

It sounds like you're on top of it, William. About the black rust: It's actually considered to be somewhat protective. Some of the conversion coatings actually convert to that black rust, which has a common name I can't think of at the moment. You don't have to get rid of all of it before applying whatever final treatment you have in mind.

Aside -- my desktop computer crashed; it may be the final push I need to get off of Usenet altogether. There is so little left of interest, and so much trash, that it really isn't worth the time. So if I don't reply, it's not because I'm ignoring anyone. It's because I've found better ways to use my time.

Good luck with your derusting. The electrolytic method is a really valuable tool to have in your toolbox.

Say what? The guy who invented it used to eat a big spoonful every day, fanatic about it he was. What might make Vaseline(tm) not food-safe?