Old De-Rusting Trick Works!

I was surprised.  Actually, floored is a better word.  But first, I have to do a Grandpa Simpson story for a while.

I ordered a lot of the metal for my new engine build last weekend and received all the pieces by last Friday.  The issue with buying small quantities of metals is like buying small quantities of radio parts or a couple of screws.  Their default is to sell you more than you need and then stick on rough shipping charges on top of that.  "Too much" is fine - to a point.  Everyone likes having some steel or aluminum pieces to have around for repairing things, or unexpected little projects; and in the words of Mae West, "too much of a good thing is wonderful".  We just always end up needing something like a one inch long piece of 3/16" diameter drill rod and the dealers want to sell you 36".  I'd be happy to get 12".  It's still more than I should need, but not excessively.  I was able to get about a dozen pieces of various things like that from a place I'd heard of, but never shopped at, Hobby Metal Kits.  Fair prices, $10 flat shipping.

The flywheel finished dimensions are 3.750" diameter, and 1.125 thick at the hub.  Like this:

Note that it says the material is either cast iron or cold rolled steel (CRS).  So off I went to the metals dealers to find a piece of CRS that could yield this.  Some shopping around, first at Online Metals and then on eBay, resulted in me finding that a 4" diameter by 2" long piece was going to cost about $55 with shipping.  Then I stumbled across an eBay seller selling a slightly smaller piece, 3-3/4 by 1-3/4, but saying it was D2 Tool Steel.  His price was $18.75, including shipping.  I figured that the important part was that flywheel has a density more like steel or iron than aluminum and the alloy doesn't really matter.  I took what's probably a better piece of steel for many uses at almost a third of the price as the 1018 CRS.

When I received the package, there was a 5 lb 10 oz hunk of rust in the box.  That's an exaggeration, but not much of one.  There wasn't a single spot on the disk that wasn't rusty.

The thing is, the rust probably isn't an issue.  I'm going to skim the diameter of the disk down a little and take off much of its length, and if it's just superficial rust, it'll be in my shop vac within minutes of starting.

Over the years, I've read many "how to fix rusted tools" articles that involved soaking the tool in a bath of vinegar with added salt.  (Here's a more in-depth source.)  One of the voices in my head suggested I try this, just to see if it works.  It was such an impulse decision that I didn't even take a "Before" picture.  It was in a plastic leftover storage tub, covered with vinegar by about noon Friday.   Naturally, I went by and looked into the clear tub a few times, but the vinegar went nearly black as the day progressed, so something was going on in there.  Saturday afternoon I took it out, gave it a light brushing with a Brillo pad and was shocked to find it looked like steel.  It looked etched with a matte gray finish, but with the exception of some black marks that I could probably scrub away the rust was gone.

This disk was the solid reddish-brown characteristic of rust, with a fair amount of black in the color, too.

Rust comes up as an issue all the time.  I'm sure we get more of it here with our humidity and salty sea breezes, but it's an issue in most places.  I can't tell you how many times I've come across this idea but dismissed it.  I waited until now to try it and it actually works.  I may be the only guy in America who dismissed the idea of soaking files or pliers or other tools in vinegar to de-rust them, but I doubt it.  Give it a try.


Edit 5/20 2147 EDT:  The bad writing fairy snuck in between editing and posting