From: okunewck@psuvax1.cs.psu.edu (Phil OKunewick)
Newsgroups: rec.antiques
Subject: Re: Cleaning rusted steel ?
Date: 6 Apr 92 22:40:51 GMT
Organization: Random, at best

g5rsn@nssdca.gsfc.nasa.gov (Robert S. Nerem (Steve)) writes:
>I just bought an antique sled. It is all wood except for the steel 
>runners and a few steel braces. The steel is quite rusted, so I
>plan to remove the steel parts and clean them. My problem is, I
>don't know how! I've cleaned up brass before, but steel is new
>for me. Can any of you netters out there give me some advice on
>the easiest way to clean the rust off of these steel parts?

This one ought to make some purists faint...

Muriatic acid.  This is used for removing rust stains from concrete, and
works well on steel.  It also does a wonderful job of removing the inside
of your nose with the fumes and corroding all the chrome in the room, so
do it outside.  You can buy muriatic acid in any hardware store.

SAFETY FIRST (This is no joke - I tend to ignore warning labels myself):
   Do this OUTSIDE, or you will corrode all the metal in the room.
   Keep a hose available to dilute a spill.
   Wear acid-resistant gloves and safety goggles.
   Wear old clothes.
   DO NOT get a whiff of the acid.  This is very painful.
    The smell isn't too bad, but the acid burns inside your nose are.

First, use a wire brush on a handheld grinder to remove as much flaked
rust as you can.  Turn the brush around occasionally to keep it sharp.
You may need a hammer and small chisel to remove some of the stubborn
chips.

Next, pour the acid into a bowl and paint it on with a paintbrush.
Don't dilute it - that won't do any good.  When the acid goes dead,
wash it off with plenty of water.  Repeat the process until you have
gray metal (it may take 10 to 20 applications).  You may decide to
chip away more rust flakes between applications.  This clean surface
just loves paint, as the acid removes all oil and other coatings as
well.

Note: This also removes some of the steel (just like sanding).  It
also does a nasty job on high-carbon drawn steel - you get massive
pits the size of raindrops, and you can see the grain.  If the pits
start forming, forget about any more acid applications.

Naval Jelly is okay, but not as effective.  But Naval Jelly stays in
place.  Just make sure you clean it off before it deposits an
acid-resistant layer of white scum.  Naval Jelly is available for auto
body work.

For small parts, I use a 1:10 diluted solution in a half-filled
plastic 5-gallon paint bucket with lid.  The lid keeps the fumes
contained, and keeps the acid from going dead.  Again keep plenty of
water on hand and wash the acid off the outside of the bucket when
you're done with it.  You can store the acid bath in the bucket; just
label it well and keep it somewhere that it won't get spilled.


Sandblasting works wonders.  You can rent a sandblaster and compressor
for a reasonable price.  Do this over a clean concrete pad and sweep
up your sand for re-use (run it through a screen to filter out anything
that may clog the nozzle).  

At least two kinds of sand are available for blasting - regular sandblasting
sand and "glass beads".  The former leaves you with a finish that looks
like a print of 80-grit sandpaper.  I've never used the latter, but I've
heard it does a gentler job.


I rebuilt a couple cars using both acid-washing and sandblasting.
Both work well, and I don't know of a more thorough way of removing
rust.
Organization: H&SS Academic Advisory Center, Carnegie Mellon, Pittsburgh, PA