The Stovebolt Site Forums The Shop Area Paint and Body Shop Painting dirty cast iron

I'm doing a rattle can restoration of an old 1940s garden tractor chassis.
It has a lot of cast iron parts that are greasy and oily. How can I clean them so that primer and paint will stick?

Pressure washing them should work good.
Samantha

you can scrape off what you can. you could use some degreaser too. powerwash it after that. it may not all come off anyway.

Kerosene. It's great. Like Tony the Tiger great. After that, steam is nice if you've got it. A putty knife and a wire brush is also helpful.

Soaking it with something like Simple green and then pressure washing will get a lot of it. You will probably never get all the dirt, but painted dirt doesn't always look that bad.

Cleaning cast iron parts is one of the few things rotary wire brushes excel at. Get all the oil and grease off with solvents or pressure cleaning and then put the wire brushes to it. You'll be amazed at how much hard, dry crud remains especially in the all the nooks and crannies. It's almost indistinguishable from the iron.
EXAMPLE

You could try electrolysis to get rid of the rust.

Read all about it here: http://www.jalopyjournal.com/forum/showthread.php?t=10461

The '40 216 engine that I am working on was covered with 68 years of oil and red clay, some of it hard as a rock. We sprayed it with simple green twice, pressure washed it 3 times and it still had a quarter inch of crud on it. Then I got 2 cans of oven cleaner at the dollar store. Sprayed it on and let it sit for a day. Pressured washed it and got to bare metal. Then you can see all of the hard stuff in the corners to scrape with a dull knife. Good luck.

We use oven cleaner and hot water powerwashers on antique tractors then primer with a buff colored primer and paint

Scrape or wire brush what I can.
Oven Cleaner and pressure wash large intricate stuff (motors frames, etc. and kerosene on small stuff (fits in rubbermaid tub).
Pressure wash to remove oven cleaner.
Phosphoric acid (Phospho - Home Depo) brush for large stuff, dip-n-soak small stuff (again rubbermaid tub).
Large stuff looking at Eastwoods Rust Encapulator http://www.eastwoodco.com/jump.jsp?itemID=24048&itemType=PRODUCT
Wire brush small stuff.
Primer and paint.

Looking for a way to preserve the beutiful finish of the cast. Clear laquer does not seem ot hold up, but without primer can't say I blame it. Anybody know of a clear primer or good cast iron silver/gray paint lookalike?

Brett

If the parts are removable and small enough to fit in a bucket or small barrel, a long soak in a solution of lye works really well (take the appropriate steps to protect yourself from a caustic solution). You can leave the parts in there for as long as it takes, they won't rust or ablate. Lye only attacks the grease and oils. Its the same active ingredient as oven cleaner. A can of Red Devil powdered lye will do you right up.

I would just throw the parts in lye for two or three weeks, leave them in the sun, and stir them once in a while. A good rinse and paint is all you need after that. Engine manifold paint resembles virgin cast iron pretty well, but does not cure very well without heat.

I use the foaming engine cleaner, then pressure wash. Then repeat. Then use POR15.