Removing rust, paint and grease: Cement mixer tumbling

[Machinitect]

Hey, I thought I would share this experiment for cleaning rust, paint, and grease off of old parts and sturdy tools like hammers.

I use a lot of the common rust removal methods. Wire wheel, cup brushes, media blasting, Evaporust, needle scaler, and sanding. With several large projects that require tons of cleaning, I am experimenting with tumbling in a cement mixer. My mixer is plastic so there isn’t much noise.

This media is sand, gravel, water, some Dawn dishwashing liquid, and some Zep purple power type degreaser. This batch of parts has old rusty tools mixed with some car parts and grease caked gears from another cement mixer project.

Let’s see how it goes! It’s like a dishwasher for old parts. Toss them in and walk away, rinse and protect from future rust.

 

[Machinitect]

Here is one of the hammers after about an hour in the mixer tumbler. It needs some more time, but this looks promising.

 

[tarbellb]

I like where this is heading

Keep us posted!

 

[Bighead38]

Interesting

 

[Hammer1963]

I like the approach on this. I have used this method several times when I have had multiple castings that I need to clean up. Depending on whether I am working with steel, aluminum or cast iron dictates what media I use.

 

[Machinitect]

Here are the results after 4 hours. The hammers are ready for finishing and new handles. The grease on the car parts is 90% gone, and rust is 100% gone. Most of the paint was removed. The exhaust manifold casting is clean inside and out. The brake drum is clean and ready for paint. This will be my first choice if the parts aren’t delicate and if I have the time to wait. This took around 10 minutes of my time to rinse and air dry the parts, and a few dollars worth of sand/gravel/ and soap. The media could be reused over and over again.

I really like the finish. It’s not as harsh as sandblasting and not as directional as sanding with grooves. I’d describe the finish as a multidirectional satin polished finish.

Go try it out! I’d like to see what happens when some other people try and experiment with different media.

I bet if you wired big vise castings to the mixing tines, the sand and water would wash and polish the inside of the castings.