Media blasting materials, k member, steering box

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Mopar Momzee

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Want to sand blast/ media blast k member and steering box what’s the best way to get a clean product. Going to do it at home what material should be used for this process?
 
Clean oil and dirt from all parts first. Me= use sand on K-member (and all hard steel parts) and glass beads on your box if aluminum. Beads are more gentle on softer metals.
 
I use #3 crushed glass. Make sure to wear a respirator so you dont breathe any of it in. If doing open air use a big tarp to capture and reuse the media. This **** goes everywhere. Its messy.
 
Degreasing everything first will help any media last longer and keep your cabinet contents from getting contaminated if you aren't doing this outside with a pot blaster. DO NOT use silica / sand without an adequate respirator system; silicosis is a nasty disease no one wants, and a wet bandana wrapped across your face is not "adequate."

This blasting media resource thread on the GarageJournal has been going for such a long time it's almost too much info nowadays but the Search can help you find key points.

Grainger also has a much handier chart you can print out and hang up by your blast equipment or save on your phone. (I tried to copy and paste the chart here but it's incompatible with the message board layout. Click the link and scroll down a little. It's perfect.)
 
When I recently refinished my K Frame, I took it to a local NAPA store that had a large oven to really clean the part. I'd heard that it's nearly impossible to remove all grease/oil doing it by hand. Total cost was $25 to bake the K Frame, and it came out perfectly clean, bare metal.
 
This is a new one for me. I'm picturing hot grease and dirt. Where does it go? How does it jump off the K-member and into the air? Sorry for being so stupid- educate me.
 
@Murray, these pics might help illustrate what 69 M Code is trying to explain.

In my industry it's called "outgassing," the process of pre-heating all parts for a longer time and at a temperature higher than that used to cure powder. What it does is bring any trapped air bubbles, impurities and chemicals in/on the metal to the surface where they can be blasted away as part of the prep work. Aluminum shows the results even more dramatically than steel does, which mainly turns a blue / purple color while any grease just turns blacker.

Outgassing results.jpg


Outgassing results 2.jpg


What's most telling about this particular valve cover is that it was BRAND NEW, shipped direct to me from Jeg's by my customer in Oklahoma along with an air cleaner assembly. Aluminum is very porous and absorbs all kinds of gunk, especially oils. Steel doesn't absorb as much but heating it up turns its impurities into chalky dust instead of sticky grunge. Sometimes I even get out the big propane flame thrower with a 3 foot handle to speed things along on k-members, suspension bushings, etc.
 
This really is new to me. Thanks for the help. In the case of aluminum, are those v/covers now better prepared for polishing or better prepared for powder coating because of the high heat process ?
 
This really is new to me. Thanks for the help. In the case of aluminum, are those v/covers now better prepared for polishing or better prepared for powder coating because of the high heat process ?

Yes sir. Without that crucial step, all of that grunge will actually come through the powder if it isn't removed first. Extreme cases will produce fissures in the finish you can actually see and feel, and if you examined them under a microscope it would look like miniature volcanoes. Part of the grunge that outgassed from the topside of the parts was probably factory metal polish.

Here's how that big spread turned out.

IMG_1001.JPG
 
Thanks everyone lot of info just picked op blasting cabinet from harbor freight looks like there are some mods to make.
 
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