Media blasting question

[Jeff Wilk]

Just got my blast cabinet assembled and compressor is coming this week.....very exciting!!

Looking at my various suspension and engine parts i am now wondering how free of dirt and grease
They should be before blasting them inside cabinet?

I am using glass beads which i also hope is correct???

Any advice on pre cleaning and choice of media?

Different media for valve covers and air cleaner than for cast
Metal parts of suspension parts?

Excited but nervous........jeff and noah

[Jim Stamper]

      I only use glass beads, and, although you will find blasting is a much more complete cleaning and prepping method, you can still soon get tired of standing there.  Pre-cleaning will make the jobs go much faster as well cut down on your compressor running time and keep your media much cleaner.  It is a great tool, but best when used in conjunction with some prepping first, if necessary.

     I use glass beads on air cleaners and such too. It preps the metal by providing a good surface for the paint to adhere to, and cast metals usually have plenty of roughness for the paint to stick to anyway, and the blasting cleans those surfaces out good.  My thoughts on the subject.

     When worried, try a test piece of material, or a surface that won't be easily viewed.

                                                           Jim Stamper, CLC#13470

[kkarrer]

Jeff,
    That's one of the most useful tools you'll ever have.   You'll find that you'll still need a post blaster as well as, like a garage your bead blasting cabinet is never big enough.  I found glass beads to be the best all-around blasting media and you can get it at Harbor Freight and other suppliers.  Prepping your stuff before blasting is VERY important.  I tell guys who want to run stuff through my cabinet to clean up their parts first.  Heavy grease/pariffin will only "catch" the beads as they're blasted.  If something is particularly greasy or has a lot of dirt or loose paint it's best to power wash it first if that's possible or run it through a parts washer or at least shoot it with some brake or carb cleaner. By the way, Easy Off Oven Cleaner sprayed on greasy parts prior to power washing works great! Whatever you blast off will wind up in the bottom of your cabinet and will get sucked up back though your system and returned to the surface that you're blasting AND it recycles through the air in the system so just keep that in mind.  Depending on how heavily I'm using my blaster, I capture the material in a big plastic container (kind of like changing oil.  You just open up the chute at the bottom of your cabinet.) and screen it over a big 5 gallon bucket and return the beads to the cabinet if they're not too "dusty."  I also save them for outside blasting with my pot blaster.  As to the stuff that accumulates in your vacuum canister...since it's mostly rust, steel, and dirt I just put it out on my yard or around trees and shrubs.  They like the iron.  Here's a quick tip.  While your blasting there will sometime be a bit of cavitation around your pick up in the bottom of your cabinet or sometimes a piece of something will get lodged in there.  When that happens, just put your gloved finger over the nozzle while stepping on your feed valve.  The back pressure will clear the area. Also pull your gloves inside out (they wind up on the outside of the blaster) from time to time to let them air out and dry and if they're dry and you're not going to be using your blaster for a while, put something inside of them (rags or a piece of styrofoam) to block them off.  I've had nesting birds in mine before and worse a damn chicken snake went after the birds and was in there when I put my hand inside!  I did one heck of a dance and that snake did not survive the experience. Oh, also remember that regardless of the size of your compressor tank, you should let it "catch up" from time to time while you're blasting.  I just finished a set of wheels (see the restoration blog of my 1941 6227D coupe) and of course ran them through the blaster first. I would blast just one side, let the compressor catch up (cycle off) and then blast another side.
Good luck,
Ken Karrer 1941 6227D Coupe

[Jeff Wilk]

Ken, and Jim, thanks so much for that information.  It just kind of hit us yesterday after assembling the cabinet....sort of wait a minute.....where does all that dirt and grease go from the parts when you blast them.....wont the glass beads just stick to the grease......and then came the posting.

You guys are all so great with the advice.  What about length of hose?  I plan on keeping the compressor in the garage, but also want to run things in my two out buildings which would require running a 100 - 125ft length of 1/2 hose.  Any issues with that?  Its a 150psi compressor that puts out 13.5 cfm

Jeff & Noah

[Glen]

I’ll add a couple of items:

Glass bead requires a lower pressure than most other blast media.  If the pressure is too high the beads shatter and it becomes worn out too soon.  I forget what that pressure is but maybe someone else will chime in with that info.

When you blast something take it apart completely.  The media will get into everything.  It goes through gaskets and seals with no problem and then you have to disassemble the part to clean all the dust and media out of it.  The media is strongly attracted to ball and roller bearings so they should never go into the cabinet, even in a sealed unit. 

You can protect machined surfaces with a good duct tape.  It will dull the surface of the tape but it is amazing how well the tape stands up to the blasting. 

Your going to love your blaster. 

[kkarrer]

Jeff,
      You do lose pressure at the working end as you lengthen your hose, but if you're not running an impact wrench on the end of the line that's usually not an issue.  What can be an issue is moisture in the line.  You want a good separator between your compressor and the blasting cabinet at the very least.  Running hard lines in or to your out buildings is also something to consider.  I used schedule 40pvc 1/2" or 3/4" but galvanized pipe can work too.  If you're running a paint gun on the end of that long line, you'll want one of those disposable, in-line driers on your gun to eliminate fish eyes.
Ken