Sandblasting problems, need help

[Jinto]

Hello everyone,

I purchased a 20 lb sand blaster from Harbor Freight (this one), I also purchased a 25 lb sack of glass bead media (this stuff).

I followed this video here from youtube: YouTube- Case Mod: Paint Computer Chassis, www.mnpctech.com
I went about using the sand blaster just as they did. However, after using more than half of my 25 lb sack of glass bead media, I was barely able to get through 1 panel (1 side only). I don't know what I'm doing wrong. I have an idea my air compressor might not be adequate enough for this project. I have a 25 gallon Craftsman Professional air compressor, it pushes 8.6 SCFM @ 40 PSI, and 6.8 SCFM @ 90 PSI

I was shooting the media at around 85 PSI, primarily because the air filter I was using on the line said to not exceed 90 PSI.

I don't know if the media I'm using is coarse enough, or whether my PSI is too low. In the video, he uses an 80 grit media as well, however, fails to mention which type it is. I did notice the media was of brownish color, maybe it's walnut shells? I know it's not the same media I'm using because my media is white in color.

After he was done blasting, his panels were rough to the touch, mine were smooth......... not a good thing for a high build primer to try and stick to.

Could it be that my 20 lb blaster is too small? I notice most people get the 40 lb version, I was just trying to save some money being that the 20 lb blaster was on sale for $60 vs $100 for the 40 lb blaster.

All I know is that after completing 1 half of 1 side of a panel for my case, I've already blown through more than half of my 25 lb sack of glass media. I cannot afford to go through this much media, due to the fact it costs $25 per 25 lbs.

So I'm asking what you guys suggest I do?

I'd appreciate any help that can be provided.

 

[captaincranky]

Why not use something like "Aircraft Stripper" then prime the case? In any event, I'd strip the case first, then blast

If you're shooting for a distressed look, I'd use sand, not glass bead. Glass beading is best done in a cabinet, where you can capture and reuse the material. Also, glass bead is notoriously gentle.

Your compressor doesn't supply enough air to sustain a heavy duty blasting operation. As soon as you start, the pressure drops. Better perhaps you should try with regular sand, and try using short bursts. Also turn the regulator all the way up on the compressor, believe me, it'll drop to 86 PSI soon enough.

As an afterthought, if you have no luck, you can take your parts to a gravestone place, I'm pretty sure they have heavy duty sandblasting equipment. Fix it to some plywood first, so they don't bend it.

I think Aluminum oxide sand is brown.

 

[mailpup]

I have the small Speed Blaster by Unitec but I haven't actually used it yet. The operating pressure is 60 to 125 PSI and the working pressure is 125 to 200 PSI. Your PSI is within range although it could be higher but you probably should change your media. You might try plastic beads.