January 15, 2015 at 4:11 am #48189
I have been trying to use a media blaster to help with a few restoration projects. I first purchased a 20lb gravity fed unit that worked somewhat but was temperamental with the media used and was slow; I then purchased a 25 pound pressure pot blaster it was stronger but had a limited area of contact and seemed to clog often. I just purchased a 90lb pressure blaster that I paid almost $500 for and I cannot get it to work at all. I am told by the manufacturer that my compressor is too small (80 gallon two stage 12 CFM). Does anyone have any stories of successfully using media blasting equipment? What type of media? What size compressor, etc.? Please help I hope I have not made a $500 mistake.January 15, 2015 at 7:53 am #48190
good media blasting equipment cost big money. far more than $500. my pot isnt an expensive one at all and was almost $4k. cheap pots usually use plumbing fittings like regular ball valves to regulate media flow. these tend to clog or maybe work for awhile then stop because they wear. a good pot will have an actual mixing valve with internal carbide or hardened steel components. as for your compressor 12 cfm is very small but can probably work for doing small parts like the size of your hand, etc. anything larger will take a very long time. my compressor will do 30cfm and for blasting even that is very small. i would never want to do a whole car with it. i have done complete cars but had to hook my pot to a 185 cfm diesel compressor. with all that said though im not saying you wasted $500. it depends on what your expectations are. if you just want to do small items like brackets, etc then its fine. the clogging may be due to how you have it tuned. try throttling the valve closed a little going to the bottom of the pot. this will allow less air going out your main line and put just a little pressure in the tank so its pushing the media a little. basically lowers the psi in the output line and raises the tank psi. clogging can also be from your media. it can be poorly sifted and have irregular crap in it or maybe its a little damp and doesnt fall into the airstream right. your supply air from the compressor needs to be perfectly dry. if not you will always have a clogging issue.January 17, 2015 at 7:53 am #48192
Jim gave great advice.
We did a lot of media blasting (with silica, #20) at a shop I use to work at. We had a separate building out back solely for blasting in, and ran off an Ingersol Rand 185cfm diesel compressor. That would do anything you needed. If you are stripping complete vehicles or large jobs, you pretty much need something close to this size, or else send the job out to be blasted.
My experience has been that anything that runs off of shop air, is only suitable for blasting very small areas now and then. Silica is a great media, it is aggressive, fast and removed rust well. The only downfalls I can think of is that it can be too aggressive for some applications, is very dusty and can cause silicosis if you don’t wear proper fresh air breathing equipment. Ive heard glass beads can be good, but have never tried them, and I have used walnut shell which is much less aggressive and doesn’t seem to remove corrosion much, but its not real dusty at least.
Any media used needs to be kept very dry to avoid clumping and, equally so, your air needs to be very dry too.
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