Question about Media Blasting and Compressors, Which is the correct combination? |
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Question about Media Blasting and Compressors, Which is the correct combination? |
ellisor3 |
Jul 23 2014, 09:28 AM
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#1
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HPWhore Group: Members Posts: 811 Joined: 23-October 08 From: Fleming Island, Florida Member No.: 9,683 Region Association: South East States |
I recently bought a media cabinet and I already had a 30 gallon compressor. I started a trial run with the cabinet on a pair of calipers. I got no where. The media barely put a dent in the caliper paint. I sprayed for 30 minutes and completed an area about 3"x3". The media was glass bead 70 grit and the compressor was set at 100 psi.
I believe my issue may be the amount of air the compressor moves, and not the PSI. What is the recommended amount that will work on brake calipers? My compressor is a 5.2 CFM. Is glass bead appropriate for enamel paint? What size compressor do I need? What is everyone else using? |
Brian_Boss |
Jul 23 2014, 10:51 AM
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#2
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Member Group: Members Posts: 324 Joined: 3-June 03 From: Dallas, TX Member No.: 781 |
My compressor is a 5.2 CFM. I think this is the root of the problem. No idea what sort of cabinet/gun you are running but the smallest blast gun nozzles I remember seeing use > 10 CFM. Is glass bead appropriate for enamel paint? What size compressor do I need? What is everyone else using? 1) If you don't have a pressure gauge at the cabinet, add one (better yet, gauge and reg). Without it you really don't know what the PSI at the gun is. 2) If you are trying blast continuously with that setup, you are almost certainly emptying the tank and running at something below the set reg pressure. 3) If you really are blasting with glass beads at 100 PSI, you are really hammering the blast media. I try to stay under 50 for best media life. Once the beads get pulverized, they are even slower cutting. 4) Glass beads, while leaving a nice surface finish, are not the fastest for stripping paint. For steel that will be repainted, I switch to garnet or Al Oxide media. FWIW, I have a 5hp two stage rated ~18CFM @ 90 PSI and it still runs almost continuously while blasting. Hope this helps |
ellisor3 |
Jul 23 2014, 11:01 AM
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#3
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HPWhore Group: Members Posts: 811 Joined: 23-October 08 From: Fleming Island, Florida Member No.: 9,683 Region Association: South East States |
My compressor is a 5.2 CFM. I think this is the root of the problem. No idea what sort of cabinet/gun you are running but the smallest blast gun nozzles I remember seeing use > 10 CFM. Is glass bead appropriate for enamel paint? What size compressor do I need? What is everyone else using? 1) If you don't have a pressure gauge at the cabinet, add one (better yet, gauge and reg). Without it you really don't know what the PSI at the gun is. 2) If you are trying blast continuously with that setup, you are almost certainly emptying the tank and running at something below the set reg pressure. 3) If you really are blasting with glass beads at 100 PSI, you are really hammering the blast media. I try to stay under 50 for best media life. Once the beads get pulverized, they are even slower cutting. 4) Glass beads, while leaving a nice surface finish, are not the fastest for stripping paint. For steel that will be repainted, I switch to garnet or Al Oxide media. FWIW, I have a 5hp two stage rated ~18CFM @ 90 PSI and it still runs almost continuously while blasting. Hope this helps I have tried it at lower PSI's (60-80) and I have not gotten any results I also have Aluminum Oxide and it works a litter better but not by much. I moved the compressor next to the cabinet and ran a 3ft hose to the cabinet to reduce the distance, but it did not seem to help. I have started to look at compressors with much larger CFM ratings and they are a huge jump in cost. |
Brian_Boss |
Jul 23 2014, 02:46 PM
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#4
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Member Group: Members Posts: 324 Joined: 3-June 03 From: Dallas, TX Member No.: 781 |
Can you do a quick test on a test piece that has a known paint on it?
As a baseline, I just popped out to shop and tried two things. First was a scrap of 914 body (factory paint and primer and second a can of rustoleum. Holding the gun steady 3-4 inches from the surface, it took a count of four to hit steel with glass beads at 50 psi. Cranked it up to 80 PSI and same result in 2 seconds (this was the 914 piece. The rattle can was stripped as shown with as short a blast as I could do, probably 1 second at 50 PSI. I have started to look at compressors with much larger CFM ratings and they are a huge jump in cost. If the compressor has cycled off, the blaster will work as well as it ever will for the first 30 seconds at least. If you are not getting good results for that first thirty seconds, there is an issue beyond the smallish compressor. BTW, are these the alfa brembos, boxter caliper, 944 turbo, something else?? Just trying to get an idea of what you're up against. |
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