Best Nozzle & Pressure settings for 10 Gal Pressure Blaster (1 Viewer)

[canman]

I have a a Princess Auto 10 gal pressure blaster, and it seems I use way too much abrasive compared to the surface area I'm blasting. I just went through one bag (50 lbs) of abrasive (recycled glass) and managed to do less than one third of my ARB bumper.

Here are the particulars:

1. Regulator is set to 95 psi (blaster manual says anywhere from 60-125 psi)
2. Compressor is a dual stage Ingersoll Rand rated at 100% duty and 14.8 CFM @ 90 psi
3. Nozzle is 1/8" (blaster manual states 1/8" nozzle requires a 4 hp compressor and 12 CFM @ 125 psi)
4. Abrasive is Opta recycled glass (20-30) grit?

I am only blasting an area no bigger than a nickel at any given moment, and I keep the nozzle tip about 6" away from the surface.

Any advice would be appreciated.

 

[Weber Sarge]

I'd bet you have a restriction in your hoses feeding the blaster - need to run 1/2" hose and high flow fittings , not the cheap off the shelf junk since they act like restrictors . It's a tough balancing act to get the right combo of nozzle size to match your system and it's also dependent on the type/grade of blast media . If you're using sand , smaller nozzle would work better (wear a respirator , please ) where black beauty or coal slag requires a larger nozzle . Not familiar with your blaster/brand , which style of gun does it use ?
Sarge

 

[canman]

Here's a pic of my blaster. Mine is older but essentially the same.

My hose is 1/2" ID. Not using sand, but rather crushed glass.

Used another 3 or 4 bags yesterday, and still have lots to do. This time though, I'm doing it inside my tempo (temporary outdoor garage), and laid some tarps on the ground in an effort to reclaim some of the abrasive. I picked up a 3/32" nozzle, and it jams right away with the grit size I'm using, so I will stay with the 1/8" nozzle. I also played around with the pressure setting, but 90 psi seems to be the sweet spot. Any lower, and it takes much longer to remove the powder coat. Maybe I'll try a little higher today. When everything is working well (no jamming of the nozzle with larger pcs of crushed glass), things seem to work better, but the abrasive consumption is also high. I think the media I originally had was laden with moisture as it had been sitting inside the blaster for almost a year. That caused a lot of jamming.
I only have 3 more bags left, and after that I will just sand whatever remains. In the future, I'll think twice before trying to sand blast something. When I'm done, I'll post up some pics.

 

[jblueridge]

I had a blaster like that and it always jammed up at the bottom line f the tank where the hose attached. Is it possible to change the plumbing fittings so the abrasive has a straight line of flow from the tank to the hose? Maybe try some coal slag like Black Diamond... It is made in various grit siz s. Try the "extra fine" size. I get large bags from a tool rental company that rents blasting equipment. Coal slag is harmless and less noticeable when spewed all over the ground.

 

[canman]

I finally finished last night after almost 6 hrs of fuzzing around. Super frustrating with all the blockages. In total I have probably close to 14 hrs of time into this. Sometimes it would run fine for a few minutes, but ultimately it would stop. After recovering the media and filtering it with a large seive, I think only 2 blockages were due to large pieces of glass. At times it appeared blockages were due to moisture in the air. So, I drained my compressor tank before I started yesterday, but only two small margarine containers of water can out. After what seemed were more issues with moisture, I added a small water separator directly to the blaster, but it collected absolutely no water (I have another water separator located in my garage).
I agree that the plumbing at the bottom could be streamed lined a little. I will take mine apart and redo. To keep the media flowing, I resorted to tapping the bottom of the tank and fittings with my 2 lb brass hammer which helped at times. Twice I had to remove the drain plug at the bottom of the vertical plumbing below the blaster and remove the blockage with a piece of coat hanger. I could see that the glass media was damp. It seems just a little bit of moisture will cause the media to stick and then jam. It seems that for long continued durations, some type of large type desiccant drier is required or refrigerated drier unit, as the compressed air gets very hot, and it was only something like 45F outside=condensation in the long air house I had coming from garage to my tempo. I have used the slag before with some success when I did my trailer hitch a couple years back. It produces a rougher finish which is more suited to thicker metal that had more rust scale. I originally started out with "medium" crushed glass, but it was a bit too course and left a rough finish. It worked well where there was some heavier corrosion, but left a touch surface where the surface was rust free and I just needed to remove the powder coat. So, I basically redid the whole bumper using the "fine" crushed glass which left a nice smooth finish for paint. To summarize my lessons learned for blasting with this type of blaster:

1. Have a compressor rated for 100 duty cycle that can provide at least 12CFM @ 90psi.
2. Do the blasting in an enclosure with tarps on the ground to maximize recover of media and to keep your neighbours happy.
3. Use a professional grade full face mask covered by a blasting hood. I had a 3M face shield that came with peel and stick protective plastic cut outs that could be placed directly on the face shield to protect it. The cheap hood I purchased was garbage. You need one that covers your shoulders. I ended having to make several replacement "windows" using a sheet of clear plexiglass I had lying around, but they didn't last long. In total I probably went through 5 or 6 of these, resorting to covering the last one clear shipping tape which was almost impossible to remove. In the end, I ditched the blasting hood and just used it as a shield on one hand.
4. Choose media and grade best suited to what you need to accomplish.
5. A means to remove moisture is absolutely necessary. The centrifugal type water separators are not enough.
6. Last but not least, keep the swearing and cursing to a minimum so as not to have your neighbours think your some type of alien looking madman.

 

[canman]

Some pics...