I've used that particular blaster on the frame of a 83 GMC truck. The pressure washer I used was putting out just over 3700 psi with a pump rated at 4 gallons per minute.
Your results may certainly be different than mine, but I found two thing's are VERY important:
#1- The media you are using MUST be carefully screened and dry. This blaster, in my use, pulled through Black Beauty coal dust (I tried both fine and medium grades) in clumps. One moment I had terrific results. The next, I was simply spraying water. VERY uneven, and I'd tried to take every precaution.
#2- Be prepared to make a HUGE mess. Dry media was somewhat easier to control. The wet mush that you'll be spraying will continue to travel with the water AND portions will fly through the air in a semi-dry state. It will hit you AND stick to you! Dry media can be swept-up. Slag mud, on the other hand, is tough......even worse when it dries!
That water blaster will work, but it has its own quirks. Halfway through the job, I went back to my small dry-media pressure-tank blaster. It worked slightly better, even though it nearly killed my compressor.
Hope this helped, and Good Luck!!!
