A 4 inch angle grinder with guard removed and a rubber sanding disc attachment is a better option.

If you have a decent sized compressor it is cost effective to buy a pressure blaster from Trade Tools (less than $200) and sand blast the hard to get at area's yourself. The ceramic nozel tips wear out quickly and are expensive to buy in Australia, can also be hard to find a supplier as Trade Tools don't sell the consumables.

You can buy packs of ten tip in different nozel sizes from the US on Ebay for $5 to $10 a pack. I buy 5 packs at a time and postage is less than $10 priority mail.

I have used my blaster on wheel rims, various panels, steel handrails, my work trailer and for frosting glass window panes..... it was well worth the money to buy it and has saved me ten times it's value.