In a message dated 7/29/98 10:15:01 PM Eastern Daylight Time, [log in to unmask]
writes:

<< Query:  How to best remove peeling paint from a terne metal roof prior to
repainting? >>

One suggestion is that you use walnut shell, corn cob or saw dust aggregate to
blast the paint off using a small blasting pot (Lindsey) hooked to a 175 cfm
air compressor. You should be able to rent this equipment, though the blasting
pot may require some searching. If you cannot find the aggregates local to SC
let me know and I'll give you supplier information. You will need a hood, the
stuff blows around and makes a mess. I suggest that since visual range is
limited when using the hood that you have someone to assist with a rope to
keep you from falling off the roof. OSHA requires a full body harness, but
since you are working on your own roof you have discretion in method of
personal protection. Make sure to wear shoes that give you tactile grip to the
roof. The organic aggregate is soft enough that it will not pit or severely
burnish the terne metal. You want to use a relatively small aggregate, I can't
remember the size right now, but think in terms of fitting within the "O" key
on your keyboard. You do not want to use a powder as you run into a problem of
condensation in the pot and clogging. A ceramic nozzle works fine, you do not
have to go to the more expensive ones unless you decide to thrown in a harder
aggregate. This is a lot faster method than a hand machine and a lot more fun,
though be prepared for a cloud of dust. We have used this method for removing
paint from cast iron buildings with good success... until we became aware of
lead. The airline industry uses the method with plastic aggregate to remove
the paint from the jetliners. We have played with the plastic aggregate to
remove epoxy paint from granite, but it is an expensive media.

Another option, if water is not a problem, is to get one of the $100-$200
water blasters now on the market and blast the paint off with a pressure water
spray. You may be able to combine this with a paint stripper. Be prepared to
do mock-ups before buying a lot of stripper.

Both options are contingent on the coatings not having lead.

][<en Follett