From: djb@invalid.com   
      
   On 26/10/2025 18:40, Jim Wilkins wrote:   
   > BP wrote in message news:10dlm7r$5f5t$1@dont-email.me...   
   >   
   > Long ago I remember a priming paint sold for use on rusted steel   
   > surfaces without cleaning beyond removing loose rust.   
   >   
   > Physically it resembled white glue, but when coated on rusty   
   > surfaces the rust turned black and became paintable. It was   
   > nowhere near as good as abrading to clean metal, but helped some.   
   > I believe the product was a latex paint with phosphoric acid, but   
   > don't have any firm evidence, nor evidence the idea makes sense.   
   >   
   > I can't remember the name and now find nothing that matches the   
   > description on line, so far as I've looked.   
   >   
   > There's a stretch of gutter on my roof that has pinholed rust.   
   > It would be nice if I could try such a primer on the interior   
   > surface of the gutter to extend its life by a couple of years.   
   >   
   > If this tale jogs any memories please write.   
   >   
   > Thanks for reading,   
   >   
   > bob prohaska   
   > ---------------------------------   
      
   I think the stuff that turns black is based on tannic acid and converts   
   the surface rust into iron tannate.   
      
      
   >   
   > P O R Rust Converter. When it came out I called to ask if it was   
   > suitable for car body rust and they said no, possibly because UV   
   > degrades it.   
   >   
   > I'm taking a break from grinding out body rust spots on the 91 Ranger   
   > with a 2" abrasive fiber pad on an HF air angle grinder, among my   
   > favorite power tools. It might not be as satisfactory with a smaller   
   > compressor, mine is 3+ HP, 80 gallons, a mixed breed salvage project.   
   > A swivel coupler on the tool's air input improves its maneuverability.   
   > Rustoleum primer + paint has held up well for me on outdoor projects,   
   > but I prefer SEM products on vehicles.   
   >   
   > My gutters are plastic with shop-made hangers of 1/8" aluminum flat   
   > stock that doesn't go over the top, thus I can clean them from the   
   > ground with a gutter cleaning scoop on a pool cleaning extension pole.   
   >   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)