Serge and Doug, See Imbedded text: Doug Rupert <drup...@sympatico.ca> wrote: Personally speaking Serge I would not sand them as the sanding leaves tiny scratches that are potential stress fracture points. Sanding with 400 grit paper would be what to use for final sanding. This would leave a nice finish that your primer to "grab" into and not leave any scratches worth worrying over.
Use chemical paint remover and thoroughly rinse with mineral spirits before a final washing with soap and water. If you choose to use this method, before you apply primer, "break" the surfaces with 400 grit that will allow the primer to "grab" into, then use a lint free cloth soaked in whatever thinner you are using for the paint. Allow to evaporate then apply the primer. As far as primer choice, I would probably use a good metal etching primer sold in automotive paint supply stores. Tell the sales rep that you are painting 4130 that is a highly loaded part. He or she will probably sell you some brand of epoxy primer and compatible top-coat (of the color of your choice). Heating could also ruin the strength properties of the steel unless one knows exactly what they are doing. This is simply not the case, heating to fusion welding temperatures would cause a loss of properties, and would require normalizing and re-heat treatment in the area of the weld. (according to my McDonnell Douglas Design Handbook.) Follow the manufacturer's recommendations in regard to temperatures while apply-ing and cure. Also ask the sales rep at the paint store for advise for baking the finish in an oven. (probably around 150 degrees F). My preference would be to have them powder-coated and forget about corrosion for the life of the bird. Sometimes a powder-coater isn't available (or reliable), but even if the parts are powder-coated, you still need to keep an eye out for corrosion in this area. Mainly because you would have to remove the powder-coating to get the bolts through. Scott Cable KR-2S # 735 Wright City, MO s2cab...@yahoo.com --------------------------------- Discover Yahoo! Have fun online with music videos, cool games, IM & more. Check it out!
