Stripping paint from "all" parts of newely aquired "barn fresh" 26 Roadster. Setting parts aside until enough pieces ready to warrant bringing out the the primer paint. Years ago I use to wash the parts with a "metal prep" just before priming to get the newly formed surface rust under control. What is the current thinking on what product to use just minutes before priming. Have a Happy NY
I use it all the time. Just be sure to wipe it all off with a clean rag before priming.
Dupont makes a Metal Conditioner Part Number 5717S Step A for this purpose. A quart bottle costs $29 retail and is mixed 1 Part conditioner to 2 Parts water. Stores that sell Dupont paints usually have it.
Jim, I checked the Dupont website and they recomend the 5717S as you suggested to be followed by their 5718S. Any experience w/this product?
I buy PPG products. They have a two step process similar to the Dupont process, but the local jobber never seems to have any product in stock, and flash rust always shows up before I can get the paint mixed and applied. I have been using Naval Jelly, applied with steel wool, as described in this discussion - http://www.metalmeet.com/forum/showthread.php?t=2257&highlight=metal+prep . The end result is a clean panel that does not immediately flash rust.
One precaution with any metal conditioner use is to be sure to wear good protective gloves (I use the medical style nitrile gloves) whenever you are working with these acids.
It's been a while since I painted stuff, but the PPG DP epoxy primer used to stick best to bare metal, with no metal conditioner. If you get the Safety Data Sheets, that'll tell you what works best.
Good point. I had to go back to the PPG "P sheets" to refresh my memory. Looks likt PPG has changed its tune with the lead free products. For example, this is what they have to say about prep-
Wash the area to be painted with soap and water, then clean with DX330
ACRYLI-CLEAN® Wax and Grease Remover, DX393 0.6 Low VOC Cleaner or
DX394 1.4 Low VOC Cleaner.
· Sand the bare metal areas completely with 80–180 grit abrasive. Sand old finishes with
320–400 grit dry by hand or machine or 600 grit wet.
· Re–clean with DX320, DX330, DX393 or DX394. Final wipe with a clean damp cloth
to remove any DX393 or DX394 cleaner residue.
· Chemical treatment or the use of a conversion coating will enhance the adhesion and
performance properties of the finished system.
· Prime aluminum substrate within 8 hours.
Prime carbon steel immediately after cleaning.
and under 'Compatible Surfaces' they say -
+ Film build of 1.2–1.5 mils of DPLF is required or the surface must be treated with
Metal Cleaner/Conditioner or coated with DX 1791/1792.
That doesn't really make much sense, since 1791 is a self etching primer???
It just proves that the paint business is continually changing, and you need to check with the manufacturer/supplier to know what the proper procedures are for your paint.
VERY interesting. I heard they had changed the DP formula. Sounds like it's not as "bullet proof" as it used to be. That's too bad, as it was super stuff (not that it isn't good stuff now, just sounds like it's not as forgiving of application).
Thanks for posting that!