Metal finishing Q&As since 1989

-----

Removing paint from bumpers

Regards,

Peggy-Roshan
materials engineer - Whitby, Ontario, Canada
2004

We are going to de-paint bumpers by burning them in a furnace at 870 °C. We would like to know if the mechanical properties change during this cycle.The bumpers are steel (1008 or 1010).

---

2004

Just curious: what kind of paint do you have to remove that needs a temp. of 870 C? Normally, thermal de-painting takes place at temps like 400 - 450 °C. This seems to me like a waste of energy. And what is left of the mechanical properties of the bumpers after de-painting?

Remmelt Bosklopper
- Enschede, The Netherlands

---

2004

Personally, I would take a piece of sandpaper and see what kind of paint it is...I can't remember offhand what the results are for what types of paint (lacquer or whatever)...but that can be looked up or by calling a local automotive place or paint shop to find out what type of paint it is. If the paint layer is like a mist or very thin, try using just regular paint thinner and a little 'elbow-grease', or a polishing compound and just rub for a while "elbow-grease"...regular paint thinner or even gasoline could work without damaging most materials...for thicker or older paint grab some 400-600 sandpaper and find out what paint it is.

If a thick or older paint, TEST IT with sandpaper and find out what paint it is, if compatible to the strippers label, try out a paint stripper, nearly any type (TEST IN A SMALL SPOT FIRST JUST TO BE SAFE...in case the bumper is plastic) and follow the directions. Before applying the stripper though, I'd sand a corner of the bumper down to the original material to make sure what it is...if it's a plastic bumper, you may need to get a different more SPECIFIC type stripper for the bumper.

Shannon
- Spirit Lake, Iowa, USA

---

2004

Hi There,

NMP (N-Methyl-2-pyrrolidone) Works well at low temperatures at breaking down urethanes and polyester paints and is a water rinse (Use a high pressure unit. Karcher or similar) should any paint remain try another brush application of NMP and leave it on as long as possible more than three hours. It won't evaporate.

Hope this helps.

Robert Fyfe
Audio Eng. - Wyoming, NSW, Australia