FMJ

iTrader: (2)

Other options I tried were:

Sanding discs (flap type) on angle grinder. These are good but clog and wear very quickly. They are also aggressive enough to cut the metal which is bad. Use a fine one and it clogs within minutes. They are great for rounding metal but not for this.

The paint remover type wheels that are like a resin hardened sponge. These are great but expensive and again wear down very quickly.

Shot blasting. The undershield is too absorbent and unless you use a very strong setup it doesn't work. It is also VERY VERY unpleasant and messy to DIY.

Chemicals will cut through but you would need a lot of it. And they are messy. Also they leave lots of residue which you would need to clean off to avoid problems when recoating. Plus you would then need to remove any rust anyway.

So all in all when we are talking about removing factory undershield and the paint layer beneath plus any rust the only thing that worked for me cost wise and time wise was a steel angle grinder brush. It still takes ages to do a whole car (days and day and days) but it was the best of all the options I tried. But it is dangerous and you can burnish the metal if you go too hard.... you can also set fire to things the other side if the metal is thin and you still have plastic/fabric in the car.

Admittedly this is not the way to do it professionally but I was limited by facilities and equipment.

gary77

iTrader: (1)

Was it a Subaru you did it to , have you got a project thread , how did you go about getting under the car , I'm thinking about getting the ramps I can drive up , do the front half then reverse up and do the rear , I'm not sure if I should remove what's there if it looks sound and just do the bits that need treating , and paint over the whole lot