Earth connection

[vixen]

I have my chassis sandblasted and powdercoated.
If I want to make earth connections to the chassis for electric cables must I then remove the powder coating to bare metal? If I am right the powder coating is some kind of "plastic".

[Sam_68]

Yes, you need metal-to-metal contact for the earth.

[tribbles]

What you can do is weld some bolts to the chassis. Before going to powder coating, cover them with masking tape, so when you get it back, you remove the tape to leave your bolt exposed.

On mine, because the chassis came powder coated, I had to grind it away, weld the bolt on, and then paint over the welds.

[grahambell]

If the chassis is thick enough (3mm) you might get away with drilling and tapping it either M6 or 1/4" UNF and bolting your earth connection to that.