Installing a ground stud for sheet metal

[Hagatronics]

Hi all

I'm relocating a battery in my weekend track/race car and need to install a new ground (earth) point on the chassis.

I want to make a reliable connection that doesn't corrode and conducts well. How would you go about it?

 

[PAToyota]

I'd weld a stud or tap a hole in the frame - not the sheetmetal.

 

[toplessHO]

if you want to ground the sheetmetal also use a rivnut

 

[mrolds88]

Do a combination. Weld a stud on frame and jumper a ground to the sheet metal. Rivnut a good solution to this also.

 

[rattle_snake]

Assuming the vehicle has no frame...

Drill a hole for a bolt/stud
grind paint off both sides
Use toothed washers (kep or whatever) on both sides
re-coat bare metal if in wet/humid climate

The starter current has to get back from starter to battery. Make sure your engine-to-chassis ground is of equal size (#2 copper or bigger) as your battery-to-chassis cable.

This is how I did ground for high power audio systems. 100A+

 

[matt_i]

For my boat trailer lights which goto ground, I did similar to Justin above, used a brass screw, scraped the paint, tightened, then buried the thing in dielectric grease.

 

[BD1]

Solid copper bolts are avaiable as a option.

 

[Hagatronics]

I found a welded nut (used for the rear seat belt - since removed) nearby I can use.

Obviously I'll remove the paint first before bolting in the ground lug from the battery.

It needs to carry up to 250A and not corrode the bare mild steel. Do I apply white lithium grease on the bare metal or only after bolting in the ground lug?

 

[gofastwclass]

Use dielectric grease on the connection(s) to prevent corrosion and help with conductivity under adverse conditions. Lithium grease may keep corrosion lower than bare metal but might hurt long term conductivity.

 

[toplessHO]

big misconception here is that dielectric grease DOES NOT conduct electricity.
Hence the name Di-electric.
It merely slows down corrosion.
Conductive paste is what promotes conductivity,such as CUPURCOAT

 

[matt_i]

I have used Jet Lube SS-30 pure copper anti seize for improving electrical qualities and it does also inhibit corrosion right there as well.

 

[BORING HOP YARD]

when bonding in aircraft we used a rotary wire brush in a drill motor to remove all surface treatment to assure it was bare metal on all area that were to be bonded. Parts were assembled with nothing on the areas to be bounded.
After assembly, the area would be covered with sealant or primer to seal off the bonded areas. You might also want to look at what type of metal your bonding and be on the look out for dis-similar metals, the last thing you want is galvanic corrosion in your bond.
Hope this helps