At the risk of sounding stupid will a rivnut be any good for making an earth on the chassis?
If not are there any decent ways other than welding bolts on?
Thanks,
Mark
Rivnut works fine for me + cleaned a small area around it for a locking washer.
Paul
I've been told it takes six days to make the earth , then you can have a day off! but I hav'nt seen this proved yet!
[Edited on 23/7/08 by tomblyth]
Hi
I would not personally use a rivnut, they do not allow sufficient torque to be applied in my opinion. I would pick an area of the chassis consisting
of a 3mm+ plate and drill an 8mm hole in that. Thouroughly clean the area around the hole both sides and install a spotlessly clean 8mm bolt and two
nuts, torque the first nut and use the second to lock it. Then protect all surfaces except the outside face of the second nut and exposed thread with
paint, silicon etc. If you have a multimeter you can check the resistance from the bolt shank to another clean area of the chassis and it should be
very low, about 50 milliohms. For convenience I would suggest installing two or three earth posts at convenient locations.
Regards Mick
You could run a seperate earth wire. I used car amp power cable running from the batery, front and rear.
Darren
quote:
Originally posted by Paul (Notts)
Rivnut works fine for me + cleaned a small area around it for a locking washer.
Paul
quote:
Originally posted by tomblyth
I've been told it takes six days to make the earth , then you can have a day off! but I hav'nt seen this proved yet!
[Edited on 23/7/08 by tomblyth]
I welded a bolt into a small metal plate, then welded the plate to the chassis. This is located on a cross-piece between the engine and battery.
Ive used several methods.
The Main Battery earth is a small welded plate with a bolt welded to it.
The headlight earths are a hole in a bracket with a bolt through.
The rear lights are a Rivnut.
All working OK after 3 years and 4000 miles.
All earth points were rubbed back to bare metal, then smeared with grease to prevent rusting on the bare metal parts.
Allow 6 working days + 1 day of rest for the job.
I wouldn't. Aren't riv-nuts made from ali? Is it a good conductor of electrikity??? I know it conducts heat nicely but not sure about electrons... I'd also worry the contact area isn't huge....
Just looked it up. Ali has 3.9x the resistance of steel per metre (for a given diameter)....
Talking about the grease on the earth point would it be better to use copper grease to make a better connection
I wouldn't put copper grease (or any other grease) between the bolts / washer or whatever is making the contact. Copper slip has copper in it but only as a lubricant. It will still act as an insulator. Normally you just do plain steel/steel but liberally apply the grease over the top to prevent moisture getting in. It won't make any difference if its copper slip or not...
ok, thanks all. I'll try to nut n bolt if poss.
Tee He
I just can't see the problem. 
Paul G
Aluminium is a good conductor,
Aluminum is a silvery-white metal with many valuable properties. It is light (density 2.70 g/cm3), non-toxic, and can be easily machined or cast. With
an electrical conductivity 60% that of copper and a much lower density, it is used extensively for electrical transmission lines.
Or from wikipedia (if you like that one)
Aluminium Electrical resistivity (20 °C) 26.50 nOhm·m
Iron Electrical resistivity (20 °C) 96.1 nOhm·m
The ratios are 1:3.9 but the aluminium is more conductive (lower resistance). Conductivity and resistivity often confused.
Matt
[Edited on 24/7/08 by matt_gsxr]
Bizarre! The website I looked at had it per metre and it was the other way round
Oh well I live and learn!!!
Then again.... wikepedia 