[alpinelakespilot2000]

I'm using a brass stud through my firewall as my main ground point for the battery and main ground tab block at the panel. I've found the brass bolt, brass nuts, and brass (regular) washers, but I can't find brass lockwashers anywhere. I've tried ACE, Lowes, HomeDepot, and a specialty hardware store.

I have, however, found various grades of steel, zinc/steel, and bronze lockwashers. Are any one of these better than the other for ground purposes? (It appears as though the relays that Van's sells just use regular zinc/steel lockwashers on the copper studs, so I'm assuming that, electrically, it doesn't really matter that much for the lock washer part of the assembly.)

Also, and for future reference, is there generally any rule of thumb re: when you use the round split lockwashers as opposed to the star lockwashers?

Thanks.

 

[CESSNADON]

Check Mcmaster Carr. If it's made, they carry it. Don't think it is necessary though. I'd install the lug followed by a brass washer then a zinc or cadium plated star washer.

 

[az_gila]

Star washers......

....
Also, and for future reference, is there generally any rule of thumb re: when you use the round split lockwashers as opposed to the star lockwashers?

Thanks.

If it's to create an electrical ground, then the star type will probably work better since they have many teeth to slightly dig into the surface, which is good in this case...


Materials.....

Page 80-82 of this section of AC43.13 seems to say the plain old cad. plated steel hardware would be OK...

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/99c827db9baac81b86256b4500596c4e/$FILE/Chapter%2011.pdf


gil A

 

[elippse]

Try an internal-tooth lock-washer. Now to prevent corrosion on the joint, wipe the mating surfaces with petroleum or silicon grease, abrade the surfaces with sandpaper or crocus cloth, then assemble. Even better additionally use a spring washer under the nut or bolt-head to keep compression on the joint.The grease will keep air from corroding the surface after abrasion, and will be squeezed out during the assembly. I know it sounds heretical, but this is the method used by the power companies to assemble their aluminum conductors at the sub-stations, and this method came out of the ALCOA instruction manual, except they used NO-OXID grease.

 

[gasman]

Check this out......... http://www.vansairforce.com/community/showthread.php?p=162304&highlight=de-ox#post162304 ....... read#2

 

[Bob Brown]

I used a double nut instead of a lock washer.

 

[Mike S]

What does a lock washer do??

A lock washer is to prevent the nut/bolt from loosening. It does this in two ways-----spring tension to cause the threads to have side clearance drag, and teeth that cut into the face of the parts that are being held together. These teeth are directional, and resist rotation in the direction of loosening.

Brass makes lousy springs, and also lousy teeth-----at least teeth that can bite into steel.

Make a good electrical connection, clean and smooth mating parts, and use the lock washer to keep the connection tight.

The use of corrosion resistive grease is a good idea when mounting to aluminum. A good source is electrical supply stores. You want the stuff designed to be used when hooking up main boxes, where the feed line is aluminum.