Champ Electrical bonding

[Eric Brown]

In my firewall blanket post, electrical grounding of the firewall was mentioned. I have been installing the fuel system (13 gal wing tanks) plumbing and my thought was to check the bonding of the fuel system to the frame. Using a plain ohmmeter, I found that not all of the fuel lines were bonded to the frame. Installing bonding jumpers at the rear fuel manifold and being sure the fuel selector valve was mounted to bare metal seems to have cured 90% of the problem.

It appears that the blue aluminum fittings in the front and rear manifolds don't provide a sufficient electrical bond. Champ fuel system installation drawings 7-1102G and 7-10002E do NOT make mention of electrical bonding. Any thoughts ?
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[Big Ed]

My thought is that if jumpers were a requirement, the type design drawings would include them as discreet parts.

However, if bonding were via direct frame contact, it might be easier to miss. Would be useful to know what areas of frame must have finish removed for proper bonding.

The factory told me to mask the frame ends when I called to discuss the powder coating process. But it is not explicitly stated in the specs, which just say to mask grounding lugs and studs.

 

[Bob Turner]

Cubs used brass fittings in fuel lines. Good idea?

I changed engine mounts a couple years ago. Just enamel paint, but I still found that I lost my ground.