counterweight corrosion

[-goose]

Hi fellow builders:

A local RV-6 is reportedly suffering some corrosion around the counterweights presumably from some kind of electrolysis between the lead and aluminium. Although I have primed internally, my tech councellor has advised that I remove & refit my counterweights with a coating of duralac or similar to guard against future problems, but I thought I'd sample other people's experiences before diving in and de-riveting skins! Any input would be greatly appreciated.

[Bob Axsom]

No problem with mine using the bolt on weights from Vans. Flew for a year before painting and the weights were in there for years in California near the coast before I finished the plane and flew it. I added no coatings to the weights before installation. If the weights were formed in place with melted solder I would suspect that rather than solid pure tin/lead (such as solid 60/40) some joint etching/cleaning/preserving material was introduced to the process. If that is the case and you knew what was there you might try to neutralize it but that introduces a new contaminant with unknown consequences. If it were mine I would clean it and live with it as long as I could stand it, then I would take it apart and fix it as necessary.

Bob Axsom