The International Cessna 170 Association

I have a replacement Grimes Rotating Beacon (Ebay) and would like advise on installation.

Fits on top spine of fuselage w a few screws in the side.

To prevent water from entering; what type material should be applied?

Prior 40 yr old installation appears to have been some compound from a tube.

What is new and appropiate method and materials?

Regards

Are you familiar with butyl tape? Used on sheet metal bldgs. Cheap. Any hardware or RV supply.

We wrote about fuel tank sealants here. There you will see a link to a great introduction to sealants written up by a fellow on Van's Air Force website. On page 122 of the December 2017 issue of Sport Aviation a builder recommends Dynaflex 230, a siliconized latex caulk you can buy at the big box stores. Cheaper and easier cleanup than Proseal.