Steel fitting corrosion protection

[Esser]

I have a couple steel firewall carry throughs, they were showing a bit of surface corrosion so I cleaned them up but now I realize I removed all the remaining corrosion protection. What’s the best way to reprotect the fitting with out gumming yo the threads. Is there an alodine product for steel?

[jrevens]

By “carry throughs” are you talking about bolts, Josh? There are coatings for steel, but aircraft bolts are usually cadmium plated. New bolts are cheap.

[Esser]

For fuel lines.

[jrevens]

Ok... I was editing my reply when you posted the picture. In my opinion, I wouldn’t worry very much about that fitting. You could “paint” it after installation with any number of protective coatings - primer, light oil, etc., if you wanted to. The inside shouldn’t be much of an issue as far as corrosion is concerned. Auto paint supply stores should carry painting pre-treating chemicals for steel, similar to “Alodine”, that may give some limited corrosion protection. Others on this forum may be aware of some product(s) that would do what you want.

[Dave S]

Gotta agree with John - the part does not look bad at all. Many parts can not look new but are perfectly serviceable.

FWIW - I have gotten in the habit of giving misc small parts and fasteners a shot of moisture repellent lubricant. Lubricants, paints and sealers can be very useful in retarding rot and corrosion.

All metal parts will corrode - much of the corrosion resistant stuff coating fasteners is a sacrificial metal - such as zinc in the case of galvanizing - the zinc goes first extending the time when the weather elements will start working on the steel but it will go away with time.

[Delta Whisky]

Esser - I agree, doesn't look like a problem. If in doubt, grab a can of Boeshield T-9 (sometimes available in the aviation department at your local hardware store, otherwise at lots of internet sources). The liquid or the spray both evaporate and leave a protective wax coating.