Page 3 of 3 FirstFirst 123
Results 21 to 23 of 23

Thread: Corrosion X in building a metal homebuilt.

  1. #21

    Guys, thanks for the input. I believe I will take
    Ron Wanttaja's advice and prime spars and skin joints. Once I paint, I will go the Corrosion X route. I will be little bitty and want to be seen.

  2. #22

    Join Date
    Jul 2011
    Posts
    16
    martymayes I believe that you are correct about the polyurethane paint. About 1977 we has a Cessna 180 painted with that stuff and about 6 months we had an unbelievable amount of filiform corrosion . It had no corrosion with the factory paint . It looked like worms all over the C-180 . This was in Florida where there is high temps, high humidity and salt air .

  3. #23

    Join Date
    Sep 2011
    Posts
    134
    Metals corrode according to the galvanic series. Those high on the scale are most reactive when coupled with materials lower on the list. Magnesium is very high and gold is lowest. All other engineering materials are in between. Aluminum is below magnesium so if these two are in contact with an electrolyte (water, especially salt water), the mag corrodes first. If you look at alum alloys like 6061 or 2024, the 6000 series has mag as alloying constituent. Since mag and alum are close on the galvanic series, there isn't too much activity. With 2000 series, the alum is coupled with copper as alloying element, which is lower on the scale, so the reactivity is higher. Therefore, 2024 has higher galvanic activity and corrodes easier. So you have to protect 2000 series more than 6000 series. By cladding the reactive alum alloy with pure alum ( cladding) you reduce the galvanic activity at the surface and hopefully reduce corrosion.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •