Re: Aluminum Primer Type
I also read a cautionary note about using something like steel shot for sandblasting...the embedding thing.....a fairly lengthy technical article here:
http://www.ronjoseph.com/painting-aluminum.htm
On a related note, since I am not set up to weld aluminum, I am considering
putting a galvanized steel box arrangement at the rear of a 17 foot (aluminum) boat which would bolt to sides and floor directly to or near existing lateral supports on sides and floor and would extend 2 or 3 feet to transom and incorporate the engine mounting bolts in the structure. Probably a mix of square tubing and/or angle iron...maybe 3/16 X 2 X 2. The thought would be to spread any transom impact throughout the rear structure of the boat to both sides and bottom along with the transom itself.
As it turns out, I have 3 engine lower units to go through, but only the one transom.
Probably put a lid on top that could be raised for access to bilge batteries, electrical...some storage, maybe mount some fishing seat bases...basically a raised 3 by 6 foot deck at the rear of the boat.
The question I would ask about that is would it be necessary to isolate the
galvanized steel from the aluminum with electrically non conductive washers/barrier to prevent electrolysis-type corrosion? I'm thinking so, but have not used these two materials together before to any extent.
Croag, I am with Bouymarker - as an aircraft mechanic I can tell you there is only one way to do the job, it may cost a little more but the result will last langer. Lightly sand the surface with aluminum oxide paper, acid etch, alodine and use a two part epoxy primer then paint as desired.
One thing that would concern me if we weren't talking about a 12 ft boat is the fact that you used a wire wheel. You should never use steel wired brushes on aluminum as small particles of the steel can become embeded in the aluminum and cause corrosion when placed in the precence of a weak electolyte such as salt water or lake water. Just saying for future knowledge.
