: Hi,

: I'm ready to fasten my 1 3/8" aluminum inserts into the aluminum 1
: 1/2" outer sections to make a take apart mast similar to the Balogh
: masts. The outside part of the mast should be free of rivits or
: obstructions as I am using Sunfish sail slide rings that have very little
: clearance. I think someone told me that Balogh epoxied the insert into the
: mast but that the aluminum must be sanded and quickly epoxied before
: oxidation took place. Any ideas about this or has anyone epoxied aluminum?

: John

Hi John,

Ok...distant memory here, there was an aircraft designer a while back (like 30 years) that came up with this procedure, I think his name was Molt Taylor. Anyway, his method is you sand the aluminum in a bath of thinned epoxy then the oxides that form almost instantly (within milliseconds) on the aluminum in the presence of air can't form since the aluminum isn't in the air. And the aluminum is then coated with epoxy so they can't form later. The aircraft industry does this with a specialized anodizing treatment. (phosanodizing)

Since you're not building an airplane I don't think you need to go quite that far But you do need to know that the grayish color formed on aluminum has virtually zero mechanical strength and bonding to it isn't reliable. Just vigorously sanding then right away using the epoxy should work fine for your application.

Bill H.