[TowerTalk] Defects in Galvanization

[Ron Hylton]

Any galvanization experts out there?

I have two section of used Rohn 45 that had a number of rusty spot on them,
so I decided to take them to the local galvanizer to have them stripped and
redone (hot dipped, of course).  The exterior of the sections came out
beautiful; the coating was very uniform, and defect free.  From a distance
they almost looked like they had been chrome plated.  On the interior of the
legs, particularly on one, there is some material that for lack of a better
term I'd call "slag".  It is dark in color, and very rough.  Fortunately, it
is at the top of the section, so it won't interfere with the sections
fitting together.  However, I'm concerned that this might be a possible
point of corrosion or degradation of the coating.

Does anybody know what this stuff is, and if it is anything to worry about?
I should point out that it doesn't totally obscure the interior of the leg,
so drainage can still take place.

73,
Ron  AD7L
Hillsboro, Oregon