Are you sure it isn't some droplets of Zn causing the interference? A
quick file touch up has worked for my re-galvanized mast. IIRC the UST
mast tube id was about 1/16" ID oversize vs the usual 0.005 to 0.010"
spec for HDG Zn thickness. What are your id/od measurements?
I don't think a hone will work, Zn is too soft and gummy, assuming the
tube was (should have been) HDG at the factory inside and out. Try a
coarse flap wheel on an extension in a drill. Wear a mask as Zn dust,
while not particularly hazardous, can give you "welders flu", which I
have verified as not fun after welding galvanized pipe.
Plan B: cut off the tube with a recip saw. Grind away what is left with
a carbide burr in a die grinder. Then you need a mast restraint to
prevent tilt when pulling a rotator.
btw the Harbor Freight metal digital calipers, often on sale for $10,
are ok accurate (+/- 0.002") for ham work. I have a bunch of them handy
all around the shop for quick checks. Much easier to throw away when
damaged than a $180 Tesa/B&S or Mitutoyo.
Grant KZ1W
On 4/22/2020 20:24, w6rgs@cox.net wrote:
Howdy folks,
Having galvanized a 2" mast for my tower, it's now too tight of a fit in
the 2" wide x 3" long mast opening at the top plate of the tower. I
already knew that galvanizing would slightly increase the diameter, but
did not expect as much as it did.
So, I'm thinking of honing out a few thousandths of steel inside that
2x3 tube for the mast to fit. There is already a thrust bearing on top,
so I'm not worried about a lack of support after honing.
Any thoughts on using a 3-stone cylinder hone to open up the tube a little?
Bill W6RGS
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