[TowerTalk] painting DOM

[Jim Thomson]

Date: Thu, 27 May 2010 02:46:14 -0400
From: "Roger (K8RI)" <K8RI-on-TowerTalk at tm.net>
Subject: [TowerTalk] painting DOM

I have three sections of 2" OD DOM to paint. Two sections will be 
spliced in the 45G and run through two sleeve bearings above the rotator 
which will support all the weight.  The paint needs to be really durable 
because of the sleeve bearings, boom to mast clamps, and raising fixtures.

Epoxy paint does not stand up well and the spray on stuff is very fragile.

Rustoleum?  I don't know how mechanically durable it'd be. The sleeve 
bearings will be greased and have rubber gaskets protecting them, but it 
doesn't take much pressure to flake paint off steel.   Also it's amazing 
how much space you have to leave between the OD of the inner sleeve and 
the ID  of the outer sleeve. Just a 1/16" of paint requires an 1/8" 
difference between the two.

Any suggestions for a good strong, long lasting, durable paint.  I do 
have a spray gun.

73

Roger (K8RI)

##  This is the one drawback to your  "sleeve bearing scheme" 
You end up with metal rotating on metal..tearing everything off. 

## yrs ago, when painting steel masts... the paint always came off.  I tried red
oxide primer, then paint on top... and both the paint and red oxide primer came off.  Then
with some 5" diam steel guy anchors, I tried several coats of red oxide primer.. and NO paint
on top of the primer. This works good, and the primer never came off.    I also tried ZNC [srpay bombs]
.. and that stuff lasted 18 x months.  I was going to try zinc chromate... but never did [ yellow in colour]
Red oxide primer of course is red.   

##  !st choice these days is a hot dipped galvanized mast.    You can always slop some ZNC on top of 
that if you want.. [and pour some down the inside]. The procedure for the inside of the mast was to seal
the bottom.. and straddle the mast on a single saw horse... pour the znc /primer/etc into it.. then seal off
the 2nd end.   Then roll it back and forth on the saw horse.. and also tilt it up/down.. like a teeter/totter.

##  A friend in W7 land recently got his new 8.625"  OD guy anchors  hot dipped galvanized at a reasonable cost.
He also had some other stuff powder coated, and both are holding out. 

## Has anybody used ZNC, or similar, not spray bombs.. but the stuff that comes in gal + pint containers? 

later... Jim   VE7RF