>We have had several Rohn 25g towers re-galvanized at the facility in
>Ashland Virginia.
The work has been excellent but we have also learned some things to
make sure happens to make the re-assembly of the tower simple.
1. If possible mark sections -- latching leg to leg when
disassembling the tower before taking it for re-galvanizing. We mark
one leg of each section with a die # to identify each. This # from
the die lightly indented into the metal of one leg ~12" above and
below the joints will be visible after the re-galvanizing process and
simplify re-assembly of the tower.
2. Make sure when the galvanizing company takes the sections out
of the liquid zinc galvanizing solution they lift them from the
bottom of the section to allow the excess solution to drain to the
top of the tower - not the bottom. This will eliminate the formation
of globs of zinc inside the legs of the tower at the bottom of each section.
3. Even after having the hot liquid zinc drain to the top of the
tower we have found that fitting each section together -- one at a
time on the ground to the sections they mate with will greatly
simplify erection. The new zinc coating adds more diameter to the top
of the section which is swagged to fit the bottom of the next section
higher. It is much easier to clean this while standing on the ground
with the section lying down than to try to do it on the tower. We
have used a small cylinder bore honing tool to ensure the inside of
each leg at the bottom of each section is clear of excess zinc
galvanizing debris.
Excess zinc on the inside of the top of the section legs and excess
zinc on the outside of the bottom of the section presents no problem.
However, any large chunks of zinc can easily be tapped with a small
hammer and they will pop off. It is the excessive zinc that is built
up inside the portions of the tower sections that must telescope
together that presents the major issues when having a tower
re-galvanized. Just a few steps of preparation when dealing with the
company that will be doing your work will eliminate lots of
frustration when you attempt to assemble the sections.
73's
Tom Gregory, N4NW
n4nw@n4nw.org
N4NW LLC - Complete Merchant Services
Check out local N4NW weather conditions real-time -->> http://www.n4nw.org
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