Topband: G10, GPO3 was Re: rohn insulators

George Dubovsky

2015-12-18 14:08:07 UTC

Post by Tim Shoppa
I notice that the G10 insulators I have made (wire insulators, turned or
cut on my crude home tools... I don't have a tower!) start out "G10 green"
but then turn brown after a few years in the weather. I suspect this is UV
although I cannot rule out cut fiber ends absorbing something (moisture?)
and then turning brown. It seems somewhat worse at the rough cuts I have
made than on the "shiny from factory" surfaces although both turn brown.
This browning never happens in indoor G10 applications.

It's UV degradation.

Post by Tim Shoppa
Is this entirely cosmetic?

It's structural damage. The next step is for the binder to disappear from
the surface, leaving the fiber strands to stand out like a rough pair of
wool socks. A coat of just about any exterior paint will protect the
material. I use Rustoleum and I have some fiberglass insulators in service
for over 10 years with no apparent degradation.

73,

geo - n4ua

Post by Tim Shoppa
I really like G10 as a material in the workshop because it combines
toughness with being easy to work (especially the ability to punch holes in
thin sheets.)
I have also been using the red GPO3 Electrical Fiberglass in indoor HV
applications, it is a very nice material but wears the heck out of saws or
drills that are not carbide. I might try some outside.
Tim N3QE

Those look identical to the ones I made for my 8m 4 Square Towers.
Use G10, not just any fiberglass. The G10 rod is more like $20.00 per
foot retail, unless you do a little searching. The one thing I would
do differently is add a washer over the machined ends of the
fiberglass insulators to put a flat against the unturned portion of
the insulator instead of the sharp edges from the ends of the tower
legs. Those sharp edges can splinter the fiberglass. Also if you
span the joint with flat G10 material (maybe 4 inches wide by 18
inches long by 3/8 inches thick) it will at least reduce if not
eliminate the lateral movement.
I have Fiberglas rod guying them now but for many years had four 70
foot towers unguyed with this setup at the base.
It is interesting that a lot of hams are let's say "thrifty" but when
it comes to having something made or making it themselves to save
hundreds or even thousands of dollars, many will pay whatever it takes
to buy the end product.
http://k5go.com/40-meters/
73...Stan, K5GO

20 mins work with a 5.00 fibre glass rod spun in a lathe,
sort of grossly overpriced exaggeration of a Rohn insulator.

I believe there is a slight misrepresentation here. I've never seen

these in any Rohn catalog. Rather than

calling them Rohn 25 tower insulators, I think they are better

described as insulators for Rohn 25 tower.

73, Roger

ok,the station wanting the insulators for a rohn 25.there is a set

available from ab5k.he is listing them on e-bay set of 3.look for dxer49

e-bay.I believe they are new..73 john

_________________
Topband Reflector Archives - http://www.contesting.com/_topband

_________________
Topband Reflector Archive