[TowerTalk] drilling chromoly es similar pipe

Lee Buller k0wa@southwind.net
Mon, 30 Jun 1997 11:21:10 -0500

At 01:15 AM 6/30/97 -0500, you wrote:
>i am doing some antenna repair and part of the repair requires drilling
>heavy mast.  by heavy i mean 1/2" wall thickness chromoly steel.  after
>burning up several bits and a few $$$ let me pass this tip:  use a 
>masonry bit ( carbide tip ), lowest speed on drill press, and lot of
>oil.  the most expensive bit i have used only did about 1/8 inch deep
>( cost about $12 ) and the least expensive was the carbide tip masonry
>type.  it has taken me over 4 hours of drilling to make a 5/8 hole in
>some of this stuff but i am betting it wont bend!
>put em up high and hope they stay up!
>73, de bud

Opinion:  I don't like any holes in my mast.  Now, I have never use
Chrome-Molley masts and I know they are hard, but I have used steel masts.
I have drilled holes to connect masts together..etc..etc...and the holes
wallow out over a period of time.  The beam then really moves in the wind
and damages the rotor.  I have tried all sorts of schemes to stop this from
happening...using shoulder bolts, heating the metal and pressing on the
bolts, etc...etc.  It will wallow out.  The best solution is
never..NEVER...drill a hole in a mast.  


FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:			  http://www.contesting.com/km9p/search.htm