[TowerTalk] Ham shop metalworking DE K0FF

[K7GCO@aol.com]

In a message dated 8/24/00 5:42:45 PM Pacific Daylight Time, w7why@juno.com 
writes:

<< 
 
 On Thu, 24 Aug 2000 10:04:10 -0500 "K0FF" <K0FF@ARRL.NET> writes:
  A small squeeze can of Tappit or Tappit  for Aluminum will last a decade
 in the home shop. 
 
 Hi All
 
 One thing you have to be careful of is what happens to the oil when it
 gets hot.  We used to use Maltby's in the shop where I used to work until
 someone read the MSDS sheet and found that when Maltby's gets hot, the
 smoke is carcinogenic.  You can't safely just use anything without
 checking it out.  l73
  >>
Right on.  I have exhaust fans taking the smoke away from my lathe and mill 
whether it's a Carcinogenic or not and don't use WD-40 for a variety of 
reasons.  The cutting oils with sulfur in them are still hard to beat.  I use 
wax on band saw blades as it's safe and works great.  I don't have the proper 
filters in my lungs for any of the smoke by products created by friction and 
heat.  When I was in Basic Training we had coal stoves in tents at Fort 
McLellan.  The spark arrestors outside on top of the stove pipe would clog 
and back up sometimes while we were asleep.  Some had lung xrays and they 
couldn't see details in them.  I've avoided any smoke since.  The lubricators 
that create a fine mist for cooling drills work great but also suspends 
itself in the air that would be breathed.  Cool lungs man.  Breathing it had 
it's affects.

I was involved with evaluating the drills used at Boeing to drill aluminum.  
That had a "special interest" to me for obvious reasons. Boeing drills more 
holes in aluminum than any other company but had problems like the rest.  
They had to drill holes with the least variance for rivets.  The main problem 
was most of the drills have some burrs on the cutting edge.  When drilling 
the first hole in the "Boeing Official Test Aluminum Block" for diameter 
tolerance check, the burrs would often pick up a thin coat of aluminum on the 
cutting edges in uneven ways which made them equivalent to being dull at that 
point.  If the dullness was uneven from side to side, it would drill a larger 
hole which could be out of tolerances regardless of the lube, heated more 
than they should, would continue to unless the burrs got knocked off somehow 
and then the drill did it's thing acting normal.  I took a lot of close up 
pictures of drill tips showing this and all the variations.  I pushed for 
deburred drills but couldn't get it instituted.  I was telling my boss that 
drills that drill steel get the burrs knocked off on the "first hole" and 
drill tight tolerance holes for many holes.  Then it hit me--the simple cure. 
 For the drills used for aluminum, drill one hole in a "steel test block" 
first--problem solved.  The holes in aluminum would then be proportional to 
the exact diameter of the drill with clean cutting edges repeatedly almost 
regardless of the lube.  Too much effort is often spent on covering up or 
nullifying a problem than removing the cause like with special lubes much 
like the medical profession does.  It's far more profitable for them and they 
have no intention of ever changing.  

  Firestones short cuts and other blunders have uncovered even more problems 
that will require another 48 million tires be replaced due to recommended 
lowered inflation to 26 lbs which causes more heating and tire failures.  
Alaska Airlines could have been shut down if they couldn't meet the new FAA 
maintenance requirements.  They hired 150 more maintenance people to do what 
they weren't doing before.  Whistle blowers were laid off.  I read a complete 
analysis of all the short cuts CEO Kelly did to cut s costs and it made me 
sick.  I flew around Alaska twice with W7FA.  I saw things I didn't like with 
flap operation, wrote him about it and or course--no answer.  If another goes 
down with a flap problem they will hear from me.
k7gco

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