Date:         Thu, 16 Nov 1995 20:49:41 -0500
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         SyncroHead@aol.com
Subject:      Bolt extraction (with lasers)

Vanagonites,

You may remember my recent dilema with an exhaust bolt broken off in the head
of my '90 Wasserboxer motor.  Well, here's the rest of the story.

I managed to get the broken part of the Lisle "Super Out" (which was neither
super nor an out) out of the broken bolt.  After this, I drilled out the rest
of the bolt until I could pick out the threads near the surface.  Then I put
in an 8mm tap to cut out the rest of the bolt's steel threads remaining.  I
cut out a few, but got lucky when the tap caused the remainder of the bolt to
break free.  I backed out the tap with the remains of the bolt's threads
attached.  Since using the "Super Out" (did I mention that it didn't work?)
left a crack in my head, I took the whole motor to a good welding shop where
the nice man charged me $20 to heli-arc (sp?) weld across the crack.  He
added enough new material that I'm sure that it's stronger than the original.

So this would be the end of the story right?...........Wrong!

When I got the engine back home and on the workbench, I turned it around to
find another exhaust bolt broken off on the other side of the engine!  This
one was broken off before I bought the engine, so I hadn't noticed it before
I wanted to put a new bolt back in the hole.  This time I bought a set of
Black & Decker "outs".  They're the reverse-pitch tapered style and made in
Germany.  I've used "Easy out" brand "outs" before and have had them slip
instead of gripping.  These B&D ones have a finer pitch and looked like
they'd grip better.  They did grip just fine.  Well the bottom line, after
spraying with Liquid Wrench and trying to ease the bolt out over a period of
two weeks, is that THIS "OUT" BROKE OFF INSIDE THE SECOND BOLT!  It broke off
so deep that I had no hope of removing it.

I took the whole motor to a machine shop which specializes in removing
broken: bolts, taps, bits, outs, etc from things.  Yes, this is they're whole
business, removing broken things from surrounding metal.  They removed my
broken "out" and the bolt it was in by using a Electronic Desintegration
laser.  The laser created a smoth bore hole where my problem was.  The
machinist then tapped the head for an "insert" and installed the 8mm insert
in the head.  The "insert" is (according to the machinist) like a
professional quality Heli-coil.  I had him install an insert in the first
hole also, since the threads were a bit wobbley from all my bolt extraction
work.  The laser excraction, and the installation of 2 inserts ran $90.  I
thanked the "extraction machinist" for his work, but also told him that I
hoped I'd never see him again.  He understood.

If anyone's interested I could post the info on either/both the welding shop
and the extraction shop. 

Jim Davis
87 Syncro
88 Wolfsburg