Date: Fri, 17 Nov 1995 20:44:19 -0600 (CST)
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Dan Beatty <danb@sound.net>
Subject: Re: Bolt Extraction - few successes
At 11:17 AM 11/17/95 -0600, Dan Houg wrote:
>it seems the older the mechanic, the fewer the bolts broken. Olde
>Fahrts have paid their tuition at the School of Hard Knocks and
>exercise more patience than us young bucks. they soak parts in
>penetrating oil hours if not days before tackling a project, have
>developed that 'feel' of a bolt prior to its breaking point, and do
>not let anger get the best of them. they know the piece they are
>working on has no personality, no vendetta, no conscious and approach
>it from a cold, methodical standpoint until they beat the bugger.
>
>
Thanks, I think, for the compliment. Break a bolt.. not likely. It becomes a
point of honor regarding how long it's been sense you broke a bolt.
Many of us "Olde Fahrts" even took out loans at the School of Hard Knocks.
The lessons learned are these.
1. Why is the fastener stuck?
2. What worked/didn't worked before in this situation?
3. Use a high quality penetrate with proven properties. Yesterday's coffee
won't cut it.
4. Often times a couple of sharp raps with Mr Hammer on the end of the
fastener will shake it loose.
5. Next step. Another couple of sharp blows at an angle on the head of the
fastener.
6. Heat is usually good ie: it is sometimes easlier to remove a bolt if the
casting is warm/real warm and the bore has expanded a few hundreds of a
millimeter.
7. If you do end up breaking the thing off.. Work carefully.. This is where
very good cobalt/ti coated bits help (a lot). You're not going to get a
second chance at this standard sized hole so be patience and work carefully.
Center punch the broken part exactly in the center. If you are little off
carefully work the punch part toward the center by angling the punch and
hammer blows. Don't try and mark it with one decisive blow (not). Starting
the drilling process using a, for the common 8mm bolt size, 1/8 inch drill.
Try to get excactly centered. Next work up a 1/16 and keep/get this center.
Refer to the Roddick ,one of the best extractors (did I mention uncheap)
instructions for the final required hole size. Drill the required size and
insert the Roddick extractor. The theory is that drilling the bolt/whatever
will relieve a small amount of pressure and the extractor will give you a
second chance for removal. Important tip, use a suitable handle that will
you to apply a pure twisting force. No bending, lop sided whatever motion
allowed. Use a plain old "T-handle" with the "Tommy bar" set in the middle
<g>. Genly work it feeling the broken pieces' response.
8. Yea you got it out. Boo it didn't come. You weren't foolish enough to
break the extractor were you.
9. Even if you didn't get the bolt/whatever out you have made a proper
start to cleanly drilling the piece out and installing a nice durable
heli-coil. Which is what should have done to start with.
10. Probably should have started with this but didn't want to give away the
best tip to the unwashed. Use valve grinding compound in you socket or on
the tip of the "allen" wrench. This provide increase friction and help to
prevent slippage and rounding of the fastener. You MUST do this before not
after slippage has occurred..
You can stop doing any of this when the darn thing comes loose.
Have fun.
Dan