When I have soak a bolt in liquid wrench and taken the time to properly
center punch it I have had success. When I try to cut corners and not do a
proper job the drilling out of the bolt always fails to get done properly
leading to more problems. Take the time to do it properly.

> Like I said...Best left to the Experts !!! :)
> JC...
>
> In a message dated 9/18/2004 10:03:56 AM Pacific Daylight Time,
> donalds1@VERIZON.NET writes:
> JB and fellow knuckle busters
> there are 2 approaches to this one would be to just drill the head off the
> bolt and remove the link and then try to turn the remainder of the bolt
> with
> the help of the blue wrench (torch) and a good vise grips or core the
> entire
> bolt and hope to remove the remains with a chisel. Easy outs might work on
> new parts but in the real work of rust that trick never works
> To drill out a broken bolt I grind the end flat and start with a 1/8 th
> inch
> drill bit after marking the center of the bolt with a punch. Snap on tools
> sells a great little double ended 1/8 th inch bit that has saved me many
> hours of grief and go up in drill size as needed . The hard part of coring
> out a bolt is to get the remains out of the hole without taking out the
> good
> threads. To prevent damage to the threads I have found that the center
> punch
> to mark the starting point of the drilling is the first thing to get right
> and staying on center is next. I use a slow drill speed or the off and on
> the trigger method to keep the bit speed down so as not to overheat the
> drill bit end. The next important tool is a good quality punch I use a
> Snap
> On 7/32 part # PPC107 LA straight shank 3.5 inch shank length punch. This
> comes with a flat contact surface that I have ground to a 70 or so degree
> angle without overheating and weaking the punch.  Once the bolt is cored
> and
> the thin wall and threads are all that remain I use the punch to collapse
> the wall and threads in on themselves this can be much harder to do if the
> hole is blind. This can take out a little bit of thread so you want to use
> caution and focus on the collapsed part of the bolt. If you decide then
> the
> cored bolt is out that not enough thread remains ( That's NEVER happened
> to
> me ) then I like Heli Coils brand thread repair rather than other types of
> inserts except for drain plug repairs but that's another story
>
> PS I own more Heli coil kits than the tool salesman
>
> Going faster miles an hour with my new radio on
> I remain
> Boston Bob
>