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I'm in trouble.
Posted: Wed Jan 25, 2017 6:06 pm
by grandpascot
I wanted to replace the locating pins on the header rail of my convertible. The old ones were in a bad way very badly rusted and inevitably on one side both screw heads broke. I have spent a couple of hours trying to drill these screws out and nothing. Hardly a dimple . What are these little devils made of. However I have bought new Cobolt drills today and tried with these. No further advancement and yes I have been drilling very slowly and with lubricant. Any ideas would be much appreciated.
Re: I'm in trouble.
Posted: Wed Jan 25, 2017 6:13 pm
by Budgie
You'll have a devil of a job as they're made of hardened steel !
Re: I'm in trouble.
Posted: Thu Jan 26, 2017 12:03 pm
by grandpascot
I am going to try bonding with Araldite after all I have nothing to lose.
Re: I'm in trouble.
Posted: Thu Jan 26, 2017 12:47 pm
by grandpascot
I am going to try bonding with Araldite after all I have nothing to lose.
Re: I'm in trouble.
Posted: Thu Jan 26, 2017 1:52 pm
by RobThomas
If you have a Mig welder, try welding an old screwdriver head to the screw?
Re: I'm in trouble.
Posted: Thu Jan 26, 2017 11:25 pm
by colin addison
Not being funny but you might just try a left-handed drill, if you can find one about the right size, and try changing the angle from side to side etc. If the screw can be started then it will wind out.
I had a problem with the locating pin coming out of the flat plate, the MIG sorted that out with a bit of grinding flat after welding.
Colin
Re: I'm in trouble.
Posted: Fri Jan 27, 2017 9:23 am
by biomed32uk
If you don't have access to a welder get a piece of metal, similar diameter to the screw red hot and apply it to the end of the broken screw, several times as that will get some heat into it. When it is hot apply some releasing oil, not WD40 so Plus gas or the like. Even better is 50/50 Acetone and ATF but that means buying and waiting probably.
That may help to crack the rust, the left handed drill bit is an excellent idea, it may just grab it then and get it out.
Good luck.
Re: I'm in trouble.
Posted: Fri Jan 27, 2017 6:19 pm
by grandpascot
Sadly I don't have access to a MIG but I will try your other suggestions and report back. Unfortunately yesterday I tried to cut off my little finger in the hood frame and whilst I was not successful in cutting it off I did do a fair bit of damage so it will be some days before I can return to the problem.
Thanks for your help it's much appreciated.
Mike
Re: I'm in trouble.
Posted: Sat Jan 28, 2017 8:41 am
by biomed32uk
Ouch, hope the finger sorts itself out. I remember doing similar with a bandsaw which also hurt.
If you are allowed to its a good time to keep dousing the penetrating oil on, while awaiting for you to attack it again.
Re: I'm in trouble.
Posted: Wed Feb 01, 2017 7:32 am
by Matt Tomkins
be careful about introducing too much heat to the header rail, either with a lamp or with a welder. It's heavily lead loaded.

- lead loading.jpg (64.29 KiB) Viewed 2900 times
if it was me, i would first try using a slit disc in a grinder to cut a slot for a screwdriver in the top of it. Failing that, very very gently i would straddle the stub with a nut, surround it with sand to keep heat down, then puddle it full of weld as quickly and gently as possible to avoid melting the lead. then wind out with a spanner.