Broken bolt extraction tips!

[rich112]

Silly me! I decided to take a look at my thermostat.

Needless to say one of the thermostat housing bolts sheared.

So best way to get the remains out? MIG a nut on it and melt some wax over it seems to be the best solution.

I'd like to do this in situ if possible. I don't really want to take the carb and manifold off if possible.

(At least I discovered there was no thermostat...)

[Ian Anderson]

Easi out?



But if you have the welding kit welding on a nut will work. The heat from the welding will also assist in listening the stud

Ian

[ChrisJC]

You will have to get rid of that water before doing anything.

But yes, I would try to weld a nut to the remainder of the stud, and then tease it back and forth to try to free it.

Chris.

[stevieturbo]

Clean it up and as there is a stub, try some penetrating fluid over many hours and maybe try some vise grips to get a feel if there is any chance of it moving even a slight bit in either direction.

If not, I'd say it will need proper heat. MIG'ing has been hit or miss for me, as usually it doesn't heat enough, and it's dificult to get a really strong weld to apply good torque to remove.

[DaveEFI]

Another vote for the nut welded on. And get yourself some ScotchClad 776, and use it on every thread that goes into ally. You'll never have one seize again. It's what Rover specified on the first RV8s, and it works now as then.

[garrycol]

Clean it all up and apply penetrating oil for a couple of days. Apply vice grips to the stud and see if there is movement. Do not force as you do not want to strip that bit of stud. If it does not move apply a bit of heat to the stud - gently do it and do it enough get the heat down into the threads. Quench the stud with more penetrating oil or freeze solution. Heat again and use the vice grips to try remove.

No luck then weld on the nut etc.

[rich112]

Another vote for the nut welded on. And get yourself some ScotchClad 776, and use it on every thread that goes into ally. You'll never have one seize again. It's what Rover specified on the first RV8s, and it works now as then.

Looks like thats called Scotch-weld fuel resistant coating. Will see about getting some. £72 a tin!

Tef-Gel also sounds good for use around cooling related parts as it's specifically for preventing gavlanic corosion in dissimilar metals. Used in marine applications.

[DaveEFI]

Another vote for the nut welded on. And get yourself some ScotchClad 776, and use it on every thread that goes into ally. You'll never have one seize again. It's what Rover specified on the first RV8s, and it works now as then.

Looks like thats called Scotch-weld fuel resistant coating. Will see about getting some. £72 a tin!

Tef-Gel also sounds good for use around cooling related parts as it's specifically for preventing gavlanic corosion in dissimilar metals. Used in marine applications.

Crikey. Last I bought, a few years ago, was about half that. But it is a litre, and lasts a long long time. Several complete engine builds. The 776 also acts as a thread lock. I'n sure there are alternatives - but have stuck with that because I know it works.

[unstable load]

Loctite 8009 will also work nicely there.
https://www.henkel-adhesives.com/us/en/ ... _8009.html
It's a formulation for Stainless fasteners, but will be good on mild steel as well.

[stevieturbo]

Cheaper option is make a stud and nut, then hopefully the stud will never need to come out again. Plenty of anti-sieze around it anyway

[rich112]

Mission accomplished!

Took a couple of false starts to get a good enough weld onto the nut and the bolt, but then it came out. Not easily, but once I got it moving back and forth, applied some plusgas and carried on.

First time I've done this, so thanks for the tips!

[stevieturbo]

well done. it doesn't always work.

[rich112]

well done. it doesn't always work.

I was lucky, it was accessable! First weld didn't attach to the bolt, second didn't attach to the nut, but I was able to add more weld to the nut. Then I couldn't get a ring spanner over it... Had to grind some weld off! Was a bit of a palava, but a lot less than taking off the carb and manifold and drilling out the old bolt.