How to Remove broken bolts With Welder

[fivestardsm]

There was a nice write up on the proper was to remove a broken Bolt with drills and easy outs.

This is a method that I learned a long time ago and use Very often. Granted, this will not be able to be used by everyone, But I hope it will help some.

This is a great way to remove rusted in bolt that have broken because of the heat that is added in the welding process. It works just as well on bolts broken into aluminum becasue it is beter to heat the metal, than the aluminum. Just allow a little bit of time for the weld to cool before attempting to remove it.

There are some risk involved with this method, but if you know how to run a welder, you shouldn't have a problem. The most common issue, is over flowing your tack. If you do not build the weld in small incraments, the weld well run, and bond to the piece you are trying to remove the broken bolt from.

The bolt that is broken, is a 10mm (14mm head) that bolts into the block to hold the axle carrier bearing. I used this for demonstration because it is easier to see. I use the same method on all bolts allthe way down to 6mm (10mm head)


The bolt Is fairly clean, So no prep or cleaning was used.


The weld is pretty straight forward.
I built the weld with a 2 second tack at a time until there was enough on the bolt to grip with a pair of Vise-Grips. Its not pretty, but it dosen't have to be.
There is another option to this that I have used before aswell. Once you get a tack that sticks out of the hole, hold a regular nut with a pair of pliers, and place it over the tack and fill weld the rest in. I usually only do this if the bolt is really stubborn.


The rest Is straight forward, screw the bolt out.





Some times it will take more than one attempt. I have had to re weld the tack on several times because of bad bonding, but it gets better after the first 1 or 2.

 

[toybreaker]

Thanks for posting this, I was going to do a part II to my write up, maybe a mod can combine them.

I use that technique as well, depending on the circumstances.

Be sure to run a thread chaser thru the hole when you're done to catch all the slag the bolt doesn't remove on the way out.

Very nice writeup! /ubbthreads/images/graemlins/applause.gif

 

[jepherz]

That's awesome, I wouldn't have thought the weld would hold for such a stubborn looking bolt. Thanks for the contribution; this will be moved to How-to after some reply time.

 

[belize1334]

I've seen this done and you'd think the weld would break just the way that the bolt did originally but it usually doesn't. My understanding is that while you weld you are also heating the bolt. This causes it to expand while the hole remains the same size. Because the bolt is expanding and the hole isn't, the rust gets crushed down between the two materials. Then when the bolt cools and shrinks the rust breaks away and the bolt comes out easier.

I've seen people heat pins inside of housings with a torch while pouring water on the housing to keep it cool. Then when the pin cools the rust bond is broken and the pin can be pounded out. The same principle is at work here.