Welding to a hardened dowel

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I'm by far an experienced welder so I apologize if this is basic knowledge. I am trying to pull some hardened dowel pins (.500 dia.) from an engine block. The engine is in the car and I don't have the fancey puller or room to pull these dowels. What I'm doing is taking a 5/8 nut and putting it over the dowel and weld it. I then use a ratchet to break loose and turn the dowel all the while with a flat blade screw driver behind the nut and against the engine block apply a levering action. it's actually a common practice.........for those with a powerful welded I presume. I have a small 110 mig using .03 wire. It seems that I can get penetration on the nut but not the dowel. I have welded it fast but when I turn the wrench after a while the nut pops off and I see no significant penetration on the dowel. Is there anything I can do to get penetration? If I take a grinder to the dowel will it in essence remove the hardening and expose the milder steel and then makle it easier to weld?Thanks,Doug1966 Fairlane1964 Comet 427
Reply:Preheat, and a bit of bevel. Before you put the nut on, taper the dowel with a grinder, just a bit. A little / \ and this will give you a bit of surface area to get better bond on. Then, slide the nut in place,a nd hit the stud with a mapp torch for 10 seconds. It will be HOT, and then weld it. You will see MUCH better penetration on the weld, and you'll be able to strip the nut like a normal guy, and then post up how the whole mess is frustrating you much worse than before!!! (I had to; you know how frustrating that stuff is!!)And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:You might try using a torch, even a small propane one, to anneal the dowel. (That may also help loosen it.) Then you may be able to just use a Vise-Grip, or at least make the nut stick better when welding. If the latter, weld while the dowel and nut are both  hot and re-anneal after you weld if it still seems too brittle when cool.
Reply:How far is the dowel protruding?  If you grind the nut down, you may be able to get the dowel raised above the surface of the nut, and will likely get better penetration on a fillet weld than on a plug weld.
Reply:There's no need to turn the dowel, that's just chewing things up. Grind two stepped flats on the dowel, clamp the dowel at the flats with a genuine USA Vise-Grip. Use two pry-bars behind the Vise-Grip to pull the dowel. Use flat pry-bars on a fulcrum, or  "lady-slipper" type bars. Sometimes a large open end wrench/pry-bar will work too.If there's not enough exposed dowel to clamp, pre-heat and weld. But use a puller-screw arrangement rather than twisting, to remove the dowel.Good LuckLast edited by denrep; 03-08-2010 at 01:52 PM.
Reply:Originally Posted by denrepThere's no need to turn the dowel, that's just chewing things up. Grind two stepped flats on the dowel, clamp the dowel at the flats with a genuine USA Vise-Grip. Use two pry-bars behind the Vise-Grip to pull the dowel. Use flat pry-bars on a fulcrum, or  "lady-slipper" type bars. Sometimes a large open end wrench/pry-bar will work too.If there's not enough exposed dowel to clamp, pre-heat and weld. But use a puller-screw arrangement rather than twisting, to remove the dowel.Good Luck