Arc plug weld feasible?

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This is a steel panhard rod , hollow tube approx .750 OD and 1/8" thick walls with the solid .550" threaded ends plug welded on. They fit into the tube about 2" deep.  Plan is to machine longer end pieces and press fit them into the hollow rod then plug weld back together.Can this be welded with an arc welder?  Will a 1/4" hole thru the tube and solid inner piece be enough? Should I drill all the way thru the inner piece?What about the 1/8" tube wall thickness, maybe too thin? Attached Images
Reply:I assume that you're thinking about stick welding it? Itcan be done with a small (3/32") rod and some skill.The hole may have to be more like 3/8" or 7/16" and countersunk.It wouldn't hurt to drill into the inner piece a little, maybe 1/16",or so, but it's not absolutely necessary.The key here is that you see the penetration occur and not just hope it occured.Tig or mig would be a better option.Rich
Reply:That's going to be hard. You will want to strike your arc in the holes, and you have to weld in a small circle without trapping slag. I think it would be darn near impossible to do. You might be better off threading the hollow tube and end pieces and putting them back together that way.Miller Multimatic 255
Reply:Originally Posted by martik777This is a steel panhard rod , hollow tube approx .750 OD and 1/8" thick walls with the solid .550" threaded ends plug welded on.
Reply:Lots of strain on these things. A lifted 4x4 seems to get used harder than stock, and lengthening it increases the likelihood of bending. I'd replace the tube with DOM tubing of equal ID, but thicker walls then drill large holes, Stick brings with it significant risk of slag inclusions. I'd favor MIG, Or machine it in one piece.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Yes, I am stick welding.Not really enough material for internal threading and maintaining strength.What if I was to drill right thru the tube and solid piece? Then I could check the weld from the other side or push the rod into the hole and drag out. I'll test weld a few and see how it works.Worse case, I can machine the whole rod with solid round material - I assume it is hollow to reduce weight.Last edited by martik777; 11-27-2015 at 08:17 AM.
Reply:I don't think the through hole is going to return the results you want.  Like the others stated the slag is going to be your problem, I'd say your probably going to create more problems the deeper the hole, and your really not gaining anything over standard plug weld. Why can't the circumference be welded behind the shoulder? If you have the means and weight is not a concern,  I guess I'd machine it out of bar stock and be done.
Reply:It's only 1/8" thick tube, so drill a large enough hole to see good.If you still need it a little easier, then turn the tube so the weld is in the vertical position instead of flat. Now you can start at the bottom of the hole and work up while gravity helps you not trap slag.Got that last tip from another member here - MJD I believe. Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by Teggy1Why can't the circumference be welded behind the shoulder?
Reply:Originally Posted by MinnesotaDaveIt's only 1/8" thick tube, so drill a large enough hole to see good.If you still need it a little easier, then turn the tube so the weld is in the vertical position instead of flat. Now you can start at the bottom of the hole and work up while gravity helps you not trap slag.Got that last tip from another member here - MJD I believe.
Reply:Originally Posted by martik777I have a mill so I could mill a slot, say 3/4" long, on each side
Reply:spend some money on a scratch start TIG setup...perfect for this application and not a lot of cash. You can power it from your DC stick welder.Miller Multimatic 255
Reply:Originally Posted by martik777Do you think that would be strong enough? Weld both under and on top of the washer? I could also tap some threads and use screws instead of the plug welds.
Reply:And I agree with the previous posters, sounds like a great excuse,  errrr, reason to buy a scratch start setup.
Reply:Originally Posted by Teggy1And I agree with the previous posters, sounds like a great excuse,  errrr, reason to buy a scratch start setup.
Reply:Originally Posted by martik777lol   Yes, I have been investigating those scratch setups but my welder is AC only, however that can be converted too, but I'm sure a cheap DC box will turn up on CL.  I have 3 lathes, why not 3 welders!.