Weld on a bolt

I need to tig weld on the end of a 1/4 inch bolt but the bolt must be in the
threads of a nut welded to a plate (it's a boss) during the weld. I assume
there may be arcing and I might weld my bolt to the nut. Correct?
Can I reduce the possibility of unwanted arcing by grounding on the bolt
itself and not the plate?
If "yes" to my most previous question, then does it matter if I ground on
the part of the bolt that is past the nut and closest to the weld?
Here is an ascii picture:
Bolt head end here----> [========[]========
Reply to
David Todtman
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Grounding to the bolt is best, do NOT use oil, you will just make things worse. One trick is to hacksaw through one side of a proper sized nut. (Cut it in half if you need to get it off). Set the nut on the threads, clamp the ground clamp around it.
David Todtman wrote:
Reply to
RoyJ
The main problem you will see is cleaning off the galvanizing or cad plating. Either will screw up the weld and both are health hazards. If you can get un-plated or stainless bolts, you can avoid that problem.
I have welded bolts while grounding on the nut or the plate that they were threaded into with no problems. If you ground on the bolt head like your drawing shows, there should be no chance of arcing to the nut or boss.
I would skip oiling the threads, the heat will just turn the oil to garbage and make the threads rough.
Good Luck, Bob
Reply to
MetalHead
I had to weld a bolt to a welding table I made but I did not want the threads affected either... I used the spatter spray on the parts I did not want spattered I worked for me... My .02 worth, I think that may work for what you want to do.... anyone correct me if I am wrong... I am still learning from this newsgroup.
Don D.
Reply to
Don D.
I remove galvanizing from bolts, nuts and threaded rod with Sno-Bowl toilet bowl cleaner. The liquid version, not the "Newer, Thicker!" stuff. Bubbles of hydrogen gas will form so venting is probably worthwhile. After removing the galvanizing, the bolts are rust prone, so you may want to just remove it from the head.
Reply to
mark
I tried to do just the opposite welding a nut to the leg of a welding table. Could not get the weld to hold on the nut without burning through and messing up the threads. Ended up just welding a flat plate on the bottom of the angle iron legs drilling a whole and bolting on the casters. There must be a better way of doing this.
Chris
bolt
Reply to
Christopher Robb
Perfect! Thanks for the info, all. David
Reply to
David Todtman
Best is get an uncoated nut (they are available) but a GOOD grind will remove the coating. Keep the heat low and wash the weld onto the nut, if using stick, MIG run right into the bottom using short bursts (basicly run a seriaes of tacks) and with TIG, the control is there. If you can afford it, a SS nut will weld to darn near anything, even with mild steel filler, but a compatible SS filler is better.
Christ> I tried to do just the opposite welding a nut to the leg of a welding table.
Reply to
enl_public
I have access to a lot of ss nuts (and bolts) via the local scrap yard. But I am shy to the idea of using them for bosses because I have heard they gall. Am I off track on this or what? Ciao, David Todtman
Reply to
David Todtman
I never install stainless nuts and bolts without copper or nickle based anti-sieze. Too many times they have welded on me and were un-removable. You end up shearing off the bolt before the nut comes off. Anti-sieze fixes that.
Also never try using stainless steel sheet metal screws as self-threading screws. The heads pop off like plastic. I use them as wood screws, of by threading the hole beforehand with a steel sheet metal screw of the same pitch.
Reply to
Ernie Leimkuhler

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