Need a welding opinion-

[Lil Foot]

I attempted to change the oil & filter in my B670 Backhoe a couple days ago, but the drain plug refused to budge.
It's what appears to be a steel 1/2" pipe plug, with a 9/16" square head. I tried a 12" crescent, and it easily started to round off the corners before moving. I switched to a 3/8 drive, 9/16" 4 point socket; nothing. Used a 1/2" breaker, and split the socket. At this point I should have quit, and went shopping for a heavy duty 9/16" 1/2" drive socket, (nearest likely store 160 mi trip) but I the tried a pipe wrench, vice grips, & heat till I burned the paint on the drain spigot, but no luck. The plug kept shredding smaller & smaller & getting rounder & rounder.
(I think it may be cast iron by the way it crumbled)

My question is this: I want to try Mig welding a nut on the "stub", maybe a 1/2-13 or slightly larger metric size.
It will be tight getting in there, but I think I can reach it.
Do you think my 135 amp Miller will get hot enough to get a good weld?

Meant to take a pic, but had to leave in a hurry for a family emergency.

 

[SidecarFlip]

I do that all the time. The combo of the heat from the weld and the nut welded on, usually gets a plug moving.

 

[hagrid]

You'll know if its cast iron when you weld the nut on.

 

[Thunder Fish]

If you can weld and it is not cast,your 135 will do the job

 

[North Idaho Wolfman]

Yea I would think it would do it!

 

[Lil Foot]

Thanks.
If I can't weld it, I guess I'll have to siphon all the oil I can & drill it for a large screw or pipe extractor.
I'll report back whenever I get back up there.

 

[bearbait]

Thanks.
If I can't weld it, I guess I'll have to siphon all the oil I can & drill it for a large screw or pipe extractor.
I'll report back whenever I get back up there.

Flip is right, the heat from welding it on and if you have access to a good impact it's amazing what those buggers will take off. Hit it to the left and then right working back and forth once you get it started. Good luck.

 

[Daren Todd]

I have those same plugs on the bearing housings on a bunch of equipment at work. I've gotten pretty good at it. But I've found a 3/4 inch nut will slide right over the plug. It gives me the added benefit of slipping some of the weld to the sides of the plug for a greater bond.

I then hit it with the impact and 1 1/8" socket They come right out

 

[Lil Foot]

It's so chewed now I think I can use a 5/8" or 1/2" nut. Plus, it is in a spot that I can't get an impact on it, unless I pull the backhoe off the tractor, PITA.
Blue arrows:

 

[GreensvilleJay]

They do sell proper sockets for them 'pipe plugs' and well worth the price !!!
yeah i know ,kinda late BUT when you're in town, get the correct one !

 

[michigander]

picture looks like large set of vise grips would go on that ?

 

[ccoon520]

Once you get the weld nut on there (or not) try spraying some PB Blaster or whatever your preferred penetrating oil of choice is and let that soak into the threads for a few hours. Also might be a good idea to double check that it isn't left handed threads (I doubt they are but I'd be lying if I said I hadn't been bit a couple times by that).

Also you could try getting some dry ice from your grocery store and holding that against the plug itself. Don't hit it with an impact if you use dry ice unless you want to set off alarms at the airport for the rest of your life though. I remember when fitting bearings onto the crankshaft of one of my RC cars it would only fit if I put the bearing in the oven for 5 minutes and the crank in the freezer for an hour. It won't shrink much but all you are looking for is enough.

 

[SidecarFlip]

Interestingly, I just did it to the frozen fill plug on my wife's Suburban

Cast steel plug in an aluminum case. Locked solid. Tried P Blaster, acetone and ATF, a pipe wrench, hammered on a 6 point impact socket and the impact wrench. Nope to all.

Got a nut that would fit over the now buggered end, too my MIG welder, put in a roll of flux core, disconnected the vehicle battery (negative side), grounded the clamp as close as possible and glue gunned the nut on the buggered up plug Lots of goopy weld in the hole in the nut, got her plenty hot. Let it cool off and slipped a socket over the nut and got a breaker barn and off she came. Easy-Peasy.

The replacement one, I pre welded a nut on it so next time the nut is already there for this 'nut' to remove. Poor design, steel plug in an aluminum housing. Typical GM......

 

[Lil Foot]

picture looks like large set of vise grips would go on that ?

Tried that, that was the main culprit for rounding it off. Used two sets of hands to squeeze the jaws shut, and it still slipped. What I need is a set like they had in the maintenance shop at work- a little larger than normal jaws, but two foot long OAL! They really clamped tight, and then gave plenty of leverage. Can't find any that long.

 

[Lil Foot]

Also might be a good idea to double check that it isn't left handed threads

I would have remembered that, but just in case, I checked my 2nd B670- RH threads.

 

[Lil Foot]

I already have a replacement plug with a hex, so next time I can use a six point socket.
If I ever get this one off, that is.
I'm rounding up every tool that might be of use to take up there next time- my home shop is much better equipped that my high country shop.

 

[bearbait]

You could cut a whole in a piece of angle iron or flat bar just a little larger than the nut, cut to whatever length you think you will need and weld it on the nut like DT's idea. Make sure it's strong enough to take the amount of torque you're gonna throw at it.

 

[Lil Foot]

Also you could try getting some dry ice from your grocery store and holding that against the plug itself.

I may try that. When I was working, I had access to LN2, but not anymore.
Never used dry ice, (-109F) because I could get LN2 (-320F)

 

[Lil Foot]

You could cut a whole in a piece of angle iron or flat bar just a little larger than the nut, cut to whatever length you think you will need and weld it on the nut like DT's idea. Make sure it's strong enough to take the amount of torque you're gonna throw at it.

I like that idea; drill a hole in the bar, slip it over & weld it. I'm going to look at the stock stash right now.

 

[GreensvilleJay]

re: Used two sets of hands to squeeze the jaws shut, and it still slipped.

THAT"S why the proper socket( 4 sided) is necessary. The vicegrips only grip 2 opposite sides, socket fits all 4. BTDT... I now own 3 or 4 sizes of them 4 sided sockets. They're one of those tools you never think you need, 'only collect dust'.,naw I don't need them ...BUT.... all it takes is ONE PITA pipeplug and you'll be going to the store next time....
heck you've got to buy another plug so while you're in town..... buy the plug THEN goto store and get the proper socket...