Need a welding opinion-

Lil Foot

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1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
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Peoria, AZ
I then slowly pulled on the strap, thought I was going to pull the tractor over, but it finally moved (with a lot of friction) thru about 30 degrees. YAY!
I stopped, shot it with PB Blaster, and pulled some more. It moved thru another 30 degrees, and snapped off. CRAP!
The stub broke off, not my weld.
Sure enough, the plug is cast iron.
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Lil Foot

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1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,516
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Peoria, AZ
After pouting for a while, I ground off the stub & weld, and drilled the hole out to about 7/8", and counter sunk it heavily.
The plug had almost 1/8" of thread showing, so I put the strap over that and welded the hell out of it again.
This time it moved about 90 degrees, so I shot it with more PB blaster, then cut off the strap with a pnut grinder C'off wheel.
Then I used a giant Channel-lock to unscrew it the rest of the way. YAY!
After it was out, I found it had no sealant or locktite, & threads on the plug looked perfect.
I chased the threads on the drain spigot, and they looked perfect also.
I am still at a loss to explain why it locked up so tight.
After draining, flushing, and changing the oil filter, I put in a new hex head brass plug and tightened the hell out of it, to see if it would stick. It came out easily.
So crisis averted, oil changed.
Typically, the oil was so clean I probably could have let it go another 5 years.

Not my prettiest weld by a long shot, but one of the most satisfying.
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D2Cat

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Mar 27, 2014
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Too late now, but when you get the seized part to move even one degree, go back the other way 2 degrees. It's necessary to move both directions in small increments. Usually keep flushing the seized part with a solution like PB Blaster as it is being worked.
 

Lil Foot

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1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,516
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Peoria, AZ
After it moved thru the second thirty degrees, I started to reverse, and that is when it broke. I suppose I should have moved in smaller increments, both forward and reverse. I'll know for next time. Hopefully, there won't be a next time.:)
 

lugbolt

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ZG127S-54
Oct 15, 2015
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you have a tapered pipe plug. The female threads are tapered, the male plug threads are tapered. When they are screwed together they lock tightly, and don't usually leak. Because they don't leak, PBblaster, candle, wd-40, teflon, oil, nothing will penetrate into the threads because the threads are designed to seal up tight.

You have a cast STEEL plug, not cast iron. If it were cast iron, a mig would never have really worked. If you've mig welded (or attempted to) cast iron, you'll know what I mean. You might be able to tig it, or better yet braze it, but a mig gun doesn't do squat, real similar to trying to mig weld aluminum with er70s-6 wire.

tapered plugs that screw in tight like that often get seized after they've been in for a length of time. The tighter they are put in initially, the harder they are to get out. My brother is the worst. Every bolt he touches must be thought of as a 2"+ diameter bolt....in other words, crank it down til you feel it start stretching, then a little more & then stop. So the next guy who has to take them out? Good luck!!

yes I've done a bunch of them over the years. Same deal, weld a socket to the square and pray it comes loose. Sometimes they don't and you have to just resort to alternative bolt management, i.e., drill & tap.

it has been said that a 20 minute job is a broken bolt away from being a 2 hour job. Lot of truth to that. Expecially when it comes to turbochargers. The heat affects the material, if the down pipe(s) are bolted rather than clamped via v-bands, almost all of the bolts break off, nearly every time. Doing one now on a Polaris rzr. Yay.
 
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