[cloves]

We have a snapped bolt near a coolant filler neck on an engine. We are flux welding a nut onto the stub. My questions is it better to quick cool down the bolt with penetrating fluid for example or just let it cool down for a few minutes. What would give the fresh weld the most strength?

[cj737]

Slow.

[tweake]

wait until its cold.
the good thing about welding a nut onto it is you expand then (more importantly) shrink the stub. that break loose the corrosion. so wait until its cooled right down and you will find it will come out a lot easier than if you just quick cool it.

[drizler1]

wait until its cold.
the good thing about welding a nut onto it is you expand then (more importantly) shrink the stub. that break loose the corrosion. so wait until its cooled right down and you will find it will come out a lot easier than if you just quick cool it.

What he said. Don’t go cranking on it either if it fights. Try back n forth. And / or use an air chisel with blunt taper tip. Oil it up with penetrant and with your best [emoji14]” limp wristed “ style on the end of the bolt let it bounce. Works miracles , add beer as desired


Sent from my iPad using Tapatalk

[drizler1]

Double tap, whoops

[tweake]

Don’t go cranking on it either if it fights. Try back n forth. ....... . Oil it up with penetrant and with your best

+1
work that penetrant into the threads by working it back and forth gently.
some engines have bolts that go all the way through into the coolant passage. they can be a nitemare to get out.

[drizler1]

First and foremost, if you’re the kind of guy who wants to “ get er done” , is a gorilla or gets passed off easily remember this . Let someone else do it or tears will flow.......... this stuff sometimes takes time and patience. Something I wish I could get through my wife’s head...


Sent from my iPad using Tapatalk

[cloves]

Thanks everyone this will help in the future. I left the bolt soaking overnight and then cleaned it off and tried to weld a few more nuts onto the stud. Then let it cool naturally for about 10 minutes, nut kept breaking off. I think I wasn't putting up the flux welder up hot enough and kept getting partially cold joints. Eventually just started drilling it out. This bolt is just for the housing so its not connected to the coolant passages. Most likely the previous mechanic over cranked and def didn't use anti-seize.

I was under the impressions that cooling the bolt down with penetrating fluid right after welding would wick in the fluid. Would wicking in some wax right after the weld also be a bad idea?

[tweake]

Thanks everyone this will help in the future. I left the bolt soaking overnight and then cleaned it off and tried to weld a few more nuts onto the stud. Then let it cool naturally for about 10 minutes, nut kept breaking off. I think I wasn't putting up the flux welder up hot enough and kept getting partially cold joints. Eventually just started drilling it out. This bolt is just for the housing so its not connected to the coolant passages. Most likely the previous mechanic over cranked and def didn't use anti-seize.

I was under the impressions that cooling the bolt down with penetrating fluid right after welding would wick in the fluid. Would wicking in some wax right after the weld also be a bad idea?

trouble is the fluid just evaporates off due to the heat. need to let it cool enough that it stays liquid.
wax won't so anything.
10 minutes is not long enough. as mentioned this isn't for anyone who is in a hurry.

flux core is not good for this. the flux gets in the way.
best is bare wire mig.

[cj737]

wax won't do anything.
10 minutes is not long enough. as mentioned this isn't for anyone who is in a hurry.

flux core is not good for this. the flux gets in the way.
best is bare wire mig.

Actually, wax does work also. Not as well liquid penetrants though. MIG or TIG are best. Often, just using a TIG torch to heat the bolt up red hot with the arc is sufficient to break them loose, if you have a nut to wrench by.