Remove nuts from old hold down bolts 10

[mte12]

Does anyone have experience with removing nuts from hold down bolts which have been in service for 50 years?

Assuming corrosion has occurred and material built up in crevices.

 

[SWComposites]

Use a nut splitter.

 

[mte12]

Thanks SWComposites, do you know if these are effective for 1" bolts, in terms of preserving thread?

 

[SWComposites]

Nope, sorry, don’t know specifically. Have only used a splitter on car parts. You might need to use a die to clean up the existing threads to get new nuts on.

 

[dvd]

Enerpac offers nut splitters in this range. They also have rentals, and bolting services units who can provide equipment and a technician to come to your jobsite and perform the task.

 

[dik]

Can you use a good penetrating oil? and heat with an oxyacetylene torch with a good impact wrench, prior to using the nut splitter.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[HTURKAK]

I would consider the ''nut splitting '' the final alternative if other simple options do not work,

I would try spraying WD 40 or similar product , then brush the corroded parts and use a plier/ wrench. If does not work, heat the nut and corroded part which may help to break the bond.




Use it up, wear it out;
Make it do, or do without.

NEW ENGLAND MAXIM

 

[bridgebuster]

Sounds like a chance to see if Superzilla actually works.

 

[JStephen]

From long ago with truck lug nuts:
Use the 1" impact wrench (normal tool for the job).
If that doesn't work, tap on the side of the socket with a sledghammer while using the impact wrench.
If that doesn't work, use tire tool + cheater pipe.
If that doesn't work, use tire too + cheater pipe + tap on the socket with the sledgehammer.
If that doesn't work, heat the nut up with a torch and start running through the previous steps. At some point, something will move.

You specify "hold down" bolts. Does that mean anchor bolts?
If so, my concern would be twisting the bolt off at some point below the nut. And in that case, the nut splitter might be the first tool to try.
Also, with an anchor bolt terminated in a nut, I have wondered how hard it is to twist that bolt out of the embedded nut. Impossible? Happens every time? Rare but can happen? I dunno.

 

[3DDave]

Nut splitting isn't the final alternative.

A nut cannot remain on a bolt if the nut is liquid.

So Sayeth the Book of Oxy and the Acetylene.

One skilled in the Ways of the Torch can chew just to where the nut threads give up and the bolt threads get sweaty but don't give up.

 

[mte12]

Thanks all for responding.

Yes these are hold down bolts or anchor bolts for columns onto concrete, the columns will be replaced.
Apart from removing the nut, the other challenges are to preserve the thread for a new nut, and maintain the galvanized coating.

JStephen, I also had a concern about twisting the bolt and damaging the concrete bond.

Ideal situation would be to applying lubricant, soaking over a long period and nut would become loose, but have my doubts. The nut breaker seems like an option but unsure if threads are preserved, for a 1" bolt with a service period of 50 years. With the heat application, think it is a good idea but need to think about damage to bolt coating and concrete.

Was hoping for case studies and outcomes for similar situations.

 

[Compositepro]

One of the benefits of heating the nut is to remove any moisture from the corrosion. Then a penetrating lubricant can actually penetrate. Then an impact wrench to provide torque and vibration to fluidize the corrosion in the thread.

 

[mte12]

Thanks for additional suggestion.

 

[phamENG]

If they are heat treated, be careful about heating them or using a torch to cut off the nut. Too much heat can alter the mechanical properties of the steel.

That said, heat treated anchors are not common.

 

[mte12]

OK thanks for advising.

 

[dik]

Thanks Comp... didn't know that sequence...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[XR250]

Use PB Blaster instead of WD40 to soak it

 

[mte12]

OK cheers.

 

[XR250]

Mechanics are now using induction heaters to remove frozen fasteners

 

[RontheRedneck]

I know I'm a little late to the game. But rusty nuts and bolts are something I deal with regularly.

WD-40 is not a good penetrating oil. I like it for other things, but not that. Kroil is a good brand, as are several others.

I have a 3/4" socket set. That and a long cheater pipe often do the trick.

Tightening them up and then loosening them can sometimes help. The back & forth works the oil down into the threads.

Heat is the next step, if you can do it safely. Be sure to heat the nut and not the bolt to the extent possible. You want the nut to expand away from the bolt.

I'm not a fan of nut splitters. If the above steps don't work I use a torch to cut s slot in the nut. That usually opens it up enough so it will back off.

Take your time, and don't do anything stupid.

I only say that because I've heard that others sometimes do stupid thing. It's not the voice of experience.