Restoring antique plow - need to remove rusted nuts/bolts - how much heat?

[fried1765]

Kroil and an air impact has worked well for me in the past.

Exactly correct!

 

[beenthere]

I don't own or need a full cutting torch set. Will the small Benzomatic Brazing Torch type kits (w/ oxygen) produce enough heat to get the nuts red hot? If so, any recommendations on a kit?

Thanks

I just had a similar problem getting the wheel lug bolts free from a JD 1958 running gear. Well rusted rims and extra long bolts..
Used the best penetrant, called Blue Creeper.
Has Kroil beat by a long shot. Small company in CT. called LogRite, famous for their new line of logging equipment, such as log cant, log peavey, tongs, etc.

First wheel I soaked a few drops on each lug nut for two days. Turned right off, no problem. Next three only put drops on the threads once, and the second day they all came loose easily.
Couldn't budge any of them before the Blue Creeper.

Had same experience with my fathers' 1964 JD 110 lawn tractor, that was left out in the weather for 30 years. Easily turned all the nuts and bolts loose using the Blue Creeper penetrating lube.

 

[coondle]

A very old fitter taught me the way to remove old rusted nuts is heat to cherry red and quench with water. Beware of the steam, it can burn.

There us a scientific explanation that goes with this technique:

Heating the rusted nut/bolt combination causes a process called "AnnularExpansion", which is. The outer metal object (the nut) has a greater length of metal than the inner (the bolt). Heating metal causes expansion and the outer expands further than the inner even with both at the same temperature, causing a fracturing of the iron oxide (rust) bond between the two surfaces.
Furthermore the heat applied from a gas torch causes the rust the flame physically contacts to break down so further reducing the bond.
The last process reverses the annular expansion through temperature reduction by quenching with water (I could go on here about the latent heat of vaporisation of water, but won't, sighs of relief all round) causing a sudden contraction of the constituent parts and the inner (bolt) suddenly shrinking more than the outer (nut) again working to fracture the rust bond, if any remaining.

The cooled nut and bolt can then be safely and easily removed and for old untempered bolts as used for old ploughs the temper is unchanged, that steel was untempered and that is why they chose to use such large components.

 

[Flad]

Hi' I am an old fitter, and that heating and quenching works, how ever what you neglected to say was that it also stuffs the integrady of the bolt and nut and should not be used again, especially if the fasteners are hi tensile like wheel studs and nuts.
A better method these days with the battery drills is to drill two holes opposite each other through the nut then use a wrench or split the nut with a chisel, nuts and bolts are cheap enough to fit new ones with a bit of anti seize on the new threads, induction heaters work well and much quicker but there is the same problem with the integrady of the bolts and nuts. If its a nut and bolt situation I have undone hundreds of 5/8 and 3/4 rusted 6 and 8 bolt steam flanges simply by over tightening and snapping the bolts it's a lot easier than trying to unwind a rusted thread.

 

[sunandsand]

I use Kroil or the 50/50 acetone-ATF mixture. Most of what I work on is far too delicate to consider an air wrench. I have to use finesse, not force. An air wrench will definitely get it apart, but will utterly destroy it in the process. Of course, on the BIG stuff, a torch and an air wrench will do the job nicely. As was noted keep the 50/50 mixture tightly capped, the acetone evaporates.

 

[ArlyA]

Side bar,,, For cleaning parts and things to be painted, I use 30% acetone and the rest piant thinner. Of course I wear gloves with this strong/bad crap. Cleans metals like a dream...

 

[muddstopper]

First off, never heat the nut to red hot, doing so also heats the bolt and will cause the threads to gauld or strip. If you are going to use heat, just heat one flat on the nut, the nut will expand and it doent need to be red hot to do so. Have a long cheater bar on you wrench or ratchet and as soon as the nut is hot, 600degrees or so, give the nut a twist and it should come off or break free. Then spray down with your Kroil, transmission fluid, breakaway or what ever and let the nut cool off. As the nut cools it will suck the oil down into the threads and provide lubrication for easy removal of the nut or bolt.

 

[Flad]

Regardless of weather heat is used or a rattle gun to loosen a RUSTED and SIEZED bolt you destroy the integrady of the nut and bolt, forcing rusted fasteners often passes the maximum torque range of the bolt or nut, I am not being **** it's a fact, you might get away with re using these bolts and nuts but failure is more than probable, if more torque is used to loosen the bolt than to tighten it in the first place the bolt or nut more likely will be stretched, at or near its yield point.

There are some excellent anti seize compounds around including food grade, high temp formulas and stainless steel without graphite in them to prevent electrolisis, it's good practice to use these compounds, certainly makes life easier.
Just another thing I have seen the DIY community do is to put a flat washer underneath a spring washer , some what defeating the purpose of a spring washer.

 

[Roon81]

I don't own or need a full cutting torch set. Will the small Benzomatic Brazing Torch type kits (w/ oxygen) produce enough heat to get the nuts red hot? If so, any recommendations on a kit?

Thanks

I was able to use the stove on this one

 

[Sidney71]

Use your Dremel with a cut-off wheel or an angle grinder if you can to cut the nut then knock out the bolt. When you heat with a torch it's very easy to heat both the nut and the bolt and you are expanding both so you have defeated your purpose.