Heating very seized fasteners

[mark_in_manc]

Hi Folks

I've had great success recently in freeing really, really rusty fasteners using heat.

On here I've read of people using soldering irons to supply the heat - not tried that yet - and I've also learned about on here, and used, a hairdryer to free-off a seized, plastic BSR platter.

If you need more than a hairdryer but there's too much in the way which might burn or melt to use a blow-lamp , try one of the cheap 'chef's torches' which are re-filled from a very small disposable butane canister. Someone bought my wife one, and since she never makes whatever one makes in the kitchen with those things, it sat about until I found it a new job.

Also very useful for BIG soldering jobs - so useful that if it broke, I'd buy another!

cheers
Mark

[Tim]

I consider a gas torch an essential for the amateur engineer/professional bodger. You can do so much with them. I have several, from the chef's size up to a virtual rocket engine which I use for roofing.(As you do!)
I have used mine(and hot air gun) for so much over the years I have never regretted buying it.

[Nickthedentist]

Good tip!

A gas-powered soldering iron with the bit removed often does exactly the same thing, with a nice, controllable, pencil-point blue flame.

I use mine for exactly the same purposes as you describe, the last time being to free-off the speed change mechanism of my Garrard 4HF.

N.

[paulsherwin]

You can buy small pencil torches for very little money from market stalls and cheap tool shops. You just refill them with gas like a cigarette lighter.

Electric hot air guns intended for paint stripping are also useful. There was a big fad for using these about a decade ago, and as they don't work very well with paint they often turn up at car boots and flea markets after somebody's had a garage clearout.

[Nickthedentist]

Originally Posted by paulsherwin

There was a big fad for using these about a decade ago

... or a bit more where I lived (London)

My parents bought one in 1986 when they were all the rage. It got used once but was put away because it was just too slow, then I nabbed it for use with heat shrink sleeving and have used it ever since. Note that the pointy nozzles often have little vents on the side too, which emit enough hot air to cause colateral damage!

Nick.

[Radio Wrangler]

The little pencil flame torches are great. The real benefit is in having sharply focused heat so you can create differential expansion to crack seized surfaces. I definitely miss having oxy-acetylene gear, that was the ultimate freeing tool, but if pushed, I might arc the TIG up on anything reluctant, it goes down to 3 amps if necessary, though the 30mm starting HF arc capability may not be wonderfully compatible with electronics...

David

[Herald1360]

Originally Posted by paulsherwin

Electric hot air guns intended for paint stripping are also useful. There was a big fad for using these about a decade ago

Apart from heatshrinking, mine gets used mostly for lighting the barbecue. Quick, clean, no nasty tasting fuel residue and better than a hairdryer for reviving it.

[emeritus]

Here's my gas gun, bought in London's Leather Lane street market many years ago for 50p I think, and no doubt intended to be a novelty cigarette lighter: all of 10" long, gives a lovely bunsen flame for localised heating!

[Radio Wrangler]

In keeping with the vintage technology theme, how about a valtok?

[Herald1360]

Seems Valtok is an Argentinian cement products company or a warlord in Warhammer.

[Radio Wrangler]

Picture two brass cylinders, each an inch in diameter and 4 inches long, held together by a big clip, held in your hand, one cylinder in front of the other. both are capped at the bottom, both contain wadding soaked in meths, the cylinder furthest from your wrist is open at the top and lit. There is a screwed cap for storage. The second cylinder has a cap with a curved tube coming out of it. The tube ends in a horizontally facing jet, right in the middle of the flame of the open tube. It produces a vey hot, fierce small diameter flame and can do brazing and silver soldering. There's a small diameter cap to screw over the nozzle.

all chromed brass, and a very neat little toy. A jeweller's blowlamp.

David

My dad had one of those, in keeping with the vintage theme they took time to warm up. Here's one (ended) on ebay http://www.ebay.co.uk/itm/Watchmaker...p2047675.l2557

[arjoll]

My dad had one of those too - I had no idea what it was for!

[Mike Phelan]

Originally Posted by Herald1360

Seems Valtok is an Argentinian cement products company or a warlord in Warhammer.

Try Valtock.

I had one of these for years - extremely useful.

[LXSTEIN45]

I bought a second hand chinese smt rework station and find the hot air out of that is an excellent source of directional heat - especially for drying awkwardly shaped buttons etc after a deep clean or when drying mirrors and optics from SLR's and lenses without having physical contact.

I need to make a modification though - annoyingly when you turn down the heat, the air flow is much reduced, so I need to work out how to manually control the airflow separately to the heat whilst not allowing heat without air!

[Billy T]

Originally Posted by arjoll

My dad had one of those too - I had no idea what it was for!

My father had one also, and I still have it on my workbench so I must give it a try. I do have a 'chef' size gas torch as well, and find that very useful, but I suspect that the 'meths' torch could be more appropriate for small jobs.

I reckon that I could speed up operation of the meths version by using the gas torch on a low-pressure flame to get it up to temperature.

Cheers

Billy

[Herald1360]

Ahhh, that reminds me of using a butane blowlamp to light a Primus stove

[Tim]

Aldi is currently selling a gas torch/soldering iron for £19.99. Can't vouch for quality but might be OK if only used occasionally.

[Anthony Thomas]

Just a suggestion when using heat to loosen things that have seized:

Heat the centre or bolt section so that it is good and hot then let it cool well before attempting to turn or rotate it. My theory is the heat expands the bolt loosening it and when cooled will be easier to remove, turning the screw / bolt whilst hot WILL cause the expanded threads to gall and perhaps even friction weld themselves together.

You have been warned

Sometimes in my trade we only had ONE attempt at loosening a seized bolt or stud and one attempt only so I wager evrerything on the first time being successful. Broken studs can sometimes be impossible to drill out especially if the heat has hardened the broken off screw or stud.

Tony

[Radio Wrangler]

Hi Tony,

I think the worst thing is when someone has already tried an "Easy-Out" extractor. The things never work, and the tips just snap off in the stuck part, so now you're presented with a piece of ultra-hard steel jammed in the thing you'd now like to drill. If you can't shock it free, then you desperately need a spark eroder.

I've been playing with a TIG machine down to 5A current for producing extremely focused heat to free small rusted nuts. Heating one flat, or opposed flats creates asymmetric expansion to peel the rusted interface apart. Heating the whole nut expands it to make unthreading easier. You have to keep the arc moving quickly so you don't get localised melting, and use a carefully ground tungsten with the grinding pattern running radially back and outwards from the tip - otherwise the arc isn't stable enough and the attachment point is inclined to wander. This isn't safe near semiconductors, especially with HF ignition.

David