[Healeys] Gas torch. No Healey....

[Michael Salter]

Hi Simon, I spend a lot of my time extracting broken studs and bolts ... it
comes with the territory and can be both a rewarding and frustrating
experience.
Here are some things that I have learned (The hard way in most instances)

   - There is a huge difference between steel bolts seized in steel as
   compared with aluminium.
   - When it comes to corroded bolts the problem is that the product(s) of
   the oxidation which occupy considerably more space than the original metal.
   - With steel in steel (of cast iron) the usual culprit is iron oxide
   which has a wonderful property in that it changes to something else of
   lesser volume when heated sufficiently so, when you can heat the bolt and
   its surrounding material to a sufficient temperature (not always practical)
   the seized bolt will miraculously be released at least to some degree.
   - With aluminium, unfortunately, the same treatment does not work. Heat
   it until the surrounding material melts and it still will not be released.
   - If the bolt or stud has been broken as a consequence of over
   tightening, which is very common with BSF threaded fasteners, and you can
   get a grip on the offending piece, it will usually come out easily. One of
   the easiest ways to do this is to place a nut over the top of the broken
   part then TIG or MIG weld the nut to the fastener. This achieves 2 things,
   firstly it gives you something to grip and secondly the heating caused by
   the welding will often help release the fastener.
   - If someone (never you of course) managed to break off a fastener while
   trying to undo it then it is almost a certainty that the thread is seized
   in the component and just gripping and trying to turn the remaining part
   will not work.
   - It is really worth learning how to accurately "drill out" a broken
   fastener. This is particularly useful for fasteners seized in aluminium.
   The process takes practice and involves.


   1. If possible filing the top of the fastener flat then VERY CAREFULLY
   center punching exactly on center.
   2. Drill a small diameter hole well into the fastener (be careful not to
   break off a drill bit as they are hardened and impossible to drill out).
   The center drilling is best done on a drill press although a hand held
   drill can be useful for correcting that critical center position.
   3. Once you are satisfied that you have the "pilot" hole drilled on
   center start drilling the hole out with increasing diameter drills until
   you reach the root diameter (tapping size) of the fastener and right to the
   bottom of the fastener. It is critical that this part be done on a drill
   press and that high speed and lots of cutting fluid are used and take extra
   care as you "break through" the end of the fastener as you drill it out.
   4. Use a pin pinch on the outside of the remaining fastener to collapse
   it inward. If you are lucky you may be able to grip the end and pull the
   old fastener like a spring.
   5. Carefully run a tap of the correct size down the hole to clear out
   any debris. Take your time and DON'T BREAK THE TAP OFF OR YOU ARE TOTALLY
   SCREWED !

So back to your question. If the fasteners have been broken off because
they have seized into the seat base it is very unlikely that you will be
able to achieve your aim using any sort of flame heating and soldering
definitely will not work. I would recommend trying the nut and MIG welder
process first. If that doesn't work it will be a good opportunity to
practice your "drilling out" skills. Looks as though you need a friend with
a pickup truck MIG welder.

Good luck.

M


On Tue, Dec 1, 2020 at 9:53 AM Simon Lachlan via Healeys <
healeys at autox.team.net> wrote:

> I should like to buy some form of blow torch, something hot. I’m looking
> for something hotter than my regular plumbing item and much cheaper and
> more portable than the big set-ups…with which I’m barely acquainted….MIG,
> TIG(?) and oxy-acetylene rigs with vast bottles on a trolley.
>
> I’m after something with which to heat up stuck bolts, maybe do a bit of
> light brazing or heavy soldering. Something portable…..pick it up, click,
> use it, switch off & move on.
>
> I’ve seen one set-up which has two small bottles, one of oxygen the other
> of “High power gas mixture AT 3000”. This latter bottle apparently being a
> 65% butane & 25% propylene mix.
>
> As you may have gathered, I know nothing of these matters…
>
> As a sample of what I’m looking for, the first task will require a rapid
> heat to solder or braze nuts onto broken off bolts. Rapid because the bolts
> are in the underside of the (previous) seat for my ride-on mower. These
> bolts are surrounded by the foam rubber of which the seat is largely built.
> Were I able to extract them without wrecking the seat, I could probably
> flog the seat on eBay for +/-£75.00 which would largely recoup the cost of
> a torch?? (Parts and labour on ride-ons are ridiculous over here. (UK). For
> example, I used to take my wife’s Porsche 944S2 to a specialist Porsche
> garage. Not a Main Dealer. His hourly rate was less than that of the local
> garden machinery thieves). As ever, I digress.
>
> So, what should I be looking at? I see MAPP torches, but they don’t appear
> to be much better than my plumbing torch….? Or are they?
>
> Thanks,
>
> Simon
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