Induction Heater how many seconds ?

[Sharkbitemarky]

Putting new exhaust on 76 car and trying to avoid damaging any of the exhaust studs, I have a Mini Ductor II and was wondering how many seconds heating is the optimum time for our exhaust nuts ? I have tried however, I have not held button longer than 20 seconds, other than a small creaking sound when I first try the nut I have not managed to get one off (I'm taking it very easy) !

The MDII is heating well...

I have been PB Blasting the nuts and again end of the day yesterday, plan on having another go tonight.

Any tips much appreciated.

Mark

[boyt911sc]

Mark,

Are you doing this with the motor installed in the car? If that is the case, it would be more tedious and cumbersome to get the it done. I was skeptical at first until I used one and removed the exhaust nuts from the engine and heat exchanger without breaking a single stud or bolt.

I heated the stud/bolt between 1~2 minutes until it glows to cherry pink in color and zap it with a impact wrench and comes off immediately.

Tony

[john walker's workshop]

Oxy/acet until red. I use a long 8mm 3/8 drive allen and a 13mm 3/8 drive wobbly socket with a long extension and a ratchet. If they don't come loose on the first heating, stop and reheat. Sometimes on real crusty ones, heat until orange, then wait until they fade to dull red before trying. Too soft at the orange stage on the allens, might round out.

[Sharkbitemarky]

Thanks for responses

Would like to try gas, but on my back all feels a bit cramped and busy under the car.

Engine in car,

Just got first barrel nut off 1 down 11 to go ! For this nut I went 45 seconds longest/hottest of all efforts so far.

I have reapplied penetrating fluid and will try again tomorrow with 1-2 minutes heating.

[911obgyn]

The color is the key, don’t wear sunglasses

[ClickClickBoom]

Originally Posted by john walker's workshop

Oxy/acet until red. I use a long 8mm 3/8 drive allen and a 13mm 3/8 drive wobbly socket with a long extension and a ratchet. If they don't come loose on the first heating, stop and reheat. Sometimes on real crusty ones, heat until orange, then wait until they fade to dull red before trying. Too soft at the orange stage on the allens, might round out.

This^
On the nut and exposed stud, wire brush the rust/corrosion as much as possible. The action to loosen is hard to describe, its a steady torque with pulsations. Its a feel thing, heat, and technique, only took me a few thousand to figure out(airplane exhausts are always coming off). Setting the stud to the correct depth is a tedious task, double nut and adjust until its right. You want one stud thread to protrude through the barrel nut interior. Any more and the allen wrench will not get enough engagement and the troubles get more complex if you strip the nut. Working on exhausts is as much art/voodoo as mechanics.

[Sharkbitemarky]

Status update:

All 12 nuts off OK, Inductor, Penetrator, used the Dremel and small modified nut spliter mainly. studs OK ish but some not looking their best after 44 years on the car.

Engine still in car

I have it but want to avoid use of Oxy/AC open flame as induction heater great substitute for this job and safer.

Now stud removal (Thought best to change 1 or 2 of the least impressive studs while i'm here)

Many days of penetrating fluid applied, heating stud with induction heater until red, then sprayed the stud with freezer spray until an icicle hung off it (-50C), using a Makita driver (ramping the clutch torque up every few seconds until max) via a M8 roller stud removing socket l gave it some gun.

So what happened !

The roller socket extractor gripped well and a lot of torque was being applied felt good and then I thought it was starting to move however, all that was happening was the last of the M8 stud threads were being rolled flat causing my M8 stud to become a M7 and the roller stud remover could no longer grip it. End of the day defiant but thinner stud still in place !

What next:

Ordered a M7 stud remover

Just in case a Laser Tools 6587 Universal Drill Guide Anybody used one?

Keep the idea's. Coming.

Cheers and have a great weekend

Mark