Best penetrant to help remove spark plug stuck in an aluminium head.

The syntax and tone seem remarkably similar to that used by a chap associated with November 5th. I apologise in advance if I'm wrong.

Julian.

Reply to
Julian
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G'day

Here is a method I used when the penetrant did not loosen a plug.

I broke the porcelain out of the plug with a few whacks of hammer, and then drilled down the centre of the plug leaving about 1/16" wall thickness.

The next step was to use a hacksaw blade to cut the through the remaining wall of the plug stopping just short of the threads. I did this in several places. Some judicious use of heat and gentle tapping with a punch broke the corrosion and I was able to extract the plug in pieces. The corrosion was so bad in spots that I had to chase each thread down to clear it out successfully. I finished the job by re-tapping the thread and all ended OK.

Hope this is of some help.

regards

Ian Donaldson

Reply to
Ian Donaldson

In actual fact "Guy Fawkes" has not posted on usenet since 27th July, when a fruadulent court case of his was struck out, leaving him with £38k costs (which remain unpaid).

k
Reply to
Ken

Surely you KNOW what attracted you? Or are you confused about that too?

If you get the aluminium red hot then it has melted. I would suggest you were working with an alloy head.

Bright cherry red is 790 degrees C in the dark, or closer to 950 in ambient light when viewed with the naked eye.

Having worked with metals in a laboratory and foundry environment I must say that I have NEVER seen red hot aluminium. Aluminium melted in bale-out furnaces we used was silver when molten, not red.

Alan

Reply to
Algernon

Not for sure but the warning says extremely flammable, so I would guess some kind of hydrocarbon, possibly just propane. Also looks like there is a little penetrating oil mixed in with the spray, which would not be in the canned air. ______________ Andre' B.

Reply to
andre_54005

Maybe you should stick to working in laboratorys...........you certainly know f*ck all about practical problem solving!

k
Reply to
Ken

I think it *may* be a bit more complex than that, ISTR the blurb talks about some sort of chemical reaction. I have used it, though not for exactly its intended purpose. Pretty sure the can has been chucked by now so can't check what it says.It's certainly pretty effective at cooling stuff.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Reply to
Tim Leech

Your potty mouth does indicate a lower intelect than I am used to dealing with, that is true...so time for killfile I think.

bye bye

Reply to
Algernon

Hmmmmmmmmmm..................yet another eggsucker who seems unable to grasp the fact, that there is any difference between theory and practice!

k
Reply to
Ken

Early MZ motorbike used to have the same problem due to the last turn of spark plug thread filling with carbon, I still remember paying for the helli coil to put the torn threads back to working order. Removing the head and clearing the end of the plug thread if projecting may help. Hot and cold is always worth trying the different expansion/contraction rates can crack the seal, putting the head in a freezer overnight and then warming the aluminium trying to keep the plug as cool as possible is easier than chilling the plug.

Health and safety warning, putting bits of old engines in freezers without sufficient camouflage can result in physical violence and possibly divorce, it is vital not to get caught!

Reply to
Bob Tidy

Melting point of pure aluminium (near enough for casting alloys) is about 350=B0C and the first daylight-visible red is about 600=B0C or a strong cherry red at 900=B0C

I'm planning on spending my weekend doing some more bronze foundry work. What are you going to do? Sue someone else?

Reply to
dingbat

Hey Ken, if they're eggsuckers, what do you suck?

byebye KF

Reply to
Max

I'm hoping it won't come to this, but if it does I've done similar things in the past ;-) And, for the rest of you have been joining in, please don't get too wound up over the oxy/acetylane torch suggestion. I'm not about to melt my two heads into puddles... *All* advice is being taken on board and weighed before action. I've long since learned that pateience is a great saver of both money and awkward to replace parts.

Gyppo

Reply to
J D Craggs

My only experience is with car engines and from that I'd say if the aluminium has "picked up" in the steel thread then the force required will snap the plug at the end of its body, leaving the thread in the head. This is not a big deal to replace with a helicoil.

Best avoided though and I think heat cycling is likely to work better than penetrants. What I always wanted to try, but never got enough tuits, was to leave an air impact wrench gently tapping away to see if the jarring would gradually break any corrosive bonding.

Andrew Heggie

Reply to
AJH

Anyway, after all the argy bargy, insults and palaver, have you got the bloody plug out of the head yet? Did it come out undamaged? And how did you do it?

Reply to
Bob Spowart

Aye, I've yet to fail with a squirt of Plus Gas and a weeks wait with the odd addition squirt in the mean time. If that failed a bit of diesel would get added to the mix. Heat I feel is a more of a "time is of the essence" thing ie you've got the patience but not the time to actually wait.

Interesting idea, tie that in with the couter intuative tighten to loosen and auto reverse. 5 knocks tighten, 5 knocks loosen, repeat... What might be useful would be a machine to provide powerful but carefully controlled single blows.

Reply to
Dave Liquorice

Right this minute one of the heads is in the oven and the kitchen smells like a well-thrashed bike after about 200 quick miles ;-)

I'm trying the heat and penetrant combination first.

Rest assured I'll let you all know when the problem is resolved.

Gyppo

Reply to
J D Craggs

Don't forget to baste it regularly :)

Alan

Reply to
Algernon

Or your wife kicks you out of the house :-))

Martin P

Reply to
campingstoveman

No wife to worry about these days. So I can barbecue cylinder heads or melt chain lube with a clear conscience. But to be fair she was always pretty good about such things. For those of you still blessed/cursed with a 'cuddly encumberance' I can confirm that a lot of hassle is avoided by 'cleaning up properly', as opposed to just wiping the kitchen surfaces with a grubby rag which leaves as much as it removes. As a male I *know* that you intend to go back later and do it properly, but for some reason the ladies never believe this. They jump in and attack 'your bloody mess' before you get a chance, and then grumble about 'doing *your* job' ;-(

Mind you, coming back in from the garage at night when the trip switch trips and leaving oily hand prints along the wall as you search for the trip box in the dark takes a bit of living down ;-)

Gyppo

Reply to
J D Craggs

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