After posting a video that included an oil change and a compression check, I received several requests to demonstrate how to anneal the copper gaskets that are used on the aviation spark plugs
Thank you Kevin - I have nothing to do with aviation whatsoever but I was always curious about the crush washers on my car or motorbike spark plugs, I wondered if taking them out for inspection meant I should use a different torque setting on reinspection due to the crush washer already being crushed. Anyway so it was really interesting to see the before and after state of that aircraft washer. Also I don't do any metalwork but always got confused between which heat treatments did what (quenching vs natural cooling in ambient temps) but I think your demonstration will help me always remember from now on. Thank you for sharing your knowledge mate. Good show.
You can do this same process to copper head gaskets for cars/motorcycles as well. The difference is, for cars/bikes you usually anneal the gaskets when they are new to make them soft enough to crush. Not when you want to reuse them.
Neat trick--I had forgotten about this. Used to do it frequently, back in the 80s when I worked on aircraft a lot. Good to dust off those old brain cells.
An IA told me that at the biannual meeting he heard annealing spark plug gaskets is not allowed anymore. As for quenching, quenching time does not matter on copper like it does steel unless it is seriously fast. If you disagree or are unsure there are articles on annealing copper that will say so. It's not the same as steel and other metals commonly worked on
So I have a question i’m in a 147 school and we are learning about annealing but to cool it you let it slowly cool in a furnace. Now is it because it’s copper that you quench it right away?
Kevin, good video on annealing spark plug gaskets. Im rebuilding a Stinson 108 down in Terrell and my brakes have copper coils on the master cylinders. I have had a few people tell me to anneal the coils before reinstalling them. What are your thoughts? is that really necessary for that part? Thanks for sharing your knowledge
Andy Smitty ... Actually, water, oil, sand, or air quenching copper has no effect other than cooling the copper so it can be handled sooner after it is annealed by heating to at least half of the melting point temperature. The nonferrous crystal structure of copper is significantly different than that of ferrous metals that require slow cooling after heating to their critical temperature (indicated by the loss of the ability to be attracted by a magnet) to return to their dead-soft state. It's not the heating by the cylinder head that causes the copper washers to harden, but rather the work-hardening effect of tightening to malformation upon proper installation. In this way, the washer becomes a seal.
interesting, I was under the impression that if you cool a metal quickly it hardens and if you want to to soften you need to let it look slowly in air.
It's not the heat that hardens the copper, it's the clamping pressure from screwing the plug in. Copper 'work hardens'. The heat softens it again. Unlike ferrous metals copper, which is a non ferrous metal, doesn't harden when quenching - it's just cool again sooner. The stuff you learn jobbing in metal shops. =D
@@KevinLaceyTX The copper becomes hard because of the compression of tightening. Some people confuse the "Annealing" of copper with heat hardening of steel. You still heat it to the proper temperature. But you wait until the proper time to quench it. Its like putting steel cylinder sleeves in an aluminum engine. You heat one, and freeze/cool the sleeve. The sleeve slides right in. Same with valve seat inserts. Get a piece of soft copper tube. Heat it up until it is cherry red. Quench it in water. It won't bend much and will probably king. I'm not saying that you can't heat up copper plug gaskets. Its just that whether you cool them in water or leave them to cool by themselves. it won't make any difference once you torque the plug in place.
I like old-school fixes, but you spent more on time and propane there than the cost of a new washer. $0.37 each.Probably less if you buy in bulk. The only reason you would do this is if you're stuck somewhere and can't get a new one.
I had a Champion rep tell me to always use new gaskets because the old ones aren’t as thick, so may cause the piston to hit the plug...not to brag or anything, but I’m not as dumb (nor gullible) as I look: the tolerances for cylinder heads, spark plug bodies, and gaskets are greater than the few thousanths a used gasket may have been squished. As an A&P/IA, I wait until I get about a hundred or so used gaskets before I hang ‘em on a piece of .041 safety wire and use a rosebud torch to get ‘em glowing and dunk ‘em in a bucket of ice water. I set ‘em out on a towel to dry and quality check ‘em. I put the keepers in the “annealed” bin and use ‘em every time I remove a spark plug: reuse, recycle!
Must be the BS degree in metalurgy I earned from Ohio State University. When you heat copper to a cherry red color and quench it in water, the copper is annealed. It's a two for one deal! You won't get that with steel...
You are correct. The procedure will not yield the same results in terms of quenching when applied to copper. Nonetheless, many in the Airframe & Powerplant (A&P) sector use the terms interchangeably, treating them as if they were synonymous. There might come a time when these practices are attempted on steel, and that could lead to significant issues. I withdrew my earlier post after realizing my explanation wasn't fully accurate. Additionally, it is illogical to suggest annealing followed immediately by quenching since these processes are diametrically opposed. The presenter in the video seems to have a misunderstanding of quenching, apparently associating it with the noise produced during rapid cooling, at least that is the impression given by his commentary.
,,, waste of time, same spark plug, in the same cylinder, throw the same gasket back in ! As long as it's not gouged or spread. All right bring it on nambees.
Champions' maintenance document AV6-R..... (page 10 and 11 if your too lazy) new gaskets are installed for a reason. What silliness this is, annealing gaskets to save $2. Are cylinders not more expensive? Ever heard of the dirty dozen...this video is a fine example of Kevin compLacency. That being said obviously you have been taught improperly by your mechanic. Now you've heard it from a mechanic that knows better. If you can't afford to fly safe, you can't afford to fly!
Aah another idiot armchair mechanic that likes to waste perfectly good part that are safe to reuse many times again wrongly thinking the answer allways: is new parts some how make ”amejaremy” artificially feel safer when you factually are not.
I’d disagree with both. I am sure it’s perfectly safe to do this. But they are under 50 cents a piece, so for a four cylinder 8 plug engine your well und 4 bucks. My time and propane are worth more than that. Good to know how if I’m some odd situation where I need to pulls plugs and then fly without access to new ones. But seems a waste of time to do normally. And with a manufacturer bulletin out saying don’t do it... doing it still ain’t gonna cause a failure, but it could very well make you liable if a failure occurs after you did it.
