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spark plug washer heat treat method

A5555

Well Known Member
I don't buy new spark plug washers. For spark plug changes I heat treat the used washers with a torch until red hot and let them air cool to make them soft again. Thereby saving the planet and added expense. But today, I didn't have my torch so what to do? Well, I have a hot plate so I thought I would give it a try. I tried bending a used washer firstly and yes it was stiff, as I thought it would be since I have checked them before in this condition. Then I put the washers on the hot plate for 10 minutes. They become black but once air cooled and shaken together, the black oxides falls off and they are supple once again. This is my new method. Forget the torch.

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bent with fingers

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BTW: spark plugs at 650 hrs as removed. except for one that was replaced because it was dropped, #2 down. they look OK.

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Two comments:
1. Unlike iron, you can dump the copper into a water bucket after heating. It will still be soft, but less black scale.
2. #4 bottom plug, maybe others, look to me to be near the end of their service life - center electrode looks to have a 2:1 aspect ratio.
 
Two comments:
1. Unlike iron, you can dump the copper into a water bucket after heating. It will still be soft, but less black scale.
2. #4 bottom plug, maybe others, look to me to be near the end of their service life - center electrode looks to have a 2:1 aspect ratio.

thanks for the note on #4 bottom plug, time for that one to be replaced.
 
Good idea. I recently changed out the new “old” hangar trucks power steering pump. The main hose fitting is a bango fitting that has two new copper compression washers that come with it. I couldn’t get them to seal to save my life. Heated them with my torch (careful, they are easy to melt), and they sealed well. You can feel the difference as you torque them down.
Might need to find a hot plate.
 
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With the cost of electricity added to the labor to heat-treat the washers, I'll save more $$$ buying stock of washers and just using new each time I pull a plug.

-Marc
 
Take a harder look

Quite honestly, I would be replacing all of them (except for number 2). They are definitely footballed. Did you check for resistance?

Vic
 
Electricity is less than a nickel to heat treat these. I also regrind my wire flush cutters when they become dull.

With the cost of electricity added to the labor to heat-treat the washers, I'll save more $$$ buying stock of washers and just using new each time I pull a plug.

-Marc
 
resistance check was fine and you can see the plugs have a nice color to them. for the most worn plug: wide diameter = .142 inch, minimum narrow diameter = .122 inch. so appearance is worse than it actually is. I reinstalled as is. I can get more life from these but placed an order for a new set to be ready in another 100 hrs.
 
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700 hr spark plugs

replaced all but one of them. 700 hrs was running fine but time to change. one had been dropped and replaced earlier, #3 down.

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I have 1200 hrs on fine wires wouldn't run anything else with magneto ignition
Quite frankly, I have run fine wires, and have had more trouble with them, at least in the Champion brand than with massives. Most eventually failed resistance test badly, going over 100K ohms. One recently removed failed in flight test, while okay on resistance and appearance.
Usually have trouble with intermittent misfire with older fine wires.
The other issue is that they are fragile to adjust gap, and waste a lot of money if one is dropped. To compete economically with massives you have to manage a full 2000 hours on a fine wire.
GAMI issued a service bulletin strongly recommending against fine wires of the C brand in a turbo normalized or turbocharged engine, where electrode ceramic failure was common.
 
Kelly,
I've heard that Champions fine wire plugs are more of a "stay away" product. I've been running fine wires in my -10 for well over 1,000 hours with no issues, and nearing 300 on the -14. But, mine were Autolite/Tempest. I treat them very well when I pull them though because as you mention, dropping one is an expensive lesson.
 
I’ve been annealing spark plug washers with a propane torch and some tap water in my last empty Starbucks coffee cup for awhile now. Just torch ‘em till they glow orange. Then quench in water and burnish with scotchbrite when cooled.
 
I guess I'm getting lazy in my old age because for 30c each, I just buy new ones (I have a box of 100).
 
that equals 3000c.

That’s a lot more! Ha!

I am a “buy a box” guy. However, I am also a poor planner. I buy bulk to overcome this, then end up borrowing from a neighbor or waiting on my order because I forgot to re-order. Filters, gaskets, cotter pins, you get the idea.

I won’t be afraid to anneal these if I run short. Thanks Steve.

By the way, I just replaced a PS Pump on an older Toyota Pickup. I could not keep the banjo fitting from leaking. A quick internet search revealed that most of these replacements come with cheap Chinese copper washers that have age hardened, or never where properly treated. Based on this oringinal post, I annealed them, and presto, leak free. (This was after I melted one with my torch, so, be careful with your heat source, the electric stove top would work well.)

Good post Steve.
 
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