spark plug washer heat treat method

Steve Melton · #1 04-28-2018, 05:32 PM

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.

bent with fingers

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

BobTurner · #2 04-28-2018, 06:29 PM

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.

Steve Melton · #3 04-28-2018, 06:54 PM

Quote:

Originally Posted by BobTurner

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.

JonJay · #4 04-28-2018, 08:16 PM

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.

Plummit · #5 04-29-2018, 12:13 AM

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

vic syracuse · #6 04-29-2018, 05:16 AM

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

Vic

Steve Melton · #7 04-29-2018, 05:42 AM

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

Quote:

Originally Posted by Plummit

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

RV6_flyer · #8 04-29-2018, 09:38 AM

Quote:

Originally Posted by vic syracuse

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

Vic

IF the plugs were in my hangar, I would use a spark plug erosion gauge to see if they are still in mechanical spec as well as do a resistance check.

Sam Buchanan · #9 04-29-2018, 11:13 AM

Quote:

Originally Posted by RV6_flyer

IF the plugs were in my hangar, I would use a spark plug erosion gauge to see if they are still in mechanical spec as well as do a resistance check.

That was my thought as well, and it appears to me seven of the plugs would fail the erosion test.

Steve Melton · #10 04-29-2018, 05:58 PM

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.