1/4 " spark plug copper washers

[Vixen]

I don't know about you, but I am forever losing the tiny copper washers for my 1/4" spark plugs. One moment they are there on the workbench, the next moment they are gone.... lost forever. I blame the shop elves. 

Do you know of a reliable and affordable source of affordable 1/4" copper washers in the UK? I have found some 0.265 x 0.375 x 20g washers but they may be a bit too loose on the 1/4 spark plugs. Has anyone tried these?

Cheers

Mike

[Dan Rowe]

Mike copper is crazy  expensive. Here is what I found from China:
https://www.ebay.com/itm/133697769158?hash=item1f21020ec6:g:Bz8AAOSw-HlgU3l-

Do you have a better source than that?

Cheers Dan

[Quadra]

Hi Vixen

Try Minimag for 1/4 copper washers.

John

[wirralcnc]

Can you not make them if you had some copper?

[Dan Rowe]

Can you not make them if you had some copper?

Yes but it takes time to make a tool and copper sheet is still crazy expensive so factor in the time to make them and I do not really see any cost savings to the old pocketbook.

The only advantage is that the maker will have very good size control so that might be the deciding factor in the equation.

Cheers Dan

[wirralcnc]

We have to make copper washers all the time in work.
Some times 40 at a time. We make from round bar stock and part off. As you say perfect control of the sizes.

[Roger B]

Do these look like what you need?

https://holzapfeldampf.ch/produkt/dichtungsscheiben-kupfer/

I can send a packet or two if they suit.

[Dan Rowe]

I use red fiber washers for model boilers and they might be useful for spark plugs. I have no idea of the service life in that application but they are cheap and I get a chance to tell one of my favorite sea stories.

https://www.ebay.com/itm/403381767615?var=673413051921&hash=item5deb6d4dbf:g:qYcAAOSw87ZgSdTm

I was the first assistant engineer on one of the US Lines Econ class of ships with a 7-cylinder RLB Sulzer main engine. This was the first time I sailed first on a new class of ship and I was feeling a bit out of my depth. I know my way around a shop and I have a good memory of resources I spot that might come in handy.

The ship had been in a two-year layup and everything was stripped or stolen. No spare parts to speak of and almost all the tools had taken a hike. In the middle of the big pond all the air start valves had overheated and burnt the paint black. This is very bad as it would not be possible to restart the engine in this condition.  We checked the spare parts box and no copper gaskets were found inside it. The Chief Engineer asked me if I had ever heard of Klingerite being used for a head gasket. I said no but I could make them quick to give me time to make a proper gasket.

I had spotted a sheet of copper about the correct thickness but I knew there were no tin snips to be had. I had also seen a dozen carpenters' hatchets the kind with a straight blade and a hammer head on the other end. I threw the copper sheet on the steel workbench and used angle iron and the hatchets to cut out some copper blanks. Now over to the lathe which was a big industrial unit and I had no idea how to turn it on. With the blanks screwed to a board on the faceplate, I used the jog button for the on switch. I had a set of gaskets ready for shutdown and replacement in the morning.

The Klingerite gaskets held just fine and we replaced them with the copper ones and sailed happily on our way. Several years later in a bar in Boston harbor the chief reminded me of the story. Both the ship and my skills as a first were in question in his mind at the time. He said, "I was so relieved when you made those gaskets because I knew I had a first."

Well in conclusion will red fiber washers work? I have no idea but they are cheap and easy to replace. Your milage may vary.

Cheers Dan

[Roger B]

I had a quick look at what I have. The first picture is a Holzapfel 6 x 10 washer, the original washer and a Regner Dampfmaschine 6mm washer. I think that the Holzapfel 6 x 8 mm washer may be better but I don't have an example. The last picture is the 6x10 washer on a sparkplug.

[stevehuckss396]

Get some 5/16 or 8mm copper or brass , heavy wall tubing , and drill the center out to about .255 inches and them part them off. I make mine .040 inches thick. Brass is easier to machine and I have not had a problem with a poor seal.

[Jo]

Its a pain trying to find somewhere that makes the right size. I keep planning to make myself a press tool to make my own so they are the right size 


I wonder how many of you out there remember to anneal your copper washers every time before you tighten on to them? 

Jo

[Dan Rowe]

Jo we used hundreds of them on the diesel engines. If you did not anneal them you would be redoing the job very soon. A good teaching system. Daihatsu generators have rocker arm cooling oil and HP fuel lines in the rocker box, if the rocker oil level started to go up it had a fuel leak. The quickest way to fix the problem was to change ALL the copper gaskets in all eight cylinders and do it your self with newly annealed gaskets. You might be able to guess why I know this.

  Dan

[Vixen]

Thanks guys and gal for all the good advice and so many options. The MEM forum never fails.

My Chinese 1/4 x 32 spark plugs actually measure 6.1mm OD, a bit short of the theoretical 6.35mm = 1/4". So with a little luck and a following wind, a 6mm copper washer may just fit. I guess a tight washer could be stretched (expanded) with a taper drift.

So what to do?
I have located some 8mm x 1mm wall copper tube. I will try parting that into thin washers and see how that goes. Failing that, I will try some of Roger's  Swiss 6 x 8 copper washers. Having a little difficulty with their website but I think the 6 x 8 x 0.5 copper washers are qty 20 for 6 CHF (about £5) plus some postage.

Thanks again, I will let you all know how I get on, as we all need extra spark plug washers (annealed) from time to time

Cheers

Mike

[Dan Rowe]

My Chinese 1/4 x 32 spark plugs actually measure 6.1mm OD, a bit short of the theoretical 6.35mm = 1/4". So with a little luck and a following wind, a 6mm copper washer may just fit. I guess a tight washer could be stretched (expanded) with a tapered drift.

Mike I would use a tapered reamer to fit the copper gaskets that are a tad off. I think that would be much simpler than an expansion drift.

Cheers Dan

[Vixen]

Hello Dan,

Yes, I have a couple of taper reamers about that size, but they are no longer that sharp. I would have to reamer the raw tube before parting off as it would be near impossible to hold the tiny washer afterwards. Whereas the expansion drift tapped through the washer into a drilled hole, does not need the washer to be held. It's another one of those 'try it several ways until you find what works' situations.

Cheers

Mike

[Laurentic]

Just thinking on how to part off the 8mm x 1mm wall tube into washers - sounds like a tricky animal to me. 

I wonder if mounting the copper tube on a 6mm dia steel rod first might help???  Not done it, mearly thinking out loud!

Might need to support the rod both ends too???

Chris

[Dan Rowe]

Mike, yes my repairman's reamer is a bit dull also so yes a good point. If I was doing this for my shop I would make a special chuck to hold the OD of the ring and have a screw on cap that held the ring in place then a very sharp boreing bar in the lathe would do the trick.

  beer 00:30 here!

Cheers Dan

[Vixen]

Hello Chris,

Turning and parting copper needs razor sharp tools. Mounting the copper tube over a steel or aluminium rod sounds like a very good idea. Yet another of those 'try it several ways until you find what works' situations.

And there I was, happily draining the swamp until this happened. I only wanted to buy a stock of washers, now  It looks like I will be making them, custom size.

Cheers

Mike

[Vixen]

The 8 x 6 thick wall copper tube turned out to be 8 x 5.5, a shade thicker wall than I expected.

I decide to follow Chris's idea of mounting/ supporting the copper tube from the inside with a steel rod. I turned a piece of steel to be a nice running fit inside the 5.5mm ID copper tube. I milled a slot along one side of the steel rod to give somewhere for the parting tool to overshoot into. I ground a special, razor sharp, 20 thou (0.5mm) wide parting tool with plenty of top rake to minimise the amount of copper to be removed

Here you can see the set-up to part of 30 thou (0.75mm) thick spark plug washers from the 8mm thick wall copper tube. I parted off the first few by hand and became confident enough to write a short CNC program to part off eight washers in a batch. The tool position was incremented by 50 thou after each washer with the parting feed rate set very low at 1 inch per minute. The slow feed rate ensured the minimum kerf to be cleaned up.




I now had a pile of undersized (5.5mm hole) copper washers. I made a very simple ring expander by turning a very slow taper on some steel rod. The taper went from 5.4mm to 6.2mm, the size I wanted for my 1/4 x 32 tpi spark plugs. The diameter of the bar above the 6.2mm diameter was relieved and used to catch the stretched (expanded) spark plug washers as they were produced.




This is the result of an hours work. All that's needed now is a careful cleanup and then annealing to soften the copper




When I started I only wanted to buy few spare plug washers. Instead, I ended up making them, enough to last me several lifetimes. Much more satisfying.

Mike

[Dan Rowe]

 

[Admiral_dk]

Great result that easily can be copied by others     

Per

[Vixen]

Great result that easily can be copied by others     

Per

Thank you, Dan and Per,

Per, that's exactly why I go to the trouble to write up and post my methods.

I now have far more plug washers than I can possibly loose (use) in a lifetime: so if anyone sends a stamped/ self address envelope they can have a few for free.

Mike

[propforward]

Nifty solution - I really like the tapered expander idea.

[Vixen]

Hello Stuart,

Reducing the diameter of the tapered expander above the desired diameter, means you don't have to fight the copper ring off the taper.

Mike

[Roger B]

That's an excellent solution to your problem