Are copper and aluminum sealing washers interchangeable?

[donbecker1234]

Reading thru the PET I recall seeing some sealing washers that on my car were copper but in the PET were listed as aluminum (a capital A on the size info).

Does anyone know if copper and aluminum washers are interchangeable if the same size is used, or if that would be a bad think/not functionally the same.

Thanks!

[dannobee]

From personal experience, the aluminum ones seal better. The copper ones are sometimes too hard to deform correctly, notably when they're used against aluminum. A copper washer between two steel parts seals ok, but if either of the other parts are aluminum, it's best to stick with aluminum washers.

[donbecker1234]

Originally Posted by dannobee

From personal experience, the aluminum ones seal better. The copper ones are sometimes too hard to deform correctly, notably when they're used against aluminum. A copper washer between two steel parts seals ok, but if either of the other parts are aluminum, it's best to stick with aluminum washers.

Does this mean you'd use an aluminum washer to replace a copper one, if the parts involved were aluminum?

[RobTT]

I always anneal copper washers in fuel systems. Heat them up until they glow orange.
Does anyone know the correct process for annealing Aluminium?

[OSC911]

With Aluminium it won’t glow red ever so the most accurate way is to get a candle flame and run it over the Aluminium until it gets soot over it. Then use your propane/ butane/oxy or whatever to heat it up. When the soot is burned off it and back to clean Aluminium it is at the correct temperature and is now annealed.

[donbecker1234]

Is annealing either copper or aluminum washers mentioned in any Porsche workbooks? I’ve never seen a reference to it.

[boyt911sc]

Originally Posted by RobTT

I always anneal copper washers in fuel systems. Heat them up until they glow orange.
Does anyone know the correct process for annealing Aluminium?

Why would anyone “heat treated” copper or aluminum crush washers? The basic objective of using a crush washer is to seal and prevent leak using a malleable material like copper or aluminum. Plus, these are supposed to be disposable items and very cheap. But I use them multiple times for my work and replaced them accordingly.

Tony

[roblav]

Anneal is not heat treat. More like opposite of it. Heat treat makes things harder, Rockwell C numbers, whereas anneal softens. Personally, I use copper between steel and aluminun between aluminum.

[winders]

Originally Posted by roblav

Anneal is not heat treat.

Of course annealing is a heat treatment. Heat treatments are not just make metals harder.

https://www.bodycote.com/services/heat-treatment/annealing-normalising/

[winders]

Originally Posted by boyt911sc

Why would anyone “heat treated” copper or aluminum crush washers?

Why? The washer is work hardened and can be annealed and reused. This is real handy to know if you don't have a replacement washer yet need to put something back together.

[jjeffries]

Yes, that was taught to me by an experienced Alfa mechanic years ago. As Winders says, can keep a project moving when otherwise you might be left waiting for UPS.

Tony, my ultra non-scientific feeling is that the annealing relaxes the molecules, gets them back in the mood for creating a good seal.

Best, John

[OSC911]

I have had new copper and aluminium washers leak on many occasions. Annealing is just a simple, quick fix that works. In fact I recently had to fit a Bosch fuel pump to my 911. It didn’t come with any washers so I got some from Porsche. They just wouldn’t seal on the pump discharge. Annealed them and no leak. Pretty handy trick if you need it.

[356911930]

I recall from some time back...or I think I recall that the aluminum washers were for oil and the copper washers were for gasoline.

Has anyone heard this before?

Rahl

[winders]

It doesn't really matter. Both materials are non-reactive to anything you would encounter on a car. I prefer copper because that is what I was used to using on my race bike brake lines. Aluminum seemed to be leak more often than copper. But, I have used both copper and aluminum on my race car without issue. If I had to choose one it would copper.......as it is easier for me to anneal.

[donbecker1234]

As I was poking around on Amazon regarding sealing washers, I stumbled upon these:

https://www.amazon.com/Swordfish-32241-Automotive-Self-Centered-Assortment/dp/B014S1J4TE/ref=ya_od_pd_dx_s_1/131-2477508-6286014?_encoding=UTF8&pd_rd_i=B014S1J4TE&pd_rd_r=84d00641-46ce-4bd8-9384-0680c5279dc4&pd_rd_w=HLbaw&pd_rd_wg=g6lw2&psc=1&refRID=009PJRN2SPNTQZ95F1F9#customerReviews

I've never seen these before, it's like an Aluminum sealing washer with a bonded rubber inner ring. Not sure if they would improve the metal only sealing rings that are traditionally used but looked interesting enough to post.

[911pcars]

This is how to anneal aluminum body panels....... and work-hardened aluminum bits:



Notice the amount of filler used.
Now get to work on your aluminum body panels.

Sherwood

[911pcars]

Fabricating a cabin air connection from 993 heat exchangers to the factory heater valves.

Aftermarket aluminum duct adapters are round and must be formed to connect to the oval-shaped heat exchanger cabin air outlets.


After annealing and shaping to match the oval connector.

[boyt911sc]

Originally Posted by winders

It doesn't really matter. Both materials are non-reactive to anything you would encounter on a car. I prefer copper because that is what I was used to using on my race bike brake lines. Aluminum seemed to be leak more often than copper. But, I have used both copper and aluminum on my race car without issue. If I had to choose one it would copper.......as it is easier for me to anneal.

Scott,

I tend to agree with Rahl’s comment. For the CIS components dealing with gasoline, like WUR’s and FD’s, I only find cooper crush washers on them. While engine parts like valve covers, auxiliary oil thermostats, pressure senders, oil temperature switches, drain plugs etc. all dealing with oil have aluminum crush washers. While they are interchangeable, there seems to be trend for their respective application/s.

Tony

[donbecker1234]

In the PET it seems that Aluminum are specified by a captial A.

On my car when I pulled the injectors, the sealing rings were copper although they are specified in the PET to be aluminum on 930 engines. No captial A on non-turbo, so I assume that means copper?

[Speedy Squirrel]

Super common now. A lot of newer vehicles use them on the oil drain plug.

Originally Posted by donbecker1234

As I was poking around on Amazon regarding sealing washers, I stumbled upon these:

https://www.amazon.com/Swordfish-32241-Automotive-Self-Centered-Assortment/dp/B014S1J4TE/ref=ya_od_pd_dx_s_1/131-2477508-6286014?_encoding=UTF8&pd_rd_i=B014S1J4TE&pd_rd_r=84d00641-46ce-4bd8-9384-0680c5279dc4&pd_rd_w=HLbaw&pd_rd_wg=g6lw2&psc=1&refRID=009PJRN2SPNTQZ95F1F9#customerReviews

I've never seen these before, it's like an Aluminum sealing washer with a bonded rubber inner ring. Not sure if they would improve the metal only sealing rings that are traditionally used but looked interesting enough to post.