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We all knew this would happen.

daz wrote:We all knew this would happen.

Well, DUH! Thus the early popcorn reference.

Ken in Oklahoma wrote:To add fuel to the fire, if one chose to re-use a copper sealing washer, it would be a good idea to anneal the copper. Heat it red hot with a propane or other heat source and let it cool; or dunk it in water if you like to hurry the process. Copper isn't high carbon steel.

I would anneal the old washer(s) if I had no spares and I really needed to go riding. Of course the likelihood of me not having those spares is slim. And one would want to keep an eye on the connection, at least initially.

Back in the day reusing a copper head gasket by heating it red hot was a common practice, talked about in some of the old Brit bike "coloring books".

The idea is that compressing a copper gasket work hardens it and annealing relieves the stresses, allowing it to comply with irregularities better.

Aside:
I believe that it is common practice for reloaders to anneal the case mouths (to reduce splitting and to make resizing easier and the bullet crimp more secure).

Ken

My turn to say 'not exactly'.

To anneal copper you must cool it slowly. Plunge it in water and you temper it--hardening. When working with very thin sections (I work a lot of copper) I plunge in sand to slow the cooling further. When you do a something like a flare fitting in copper the flaring does some significant hardening. However trying to anneal the flare is iffy. The problem is oxidation. The hot copper develops a thick black oxide layer in air. So you have to get that off and then you have pitting and roughness left behind. For the critical seal, you just use sealant. I use a sealant even on flare connections for simple plumbing, but nothing fancy. (same stuff can be used on petcocks I found out recently). For critical joints (refrigeration) I use the fancy sealant. Refrigerants go right through the copper, you need incredibly solid joints to not have a completely leaking pig. They get hot and vibrate...

To anneal a crush washer I would want to work in a neutral atmosphere. Starts getting complicated compared to grabbing the sealant and some wax paper. I suppose a black iron pipe nipple, some caps drilled for a nitrogen flush and a big torch might do...

I do a lot of reloading too, hundreds of rounds a month when I'm shooting regularly. I don't anneal my brass. If the brass is too soft it overly expands in the chamber and you get extraction problems and an oversized body when you try to reload again. Feed problems. I use a special jig to set my round length very precisely before I swage in the bullet. I'll reload brass only once with a jacketed round and after that I use plain lead rounds until the brass wears out. The lead takes less swageing force. Guys that are modifying brass to make custom rounds (like necking down a cartridge) get more elaborate and might anneal and then let the necking work harden the brass to where they want it.

SteveD wrote:How many crush washers are required, what size should be ordered and what locations are they fitted to?

I have one left from Spiegler kit. it's aluminum, 13.76mm OD, 10.30mm ID, 1.38mm thick.

I'd call that a nominal 14 x 11 or 14 x 10.5.

I hope this info does not self destruct in 10 seconds. Good stuff, thanks.

timkil wrote:I hope this info does not self destruct in 10 seconds. Good stuff, thanks.

The MAX fiche is weird (nuthin' new) but it has a banjo bolt coming off the splitter (WTF??) that takes a 13.5 x 10 copper crush washer as: "07 11 9 963 072  GASKET RING - A10X13,5-CU (from 09/80)"

The SNAB R100-R100RT circa 10/83 has the same deal but the P/N ends in "3" rather than "2". Technical modification after publication are only on the 'fiche, not that hard copy.

PITAPan wrote: To anneal copper you must cool it slowly. Plunge it in water and you temper it--hardening.

Sorry. Completely wrong. This is true for steel, but not for copper. Copper can be heated and quenched and it's still annealed. Some sources even say that if you don't quench it fast enough it will not anneal, but I've never experienced that.

ME 109 wrote:Rob, popcorn smilie please.

I was not reading this thread until now.



Thank heavens for PMs and pretty girls.

Maybe 30 was good enough?
At least they could trust their politicians!

PITAPan wrote:. . . To anneal copper you must cool it slowly. Plunge it in water and you temper it--hardening. . . .

Hi PITAPan. Major Softie has already corrected you that copper doesn't harden when red hot and plunging it into water. So I don't need to address that. But in the steel heat treating world "tempering" has a specific purpose and meaning.

In heat treating steel, only high carbon steel can be heat treated. That is a two operation process (three if you want to include cryo-treating). At elevated temperatures (the often used phrase "cherry red") the carbon in high carbon steel goes into solution with the iron. If you cool the steel fast enough the carbon doesn't have the time it needs to migrate from the iron and collect into carbon nodules. That is, it remains in solution by degrees. (Here's where I get a bit vague.) The carbon atoms, still in solution with the iron atoms, interfere with the iron molecular structure such that elasticity in inhibited. The resultant steel is very hard and very brittle. Too hard and brittle for many applications. The steel acts much like glass and can be fractured with a hard enough blow.

Enter tempering. A hardened but not tempered hammer would be essentially worthless, fracturing itself at a good blow. Tempering progressively turns the carbon steel from very brittle to very malleable, depending on at what point the process is stopped. Tempering is done at less temperature than the hardening process. We have all sharpened something on a powered grinding wheel only to discover that we over did the grinding and "pumped" too much heat into the steel. The clue is the rainbow like range of colors where we heated the steel too high. Those are oxidation colors and they appear on the surface of the steel, indicating the temperature the steel was subjected to while grinding. The coolest temperature shows up as the so-called straw yellow, indicating that the steel is still very brittle. The "warmest" temperature, meaning you have pumped way too much heat into the steel, means that the steel has been softened considerably. Blacksmiths (and others) aim for certain colors depending upon the application. The straw color will be the least affected and will remain more brittle. The blue-violet color will be more malleable--still hard by degrees but that's as far as the oxidation colors range. There's a reason why we all have seen clock springs blue colored. That's the optimum tempering for "springiness" and durability.

Metallurgy is a big complicated subject, and I've only scratched the surface. And that level signifies more ignorance than knowledge on the subject. I haven't touched on the other alloys put into steel such as chromium and molybdenum. That said, there's a lot of customizing that can be done on steel's properties with simple heating and cooling processes.

There are some fun and sometimes useful things you can do with carbon steel. Old hacksaw blades are fun to play with. I'm talking about simple high carbon steel blades--as opposed to exotic alloy blades or bi-metal blades. I have had fun heating an old blade to cherry red, quenching it in water, and then putting the blade on a vise and smacking it with a hammer. It will shatter like glass. The steel was hardened, but not tempered.

I recently did something useful with hardening. I had acquired some machinists tools through eBay and one of the items was a Starrett divider. The points of a good divider are hardened well enough to scratch steel and you can use a divider to scribe steel (as opposed to marking steel which is much more "vague"). Well, this Starrett divider wasn't hard enough to do a good job scratching mild steel so I decided to harden the tips. To do this I took my propane torch and heated the very tip to a glowing cherry red and then plunged it into cold water. I then carefully ground the tip to a point and finished it off with a diamond whetstone. I chose not to try to temper the point because I wanted the tip to be very hard. That means that if I drop the divider onto a hard surface I stand the chance of breaking it off. I reasoned that the long legs could be re-pointed and re-hardened if it should come to that.

The result was gratifying. I could now scratch a fine line into mild steel.

OK, I think I'm done now.


Ken