Ruining cases by Annealing

Discussion in 'Reloading Forum (All Calibers)' started by bsekf, Jan 12, 2018.

  1. Metal God

    Metal God

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    First let me say of all the propane testing I've done as well as annealing in general . The orange flame only occurs right around the brass hitting 750* or above . The MAPP gas flame has orange in it from the get go and seems to get more orange as it heats up the case .

    I've talked with a few people about that orange flame . Right now there are two thoughts on that and I think they both can be right .

    1) The carbon and or fouling from inside the neck burning off resulting in the discolored flame . I've not retested this after buying my SS wet tumbler . If I were to have very clean cases that may not happen .

    2) The flame is showing the zinc breaking down at the edges of the mouth since it melts at 782* and there's some stuff going on way above my pay grade that I could not explain . I was told what may be going on but don't remember enough to even try to repeat it .

    So those have been my working theories to date . I don't believe it's unburned gas setting off .
     
  2. FJIM

    FJIM

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    Wow every pic i seen looks over annealed to me...First of all you have to ask why are you annealing. brass is hard and splitting necks and shoulders. or just to gain some neck grip..I use the bench source. on hard brass that is splitting requires more time than what i call a maintenance anneal which is something i do every firing if using a bushing die and want to maintain a hard bullet grip. I would never want to clean that tempilaq heat paint out of them case necks. with the bench source i use a set up case to set it up for temp and time but the time gives the temp..it's not long 1.5 sec or so in the flame and your done. most of the time you don't even see discoloration on the case. but bullet seating says we have hard grip. so we did something...Now a hard case that was splitting will require more time but not much..I use the 750 deg F on inside the neck and 450 deg F on the case body to get my set up then i run my cases threw. It take some experience from experimenting on some brass to get the hang of it and i use the same set up cases just repaint them set it up and then run my brass through..It seems to work well but there is always that doubt will this give me what i want. So far it seems to. i bought the bench source because i tried annealing once and over annealed some cases that made the heads soft and it was bad.. dangerous . so far with bench source even dasher brass i never hit 450 deg F more than half way down the case....Very happy with it..But annealing is kind of like black magic..
     
  3. jimbires

    jimbires Silver $$ Contributor

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    I agree with both statements . I'll add that finished color is a very poor indicator of proper annealing .
     
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  4. JRS

    JRS

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  5. 500Stroker

    500Stroker Silver $$ Contributor

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    Boyd you have done it again, this^^^^ is the best explanation of why you want to anneal that I have seen. Thanks
     
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  6. riflewoman

    riflewoman

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    The finished color varies due to the atmosphere in which the cases are annealed. A burning flame is very often has little or no oxygen to change the color. Look at the picture taken in this treatise of an annealed case by this manufacturer. https://www.petersoncartridge.com/our-process/drawing-brass . Many of you would be aghast at this discoloration.

    As for the orange flame in a propane flame indicating de-zincification. You’d have to do spectographic analysis of the flame to determine what is burning in the flame. You can’t always tell by looking at it. Also, factories have been annealing brass at high temps for years during case manufacturing. If the brass lost its zinc in this manner, we wouldn’t be using brass.
     
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  7. John Russell

    John Russell

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    The orange flame is not because the temperature is 750°.

    The orange flame comes from the oxidation (burning) of carbon... carbon in the neck, from oil, or wax from preservatives on the new case, etc.

    It NEVER comes from oxidation of copper, Zinc, or tin... never! This is a fact of chemistry, not my opinion. Copper, Zinc and Tin all show bright green in the flame when they oxidize, and for any of them to oxidize, they must hit a temperature way hotter than melting point of brass (like above 3,000° F.).

    The zinc does not break down, since it is a basic element, there is no "down" to break to.

    Zinc 787°f
    Copper 1984°
    Tin 449°F
    70/30 Cartridge Brass - 1,700

    When metals are alloyed, they lose their individual melting points... so when you heat brass, the zinc does NOT melt out at 787°F... the whole piece of brass melts at ~1,700°F.

    If you look at this chart on annealing brass, it shows that 750°F is probably the worst temperature us use. It is right in the middle of the steepest "rate of change" on the annealing time/temperature curve.

    The curve straightens out around 900°F

    [​IMG]

    It turns out that 900°F in brass is the temperature that brass turns dark red. So it all comes together to be an easy, self controlling system without a need for a lot of technology. Heat it to dark red - time is not critical, 'cuz the curve is flat, and then you are done - no messy templaq.
     
  8. mr45man

    mr45man Silver $$ Contributor

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    LOL i have coffee can full of those (45acp)
     
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  9. riflewoman

    riflewoman

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  10. Metal God

    Metal God

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    Actually that chart at least to me indicates 750* is perfect . Keeping in mind this is rifle cartridge brass and not just a hunk of brass that needs annealing .

    The cartridge brass needs some hardness left in it to hold the bullet and to give the cartridge structural integrity . I have to say what I've shown as far as over annealing ( likely in the 900*+ range ) resulting in poor bullet hold and the other guys saying there over annealed cases collapsed on chambering or sizing has shown that hitting a temperature well over 750* when annealing cartridge brass is not a good thing .

    Your chart clearly IMHO shows that sweet spot cartridge brass needs to be at as those two line intersect . At least that's how I see it . The brass in that zone has gotten softer but not so soft it can't be used safely as cartridge brass .
     
    Last edited: Jan 13, 2018
  11. Papa Charlie

    Papa Charlie Silver $$ Contributor

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    I spent some time looking through the Popular Mechanics mag in the link above. pretty cool from November 1934.

    Anyone still wearing a tie and shop coat when running their lathes?
     
  12. fyrewall

    fyrewall

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    Good work John, but now I need to know about the orange flame shown in photo 3 (from tip) and why some winning gun guys like to have some spring in their brass necks - thus the Accurate Shooter Site Bulletin about testing for spring back using vise grip pliers & caliper (clever?).

    Also, there is the situation where member searcher toasted some necks well into max grain size and observed that bullet/cartridge run out was compromised upon feeding from magazine, feed ramp, then chamber. This might explain why Lake City brass is made with tough springy necks for use in the crude but effective M14.

    My thoughts would be stop toasting @ 400 degrees C or 752 degrees F, or start of grain growth. How to do this? templaq? or immersion in molten salt(s)? or trial & error experimentation showing the toasting process should quit after 6-8 seconds followed by a drop into cool water.

    The flame cone --- https://en.wikipedia.org/wiki/Flame#Flame_color

    I think there is excessive high tech stuff in the above link, but if the reader can get past it, different types of flame colors can be seen depending on the oxygen supply. Getting the brass well inside the blue tip of the flame would reduce the temperature. I think this would be important if the magic 750 degrees F were to be reached on the basis of timing and to do this the brass needs to be toasted at a constant distance from uniform heat then removed just at the right time. As the brass is still cooking hot a dunk in cool water would stop any unwanted grain growth.

    MAAP gas would be a poor choice because brass grain growth would be real abrupt and not provide adequate reaction times to quit heating.

    As for burning crud inside the case mouth - upon positioning a case having sizing lube inside the case neck and toasting it with max heat just at the end off the dark blue flame cone a lighter blue flame occurred (not yellow) at that time the other end of the case was too hot to hold onto. Same for an un-sized fired case. Yellow flames are an indication of sodium - possibly some contaminant inside the brass neck containing sodium made the flame burn yellow. All I got was a light blue flame from the leading edge of the brass mouth with my properly adjusted torch tip flame. My thinking remains that the yellow flame is a result of secondary combustion. Does templaq contain sodium?

    That neck tie should it get caught in a massive force spinning lathe would draw a person's upper body into catastrophe.

    ********** edit

    The MSDS for Tempilaq liquid used for a 750 F test does contain sodium (disodium wolframate - some type of tungsten - sodium compound???) upon being lit off this stuff would emit a yellow flame - the flame test for sodium is yellow. I read all of this stuff as fast as I could.
     
    Last edited: Jan 13, 2018
  13. BoydAllen

    BoydAllen Gold $$ Contributor

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    The reason that we do not use 900 degrees it that we do not want to fully anneal necks, because we need some bullet pull for best accuracy. Powders vary in this requirement. The object is not to fully anneal, but rather to put cases through a process that increases the consistency of velocities. Actually... using the word anneal can lead people astray. We do not want necks to be fully annealed.
     
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  14. riflewoman

    riflewoman

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    Please remember that there is also a time element in all of this. If you go to 750 and air cool you might be in the same area as 900 (dull red in a dark room) and an immediate water quench.
     
  15. chop house

    chop house

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    so, i was really proud of these until i just read above that coloration is no indicator of state of anneal. the more i look, and read, and think, i think they might be over annealed. they were done on my homemade drum single propane setup.

    And, while on the topic of coloration, how come it sometimes takes an amount of time after cooling for the color to appear?

    guess i need to break out the visegrips, load some dummy rounds, or do a couple more with my ir thermometer on the body at drop time.

    180113_003.jpg
     
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  16. BoydAllen

    BoydAllen Gold $$ Contributor

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  17. Metal God

    Metal God

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    I actually did testing on the "anneal marks" . Unfortunately the only photo I had that showed those differences was lost by imageshak and I can't find it on my computer . I might be on my old one though . My test showed the less heat used meaning low flame or intensity the less anneal marks are present . It also mattered where on the case and what angle the flame was to how much they showed up . I concluded there is no direct correlation between anneal marks and what temperature the cases reached .
     
  18. JRS

    JRS

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  19. msinc

    msinc

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    It does not necessarily mean they are wrong either....and one other thing about it, a quick look at yours and any reasonable person can see that you are for certain consistent. The coloration probably has more to do with how clean or oxidized the cases are to start with, not how correct they were done. Now, if you see spots that are real dark and they don't rub right off with a polish cloth or extra fine steel wool then yeah, they got scorched and will be dead soft.
    Cases with a little oxidation {like yours} come out looking like yours. Ones that are fresh from the sts tumbler and pretty bright brass tend to develop a kind of pink hue to them. Same time, same method, same temperature two different colors, again, does not mean they are wrong.
     
  20. chop house

    chop house

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    I kinda sorta tried the vise grips thing, didn't really like the (lack of) feel. looking for some comments on the following:

    using a mic measure the neck od using the instruments clutch. then, purposely compress to a reading a couple thou (or more?) smaller by turning the mic barrel, not the clutch. may not want to use your best instrument for this. relax the pressure and remeasure with the clutch (just make sure you don't rotate the case). what the standard is, or should be, i have no clue??? depends on brass composition, neck thickness, and state of anneal.

    similar could be done with a vernier... getting the feel thru the thumbwheel as you compress the neck?
     

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