Discoloration?

Discussion in 'Technical Questions & Information' started by Munch, Jul 1, 2012.

  1. Munch

    Munch Member

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    I just picked up a Star BM, and when I got it home I noticed this discolored spot, just above the slide lock. Is this just from the heat, and nothing to worry about, or is is it a sign of a failure waiting to happen
    [​IMG]
  2. Munch

    Munch Member

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    As it shows in the pic the blueing is is sad shape, I'd like to have the pistol refinished with a more durable coating. I just don't know which way to go ceracote, duracote, etc. Which is a better coating? Can I do it myself, or does it require special tools?
  3. Hammerslagger

    Hammerslagger New Member

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    From what I can see in your photo the plum (or reddish-brown) colored spot is not likely any cause for concern. If the finish is original, the gun left the factory that way. If it has been re-blued the refinisher did not properly maintain the temperature and chemical composition of the bluing bath. The same is likely true of the factory, if the finish is original.

    The most likely reason for the off color subject spot is Nickel in the slide's metallurgy, in conjunction with selective area heat treatment to make this slide "hold open" spot harder and tougher; thus, preventing premature wear.

    Steel alloys that contain significant amounts of Nickel, and especially if they have been hardened by heat treatment, are often difficult to blue. This is often seen on exposed flat springs on Mauser design rifles.The hot bath bluing solution must be chemically and temperature correct, within very narrow limits or one gets a reddish vs blue oxide coating. {I once encountered a sporterized, very late production (serial #1,500,XXX) 1903 Springfield rifle made at SA that had its whole receiver plum color. The ignorant refinisher/rebluer had almost buffed the markings off of the receiver in repeatedly rebluing it, trying to get a blue vs reddish color. He finally gave up, and left it reddish.}

    As to refinishing this pistol; personally, I would not. The gun appears to be in very good shape. A little cold blue (actually blackened copper plating) applied to the muzzle end every few years will prevent rust and be as (or more) durable as any painted finish.

    Hope this helps.
  4. fuzebox40

    fuzebox40 Active Member

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    These do have some collecter value, perhaps not allot but still something to concider before refinishing it. I have to agree with Hammerslagger and would vote not to. But I hate when I get 20 opinions and not one answer to my question so I can tell that I am not familiar with Ceracoat but I do use Duracoat quite often. It is very durable for a painted on finish if applied properly. I prefer a fine sand blast prep or fine sandpaper if thats all you have but all you need as far as tools is a little airbrush and air. If it's a one time thing they even have a premixed ready to use aerosol. Hope that's of help to you and I'll post a pic or two of some of my Duracoat work.
  5. fuzebox40

    fuzebox40 Active Member

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    Ithaca shotgun in OD Green.
    .380 auto in Titanium and Matt Black.
    Ruger .22 in Desert Sand and Matt Black.
    Browning 10g in Matt Black and Titanium.

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  6. Alpo

    Alpo Well-Known Member

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    [​IMG]

    [​IMG]

    Dammit. I have tried fourteen times to make that picture bigger and it is not working.

    BUT:

    Top right corner of the slide stop notch. Perfectly round notch that does not belong.

    It looks to me like the slide had a crack coming out of that corner and it was stop-drilled. Whoever did it ran the drill too fast and the heat caused the discoloration.

    Probably burned up three bits doing it, too, since it was too fast. Might not even have used oil.
  7. RJay

    RJay Active Member

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    Alpo is correct, it has been stopped drilled.If you zoom it up to 400 hundred you can clearly see it.
    Last edited: Jul 1, 2012
  8. Hammerslagger

    Hammerslagger New Member

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    If Alpo is correct (and he likely is) that the slide has been modified, in that the radius on the upper right corner of the hold open notch does not belong on this Star pistol; then he is likely also correct that it was overheated, and thus discolored, in the creation of the radius.

    However I would opine that the radius was likely created by milling with the flutes of a dull end mill or a twist drill vs drilling.

    The foregoing observations and likely conclusions having being said, the owner might want to look closely (or have an expert look) at the whole pistol for signs that it has been shot a great deal, is in much worse mechanical condition than its cosmetic condition; and, thus, might be near the end of its service life.
  9. Alpo

    Alpo Well-Known Member

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    I've seen a lot of stop-drilled pieces in my job. It's a perfectly acceptable solution to a crack.
  10. Bill DeShivs

    Bill DeShivs Active Member

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    The slide has NOT been modified. The red mark is where the slide has been selectively hardened. All the Star BM/BKM slides have the small hole.
    Everyone who gets a used gun wants to "refinish" it! The bluing is fine as-is. If you need to refinish, why not go to a real upgraded finish like electroless nickel or hard chrome. Both these are much more durable than any paint.
  11. Jim K

    Jim K New Member

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    The hole was drilled at the factory to prevent cracking at that point; the discoloration is due to hardening of the notch to prevent the slide stop from wearing the slide notch and rounding it off when the slide stop is released. That is a very good pistol and there is no problem with it.

    Jim
  12. Munch

    Munch Member

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    Thanks everyone for the information! I think I'll try the cold blue on the areas that have lost most of the finish. I have some, and have had good results with it in the past. I do like the look of the finish that fusebox has applied. Those came out really good.

    I loved the little Star .380 so much that when I got chance to pick this one up, It was a easy decision. I haven't fired the BM yet, but can't wait to get up and try her out.
  13. JLA

    JLA Well-Known Member

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    Spot on. Quick on the draw alpo.

    Problem with that particular spot now is the metal at the rear of the slide stop notch has been annealed from the heat of drilling the stop hole too quickly. it will peen out as you fire the pistol and get ugly in a hurry.
  14. RJay

    RJay Active Member

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    :)I've never owned a large frame Star so, don't know. Now some might say I'm a gun bigot, but if I examined a gun with that repair hole/preventive drill hole, I'm afraid I wouldn't buy it, even if it was sale for a dollar ninety eight.:)
  15. fuzebox40

    fuzebox40 Active Member

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    :eek:

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  16. JLA

    JLA Well-Known Member

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    looks like someone went a little crayzee with the stop drill holes on that one.
  17. Bill DeShivs

    Bill DeShivs Active Member

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    The spot heat treatment of the slide was done AFTER machining and drilling. It's the way they were made.
    I have 2- PDs, a BK, and a BKM. All have the "hole." It's not drilled-it's a part of the machining process used to mill the notch.
    Last edited: Jul 1, 2012
  18. ignats

    ignats Member

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    Looks to me they are all done that way.

    Go GB Auction # 293896828
  19. JLA

    JLA Well-Known Member

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    Then why does the one fuzebox post a pic of have it done on the slide stop notch as well as the safety catch and takedown notches and the one Munch posted a pic of only has the slide stop notch done??
  20. Hammerslagger

    Hammerslagger New Member

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    After reading the posts from #4 on, all in all, I have a strong suspicion that this this pistol has been reblued by someone not expert in bluing nickle alloyed, heat treated steel.

    Late US Army, Springfield, Armory produced, 1903 rifles went from double heat treated nominal AISI 1045 to 3% to 5% Nickle Steel a little before S/N 1,300,000 going through S/N 1,500,000+. {I believe that the P14 and P17 Enfields receivers were basically the same material.} many of these rifles were sporterized and successfully blued. However, bath chemistry and temperature is very important and must be maintained within narrow limits. One would think that Star could do so, unless others here have seen a lot of Star's with subject discoloration.