Good Day Folks:

I have a Merkel 141E with a colour case hardened receiver.

It has sat in the gun safe since the end of hunting season last year.

I pulled it out of the safe last night in preparation for doing some target practice today.

To my horror, I noticed a fine layer of rust on the colour case hardening of the action. Not deep enough to noticeably pit but, enough to remove the colour case hardening leaving a gray patina.

How do I stop the rust from continuing? Is there some way to re-colour that which has been lost to the rusting?

I'm obviously going to have to start oiling my guns before I put them back in the safe.

In all my years, this has never happened to any of my guns. I am sick.

Help.

Kind regards,

Carpediem

Besides a Golden Rod in my safe, I also use a siica desiccant can.

Firearms that are to be Long term stored are rubbed down (other than the wood) with Eezox or ProShot Zero friction ( WD 40 Specialist is also a good choice)
I store them in the safe in VCI socks (GunSoc Company)

Taking fine rust off is a delicate procedure on cased metal, usually with less than satisfactory outcomes.

1st attempt rub with a a heavy cloth (denim ,etc) with oil.

Failing that , the next steps remove more case--
ultra fine STAINLESS steel wool ,copious oil and ultra light pressure MAY get a semi desired result.

This works well on blue,
not any where nearly as well on case

Golden rod in my safes, also. Cheap insurance.
Now, let's dig a bit deeper. Did your other fireearms have rust? If not the problem is with the quality of steel in your Merkel.

A friend's Sabatti would get surface rust when out shooting on a cloudy and wet day. Cheap low carbon steel was the problem. If all of your guns developed rust, moisture is way too high. If only the Merkel then the problem is in the steel.

Also, for case colors to disappear is a sign of a problem in the steel. Case colors fade in decades or a century of use, but not in a year in a gun safe.

Cal

I have no way of knowing how old your Merkel is, but if it is fairly new, and as Cal says, it is the only gun in the safe to show rust, I would tend to think the rifle must be fairly new.
The reason I'm saying this is, I have two Merkel double rifles in my safe, a 140E-2, 9.3X74R and a 140-2.5 470NE, that have been in rain, and cloudy hunts, and put away with no more than a wipe down with a oily rag, and have never experienced any rust on either of them.

Merkels barrels are Krupp (spelling?) steel cold hammer forged. I doubt it is the steel at least on the barrels. I also haven't experienced any rust on the Case colors either.

I'm waiting to hear if the Merkel is the only rifle in your safe to rust. If it is not then some form of air drying remedy is in order.
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The Merkel is the only one with rust on the colour case hardened receiver. The rest of the gun is just fine. I bought the gun about eight years ago. The gun was put away in the safe dry.

I tried removing the rust with some 3 in 1 oil and a copper plated bullet, rubbing lightly, then oiling.

The photos are 24 hours after cleaning.

None of my other guns show any sign of rusting. I have other colour case hardened receiver guns.

I cannot seem to resize the images. If you right click on one of the images and select, ``open images in new tab``, then open the new window at the top of your bar, you will see better pictures.

I was on youtube last night looking for possible solutions to my problem. I found a video called:

"Color Case Hardening Effect using Cold Blue".

Check out the video.

Has anyone tried this for touching up colour case hardening?

Very sorry to hear of your rusting problem.
Not sure if this relates but perhaps. About ten years ago I had a Ruger Bisley Vaquero with “case colored” finish. It was attractive but a chemical finish and not actual bone or charcoal case coloring involving high heat and quenching in water.
That gun would rust and form a grey oxide just having out in high humidity.no amount of grease, oil or preservative would stop it.
Perhaps it’s nothing you did, just the nature of that guns finish.
Hope you can sort this out.
Larry

As to touch up. Conn Shothgum Mfg (CSM) used to sell a case color touch up kit for $ 40-50. Used an acid applied with a Q tips or artist brushes followed by a tinted lacquer. It did a fair job on light touch up of an early Ithaca Perazzi
Larry

An ultra sonic bath will soften the oxides and loosen them from the metal allowing you to wipe away the rust and leaving behind the case colors. You may even see a sight increase in colors due to oxidized oils being lifted from the surface.

quote:

Originally posted by skb:
An ultra sonic bath will soften the oxides and loosen them from the metal allowing you to wipe away the rust and leaving behind the case colors. You may even see a sight increase in colors due to oxidized oils being lifted from the surface.

Steve;

What solution in the sonic bath?

Why wouldn't you wipe your gun down with an oily rag before putting it away? Was it just left dry? I wouldn't worry about the colors, the hardening is still there.

I recently had a similar disappointing experience. With a daughter on parole, I was required to remove my guns from the walk in vault, and off the property. The nice lady parole officer knew this was stupid, and regretted it, but Rules are Rules. So, I took them all to my "work house" where I live during the week, and put them on the carpeted basement floor, under my bed. Occasionally, I'd pull one out and spot check for signs of rust.

A year later, the daughter is succeeding nicely at real life, off parole, and my guns can come back home.

I should have been checking them more thoroughly. Most were fine. The case colored T/C contender frame was brown with rust. Not pitted, but most of the color is gone. I'll claim not to have a favorite, but if asked, that would have been the first gun my mind would have gone to.

I'll probably just use it as is, and spend my money on more interesting projects. Which is why I'm lurking around here in the double rifle section.

I can't comment on derusting colour case hardening surfaces but I ended up with battery acid spilled over my Miroku O/U shotgun which apart from stripping the blue from the barrels, gave a horrible matt powdered look to the silver nitride finish on the receiver. Light use of fine steel wool and CRC 5-56 (same as WD40) restored the nitride finish to perfection.
I couldn't believe how it worked so well having thought the nitride finish was stuffed.
Barrels re-blued fine and all restored perfectly.

I have a savage/fox shotgun that will form light rust on the case harden receiver.

Just by looking at I think.

I oil it and oil it but it still comes back.

Jut the nature of that firearm I think.

A good oil and 0000 steel wool should work if its not too bad...otherwise your best bet is have it redone..A double is worth re-doing in my opine..Just cleaning it up would suit me but Im primarily a hunter and can live with such events as you describe I think I could anyway. 0000 steel wool will not ruin the finish, and brownells makes a copper wool that is supposed to be even better..???

Please use BRONZE wool when working on guns. Much softer. Available at hardware stores or good marine stores. BW and any oil plus light elbow grease will solve many problems.

I assure everyone that Merkels are NOT made from cheap low carbon steel. It rusted because it was handled and not oiled.
Removing rust might, or might not, leave spots, depending on how long it had to work and etch.
4O steel wool won't hurt bluing or case coloring, so it you have bright spots, then the rust ate the coloring off. Either live with it, or have Turnbull re-do it, correctly. European case hardening is not that pretty.

Under normal conditions, where I live, is as dry as a popcorn fart however, in the last year, we've had a ton of moisture and lots of humidity. I've never oiled my guns/ Now, with the humidity, it's a whole new story.

Kind regards,

Carpediem

P.S. Not cheap steel, just high humidity.

CC finish is normally protected by some kind of coating. I use clear cerakote. Others use varnishes of various types. Obviously Merkel uses nothing, which is dumb.

Coating CCH steel with plastic or varnish is a recent invention; no 19th century gun was protected by anything but oil. Usually sperm oil. Plenty of them left with perfect CCH and blue. You have to oil steel, no matter where you live.

One way to deal with rust is to disassemble, degrease, and boil the offending part in distilled water. The brown will turn grey or black depending on how thick it is. That will in turn absorb oil and that will prevent a recurrence. This works best on parts that have a blued finish, but it should also work on CC parts. If you don't have a tank/burner setup big enough, you can just pour a kettle of boiling DISTILLED water on the offending part standing in a sink or a shower.

CC, if bone charcoal, is nothing but a layer of higher carbon steel, which is naturally more rust resistant than lower carbon steel. Also the high polish usually applied before hardening makes the metal less likely to rust. That's why so many older guns appear to have flaking chrome finish .. it's actually flaking case. The case is less likely to flake off if it is properly "drawn" ie tempered after quenching, but this can affect the colors.

Damascus barrels made way back when were normally waxed or varnished; I don't think one can say that this was never done to cased parts. In any case, the situation here is a MERKEL that is probably quite modern, in firearms terms.

I always have this around and take with me when I travel with my rifles. Will remove rust and not harm blue - not sure why or how it works, but its really good.

https://www.ebay.com/p/1541257874

Marvel Mystery Oil and 0000 steel wool.