Author Topic: how rust resistant is 4140?  (Read 2727 times)

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Offline doubleduece

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how rust resistant is 4140?
« on: June 17, 2007, 06:04:21 PM »
Not having a metallurgical background or even a machinist background, I was wondering if the 4140 chrome moly is rust resistant? I am debating whether to paint my new GB mortar although I like the white steel look. I was debating getting out the airbrush and duracoat. Could I just keep it waxed well and prevent corrosion?

Offline Double D

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Re: how rust resistant is 4140?
« Reply #1 on: June 17, 2007, 06:32:28 PM »
4140 is  ordnance or gun steel.   Paint it. It will rust.  After shooting be sure and clean thr bore good, dry  the bore then oil it well.

Offline GGaskill

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Re: how rust resistant is 4140?
« Reply #2 on: June 17, 2007, 08:01:36 PM »
I have kept unfinished 4140 barrels rust free for over a year by wiping on BreakFree a couple of times during the year (at the beginning of the year and at some later point.)  It hazes after a while so the surface is not exactly like bare steel but it keeps the rust away.
GG
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Offline Cat Whisperer

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Re: how rust resistant is 4140?
« Reply #3 on: June 18, 2007, 12:18:48 AM »
From the mortar barrels I have in 1018, 1144sp and 4140, 4140 is slightly more resistant to rust than the others. 

I have most of my barrels in-the-white, because it's easy to wire brush them if they do rust compared to refinishing a blued barrel.

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Offline doubleduece

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Re: how rust resistant is 4140?
« Reply #4 on: June 18, 2007, 03:36:28 AM »
This is kinda what we figured. Anybody tried lacquer? that would be easy to touch up and correct.

Offline Double D

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Re: how rust resistant is 4140?
« Reply #5 on: June 18, 2007, 08:21:41 AM »
Bare steel is fine, and  as Tim says you can just wire brush it if it rusts. 

But you will get a lot more protection and the tube will look better painted. 

I made this cannon in 1984; used a good coat of rustoleum primer and flat black. This cannon has fired several hundred rounds  in 8 states and two countries.   It has never been refinished and is due for refurb in 2011 at which time the barrel will be repainted.  The carriage will also be given it's first paint job in the correct color. I only learned about two years ago what the correct color is.



Paint is the better way.

Offline Rickk

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Re: how rust resistant is 4140?
« Reply #6 on: June 18, 2007, 09:54:28 AM »
DD... I gotta know - what is the correct color?

Rick

Offline Cat Whisperer

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Re: how rust resistant is 4140?
« Reply #7 on: June 18, 2007, 12:29:33 PM »
DD... I gotta know - what is the correct color?

Rick

OD Green of course.  But that gives one a LOT of lee way.    ;D

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Offline doubleduece

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Re: how rust resistant is 4140?
« Reply #8 on: June 18, 2007, 03:16:07 PM »
Hey Double D that is a nice piece. I know what you mean about protection, but me and my buddies have two coehorns, both OD and black and a 3/4 scale '41, and a full scale '41 both OD and black. I am kinda leaning for something different. I did just find Dura-coat has a clear. That could be my answer   to protection and white steel.

Offline Double D

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Re: how rust resistant is 4140?
« Reply #9 on: June 18, 2007, 04:48:04 PM »
DD... I gotta know - what is the correct color?

Rick

Finally, somebody asked!!!!


Black

Offline Double D

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Re: how rust resistant is 4140?
« Reply #10 on: June 18, 2007, 04:50:28 PM »
Hey Double D that is a nice piece. I know what you mean about protection, but me and my buddies have two coehorns, both OD and black and a 3/4 scale '41, and a full scale '41 both OD and black. I am kinda leaning for something different. I did just find Dura-coat has a clear. That could be my answer   to protection and white steel.

Have you considered having it bronzed?  Your not going to like the clear coat after a while.

Offline Rickk

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Re: how rust resistant is 4140?
« Reply #11 on: June 19, 2007, 12:13:41 AM »
Black was the color of the caronades from Salem that I posted a while back. I wasn't sure if that was paint or if the wood turned black with age. It didn't really look like paint.... a charcoal loaded oil maybe?

Offline doubleduece

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Re: how rust resistant is 4140?
« Reply #12 on: June 19, 2007, 11:04:56 AM »
BRONZED now thats an idea....