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Author Topic: simple cold rust gun blueing  (Read 251 times)

Offline Dvlnme

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simple cold rust gun blueing
« on: November 07, 2018, 07:42:01 AM »
i figured if am guna stay around i may as well pass on some the things i have learnt in 40 years messing
 around with guns that maybe of interest.
 Bit of history on gun blueing first!there are several ways to put a hard wearing blue finish on steel gun
 parts that were allso used by engineers to blue steel tooling,many involved using hot chemical baths that
 used caustic and dangerous chemicals that allso produce dangerous fumes,so not suitable for home use,
 these hot baths can allso cause a process called hydrogen embrittlment in hardened steels,not a good
 thing for gun parts that can be under extreme pressures,as these parts can fail.
 For home blueing i use a very simple process of controled rusting,the same thing a hot chemical bath does
 without dangerous chemicals or fumes,that produces the same result.
 As there are several steps that need toi be repeated several times to blue the steel,i will post the process
 in several parts,each one covering a part the process,it takes approx one hour to complete the whole
 process,but can take longer if you want really dark blueing.
 Part one/the chemicals needed.
 Plain salt/white vineger/hydrogen peroxide/degreaser of some sort,fine steel wool,distilled water,tho have
 found rain water works just fine.
 White vineger is used for etching the parts after degreasing,salt and preoxide are the blueing solution.
 first step is to thorourly degrease everything to be blued,recommend using rubber gloves during the
 whole process,as blueing solution mildly acidic,and prevents leaving finger prints showing up later on the
 blued parts etc.
 Degeased parts soaked in the white vineger for two/ three minutes to etch the surface mildly,so it will
 take the blue better,for a satin finish,less time for highly polished finish,less than minute be plenty,trail
 and error using other pieces polished steel before doing any actual blueing on gun parts a good idea for
 first few times util you can get the finish you want.
 Want to emphise that the quality of the final finish,will depend very much on how polished parts were to
 begin with,like anything preparation will dictated the finished product.i preferr a satin low gloss finish
 on my guns,so i etch them for approx 2mins,this gives nice none refective finish that wears extremly
 well for long time.its a personal choice.
 Part two will be the blueing process,word warning needed here,if blueing barrels both muzzle n breech
 need to be sealed to prevent bore rusting.i machine up two tight fitting soft wooden plugs and force them
 into muzzle n breech etc,leaveing just enuf wood protruding to be able to hang barrel in tank on wires
 for the third process which is boiling in water,this has to be done several times over the process.
 cheers mike

Offline Dvlnme

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Re: simple cold rust gun blueing
« Reply #1 on: November 07, 2018, 09:23:24 AM »
Part two!!!
 Remove parts from etching solution,rinse of in clean cold water,dry with paper towel.
 mix up rusting solution,two tea spoons PLAIN salt/half cup hydrogen peroxide,mix well,brush this solution
 onto the parts to be blued with either clean cotton bud or fine brush,covering all parts completely,then
 immerse into allready boiling water for 4/5minutes,remove being careful not to damage any surfaces
 dry with paper towel,lightly rub just the fine powered rust film off the surface,rinse again,then reaply
 the rusting solution again,back into the boiling water for 4/5mins,repeat the process at lest 4/5 times or
 until the blue colour is what you want,keep repeating process until it is.
 once coluor is right,rinse again,dry off and while parts still hot immerse in oil for 4/5mins,remove from oil
 oil and wipe clean,parts should now be perfectly blued and ready to assemble again.
 Dosnt seem to matter what oil is used,i just use a really thin engine oil as it seems to penertrate into the
 pores of the steel well and is lot easier to clean off than thicker oils,i use either glass or stainless steel
 containers for etching and rusting solutions,the rusting solution will very soon eat a steel container away
 and will contaminate the solution as well.
 A longer boiling container will be needed to do barrels ,these can easily be made up from scrape stainless
 steel,tho will require to be welded properly,i use just a two burner gas stove for all the boiling,as its long
 enuf with the two burners going for barrels etc.
 If followed correctly this method produces excellent blueing as good as a factory rifle and better than
 many that resists wear very well and lasts for long time.
 Remember the plugs if doing barrels eh!!!.
 any questions, just ask
.
 cheers mike

Offline Jusepy82

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Re: simple cold rust gun blueing
« Reply #2 on: November 07, 2018, 04:46:32 PM »
Thanks mike !

Offline Novagun

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Re: simple cold rust gun blueing
« Reply #3 on: November 07, 2018, 04:57:14 PM »
That post needs to be put into a sticky. Should wait for a few questions and then tidy it up and put it in the sticky column. Not sure how to do it but I will find out. That ok with you Divnme?

Offline Dvlnme

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Re: simple cold rust gun blueing
« Reply #4 on: November 07, 2018, 05:37:29 PM »
Thats good idea nova,got few other bits to add as well.this type blueing very simialler to the old english
 blueing used for shot gun barrels,which cant be done in hot caustic type blue baths,due to the solution
 attacking and eating away the soft lead solder used for shotgun and double rifle barrels etc,which caused
 the upper and lower ribs tween barrels to seperate from barrels,bassically ruining the barrel set.
 This simple none caustic blueing method dosnt do that so is usable for shotgun barrels as well and other
 gun parts that may contain soft lead solder as it contains no nitrites no nitrates or caustic soda as hot
 blueing solutions mostly do,but is still mildly acidic so not only rubber gloves but saftey glasses should
 still be worn.
 cheers mike

Offline Pauly5

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Re: simple cold rust gun blueing
« Reply #5 on: November 07, 2018, 09:28:09 PM »
Yea, sticky that.
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Offline Novagun

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Re: simple cold rust gun blueing
« Reply #6 on: November 08, 2018, 10:14:11 AM »
Dvinme, a couple of questions.
1. does all  the water for boiling and washing  the parts to be distilled. ie distilled for the whole process.

2. Does the container for dipping in oil  need to be non ferous.

Getting or making the right sized stainless steel can for boiling and washing would be a bit a bit hard for most people. I suppose for all the process apart from boiling , plastic containers would be ok.

So would it be fair to say all non distilled water and any steel or galvanised container should not be used in any part of the process.

Offline Dvlnme

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Re: simple cold rust gun blueing
« Reply #7 on: November 08, 2018, 10:40:23 AM »
have found my tap water,which is tank water off roof etc,works just fine,was talking to guy know in US bout
 this who allso uses this same blueing method,hes said hes using his town water and has no issuses with
 the water,short answer is that distilled water proberly elliminates any potentual chemical reactions from
 water that may occure using town water with its added chemicals used for purifying etc,but if you want i
 guess using good bottled water could be safe option.
 dosnt matter what oil container is made from,as no chemical reaction taking place in oil bath.putting warm
 steel into oil bath really just to get some oil peretrationing into steel pores as cools down,think possibly
 to prevent any further rusting coming thru the blued finish,never did find exactly why an oil bath was
 needed,as used to just spray blued parts with oil for many years with no issuses.
 as i have oil bath for quentching heated treated steel just drop hot parts in it now,my oil bath just large
 tin can mate.
 just found bit stainless square tubing at scappy with both ends blocked off with welded caps,cut top out
 to make a trough,didnt cost me anything,dont think will matter what boiling container made from,just
 long it holds water n made metal.
 plastic container fine for the vineger,i use just glass bottle for blueing solution as not much of it,bout half
 cup full.i use new lot every time,to prevent any cross containation,you could half the mix for small jobs
 as you dont actually use much of it for most jobs we do.
 hope that answers you questions mate.
 cheers mike

Offline Akzle

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Re: simple cold rust gun blueing
« Reply #8 on: November 09, 2018, 06:17:36 PM »
I'l add more cents later. I'm doing this off my phone.

Hot bluing is well do-able at home. KNO3 and NaOH (potassium nitrate and lye) both still reasonably available.
other alternative is fume/rust bluing with HCl (hydrochloric acid)and/or nitric acid (much harder to come by) in fume cabinet. a slower process but equally durable and no concerns about heat treatment.

I've even heard tell of bluing (properly: browning) with plain old atmospheric humidity.

Offline Dvlnme

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Re: simple cold rust gun blueing
« Reply #9 on: November 09, 2018, 08:52:18 PM »
hot bluing easy nuf to do at home,did it for many years,last time purchased nitrites n nitrates got hard time
 from chemical supplier,aparently both now on the explosives register,did have the recipe for the old english
 cold bluing and browing solutions here some where,you i both seem polished steel start go the shiney  brown colour,so atmospere type blueing /browning definatly possible,i put up this method coz it an easy,
 safe way for average guy to do nice blueing without dangerous chemicals.
 cheers mike