Author Topic: metalurgist's amongst us? Blueing (Read 1270 times)

easyroller · « **on:** July 21, 2007, 10:32 AM »

Hi there been reading a bit on here about "rawing" or stripping back frames etc. Now what i am wondering is ,when you look at the chain/seat stays on a metal rebel contender raw you see how dark and burnt it is, i would like to acheive this for the whole frame. I have read a good deal about the "blueing" process which gunsmiths use to get that fantastic black/blue color whilst keeping it raw, this is similar to the baking processs, but i have read that it is possible to do it using a butane burner and paying close attention to the "hue" changing process so as not to "overburn" it, then cool it in oil, as air cooling happens to fast which causes weaknesses in the metal due to shrinking. Gunsmiths used this process with 4140 to keep rifle barrels straight and true as well as dent and knock resistant, ok sorry for the long winded explaination,has anybody here attempted this and if so all info is appreciated, thanks.

harris · « **Reply #1 on:** July 21, 2007, 12:00 PM »

i think it has alot to do with the properties in the metal/covering
such as stainless steel blues as its heated.most others just grey a tad.

harris · « **Reply #2 on:** July 21, 2007, 12:11 PM »

you could copper a frame and let it dull then lightly buff it up.

easyroller · « **Reply #3 on:** July 21, 2007, 12:23 PM »

Quote from: harris on July 21, 2007, 12:11 PM

you could copper a frame and let it dull then lightly buff it up.

Thanks for looking and to be honest "coppering " is a vague term i have heard of here and there, do you mind walkin' me through it?

harris · « **Reply #4 on:** July 21, 2007, 12:28 PM »

your best bet would be to go to a platters and ask what can be done,
i have nickel midschool frame that has gone a well nice colour goldie blue

easyroller · « **Reply #5 on:** July 21, 2007, 12:38 PM »

thanks i will do that i want to darken up the frame without sacrficing strength as i punish that thing regularly.

darkersomeday · « **Reply #6 on:** July 21, 2007, 05:07 PM »

i'd be very nervous of using heat to create the colouring of the welding burn, alot of modern frames are heat treated so re-heating and cooling the metal in oil would be kind of like adding or taking away from the treating process, which could seriously weaken the frame and will definitely leave the warranty invalid,

gun bluing would seem to be a good solution to rust proofing but the surface still needs to be oiled regularly to stop the oxidisation,
the easiest way to do it is "cold" bluing, you can buy it from most gun shops or buy the chemical version, selenium dioxide,
just rub it into the metal till you get the right shade,
the more traditional "hot" bluing would involve the frame being immersed in a boiling solition of potassium nitrate and sodium hydroxide,then you'd let the frame rust then boil it at a precise temprature and later scrub the rust off to reveal the blue finish underneath, you could end up having to go through this process repeatedly to achieve the right results

both these methods would be less harmful to the strength of the frame,

copper plating and oxidizing is something i'm working on for a project at the moment,
its the "verde-gris" or "patined" effect that you get on old boilers that i'm wanting to achieve!!
the parts i'm having plated are due to be dropped off this coming week so i'll post some pics when theyre done,

as dan said nickel plating would look sweet, as long as the frame is well polished before hand

something i have wanted to have done for years is the acid etching you see on old shotguns,purdey's and the like,
i think it would only be possible to do it on the non-stressed areas of the frame, i read somewhere that the rougher the surface of the tube, the more likely it is for cracks to form , rather than the stress waves dissipating evenly over the surface of the tube,

crazy

easyroller · « **Reply #7 on:** July 21, 2007, 07:56 PM »

hmmm ....... bit to think about there ,first off thanks for the info, looks like i might give heat treatment a miss i can't afford another knee surgery espescially not because i buggered around with me frame to make it look a little better. I am an engineering student (1st year)so i kinda understand the principles at work behind why highly polished surfaces have higher resistance to cracks and fractures, i am liking the sound of the cold bluing , polish it at like 10,000+? though CM says these new frames are already highly polished ,i might try it on my dagger first then if it don't turn out right i can neutralize the frame ( would that be nescessary?) and matte black it again,no harm done. thanks again and i look forward to seeing your future projects.

easyroller · « **Reply #8 on:** July 21, 2007, 08:08 PM »

just a quick link column to the frames that i like with the darker tubing:- http://americancycle.com/itemdetails.cfm?catalogId=149&sort=pricedesc&id=2005 the rear on homans new bike :- http://americancycle.com/itemdetails.cfm?catalogId=149&sort=pricedesc&id=2435 and of course one of my frames just click on the matte raw one :- http://www.danscomp.com/211341.php?cat=FRAMESFSD# , just for maybe any one who reads this and needs a bit of visual of what i'm gettin at.

matt · « **Reply #9 on:** July 21, 2007, 09:22 PM »

i used to do this all the time, i owned an exhaust factory and we supplied a lot of race cans for the likes of blue flame and carbon can, using T304 stainless steel it was just a case of heat it up with a gas axe until you get the desired colour and slowly cool, as it states above this will only work with good quality steel as the molecules react differently in iron, the more iron the worse it will look.

darkersomeday · « **Reply #10 on:** July 21, 2007, 09:38 PM »

could you put the links up again dude?

cheers,

billstup · « **Reply #11 on:** July 21, 2007, 10:53 PM »

Links sorted

darkersomeday · « **Reply #12 on:** July 21, 2007, 11:18 PM »

Quote from: billstup on July 21, 2007, 10:53 PM

Links sorted

youre a gent bill,
thanks

right, i'm no expert but to my eyes these look like...

the liquor tubes look like standard grade 4130 thats been polished at the ends prior to welding,

the fit van looks to have a front end using different grade tubing to the rear, the heavier gauge rears stays are darker,
the ends of the tubes probably didnt need polishing so you just get the weld burn, my old l.a.f and the s3's are the same, nice

the rebel contenders are made in the same s&m shop and look very similar to the fit/s&m's in the clear coat,

my old s&m laf was the same,
i like the look of raw frames,you get to see the tubes used and the colours of the weld burn

the craftsmanship that goes into the frame,
you dont get this with taiwanese frames as theyre usually peened before coating so that the metal has a better key to adhere to, they just look grey all over,

have you checked out the curtis t45 brazed frames in raw?

i think i can see where youre coming from, have you thought about polishing some areas and letting others oxidize? you could mask off the areas you wanted to keep polished and patina the areas in between

heres a reynolds steel grim reaper where i polished just the right chainstay,downtube and right fork leg,

this last T1 is from bg, this cat's polished everything!

easyroller · « **Reply #13 on:** July 21, 2007, 11:36 PM »

Well what initially sparked my interest was basically the same as yours appreciation of craftsmanship, I first saw it (i think) on the S&M site if you click on frames and go to the PBR then it looks like they have baked up the whole frame and i think this is a lovely example of what i am talking about

,( you can even zoom in on this) ,if you start at the drop outs you can see the weld has created the darker hue but follow it up the seat tube and top tube and while it almost looks black you can see the weld hue around the BB and head tube this is my inspiration, though it might be easier to get a hold of one of these, than risk stuffing up my contender? thoughts

darkersomeday · « **Reply #14 on:** July 21, 2007, 11:59 PM »

aah i see what you mean, that looks fantastic,
it could like you say be baked somehow, to darken/blacken the steel,
i wouldnt know how to go about this though dude, you could ask s&m how they go bout getting this effect,

it could be a dark clear gloss? like a smoked clear maybe?

easyroller · « **Reply #15 on:** July 22, 2007, 12:18 AM »

Yeh i've never seen another frame that dark and sweet, gotta say though darkersomeday you got a hefty collection going and i like what i see, i feel like a baby among giants as i have two regular rides and three frames and bunchs of parts at this stage , and a whole bunch of ideas. i bought brianp's old sta and he said to me to watch out as this gets addictive, if you read this brian yepp you were right!!! the missus ain't so happy about it, i have nightmares where she puts all my stuff on the bay with a buy it now price of 99p, after i'm dead of course. thanks for the thoughts i think i will write to S&M and ask about the frame as i have looked for a raw pbr and not turned up anything yet.....................theres something that looks very like it, but also not, at believe it or not at binstanleys guess i could ring em and ask

darkersomeday · « **Reply #16 on:** July 22, 2007, 12:38 AM »

i actually really like the finish on the liquor frame too

the company looks pretty cool, id you read the article in dire about them?

the bikes in the pics arent mine anymore, i dont collect them

ive got the ti reaper, a challenger i restored and my tonic fab fall guy,
although i can feel myself being drawn over to "the dark side" after seeing some of the work on this forum

let us know how you get on with the frame dude

FuNMoNsTeR · « **Reply #17 on:** July 22, 2007, 03:38 PM »

Gun Blueing works best on High Carbon content steel. I have a bottle of Birchwood Casey Perma Blue if you want it to try it out. If you are going to use gun blue then mask up and protect your skin as the stuff is nasty and highly carcenogenic.

easyroller · « **Reply #18 on:** July 22, 2007, 08:37 PM »

thanks for that considerate offer i'll look in to it, i am living in norway so , half the stuff thats available at you home depot in the UK or US is only available at spescialists workshops, real annoying. birchwood casey perma blue you say i'll ask around.thanks