Is there a way to remove exhaust blue and brown?

I put a new set of 750 style exhaust pipes on my early 850 Interstate and one side blued and browned funny. The other side is a nice even brown. I guess I should have cleaned them real good before I ran it for the first time but I didn't and got a funny blue splotch and uneven brown on one side. Is there any way to remove this color and start over again?

There's a product called "BlueAway": http://www.competitionchemicals.com/blu ... eaway.html


I've never used it myself, so I cannot personally recommend it.

And there's no guarantee that the pipes won't go blue/brown again when they get hot, some pipes being more prone to that than others?

Thanks Les. I don't have a problem with the brown or even the blue but my one pipe did it all splotchy so I am trying to have the colors come on a little more even.

Doesn't bluing come at a slightly lower temperature than browning ? Probably a slight mixture difference at low openings.

Best thing is to check carb synchronisation and then take it for a good thrash :twisted:

I used a couple of products for this, one of which was supplied by a Harley dealership and called "Blue Job", not a surprising name given where I purchased the product, I guess. It took a lot of work to get the pipes back to silver with this product. It is a very fine dry grinding powder which gets turned into a paste when a water is added.

The second product I have used has been around for decades and is known variously as Solvol and Autosol, made by the Hammertite Corporation. It is a fine grinding compound already in paste form. I thought it required less effort than the Harley stuff did.

Both products work by grinding off (with your labour added) a thin top layer of the chrome which is where the discoloration seems to be. After using them I could see that the worked upon areas were not as deeply polished as the untouched areas of the chrome. I suppose you could get the full lustre back if you went thru the whole polishing process again in the worked over areas, going to finer and finer polishing compounds.

The blueing of the exhaust headers or muffler is often caused by ignition timing that is too far retarded. I'm not sure what causes the straw colouring, but I kind of like it, if it is relatively even.

I used to be a toolmaker & the colours you're refering to are used to temper steel running throught from light straw (yellow) to white blue. As I understand it they are caused by the thickness of an oxide layer (same idea as oil rainbows on water) which occurs when the metal is heated.

Funny someone should now mention this...had the pleasure of getting a new helmet yesterday, as the old one was kind of groddy...and someone at the shop mentioned to me what a beautiful blue the one pipe was, and why was the other a brown? Understand it is the temp that will do this, but is this a lower speed adjust, or a full throttle difference? Also, just had my carbs apart, as part of normal maintenance and found in one of the bowls a couple shards of metal/bits of thread which came from somewhere in the carb. End of story, I could now suddenly adjust the carbs' air bypass screw in to be the same as the other carb, so the metal bits must have been in the air passage for the idle adjust/air. Even stranger, I now suddenly, without having touched the slide adjust screws, have an idle of 800 instead of 1800, even when warmed up, so the metal bits had caused all sorts of unseen problems. These Amals are only a couple years old. Gotta Love that Amal workmanship :wink:

Have currently had a great deal of success removing bluing from my pipes using a loose fold mop and white rouge on the polishing machine - very gentle. Means you've got to take the pipes off, though...

Alpha,
But what's the color telling you? Brown cooler and blue hotter? With different colors on two pipes, is that really a LOT of temp difference, or is this just a minor difference in temp, added to the fact that two pipes might have bit of difference in the amount of plating, etc. The pretty colors don't disturb me, but don't want to drive about with technicolor pipes if some damage is going on behind the scenes...just taking the coloring off, isn't curing the basic reason for it. And if it means a great difference in temp, it would seem more important to take care of that before getting hot a bothered about a bit of glow in the dark chrome. :roll:

hewho, as I mentioned above, I would look to timing as the most likely cause of pipe discolouration. If the spark is too far retarded from ideal then more flame occurs in the exhaust rather than in the combustion chamber causing greater heat in the pipes and sucking power away from the power stroke. That's the theory and in my experience it proves correct. Everytime I have had timing get too far retarded the blue shows up.

I bought a second Vincent Rapide a couple of years ago. It is in beautiful shape, completely redone thru and thru, but it had not been run in nearly ten years. The seller, Leo and I agreed on a price but I insisited that I hear the bike run before payment. When I arrived at his place for the running demo, Leo and another fellow had the bike outside and were vigorously attempting to kickstart it as they had been for about an hour.The bike had just 550 miles on it since the resto and the pipes were new with perfect chrome. Just as I walked up the bike fired up, but it would only run at about 3000 rpm. It sounded dreadful and the pipes turned blue in a just a minute or so of running. I told them to shut it off and that I would buy the bike.

It turned out that the fellow helping had been hired as a mechanic to help Leo, who was mechanically inert (worse than mechanically inept) get the bike to run. I later regretted having insisted that I hear the bike run before purchase. They had many things wrong, the worst of which was the timing. They could easily have set it too far in advance and holed a piston. They really had no idea of what they were doing.
They were also using ether to get the bike to fire. I don't care for this practice. If a gas engine needs ether to help it start, something needs putting right.

When the bike would not start right away the helper decided to "reset" the ignition timing, which was probably spot on before they messed with it as it had been set by the very talented fellow who did the resto. Leo's helper mechanic had the timing retarded by a mile, I'm still not sure how the bike managed to start and run at all. It would only run at higher RPM where the auto advance gave it enough advance that it could run in a fashion.

It took one entire evening of hard labour to remove the most of blueing on the pipes although some of it still remains today.

Temper Colors
Plain Carbon Steel Only
English Color Text Fahrenheit Color Celsius
Pale yellow 2 420° 216°
Very pale yellow 1 430° 221°
Light yellow 1, 2, Straw 3 440° 227°
Pale straw-yellow 1, Straw 3 450° 232°
Straw-yellow 1, 2 460° 238°
Deep straw-yellow 1, 3 470° 243°
Dark yellow 1, Light orange 3 480° 249°
Yellow-brown 1, Orange 3 490° 254°
Brown-yellow 1, 3, Bronze 2 500° 260°
Spotted red-brown 1, Dark Brown 2 510° 266°
Brown with purple spots 1, 2 520° 271°
Light purple 1, 2, Purple 3 530° 277°
Full purple 1, Purple 2 540° 282°
Dark purple 1 550° 288°
Full blue 1, 3 560° 293°
Dark blue 1, Blue 2 570° 299°
Dark blue 2 590° 310°
Pale blue 3
Light blue 2 610° 321°
Greenish blue 2, Grey 3 630° 332°
Light blue 1 640° 338°
Steel grey 2 650° 343°
English Colour Text Fahrenheit Colour Celsius
Converted temperatures rounded to nearest degree.

Got this off the web, as I recall tempering is taking a touch of hardness off a job. the more you take off the more flexible it will be hence a chisle will be taken to bright red & quenched then tempred to dark straw, a spring to dark blue.

No idea if the figures tie up to chromed pipes or not but they can't be far out

removing discoloration from pipes

I have used Blue-Away and found it next to useless. Just didn't do very much, despite the elbow grease.

Recently I bought a competitive product (Blue Job) and this stuff works much, much better. Somebody on this thread called it a "Harley" product, though I think he came up with that label because he saw it on the shelf at a Harley shop.

I ordered mine online from the manufacturer:
http://www.blue-job.com/

It seems to do a better job on blue/yellow/brown exhausts than Autosol, which works miracles on aluminum and alloy.

Give the Blue Job stuff a try

Thanks guys...I am on the road for the rest of the week, but will return to this thread at first chance. I DO have a different sound in the two pipes, at the exhaust, one is a "bark" and the other a weaker POOf. Will have to do the check on the timing and use a timing wheel to check the scale on the bike. Been years since it got timed (Boyer)
Got to go now...but will get back to this... Thanks!!!
:wink:

hewhoistoolazytologin said:

I DO have a different sound in the two pipes, at the exhaust, one is a "bark" and the other a weaker POOf. Will have to do the check on the timing and use a timing wheel to check the scale on the bike. Been years since it got timed (Boyer)

Click to expand...

It's not really possible to get only one cylinder mis-timed with a Boyer, so a compression test could be worthwhile as well as a timing check?

Yellow_Cad said:

I put a new set of 750 style exhaust pipes on my early 850 Interstate and one side blued and browned funny. The other side is a nice even brown. I guess I should have cleaned them real good before I ran it for the first time but I didn't and got a funny blue splotch and uneven brown on one side. Is there any way to remove this color and start over again?

Click to expand...

I have used a product called "Blue Away" which works pretty well but also seems to abrade the chrome. I have heard this said about other products as well. I don't think I would bother using anything like Bue Away any more due to the risk to the chrome. I too have noticed a difference in bluing rate from one side to another on my Matchless G12 with brand new pipes. I am convinced that the difference is due to a diffference in the chroming process rather than to a difference in timing or gas flow to each cylinder.