'Bronzing' Steel Frames

[Jezston]

My new/old steel frame arrived at the LBS this week and yesterday I was discussing painting options with the owner.

Option 1. Powder coat. Will do the job, limited range of colours and effects. £65 including sandblast, and LBS guy's cut presumably.
Option 2. Full respray and laquer. More options, slightly better results, twice the price.

Option 3 however get's unusual:

After discussing brown as a colour, and how a bronze would be a nice colour for a classic looking bike the owner suggested doing something rather unusual himself, for the same cost as the powdercoat. I can't quite remember what he said, but it involved removing the paint, then heating the frame whilst applying this weird slightly purply powdered stuff, then upon application of more heat and another chemical, it would create a layer of a very nice shiny metallic mottled bronze-like material. He's now got very keen on this idea, much to the chagrin of his colleague who'd rather he spent the time fixing bikes and bringing in cash than performing lengthy esoteric coating processes!

But does anyone know what this process I have so badly explained is? And what kind of results I might expect?

 

[Smokin Joe]

I wouldn't go near that idea.

Frame tubes are heat treated to give them the properties applicable to the particular grade of tube (531, 653 etc). letting some idiot with a blow torch near them will reduce them to gas pipe quality.

 

[Garz]

I agree with the 'colleague' and stick to getting a simple powder coat job. Am interesting in this 'bronzing' idea, it may be just a tacky coat that will flake off over time but I could be completely wrong...

 

[accountantpete]

Sounds similar to blueing steel - heat it up quite hot and then brush with oil which leaves a fantastic silvery blue finish.

I wouldn't want to try it on a good frame though and you would have to find a large oven to do the bike in one go.

 

[snomaes]

Sounds similar to blueing steel - heat it up quite hot and then brush with oil which leaves a fantastic silvery blue finish.

I wouldn't want to try it on a good frame though and you would have to find a large oven to do the bike in one go.

Blueing/blacking of steel is just a cosmetic appearance and does not rustproof the steel; this is achieved by sealing the finish from the atmosphere with a layer of oil. The only way of rustproofing a steel frame is to apply an impervious coat to stop oxidisation. This can be painting, plating with zinc (galvanization or similar), but certainly not a chemical blacking process.

 

[gbb]

Could it be a yellow zinc passivated finish ?. You usually see it on nuts and bolts, not so much bronze colour, more brass IMO.
A bike frame with such a finish certainly would be different...would it look good ?...hmmm i'm really not sure.

 

[2Loose]

Could it be a yellow zinc passivated finish ?. You usually see it on nuts and bolts, not so much bronze colour, more brass IMO.
A bike frame with such a finish certainly would be different...would it look good ?...hmmm i'm really not sure.

Ooh I think a nice mottled goldie colour like that would look luvverly! Certainly on a more rough and ready bike, not so sure on a roadie.

 

[Jezston]

I shall have to get more info on the exact process tomorrow and report back.

However I am erring towards the powdercoat.

Still can't decide on colour yet, though. British Racing Green is a safe bet. Dark grey, also chocolate brown appeal, but not sure how they'll look on the finished item.

Don't see many brown bikes about!

 

[fossyant]

Don't see many brown bikes about!

There is a reason for that............... 'orrible.

Go for enamel if you can afford it.

 

[Ivan Ardon]

Any good powdercoater will be able to get all of the colours in the RAL and ISO colour charts, so you're not limited in your choice of colours.

"Standard" colours - ones the coaters are doing all the time (white, black, silver etc) - tend to be much cheaper. There's an agricultural powdercoater near me who charges around what you're paying for a F+F in your choice of colour, or will do it for around half that if it's something he's already got in. I think my next rebuild will be in Massey Ferguson red!

 

[battered]

I like powder. I had a scruffy MTB frame powdered in orange (£25) with another fiver for metallic lacquer. Looks great. Forks would be another tenner, 15 or so. I like the sound of MF red at half price! My powder coater does a lot of machine cases so sadly most of his stuff is black, white or shades of grey.