whats me best bet?
just got off phone with a powdercoaters who will strip old paint and coat in whatever colour for £40-50, sounds pretty good!
which is going to give best finish (looks and longevity)
any colour suggestions for a gen alpitude, thinking clay grey or gay green

For steel frames:

Powdercoat is the more durable.

Stove enameling or wet paint give the better finish.

As with anything it depends who's doing it, I've had crap powdercoting (cost £20, their normal work seemd to be fencing) jobs and ones so good youd strugle to tell it wasn't a wet paint (their normal work looked more like smaller/higher value items and it cost me £50 even after I did the bulk of the stripping myself, they did mask every single thread/hole though).

Aluminium Frames:

Jury is out whether its good or bad to powdercoat, some coaters blast with too agressive a media so the frame is weakend or even looks like swiss cheese. Other people say it is too hot and can weaken the metal, but then again plenty of manufacturers use it.

Carbon:
Wet paint in a low bake oven only.

Cro-mo paint only not powdercoat!

confused!
DINO, does that mean an 853 alpitude cannot be powdercoated?

I use PC with a clear top coat, it looks great even on old steel frames. I wasn't happy with the finish a certain well known finisher did. Though if you want flams etc then you'll need a spray job. I get mine to bare metal, and coater gives it a phosphorous base? colour coat and clear coat for £40.

Powdercoat can be any of a variety of different plastic-powders.
Once an item has been powder-coated it can be difficult to remove the coating (if you change your mind about colour etc), alloy car wheels for example are treated in tanks of chemicals to soften the plastic during refubishment for repainting. Few bike frames would survive being chemically treated.
Steel needs to be free of rust before powder coating to be durable/ blister free.
Some aluminium alloys, used for bike frames, are artificially aged (heat treated) to T6 condition (eg 6000 alloys) this is done at temperatures ranging from 120 to 190 degrees C (approx). The temperature that some plastic powder coat is cured at is approx 180 degrees C, this can cause heat treated alloy to be over aged (over cooked) to T7 condition possibly with adverse effects on strength.

New frames in 6000 series alloy, if to be powder-coated can be aged (heat treated) and plastic / powder-coat cured in one go.
http://www.keytometals.com/Article39.htm

Dino, Macavity, which bits of of steel frames are goig to be affected by the stripping?

Everywhere I spoke to used solvent vapour degreasing to remove grease and soften the paint then blasted it with the appropriate media. Never heard anyone talking about the solvent/chemicals attaching the frame, unless your stripping magnesium or aluminium components in caustic solutions?

Heating prior to coating no no with cro-mo

so no powder coat if its got cromo rear end?

Cro-mo (or any of its more expensive stickered versions) isn't post weld heat treated, I think your confusing the arguments normaly applied to aluminium with steel.

Heating prior to coating no no with cro-mo

Unless your using a thermal tratment to remove the old paint the object isnt usualy heated beforehand?

OP, just get it powdercoated, unless the place does something stupid like grit blasting it with industrial diamond then soaking it in salt water and pissing on it before coating it'll be fine, I've never heard of a problem wit powdercoating steel frames and I've had a few done myself.

I think Dino is talking ****.

I like the idea of pissing on a frame before giving it a new colour. 😀

[urban myth?]

BMW in the 80's used old engines from scrap cars in their F1 cars (this in the days of the 1000bhp 2.0 turbo). They stripped them, and left them outside the factory for a year for employees to urinate on.

The theory being that the use and abuse would work harden them, they'd then machine/hone the bores and rebuild them into the F1 cars!

[/urban myth?]