Has anyone stripped and repainted a Giant alloy frame?

majormantra

In my role as best-boyfriend-evar I'm thinking about rebuilding my good lady's 2009 Giant TCX and giving it a highly gender-normative lick of paint. The existing paint looks very resilient though, and I'm wondering if removing it will be a complete nightmare.

Any tips? Reckon I'd need to get the old paint shot blasted off? I gather Nitromors (or whatever) doesn't work particularly well on some paint.

Cheers!

andcp

Not sure I'd go with shot blasting - it's a very aggressive process. Soda blasting may be a better solution, or chemical stripping. Painting as opposed to powder coating is also preferable - I believe, metallurgically speaking, alloy frames can suffer from precipitation heat treatment (artificial aging) depending on what temperature the coating/curing process is performed at. I'm sure a 'proper' materials Engineer will be along to confirm or deny this.

Matthewfalle

Nitromors won't touch it - Nitromors today (unlike the good old stuff) won't take the skin off a rice pudding.

Pop down the local motor paint shop factor and get some paint stripper off them if that's the route you want to go - you're going to wash, degrease/white spirit it and heat it anyway if you want to re spray it properly, so you'll get any traces off.

Alternatively, bead blasting is fine - local powder coasters can do this.

I've just taken all the paint off a Scott mtb frame so I can polish it - used a wire brush attached to a drill. 2 hours work, cost a fiver in bits. Leaves no gouges, all ready for cleaning and priming in your case - I just sanded it with different grades of wet and dry before Solvoling for a perfect mirror finish.

Powder coating is no problem at all for an alloy frame, so if it's a single block color I'd go that route - perfect finish, no runs, tough as old boots. Jobs a. Fish.

dowtcha

This could end up with you been worst boyfriend-evar

majormantra

Ha, perhaps!

From some more reading, it sounds like bead blasting is indeed the better option if I go that route.

Matthewfalle,

Did you succeed in removing all the paint with just the wire brush then? That could be a viable option.

Matthewfalle

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19777623#p19777623]MajorMantra[/url] wrote:

Ha, perhaps!

From some more reading, it sounds like bead blasting is indeed the better option if I go that route.

Matthewfalle,

Did you succeed in removing all the paint with just the wire brush then? That could be a viable option.

Yup - no problems at all. Essentially all you're doing is sanding it really, really, really fast. Simples, like.

majormantra

Matthewfalle wrote:

Yup - no problems at all. Essentially all you're doing is sanding it really, really, really fast. Simples, like.

I like the sound of that.

So I thinking:

1. Wire brush like mad
2. Aluminium primer
3. Paint like a boss
4. Decals (romantic)
5. Lacquer (I 'ardly know 'er)

Feasible?

Matthewfalle

100% feasible however I'd do a bit of sanding with some 600 grade wet 'n' dry after the wire brushing.

Sure you don't fancy powder coating it?

Salsa

When I rode BMX a lot I was forever painting my frame and forks once I got bored of the colour. I've stripped all the paint off with lots of effort, primed, then colour coats followed with lacquer. Other times just sanded a rough surface into the existing paint and colour coated that and truth is they all came out looking the same (a bit shoddy on close inspection).
I had my wet weather aluminum commuting bike powder coated a couple of years back and that's still looking like new, only cost me £50 and far exceeds the rattle can jobs I've done before. Doesn't cost much more than cans and lasts and looks so much better.

majormantra

Thoughts noted, thank you. I shall ponder my options.

Matthewfalle

I had my race motorbike powder coated - frame, swing arm, brackets, levers, hangers etc etc - it's so delicious its lickable, especially with all the Ti bolts on it.

For the effort, sticking it in a bog box, sending it to Triple S in Batley and sitting back and enjoying the results is well worth it.

Don't get me wrong, there's a brilliant sense of self satisfaction and learning once you've done the whole job yourself, but as its only your birds and she may/will dump you anyway (let's be realists her) I'd take the easy route - brilliant powder coat finish, minimum effort.

Anyhow, she's a bird: she won't know how easy it was to send it to Triple S (just blind her with science about how it was a ridiculously difficult job that you did yourself) and she'll only scratch it when parking it anyway.

photonic69

Hi. I wouldn't contemplate doing this yourself if you wish to keep said girlfriend. It has the potential to look far worse than the original finish unless you are well practiced at spraying and the original finish is particularly knackered.

As you are Bristol-ish then check out Argos Cycles (NOT the catalog shop!) here:
http://argoscycles.com/resprays-refurb/price-lists/

It'll save a lot of grief and time. Time that could be spent with said girlfriend rather than hours and hours of paint stripping and swearing. She'll appreciate it in the long term.

lesfirth

If you can get a frame powder coated for £50 without doubt that is the way to go.Its a no brainer.

In the past I have painted cars for a living.I am retired now so have lots of time. I did what you are planning with rattle cans. It took me ages. The cans of primer, colour, lacquer and wet-or-dry, did not leave me a lot of change from £50. When finished it looked great. After a few weeks I found that the paint chipped easily and then a reaction between the colour and laquer caused sort of crack lines all over. Its my winter bike so next summer I will be looking for a powder coat.

Fingerling

No need to take the existing paint off if it's not damaged. Sand back to create a key then paint and lacquer

majormantra

That seems like cheating.

You all may have convinced me about powder coating. Maybe.

Matthewfalle

Powder coating rocks. If you want a really long lasting, tough, perfect finish single color then it's the way to go.

Elfed

If you're not powder coating and using spray paint, you don't need to go down to bare metal, just sand it down to give the primer a key.

Any car spray shop should be capable of doing this job, not much paint involved and you'd get it lacquered and baked on for a tough durable finish, plus I bet there wouldn't be much difference in price after buying everything.

From what I've read on Retrobike, to get the crisp detail on lugged frames it's advisable to use spray paint, as powder coating is thicker. But as the TCX isn't lugged it doesn't matter, just some pointless info.

Matthewfalle

It's not the paint, it's the labour: car panels are easy as the are large flat surfaces, bikes are all tricky curves and bits, innit.

Which is why powder coating is simple, quick, cheap and ridiculously effective.

wotnoshoeseh

I wanted to get a bike painted and went to a car repair shop too to see if they could do it. They refused the job - basically painting cars are large flat(tish) surfaces, whereas bikes are small curved tubes with intricate detail points.
The nozzles that they would have used would be completely the wrong sizes and flow rates.

You need to be sure that the car respray route knows what they are doing, otherwise it could be back to removing all paint and starting again...