Best way to paint an aluminium frame?

I have an old cannondale caad frame which I painted using spray bike paint a few years ago. The finish actually looked OK, but isn’t remotely durable and has a ton of chips so needs a refresh

I’m looking to do it on a budget, its a cheap frame. I’ve read that dropping it off at the local powder coater will probably not be a great Idea. So what are the best options?

Thanks

Who suggested not a power coater? As long as they are used to bikes and mask all the threads and bearing seats, it’s a excellent solution.

I’d go powder coat, have done a few times. But you’ve got to do a bit of research, my guy is both cheap and good (though, a bit restrictive in colours), but you can easily find expensive and bad. I had a recommendation from one guy who left the frame full of blasting grit and got a load of it into the powdercoat and thought it was OK to send it out like that with basically sandpaper for the finish in places, needless to say didn’t pay a penny but it still needed redone and was a pain in the arse. Some people are also concerned about heat levels but I think that’s more or less a red herring with a competent coater, they don’t tend to bake at high temps just because it’s more expensive and can cause issues like gassing off from the metal.

(this is probably useless but, R&O Refurbishment near Bathgate is my recommendation, if you’re in the central belt of scotland. He’s done 3 sets of wheels and also a lovely job of a trials frame for me. He’s just one of those small businesses that gives a **** and they’re always worth holding onto)

Aluminium is tricky for diy painting, it oxidises as soon as you strip it back and alu oxide is a terrible surface to stick things to. The best way to respray an alu frame diy is to not sand back to the metal anywhere, and just paint over old paint, but that sounds like it’s not an option for you? Proper etch primers help, and give it a last-minute scuff back to get a better key, but it’s still less “sticky” than steel, and whatever paint you put on top is only ever as strong as the substrate. TBF biking in general is a harsh environment for paint, even for a road bike, leaning against a post or a gate or locking it up is almost perfect chip/scrape territory.

Bottom line is you’ll use way more time, and way way more product than you expect. A good result is totally possible but it’ll not be drastically cheaper than a good powdercoat if you don’t already have at least some of hte stuff. (you can improve your chances by using 2 pack direct gloss aerosols which give a great finish, and don’t need clearcoated which takes away the hardest stage to get right (at the expense of being a little less tough than a true clearcoat), but these are basically poison in a can, I’m not going to recommend it)

Honestly there are 2 reasons to diy this. One, you’re doing it ugly and you don’t care, in which case, throw random paint on it quickly. This is totally fine. Alternatively, you’re a diy sort of person and you want to do it for the project as much as the results. This is fine too but tread carefully.

(I’m a good, amateur sprayer, my old motorbike that I sprayed myself in a shed won awards… But spraying a bike is a pain in the cock, a time and money sink, and often a heartbreaker 10 minutes after you build it. All those bloody curves and niches. I’ll probably never do it again.)

Powder coat +1

Or at least a professional painter. The one I use in Reading charges about the same for powdercoat as they do paint as most of the work is in the stripping and prep anyway. On a road bike it probably wouldn’t make a huge difference, on an MTB its a no brainer to powdercoat.

I’ve DIY’d a frame before and got a good finish.  But it costs as much as powdercoating and takes ages to get it right.

Find a decent one that’s used to doing aluminium bike frames.

Strip and polish/scotchbrite it – Cannondale frames look great raw (and you can see the inevitable cracks easier!)

What’s a powder coat these days, £80?

Etch primer and 2 pack should work pretty well IME, obviously will take time (primer only needed if gone down to bare metal).

+1 for powder coating.

@northwind

I’m based in the central belt

How much roughly for a frame? Do I need to strip it first or can they do that? (The old paint, not the components!)

It was pretty cheap but I was gettign 2 frames-and-forks and some car wheels done so I got a discount. I think probably £100, £150 for a standard colour, drop him a message on his facebook, he’s not always the best communicator but you’ll get there 😉 He’ll handle the paint stripping, masking etc. I did have to do a wee bit of tidy up which ideally you’d avoid but nothing major, I should give him like half a point off for that.

Some wheels he did for me
https://www.facebook.com/photo/?fbid=804014901731878&set=a.494717282661643

In fairness Pentland Powdercoating are also excellent, a bigger operation, I’ve used them for car parts and would happily use them for a bike. Ecosse have a good rep but they did a poor job of a set of wheels for me and clearly didn’t understand why they couldn’t get a good finish on them, plus he was always overpromising and bullshitting- literally told me they were done, I turned up 2 days later, he said “if you’d told me you were coming today they’d be ready”, shit like that. They can definitely do superb work, I’ve seen it, but mine were half-assed, I wouldn’t have minded that so much if he’d not also been such a pain in the arse.

Thanks

Had good results with a powdercoater, all be it on a steel frame. Probably not important, but powdercoat added 100g to the frame compared to the old paint finish.

What’s a powder coat these days, £80?

Sounds about right, I think Aurora in Aldershot are £70, Unimet in Reading (who’ll do wet paint as well) were a bit more.