# Painting over anodized frame.



## Axe (Jan 12, 2004)

Ordered a new frame for my wife - one of those BMC frames on sale. The only problem - I was asked for a yellow one.  And this one is black anodized. 

Yeah, I know, but that is about the extent of her preferences, as she relies on me for everything else.

So I was thinking about sending the front triangle to get painted - either powdercoat, or stop by a local auto shop for single coat of urethane paint.

Do I need to do any special treatment before painting. One powdercoater whom I contacted said he will sandblast it. Not sure I like the sound of it. Maybe some particular self etching primer that works well?


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## ferday (Jan 15, 2004)

with a proper primer, anodize will take paint pretty good and have a cool finish under the paint. the auto shop should be able to take care of this. anodize is non-conductive, never tried myself but i would think if you want powdercoat you must completely remove it.


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## dbohemian (Mar 25, 2007)

Anodizing is a great substrate for wet paint. You should not powder an aluminum frame of this type (it is aluminum right?) It will destroy the heat treat and temper.

Now there are some ultra low temp powders but I can almost guarantee they are not changing the oven temp for you. 

Take it by a car place but be ready for some F-ups...Bicycle frame painting is surprisingly different which is why there are bicycle specific painters  At the least I would mask everything you do not wish to be painted because they won't know a headset from a bb.


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## Axe (Jan 12, 2004)

dbohemian said:


> Anodizing is a great substrate for wet paint. You should not powder an aluminum frame of this type (it is aluminum right?) It will destroy the heat treat and temper.
> 
> Now there are some ultra low temp powders but I can almost guarantee they are not changing the oven temp for you.
> 
> Take it by a car place but be ready for some F-ups...Bicycle frame painting is surprisingly different which is why there are bicycle specific painters  At the least I would mask everything you do not wish to be painted because they won't know a headset from a bb.


Thanks.

Yeah, I would mask everything myself or send it to a good place. I could probably do a decent job myself - I have painted a few old steel frames with respectable results with a fairly basic spray gun, but that was when I had more spare time on my hands..


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## SuspectDevice (Apr 12, 2004)

Tens of thousands of aluminum frames get powdercoated every year Dave, both 7005 and 6061. Unless the bike at hand is made out of (some)"scandium" alloy- the only ones that still are around is the Easton stuff, which is finicky about heat, and the Kinesis stuff, which I don't know a damn thing about.

The biggest issue with powder and re-powder jobs on lightweight butted frames is actually the blast process. You gotta be careful there.


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## dbohemian (Mar 25, 2007)

Yes, you are correct. 

I have powdered all sorts of aluminum things for cars and the like but I guess I just said that because sometimes we don't know exactly what the alloy is, heating to 400F is like a second artificial ageing (I wonder if big companies just do this in one step) and the stuff is super thin compared to a lot of industrial and auto products and as you said if they get a little heavy on the blasting it could be problematic. So I just kind of cop out and say no powder for aluminum.

Actually my preferred technique is just to have another anodizer strip and change the color..


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## Axe (Jan 12, 2004)

dbohemian said:


> Actually my preferred technique is just to have another anodizer strip and change the color..


Oh. Have not seen that advertized. What's the typical cost?

Indeed, with powdercoat what gave me a pause was the suggestion to sandblast it. But avoiding extra heat treatment also sounds like a prudent idea. Those tubes are kinda thin.  (I do not know what I am talking about here, but just got not sure about it)


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## TigWorld (Feb 8, 2010)

An option out of left field is to talk to a signwriter about getting some yellow shapes cut and use those to "sticker up" the front triangle. Signwriters use a very thin self adhesive vinyl that their machines can cut into all manner of shapes, letters etc. You've got plenty of options from pin-striping to curvy shapes to a full logo/graphics set. The good stuff is chemical and UV resistant and will last a long time. You can also peel it back off (with difficulty) if you ever want a change of colour scheme.


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## highdelll (Oct 3, 2008)

Apologies for the thread hi-jack, but what heat-treatment (annealing) is the powdercoater wrecking?

Is there an annealing process AFTER PC for 98% of frames?

If not we need to be very cautious....................


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## dbohemian (Mar 25, 2007)

TigWorld said:


> An option out of left field is to talk to a signwriter about getting some yellow shapes cut and use those to "sticker up" the front triangle.


You know, that is a wonderful idea! I even own a vinyl plotter and didn't think about it:eekster:

Yes, some of the high quality vinyl is great. Hard to distinguish from paint. A lot of airplane people are taking this route (piston powered not jet) because you can change it and it saves a lot of money on the repaint.


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## Deerhill (Dec 21, 2009)

(Car wrap) 3M Controltac 2mil film, the one you want is 180 series for complex curves used for fleet graphics . 3m will send you opaque swatches for free (they call it color card reference guide).

*Here's the stock Yellows from the guide -

Controltac Graphic film (don't get Comply adhesive)

180-15
Bright Yellow- Pantone 109 C

180-25
Sunflower- Pantone 1235 C (little more of orange-yellow)


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## TigWorld (Feb 8, 2010)

dbohemian said:


> ...I even own a vinyl plotter...


I'm jealous!

DeerhillJDOG - great info - I couldn't remember what the local signwriter calls the stuff.


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## Axe (Jan 12, 2004)

I have a hard time imagining how film would wrap the headtube and BB welds. I would think it could be a bit ghetto if that is not covered. Interesting idea though...

I kind of settled on doing prep and masking myself and giving it a single coat urethane. Will search around for recommendations for primer - I have learned that it is useful to do some homework even when going to a pro... Or maybe I can sell her on white and black look, with few green accents - would need new a seat and handlebars.


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## LenMcC (Apr 10, 2007)

for street cred's sake, i'll start by saying i'm a master coater at figure finishing. we do a lot of bicycles. there's one sitting up front for one of cannondale's downhill test riders waiting for pick up.

if your frame is not scandium, powder coat it.

don't know what alloy it is? they'd advertise it as scandium, so it's not scandium.

if you're really worried about over-aging the aluminum to the point of cracking, ask yourself if your wife is going to be putting 1000s of hard miles on it, bombing epic drops. 

ano is a specified pre-treatment for powder in many industrial and military applications. powder adheres great to ano (better than to raw aluminum), so it doesn't need to be blasted.

if it is blasted, ano blasts off like butter with mild media and low pressure.

DO use a coater who knows bicycles. many - if not most - coaters are industrial, and yes, they can kill a bicycle in a quick second. beyond maintaining the structural integrity of the frame, bicycle-familiar coaters will also give you a better finish than an industrial coater, and they will know what to mask off so it reassembles like a dream.

don't ask a coater if they do bicycles. it's easy to say "yes." ask them more specific questions like how they treat the bottom bracket or head tube. if they flounder around and don't know what you're talking about, they're not the one. also, they should probably have some nice pics on their website so you can *see* how they deal with these things.

bottom line 1: don't fear the powder. bottom line 2: do some homework on the coater.

hope this helps! if you have any more questions, ask away!


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