Anodising

dan smith · Jul 25, 2013

I have just got my hands on a painted zaskar frame, the paint work is not the best so i am considering either a respray or ideally anodising.

Has anyone been through this process with a painted frame before? Obviously the paint will need to be removed, i was thinking shot blasting but i am uncertain if this will leave a good enough finish to anodise?

Dan

bluedazzler · Jul 25, 2013

I have and I wouldn't recommend shot blasting, zaskar frame walls are SO thin, I got mine chemically dippped and stripped in formic acid.... but you must use a tank that's big enough to submerge the frame fully, otherwise the surface reaction will eat into the aluminium... if you're getting it polished, best to do it yourself, as polishers tend to be heavy handed, yours may not be, in which case good luck

I had trouble finding an anodiser with a tank big enough to do a complete frame, so that was hit and miss for me, you may have more luck up your way. I gave up in the end and found an original in turquoise ano, it's a beaut

paddy311 · Jul 25, 2013

I would second the recommendation not to blast the frame. I was in a similar position to you a few months ago, and asked my 'trusted' blaster to do it. He refused, and recommended a chemical dip instead. I used a place in Wolverhampton called Wood Strip Ltd (01902 450880). They dipped the frame for me for £15. It was a chemical dip rather than acid though - methylene chloride (sp?). The dip did a perfect job.

Polished the frame myself over about 6 hours after dipping and that was it for me. Obviously YOU would need to get it anodised after polishing. I stopped at the polished stage so can't comment further.

dan smith · Jul 26, 2013

Thanks guys, a chemical / acid strip sounds like a much better idea.I will make some calls

thanks

Dan

pete_mcc · Jul 26, 2013

Just remember that unlike paint anodising is not going to cover any imperfections so if the frame is scratched then the anodising will show that and often amplify if, if there is a rough patch then it will be an anodised rough patch after.

What ever time you think you need to spend on polishing, double it. Do a half arsed job on polishing and the anodising will look terrible.

Also remember that any ferrous metal will need to be removed - any rivnut bottle bosses etc as these react in the anodising tank

dan smith · Jul 26, 2013

yes the bottle cage bosses maybe a show stopper!

Until I get the paint off I cannot be sure on the condition of the metal, the pain has bubbled in a few areas which is one of the main reasons why I would like to strip it.

I will be interested to see what the metal looks like under these areas.

I will try to post some pics tonight :shock:

pete_mcc · Jul 26, 2013

Assuming the bottle bolts are rivnuts they can be easily drilled out and replaced. Most good bike/car workshops will have a rivnutter (not sure if that's the term but I bought mine on ebay for a fiver). The main thing to check is that the headtube or BB are open so you can get the bits out after you've drilled it.

bluedazzler · Jul 26, 2013

what paint job is on there, if its the later "hot mango" colour or similar from that year beware that paint is very resilient

Rampage · Jul 26, 2013

pete_mcc":2y6ozihj said:
Just remember that unlike paint anodising is not going to cover any imperfections so if the frame is scratched then the anodising will show that and often amplify if, if there is a rough patch then it will be an anodised rough patch after.

What ever time you think you need to spend on polishing, double it. Do a half arsed job on polishing and the anodising will look terrible.

Also remember that any ferrous metal will need to be removed - any rivnut bottle bosses etc as these react in the anodising tank

This.

The tubes with the bottle bosses can be sealed at each end and the exterior parts sealed too. Ideally the tubes would need to be filled with water or anodising solution so the frame doesn't float!
Generally frames that are painted haven't got the best surface finish underneath! And commercial polishers can be heavy handed and flatted the welds.

02gf74 · Jul 26, 2013

shot or sand blasting is too harsh on aluminium frames - i am not expert on this but soda blasting is kinder. some one can correct me but i understand that any type of blasting will leave a dull surface - not sure how well that wioll look when anodised.

Anodising

dan smith

Retro Guru

bluedazzler

Senior Retro Guru

paddy311

Retro Guru

dan smith

Retro Guru

pete_mcc

dan smith

Retro Guru

pete_mcc

bluedazzler

Senior Retro Guru

Rampage

02gf74

Old School Grand Master

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