Considering whether to get some aluminium bike parts powder coated or anodised. Anyone have a contact/ supplier that they have used for anodising? Costs? Any comments good or bad and the merits or pitfalls of one as opposed to the other?
Depends on what parts. If anodising, try colour anodising near Manchester. Word of warning. Cast alloy parts come out shit unless you get them machine polished.
...and they can come out a different colour to non-cast parts as the casting alloy is different to the machined-from-bar-stock parts. Ask your anodiser about this.
Yes cerakote is highly recommended by many for engines & casings. Evidently its recommended by a few as the best way to refurb a petrol tank cap that has lost its gold/brass look. I also like to use regular paint. On high use parts its not always that great as spray paint is so thin it tends not to last. Still, for black items a final spray of satin black over a few -brushed on and wet sanded- thick base coats of black Hammerite works pretty well and is fairly durable. The real bonus is that if you damage something, you can repair it yourself, unlike powder coat, anodised or cerakote finishes...
Got a reply from Colour Anodising, Manchester. " I am not sure that we can help you with this as we don't offer a polishing service. Also, masking off areas can be a little hit and miss. " Of course I can polish the parts or get it done elsewhere. Though I don't want any problems with threads etc not being masked 100%. Anyone have any other supplier suggestions?
Forgot to mention, I took my rear sets to a machine shop to get them polished. What bits are they and what needs masking off?
I was thinking that screw threads shouldnt be anodised? Also the inside of my fork leg lowers? Though maybe this anodising magic is to thin to cause a problem. This thread is doing just what I expected - teaching me what needs to be done and where. Thanks to all for your comments to date.
I have had a few parts decorative anodised with mixed results. It will not mask surface imperfections so as others have said, parts will need polishing first. Additionally something to bear in mind is that anodising does dimensionally grow the part. It is only a small increase, but for tight tolerance parts (sliding or location fits for example) it can make a difference. A good anodiser should be aware and can advise on the magnitude of any size change.
As per ^^^^ the first stage of anodising is an acid bath that ideally removes as much base material as the oxide coating (anodising) adds. This cannot be 100% accurate, but any anodiser worth his salt will do their best and be able to discuss... In general, 'decorative' anodising is around 5 micrometers thick, and 'external' anodising is around 25. Not a lot!
Regarding screw threads, it's best with new parts to leave them uncut and cut them afterwards, which is essential if you need an electrical connection as Aluminium Oxide is of course an insulator. Don't be tempted to put Stainless Helicoils or similar in before Anodising as there won't be much left of them afterwards, they dissolve and ruin the helicoil size thread in the part. No Anodiser wants to do any masking, even plugging threaded holes, but the better ones will at least try. Plugs in blind holes pop out on a regular basis mid process, and you don't know your parts are ruined until the end. Whenever we can for work we have finishing machining operations carried out post Anodising to open out holes and add threads etc. We then hand paint Iridite/Surtec on the bare metal to protect it. Masking other surfaces for Anodising involves painting on a rubberised 'Goo' or using expensive masks laser cut using the original part CAD file. As mentioned the guys at Dorset Aluminium are very good at all of that. Noel the owner is a Bike guy, and they do all the Brightly coloured Anodising for the big Motorcross parts supplier I can't remember the name of at the moment. Edit - Talon is the company I couldn't remember.
@Jez900ie, threads shouldn’t be affected by anodising. Use Kais up near Preston, they often take fork legs in for anodising. They’ll sort you.
It does sort of depend on how big the threads are. Yes I'd totally agree for a standard say M10 x 1.5, or even M10 x 1 fine, but when you get down to M2 or M3 the thread profile is completely ruined. Also, the sealing of the Anodising down a small blind hole at the 'hot water' stage can be hit and miss, so the thread surface can remain soft. I should remember I suppose that my experience with Anodising is more with small intricate complicated CNC parts for Aviation use than big Components.
OK thanks to all who contributed to my post and supplied information, contact numbers & names plus advice. Various suppliers told me a great deal of aluminium parts from yesteryear are made of different variations of metals and very often the anodising "won't stick". Also that when it does stick, the finished colours vary from part to part as the alloy composition has an effect on the shade. Finally, one went on to say that in his opinion parts exposed to sun and road dirt etc. should also be clear coated to prevent fade over time. It seems that most anodisers don't have the metal polishing gear themselves and this needs to be sourced and done elsewhere the @Nashers contact does offer a one stop service. Having thought it over for a day or two, but it seems that painting or powder coating these parts might be a better route to get the results I want. With anodising some may end up polished silver as the anodising didn't stick, others different shades of black giving a mismatch effect and all will then ideally need clear coating. I was surprised that the prices quoted weren't that high so anyone else thing about getting some anodising done -on a newer modern bike- should give it some serious consideration. Again thanks all.
I am currently looking into clear cerakote over polished aluminium on a frame I am restoring. If you Google MC-5100, apparently it gives a very durable clearcoat over the polished metal, while keeping the aluminium look. I should be doing it over the next few weeks, I'll update the thread with the results
Cerakoting is not cheap but it will not affect your threads in any way dimensionally and I've had a plethora of parts coated using this process over the years with zero issues.
