Powder coating?

[sirch345]

Never having had any bike parts powder coated before, I was wondering how you go about covering specific areas you don't want any powder coating on

I understand if it was a wheel you can bank off the bearing areas with large washers held in place with a threaded bar/long bolt etc, but how do you go about getting a Firestorm cam cover done


Any advice very much appreciated,

Chris.

[carmanbikes]

I just took mine and told them what to coat and what not to.

[popkat]

Send it to someone who knows what they're doing with bike stuff, the best I've heard of are Triple s. http://www.triple-s.co.uk/

A mate has just had his wheels powder coated, said the place had a bike department but they do all other stuff as well, he told them not to coat the disc area and bearing faces. He said this to make sure even though they said they've done lots of bike stuff.. Wheels come back coated on the disc face and the centre where the disc inner goes, they also blasted the bearing faces, this is a machined surface what were they doing blasting it. he's taken them back and they are re doing the wheels properly but there's nothing they can do about the bearing seating area, hopefully the bearings will still go in ok, if not they'll be buying him new wheels.

[lloydie]

The guy that dose my stuff is a biker and know what needs masking off .
I just use old bolts in the threads to protect them and let him mask of the rest .

[tony.mon]

With a cam cover I'd bolt it to a bit of plywood with slightly undersized washers- so that whatever colour you want is not visible once you have bolts in- but you'll need to seal up the half-moon rubber sections. For the cost of it, just cut up an old gasket- they're cheap anyway but if you want some old ones I can send you some.

the idea is that you get no powder coat on the interior surface- it could flake off given the heat and oil.
Exterior- the thicker the better....
Especially on the front one, where it will get blasted by grit and stones.

might be worth getting a spare one done so that if it gets chipped you can swap it over.

[Big_Jim59]

One of my first clients was (and still is) a powder coater. I used to fill in over there quoting jobs and pitching in when the owner needed an extra hand so I know my way around the shop. Here are the guidelines we use.

Clean and Blast: The part must be stripped and clean. By stripped I mean all the bearings, removable fitting and bolts need to be removed. Make sure nothing plastic is left in the piece you want to PC. If it is it will melt in the curing oven. Only metal parts can be powder coated. The parts must be clean of all old paint and powder coating. Many coaters have an in-house blast service many do not. Some use a chemical strip process but I don't think it is very effective. Always make sure your parts are blasted and clean. If your coater says he can coat over old paint or finish walk away.

Make Ready: Once the parts are blasted the coater has special tape to cover areas like bearing races and he uses special plugs to fill threaded holed. We never make people mask or make plugs for their own parts. If you have any special need for masking make a note of it on the job ticket. You want to be clear with your instructions because power coating is easy to mask and hard to get off.

Coat: The parts will be hung from a metal rack and a strap will be applied to the rack to pass a current through the part. The powder is electrically charged so that it clings to the part when sprayed. Parts are hung so there needs to be a hole of some kind where a hanger can be attached. Most wheels are hung by the valve stem hole. The hanging point will have a blemish in the coating. In the case of wheels the lack of powder, in this area, is covered with the valve stem.

Bake: From this point the rack is rolled into the oven and baked at over 400 degrees.

Extra-Clear Coat: If you want a really shiny wheel (and some added protection) add a clear coat. While the parts are still hot from the oven the rack is rolled into the spray booth and the parts are shot with clear. They are then rolled back into the oven for additional cure time. You can also get a mat finish clear if you don't want the high gloss.

Things to remember:

• We do not recommend powder coating for large flat metal surfaces. It is impossible to control sags and runs in the oven.
  You can't apply clear to bare metal. Every finger print shows as a smug and the part tends to discolor over time.
  You can Power coat brake calipers even though they get pretty hot.
  We powder coat Harley cylinders and heads but this is more for show. I would never do an engine on any bike I own.
  Powder coating is thick. You need to keep this in mind if you have close fitting parts. Masking them may be the way to go.
  You can't do two tone powder coating. There is no effective way to mask for a second color.
  You can do what we call a wiped rim. For a wheel, you shoot powder and then with a finger you wipe it off the rim around the bead. After cure the rim edge will be free of powder and sliver colored.
  Factory powder coating is a bear to get off. Factory powder coating on aluminum is the worst. You have to peal it off with the blast gun and it is akin to hot chewing gum.
  Powder Coating is not a good option for exhaust system that run much hotter than powder is cured. Ceramic coating is the way to go for exhaust pipes.
  There is no powder coating that I have found that mimics gold. They just look more mustard colored than anything

That's all I know. I am assuming that powder coating operations are pretty much the same the world over.

[popkat]

There's plenty of pictures on the internet of wheels for example that have 2 or more colours. I'm not sure how they do it but I read somewhere they might coat one colour then half cure before masking and adding the 2nd colour.

[Big_Jim59]

There's plenty of pictures on the internet of wheels for example that have 2 or more colours. I'm not sure how they do it but I read somewhere they might coat one colour then half cure before masking and adding the 2nd colour.

Maybe I should rephrase. We have never found a way, to mask powder that was profitable or enabled us to achieve a high degree of quality. I have seen lots of things done. I knew a guy that used clear coat over a picture transfer on a gas tank. It gave it a strange burnt look but it worked. We wouldn't do it because of the risk involved. I have seen some wonderful powder coated tanks but they required a lot of hand work to get a finished product. Most people won't sit still for the cost of all that shop time.

[sirch345]

Great replies chaps, they have been a big help
I'm glad I asked the question now.

Many thanks for taking the time to reply

Popkat, that link you posted for Triple-S Powder Coating has an impressive site. I like the way they have laid out their price list.

With a cam cover I'd bolt it to a bit of plywood with slightly undersized washers- so that whatever colour you want is not visible once you have bolts in- but you'll need to seal up the half-moon rubber sections. For the cost of it, just cut up an old gasket- they're cheap anyway but if you want some old ones I can send you some.

the idea is that you get no powder coat on the interior surface- it could flake off given the heat and oil.
Exterior- the thicker the better....
Especially on the front one, where it will get blasted by grit and stones.

might be worth getting a spare one done so that if it gets chipped you can swap it over.

Thanks Tony for the offer of an old cam cover gasket, I'll give you a shout if I do

Chris.