Why powder coating is for garden furniture...

Here are some photos from my recently removed front cradle. As you can see, the powder coat has crushed almost to oblivion between the mating surfaces.

Despite frequent torque checks, this still resulted in loose cradle bolts, fortunately I was on the dyno at the time so saw the issue and tightened things up before any damage was done (loose cradle bolts can cause fracture cases).

If this were a hard used road bike used in all weathers (rather than a big boys toy) rust would get in here, work it’s way under the powder and eat away at the metal.

What I should have done was mask off all mating surfaces so they didn’t get coated, then paint them.

Or even better, not used f***ing powder coating at all!

I’ll now be grinding off the powder from all mating surfaces and giving them a thin coat of ‘one coat’ black paint.

And this is why powder coating should be resevered for garden furniture and kids bicycles. Certainly my motorcycles will all be painted henceforth...

I found the same on mine recently and in the previous owner's time it had caused the start of the crumbling of the mounting points of the cases.

It's pretty well known not to powder coat the mating surfaces.

http://www.oldbritts.com/powder_coating.html

My powder coating is holding up perfectly.

Powder coat is a great finish but it definitely has to be removed at any contact points where torque is required. Front Iso and cradle is the most critical. Just remove the powder and touch up with paint and it wont cause any issues at all

Matt

With a race bike, when the frame cracks, it is an easy fix to weld it up and touch-up the paint. If the frame is powder-coated, or worse nickel-plated , how do you make it look all lovely again ?

I see the same on my recently acquired stock Mk3 cylinder head steady bracket - powder coating flaking at the mounting points. Hot galvanising and black paint will be applied next

-Knut

We have to think of it as a plating rather than a paint.
Then it's great stuff. I had two Ossa dirt bike frames powder coated several years ago during restoration of the basket cases.
The factory paint had almost all worn off or oxidized off, so the sand blasting to bare metal was easy.
The powder coating on those bikes has been caked in mud and dragged thru bushes many times, but still cleans up as new. Very durable material.

Glen

FE,
Maybe not so much the powder coating, of which am a big believer, but prep before assembly?
Whenever I have had a PC or paint job I simply make note to those (or myself) doing the painting/coating to apply a thin coat of silicone grease or vaseline to whatever surface I want left clean. A simple wipe down and your surface remains as you prepped it. No tape needed.

The problem with the masking / greasing option is one needs to intervene between blasting and painting, whereas I prefer to entrust the entire operation to one source.

Trusting the painter to remember what / where / how much to mask is a none starter in my personal experience.

Actually, when I had my Commando frame powder coated it was against my prior experience based judgement. But the motorcycle restoration shop that handled it fed me a complete BS story about how it’s different these days, it’s thinner, it’s tougher, none of that happens anymore, etc.

But it did.

The cradle was handled by a Norton expert whom I know and trust, based close to AN. I definitely expected him to know better.

But, we live and learn...

When I had my parts powder coated I created a visual guide based on the Old Britts article. Just telling or expecting someone to know is not enough.

I was going to use the OB method of masking off the areas on my frame, but the PC guy said not to do it because of the residual oil on the nuts/bolts. I went in and he gave me a tech and we used plastic adhesive to mask off areas I didn't want coated. I just used rustoliem gloss after assembly. Worked fine for me. Only place I didn't get was the rear axle mounting points. When I got the Madass single piece early axle, it was short by about 3/8". I removed all the PC from those areas and now it's fine. I'm not complaining.

I also broke one of those fuel tank wings and had it welded back on. Just repainted with gloss rustoleum and all is fine. Don't even notice it. But it's not for everyone. I still like it better than paint.

New engine cradle and swingarm ready to be installed, after all the effort of stripping the parts for welding, I just opted to rattle can them with black enamel... turned out good enough for me, the subsequent bangs while moving stuff around the shop have also proven that the stuff is pretty durable

If you want something better than a standard rattle can for frames (and engines) you could always try the Eastwood 2K paint in a rattle can. Not good for small jobs, as the whole can becomes unusable within 24 hours of first mixing, but great if you've got a bit to do. I've used it on a Suzuki engine and the finish was superb. They also offer a chassis black that I'll be trying on some frames soon.

acadian said:

New engine cradle and swingarm ready to be installed, after all the effort of stripping the parts for welding, I just opted to rattle can them with black enamel... turned out good enough for me, the subsequent bangs while moving stuff around the shop have also proven that the stuff is pretty durable

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A swingarm is probably one of the places I'd most like powder coat on.

I use chassis saver in jet black.Put it on with a foam stain brush and then when dry put on spray they make for ultraviolet rays.This stuff dries very hard and has not come off my frame yet. Dries flat and same color as original.Have hit this stuff with a hammer and does not chip.

panorton61 said:

I use chassis saver in jet black.Put it on with a foam stain brush and then when dry put on spray they make for ultraviolet rays.This stuff dries very hard and has not come off my frame yet. Dries flat and same color as original.Have hit this stuff with a hammer and does not chip.

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My favorite speciality Norton tool!

Bolt holes, trepan scraper, washer has bevel at outer underside edge.

Don't know who powder coated my MK 111 frame and swingarm etc. but the results were superb . G.T.A. Canada.

I have things powder coated on a regular basis at work- several times a month. It is a very durable finish, but the mating surfaces can get weird.

Instead of relying on masking, it's easily removed with a gel paint stripper.

A real pro will go through and brush off the dry powder before it's sent to the oven so no clean up is necessary and the edges are more feathered and less likely to pick up from the base metal than a masked edge, but that is only if the powder coat shop knows exactly where to remove the powder from. If there's any doubt, I just use the stripper.

t ingermanson said:

A real pro will go through and brush off the dry powder before it's sent to the oven so no clean up is necessary and the edges are more feathered and less likely to pick up from the base metal than a masked edge, but that is only if the powder coat shop knows exactly where to remove the powder from.

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And therein lies the root cause of some of the problems I think.

Firstly, it’s obviously not possible for the powder coating operative to know what needs masking off and what does not on every item he ever coats.

Which leads us to the second point, in general, the powder shops I’ve dealt with seem incapable of following any notes. In fact they seem in capable of even keeping any notes that are given to them, this being evident when I ask “did you follow the notes I gave you”? And receive the answer “errr, notes”?

And the third point is that despite what powder coating is technically capable of doing WHEN applied properly, it can only ever be as good as the person applying it.

Every single thing I’ve ever had powder coated as been too thick. Sometimes ridiculously so. I know this doesn’t have to be the case, I’ve seen it applied in industrial applications where it’s very thin and uniform. But sadly, I’ve never seen it applied like that on my motorcycle parts.

Years ago I could blame myself as I had things done through the back door etc. But my recent coating was done by a motorcycle expert who made all sorts of promises.

Net result wasn’t much different to the earlier back door jobs though.