Powdercoating problems

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komet

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Finally got my frame, swing arm and g/box cradle back from being powder coated. Looks good except he didn't mask off any of the mounting holes like he said he would. Reading OLD Britts article mentions problems if this isn't done, especially the 3 holes on the front of the g/box cradle that the motor bolts to. Would I need to remove all the paint from the places they mention to mask up, or just the 3 holes? And what about the two lugs on the frame where the front iso mounts? Any ideas for an easy neat way to do this would be welcome. Happy new year everyone.
 
Yep, I fear you are going to have to get out the little Dremel and carefully grind off paint around those holes.

Otherwise, the clearances are too tight for the fits.
 
I masked all the mounting areas, all the motor mounts, gearbox mountings too, iso mounts, plus the battery tray and the holes that mount the Z plates the dzus fastener and one of the holes that mount the coil bracket. Don't forget the headsteady. May have been a bit of overkill, but I have good grounds throughout the bike.

That stuff is hard to get off. Reportedly if you don't take it off the engine mounts, the bolts start cracking from fatigue, you can never get them properly tight on the powder coat.

Dave
69S
 
A small round file on the inside of the hole will be enough to clean up. I have at least 5 powder coated frames that haven't shown any fracturing around the holes since the parts have been fitted. I chase the threaded holes if need be with a tap. Take your time so no chipping of the powder happens on the outside of the hole. The one and only time I had an issue was when the powder guy put a little too much on the cradle and the tranny was a tighter fit.

Tim_S
 
The issue ain't getting bolts through the holes its the vibration wearing down the plastic layer to loose clamp force that then causes what ever that can and will in time.

Knife score the area, tape off the rest and pick, scratch, scrap and sand off the target. I know extra heat will soften the plastic to rub off but not sure how close a heat aim you can get that way.
 
Komet,
Thanks for asking the question because I too am in this situation. I want to confirm one thing though, I am unclear if the powder coat needs to be removed from the area around the bolt hole, or from the inside of the hole, or both. Im sure someone knows the answer.

Thanks,
Matt
 
mattthomas4444 said:
Komet,
Thanks for asking the question because I too am in this situation. I want to confirm one thing though, I am unclear if the powder coat needs to be removed from the area around the bolt hole, or from the inside of the hole, or both. Im sure someone knows the answer.

Thanks,
Matt

both really but ...... 2 things - if the powdercoating isn't removed around the bolt hole (were the stud/bolt head/washers nuts etc meet the frame) the nut won't stay tight and will require considerable retighting (or you have loose motor mounts etc)- the stuff inside the holes may/can prevent the bolt from going through - but if it goes through is less critical than thepowdercoating under the bolt/nut etc. - with the excepting of the isolastics as that will create a big mess and increase wear of the rubbers
 
mikegray660 said:
mattthomas4444 said:
Komet,
Thanks for asking the question because I too am in this situation. I want to confirm one thing though, I am unclear if the powder coat needs to be removed from the area around the bolt hole, or from the inside of the hole, or both. Im sure someone knows the answer.

Thanks,
Matt

both really but ...... 2 things - if the powdercoating isn't removed around the bolt hole (were the stud/bolt head/washers nuts etc meet the frame) the nut won't stay tight and will require considerable retighting (or you have loose motor mounts etc)- the stuff inside the holes may/can prevent the bolt from going through - but if it goes through is less critical than thepowdercoating under the bolt/nut etc. - with the excepting of the isolastics as that will create a big mess and increase wear of the rubbers

Sorry Komet, I dont intend to hijack this thread, but should the stripped area be replaced with paint, or left bare? Also when talking about the isolastics, what powder coat should be removed, just the area where the rubber gaiters overlap? And of course the bolt/nut holes.

Matt
 
I followed the "Old Britts" method to the letter and now I can see the method to the madness. The metal where the washer/bolt head meets the part is critical to have only paint or less. The powder coat stuff is thick and can present a flexible surface where you need a soild. I did have a auto body shop match the silver grey powder coat color of my frame and it was only $5 for a small touchup bottle size. I used this with success.
I did discuss the "Old Britts" method of applying a coat of wax before assembly and the powder coat dude said "Since I had a poly coat applied after the powder coat, the wax was not required." If you have no poly coat, then wax would be good. BTW, the poly gives the color a very nice "new sheen" look in the sunlight.



Powdercoating problems


Powdercoating problems


Powdercoating problems


Powdercoating problems
 
Those iso tubes really need to be masked back about 1/4" so the tube cap can go over them, with powder coat on them the cap will not go over it, unless you have a system different than mine.

Powdercoating problems


Dave
69S
 
DogT said:
Those iso tubes really need to be masked back about 1/4" so the tube cap can go over them, with powder coat on them the cap will not go over it, unless you have a system different than mine.

Powdercoating problems


Dave
69S


Dave,

The pictures were before masking. I agree that this has to be done, very critical. I was able to have my frame & bits media stripped and then armed with a box full of bolts, (Old Britts recommend list of fasteners) I did all the masking myself prior to powder coat. You simply cannot ask or rely upon the powder coater to do this masking to an acceptable level.

*After pictures of CNW rear ISO's installed after being masked back 1/4-3/8 inch, (same treatment for the front engine/ISO mount.)

Powdercoating problems


Powdercoating problems
 
I was lucky, the guy let me come in and mask it with plastic circles he had in all sizes, plus big pieces of it that we could cut up. It took us about a half hour, but I missed a few spots, but not big problem. One I missed was the iso tubes we are talking about and the other was the flats on the brake drum where it contacts the hub. I cut and scraped it off mostly with a utility knife.

Dave
69S
 
I got caught out with powder coat in about 1985 - 'De-Corrosion Services' who used to offer a discount in the NOC magazine. I should have been put on my guard by the rusty cast iron lamp posts lying around outside.

I think that they doubled the weight of my frame and I can still remember picking away at the area on the cradle where the swing arm seals had to fit.

I had persistent re-tightening problems - the coating seemed to soften with heat and squeeze out. I ended up fitting another cradle. The powder on the cradle side plates was crazed by this time too. The material should not be in any location where a clamping force is required.

The stuff is a complete effing nightmare. I wouldn't have it anywhere near a motorcycle again.
 
It sounds like they put it on wayyyyyyyy too thick. A coat just enough to cover is all you need. I have done all my own small parts for years and this is the best method. The thicker it gets the more it becomes it's own entity rather than a coating. Remember it is powdered plastic, specifically polyester. A thick layer of paint will also cause similar problems.
 
Thanks for all the info. I've decided to buy a Dremel and remove the paint from all the mounting holes before touching it up. I scraped some out of the rear iso tube and it felt hard but brittle. So am hoping it won't lift away at the edges. Am not happy having to do this, was originally going to do it 2 pak but after waiting for 3 months to get various machining jobs done the painter only had a few days to do it before shutting for Christmas. So had to decide between getting it powdercoated before then or waiting another month and double the cost. Got frame, cradle and swingarm done, still waiting for the rest so turned out to be a bad decision. Oh well, it's been 12 months so far, we've had heaps of earthquakes in the past 18 months so at least haven't had to worry about the bike getting damaged.

Graeme
 
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