coating and seals

[jan lauwers]

Hello friends,

I've had some parts of my engine powder coated (silver) and others (blacks) done by the KTL process.
I am quite happy with the result at least from the 'looks'...
Question:

Does powder coating have any effect on seals, or on liquid seals? Somehow my gut feeling tells me that it would be best if I removed the powder coating from the flanges that hold the seal. See arrows on the pic pl.

Secondly, I have been a bit over enthusiastic and I forgot to mask the inner treats. I have already tried to remove the powder with a small rotating steel brush, but that so far was not very successful. Now I am thinking of glass blasting the inner threats it in a small machine that allows for working very locally in small area's. Or perhaps I could try with taps? (not sure if they exist of these sizes). 

Any wisdom here on those 2 topics please? 

As always, ... thanks again guys,

Jan

[cfm65@me.com]

Hi Jan,
My experience is that powder coating sticks like crazy. I dont think you need to be concerned about mating surfaces. However, I would make sure they are flat, sometimes they have a little pip on, maybe a little speck of sand from the sandblasting. Might also be a little rounded at the edges.
The powder coating on the thread is another story. Sand blasting and wire brushes will not make the powder coating jump off.  Unfortunately the sand blast cleaning before the powder coating, leaves the metal quite rough, with small impact craters caused by the high speed sand during the cleaning process. The small craters and clean rough surface allows the power coating to stick like mad. Cleaning the thread will be very diffycult and may take a while.
Dont ask how I know, I have walked that road.
Good luck.
Chris

[jan lauwers]

Thanks Chris,

Sounds like I have a little problem on my hands then. I will be a bit more patient and try harder. The blasting that I am going to do is not with sand, but with glass particles, perhaps that works better on the threads. I will do that in the workshop of a plating specialist who is kindly letting me use his machine, perhaps he has some experience with this too. I will also look if I can finds thread taps of this size.

Jan

[Bonnyboy]

I powdercoated a delicate vintage motorcycle frame once and the plugs I made for the threads were accidentally removed by the kid at the powdercoating place.   The powdercoater felt bad and found me a guy locally who has some antique "thread chasing" taps in whitworth thread he leant me.  They worked a treat. 

The taps were made specifically for chasing threads instead of making new ones.  Check around some old car restoration guy must have some.   

[jan lauwers]

Thanks Bonnyboy... thread chasing taps, that's what I meant to say.. but I did not know the correct english word for it... Learning all the time here.. 


Jan

[Tyler S]

Thread chasing taps are widely available. Don't use thread "cutting" taps
http://amzn.com/B000AEX8DW
or home depot

[114015]

Sounds like I have a little problem on my hands then. I will be a bit more patient and try harder.

Jan,
Well, I had the same problem as you have with my rear axle parts before assembly.
Had all the "black parts" for my rear end powder coated.
The guy (professional) who was assembling the differential and the complete rear axle was extremely angry about me.
He removed (scratched off) all the coating from any sealing surface and yelled at me that the sealing wouldn't work (properly) with the powder coating.

Of course the same for any threads.

Maybe not so much of a problem for flat sealing surfaces without a lot of torque on the fixing bolts - like for the distributor drive lid on your picture. But maybe more for the oil housing.

Use paint remover (paint stripper) - works well on powder coat. 

Good luck,

Achim
(European neighbor)

[Benz Dr.]

And that's why I won't use it on engine parts. In fact, I don't use it.