I rec'd the valve cover back from the powder coating shop. It appears they did the inside of the valve cover also.
I was not happy.
When I asked why they did this, he said they do all the valve covers this way.
Sounds like BS to me. Should I trust the durability of the internal coating, or not?
It was sand blasted and chemically cleaned before sprayed.

Paint + Internal Engine Parts = Big Disaster!

I honestly don't know if the power coating will harm your engine, but it just seems very awkward to me to have paint inside!

I would try to get them to redo the valve cover for you.... If not, maybe use some mineral spirits to clean out the inside, THOUROUGHLY clean it, then reinstall... BUT THAT IS JUST MY IDEA! DO NOT FOLLOW IT UNTIL EXPERTS CAN CONFIRM THIS!!!!! I AM NOT TELLING TO DO THIS!!!!

Think about it: hot internal engine parts, petroleum products splashing, bubbling paint peeling falling onto lifters, cam lobes, burning and gumming up parts.

I'd take it back and DEMAND a re-do. I've never heard of anybody powdercoating the interior of a valve cover. It sounds like they just do sloppy work and hope you wouldn't notice.

Good luck.

__________________
'94 SL500 Tourmaline Green, 120K miles as of February 27, 2005.

http://home.earthlink.net/~boudreaux...ictures/17.jpg
Updated photo September 2004

I really don't think it will be a problem; powder coating is a very hard coating and is baked in an oven. I ounce read in a hot rod magazine about how you can coat the inside of cylinder heads and valley of high performance V8 engines to assist with oil returning to sump (less resistance).

Since they do this all the time, can they put you in touch with some people they have done this for 50,000 miles ago who will show you the inside of their valve covers?

Will they cover your engine replacement if the paint flakes and destroys your engine, and you bring in the valve cover with flaked paint?

On the plus side, the coating might not be damaged by hot oil, and there's nothing that's going to mechanically wear the paint, like road rash.

Best Regards,
Jim

I agree with everyone..My thoughts were along the line of delaminated coating.... inside the motor= big problems also.
Anyone here have internals coated now?

One thing people have to realize is that powder coating is NOT the same as paint. There are two types of powder coatings. One is thermo-set, the other is thermo-plastic. For applications like your valve covers, the thermo-set type is used. Powder coat is actually made up of two components, a resin and a catalyst. Each grain of powder coating contains the two components. After the coating is applied to the part, it is heated in an oven. Once a certain temperature is reached, the two components cross link and cure. It is a very hard coating and is very resistant to abrasion, chemicals, etc. Once this cross linking has occured in a thermo-set, it will not be affected by subsequent high temperatures. It remains cured and hard (thermo-plastic powder coats will soften every time they are brought up to temp). It is extremely important to prepare the part substrate prior to applying the powder. It sounds like your supplier used appropriate cleaning and preparation techniques. However, if you're uncomfortable with the coating in the valve cover, it is not a difficult thing to remove it if your supplier has the proper equipment. Their sandblaster would do the trick, but a plastic media blaster would be better, as this media does not remove metal...only the powder. FYI, an experiment I did on powder coated panels simulated 10 years of outside exposure. The powder coating did not degrade at all.

__________________
1995 S600, 1 of 618 (sold)

"Speed is just a question of money...how fast you wanna go?"

LONG LIVE THE W140!
Visit my Web Page at www.v12uberalles.com

I know whay they did it, because powder coating sucks. If they only did the one side, then the edge where it transitions would start to peel, and/or corrosion would work its way under.

Paint is the way to go.

This would occur with paint as well. Any time metal is left bare, corrosion can start. Powder coat is far superior to paint, and I have the test results to prove it. This is recognized by many industries, including the automotive industry. A day will come when paint is a thing of the past.

__________________
1995 S600, 1 of 618 (sold)

"Speed is just a question of money...how fast you wanna go?"

LONG LIVE THE W140!
Visit my Web Page at www.v12uberalles.com

I have some old Mercedes brochures showing the engine assembly process...one of the pics shows them powder coating the insides of the engine block!

If MB has been doing it for years, it's probably okay. And the valve cover doesn't see NEAR the heat stress that the block endures!

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

My experience has been that paint is superior. I work and play around modified vehicles all the time, what I see people spending a LOT of money on professional powder coating, only to have it go south down the road. The complaints I hear and see are color fade, and peeling. It seems one nick down to the metal and you’re screwed. Not true with good paint and the correct prep which the powder coat had done.
I paint my engines, suspension, and body with good paint. No problems, that is unless I want to remove it. It won’t peel off like powder coat. Paint has a bad rap because people don’t use the good stuff. Eg; on my last valve job the tech told me my heads were the first ever to survive the hot tank cleaning with the paint intact.
Maybe powder coating has the same bad rap? Or maybe the good stuff has only recently come out?

Even if it were superior, I would still use paint because it’s substantially cheaper, can be done at home, and damage repair is easy, and it’s more than good enough.

PS: I do paint certain internal engine parts. It works perfectly, just don't buy your paint from WalMart!

I can't argue with your first-hand observations Chevota. When it comes to powder, or paint for that matter, you must select the appropriate product for the application. For example, you shouldn't use a powder with low UV tolerance for an outdoor situation. That will definitely create a fading problem. If you're seeing a powder finish peeling, that is a sure sign that the substrate was not prepared properly. Some metals require a phosphate treatment prior to powder coating to assure good adhesion. It simply depends upon the materials used. I find that many people dabbling with powder assume that what worked with paint, will work with powder. That is not necessarily true. One must do the proper research first. As an FYI, many people do not realize how many products are now powder coated. Almost all major appliances, bicycles, building structural components, barbecue grills, aircraft components, etc. use powder now.

http://www.pfonline.com/articles/080305.html

A major advantage that paint has over powder is what you pointed out...the average Joe can apply a good paint job, but probably doesn't have the equipment to apply powder coatings.

In either case, paint or powder, a poorly prepared substrate will cause the coating to fail. As we say in Aerospace, I'd rather have a bad paint job on a clean part, than a good paint job on a dirty part.

__________________
1995 S600, 1 of 618 (sold)

"Speed is just a question of money...how fast you wanna go?"

LONG LIVE THE W140!
Visit my Web Page at www.v12uberalles.com

I seem to recall reading somewhere that the inside of my 722.6 transmission pan is painted black to facilitate the identification of metal particles in the ATF.It appeared to be painted black when I removed it during the ATF change and I know it came that way from the factory.

The ATF pan on my 911 is cadmium plated ...from the factory. Found it out after I removed all the Cosmoline.

I'll have to agree with the previous posters though that unless I was certain sure of the surface preparation and coating specifications, I wouldn't want anyone putting anything but lubricants on the inside/engine-facing sides of my engine's components.

__________________
2005 Pathfinder LE
2001 E55
1998 M3
1982 320i

After all the posts.....thank you.
I have ordered a new valve cover. The original metal was heavily pitted after bead blasting, and I don't trust the long term wear of the internal powder coat.
Anyone need a power coated valve cover?

pcmaher:
I Agree. I just "assume" it was done right because it was professionally done, but you know how that goes... I'm kinda anal about my paint and I do an exceptional prep work for adhesion.

deltajetfixer:
I paint select internal items for heat reflection, and/or to assist oil back to the pan. I also use ceramic and film lubricants. The dry film is the bomb, I use it on my tranny too. Very cool stuff! It's made by a company called Techline (I think).

ken_xman:
Yeah, aluminum does that... I'd probably try it just to see how it holds up. But a nice shiny new valve cover is nice too. Of course I'd paint it black right away