Those parts look great. Would you like to share the contact info for your old boys in Florida ? T

Ben up in Austin does wonderful work and that's who many of us out this way use. Sometimes he gets backed up a bit and nice to have another to call on. Thanks for the info and your project is coming along very nicely. Few pics of Wildwood calipers with Porsche stenciling that Ben did for the Just Peachy project. You also have a nice weekend. Thttp://forums.pelicanparts.com/uploa...1391814855.jpg
http://forums.pelicanparts.com/uploa...1391814865.jpg

Oops. Yeah, he shouldn't have powder coated any mating surfaces. I would remove all of the powdercoating on every mating surface before reassembly. Also, make sure you clean, clean, clean everything with a soapy brush and water in the bathtub- there will inevitably be blasting media left over, and you don't want that in your engine. For my intake I needed to wash/dry five times before there was no blasting media left over.

Blow dry using pressurized air after each cycle.

Maybe you can post pictures of the mating surfaces of:

valve covers
water crossover
throttle body

Also, did he powder coat the inside of the valve covers/water crossover? I hope not.

(BTW this is why it is important to use an experienced 928 powdercoater...)

Just a tiny pinch of blasting dust caught in some cranny of the intake has totally wrecked a number of 928's when it eventually comes loose, nothing in the motor is usable by the time the grit gets caught by the oil filter.

Sorry- I meant the air guide.

The air guide mating surface that goes to the throttle body needs to be stripped. If there is anything uneven there, you will have an air leak.

The coolant crossovers should NOT have been powder coated at the mating surface that houses the funny-shaped red gasket. You will need to strip that. That area is prone to leaks, and the technical service bulletin advises that you add a paper gasket to each side (I used Drei Bond 1209.) They also should not have been powdercoating at the junction with the block. There's a rubber gasket that fits there and you won't want any coolant squirting out of there.

The spark plug gasket area needs to be thoroughly stripped as well, the gaskets need to fit snugly there to avoid oil leaks.

The oil filler neck mating area needs to be stripped.

I say this in kindness and not with any snark intended: the powdercoater really did a number on your parts.

I think you should post this on Rennlist and have the experts take a look. There are several threads there that document the best practices for powdercoating. I don't have experience with installing powdercoated mating surfaces, but given the textured coating that was used, I would say that you need to be very careful about removing the coating, as you don't want to alter the plane of the mating surface at all.

That's the thing-- I don't know, because the powdercoater that I used masked the appropriate areas.

I see that you've posted on Rennlist- hopefully one of the luminaries there will have the answers.

Very nice. Looks like you came out ahead on this one. Love that coating... It looks like it isn't a smooth coating.. Is this the case or is it just a play on my eyes?

Wow - that stuff works great! I thought that was going to be a big headache... easy (ish).

Alan

Good job on that cleanup on the mating surfaces. How come your powdercoater didn't ask you what parts are being mated? I've learned never to assume, I was going to tell him what parts are not be coated, but he beat me to the punch.

Looks fantastic! Well done!

it's a pretty heavy texture. I deal with it all time. It's VERY rugged. McDonalds uses on their booths. There may be sealing issues on the surfaces that get rubber boots too. Anyone who powder coats anything make sure they use a powder with a UV protectant in it or it will look like poop in a year.

Paint is much smoother than the powder, but even the cast aluminum is pretty rough, it may be fine. You may just want to smooth out the contact areas with some sand paper, don't go nuts, but a quick hit to knock off the tall points may help.

With all respect, I must comment on this statement.

Many powdercoaters don't know what they're doing- regardless of how many years they've been in business.

I just took some parts to be powdercoated by someone who had been in business for over 20 years. When I dropped off my parts he was powdercoating a fence; after my job he was doing some rails.

The powdercoating was done improperly even though I spent a half hour explaining what to mask and what powder coat. After returning the part to me (three weeks late) I noticed that he hadn't powdercoated the part evenly or completely. It looked like crap.

That a powdercoater claims to have a lot of experience could simply mean that he/she has a lot of experience in doing poor work.

I've only had three different powdercoaters give me quotes and all of them had car parts powdercoated all over their place. I guess there are others that have no idea, but then those are the one I would run from. My powdercoater is about 5 miles from my house and I will use no other. He does great work and QA's everything personally. He also asks you what he should tape off if any. It's that kind of service and quality you recommend to others. I have posted many pieces here on Pelican on My Euro and S. I guess I just lucked out by not getting one that would powdercoat bolts down as well. ...and I've seen them.

Another powdercoater I contacted:

I: How long do you outgas the parts?
Powdercoater: Outgas?
I: Yes, you know... bake the part so that the oils rise to the surface and evaporate?
PCer: Oh... uh, I guess we can do that.
I: For how long?
PCer: We could throw it in there for 15 minutes or so.
I: Ok... thanks so much for your time!
PCer: Uh-huh.

There is a huge difference in powder coaters. One of my guys has a booth in a barn and the other has a million dollar line set up. They both can do things the other can't. The guy appling the powder has a lot to do with it as well. It's a low paying job with a lot of turn over so you often don't get the same guy. The big shops with expensive equipment and skilled guys usually don't want to mess with someones old car parts. If you find someone good that will do small batches of car parts consider yourself lucky.

I'm glad to see you came up with an efficient solution for the mating surfaces/overspray. Based on my experience in late 2012, here's some additional notes/thoughts on overspray prep:

Valve covers:
-Spark plug holes: look down those holes and you'll see a shoulder down there. This is actually a pretty tight fit, and there was enough coating in these bores that I couldn't get some of spark plugs installed. Trial fit your spark plug holders, and strip coating as needed to get a smooth fit.
-O-ring recesses in valve cover bolt bores. On my covers, these holes had way too much coating. The coating pooled, and some of the bores were bubbly/boogery. I had to strip most of these to get a quality sealing surface
-Spark plug keeper screw holes. There was too much coating in here, such that the new screws I ordered wouldn't go in. I had to sacrifice a few screws that I put into service as thread-cleaning taps. I finally got all the crap out
-Passenger side valve cover - oil breather fitting bosses. I went around and cleaned the coating off these too, just in case.

Intake runners
-Mating surface (you've got this covered)
-Injector bosses - again, my bosses got an excessive amount of coating in them, which was often bubbly/boogery, such that I was concerned about the injector o-rings being able to do their jobs. Had to clean them all out.
-Fuel rail bolt holes - miraculously, mine were clear of any coating gunk, but check yours.

Oil filler body, air guide
-Call me overly cautious, but with the mottled texture of the coating, I would strip the coating from all the hose fittings to ensure a smooth sealing surface for the hose

All parts
-Obsessive-compulsive cleaning. This can’t be stated enough. The intake runners were the easiest for me – just put them in some soapy water and ran some brushes and towels through them, no problem. The valve covers and intake plenums were the worst. Each of them had a fine coating of oil on their inside surfaces, and the oil was completely saturated with glass beads. It took hours and hours to get these spotlessly clean. For the valve covers, I filled the insides with degreaser and let them soak, then brushed out all the nooks and crannies with various brushes. I had to rinse and repeat the process 3 times per cover until a shop rag started coming away clean. For the plenums, I poured degreaser solution into the chambers. Then I stuffed a fresh shop towel in there and used a long screwdriver to scrub the hard-to-reach areas with the shop towel in the degreaser. Again, it took several rounds of this until a shop towel would come away clean – the glass bead-laden oil just sticks to the castings like glue.

All told, I think I have 12-16 hours in prepping all the powdercoated parts for installation. My coater has done lots of ‘dumb’ parts for me before – just simple sheetmetal parts with no concerns like those above. If I use them again, and this experience was bad enough for me to try somewhere else, I’ll prep and mask everything myself before taking it over there.

Simply gorgeous. Congratulations!!!

BTW don't forget anti seize on the bolts for the intake runners. Optimol TA.

Might be a good time to change all the vacuum lines, if you haven't done that recently.

Make sure ALL the clamps are tight. Otherwise, you will hear a whistling sound that will drive you crazy....