KBlair

Was talking to my bro tonight about making some custom interior parts out of aluminum or stainless and he told me about a process they do called "bead blasting". It's similar to sand blasting, except it uses tiny glass particle about 1/10th the size of sand, almost like a glass dust. He's doing some test parts for me to see what the finish looks like, but he says it give the metal a satin chrome look.

So, i was wondering what the intake for a 16v was made out of and whether or not this process might be feasable.

BTW, my bro works at a machine shop where they usually make parts for Lockheed, Glock, and McDonnel-Douglas(sp?). He also mentioned a process called "parkerizing" which gives steel alloy a blueish black chrome look and prevents rust.

Yes, i will post pics when I get them.

Incendier

Intake is aluminum. Should be feasible so long as you are not too aggressive.

I'd be interested in your results, particularily after all the time I've spent sanding and buffing the intake assembly. Looks nice now, but it's a PITA to maintain.

Satin finish would be much better.

Mike Schmidt

In my opinion the bead blasted aluminum looks great. I don't know how it would be to maintain the finish though.

User 4221

The Parkerizing will make it almost easy to keep. If you want a gloss black power coated intake, check E-bay right now. A local guy in the DFW area is selling it and I know he had it done right. Looks cool.

Good luck and let us know if you run with the
Parkerizing program.

Scott

WallyP

It is possible to anodize aluminum parts yourself. Process includes large plastic trash cans, sulfuric acid, 12 volt and 6 volt batteries in series to give 18 vdc, etc. You boil the part in water to seal it, and it is possible to add dye to the water for color.

Might or might not give even color, but sulfuric acid anodize is one of the most durable surfaces available.

chris928

First of all, bead blasting is a prep process. It is not a good finish for aluminum or magnesium (valve covers). As some have mentioned, it looks nice, at first. It is a rough finish (take a close look) that will attract fingerprints, grease, oil, dust, etc. I have bead blasted hundreds of parts. It would look like crap on the porous valve cover castings. You need to powder coat or plate the covers. This also seals the metal against oxidation. Bead blasting does not. It leaves raw material exposed so it will slowly get grey and ugly.

Any cast aluminum cannot be anodized unless you want it to look like crap. The silicon content is high in cast alloys and it hinders anodizing. Also the grain structure of cast metal is irregular so the anodize will be mottled.

Machined billet looks great anodized, but I have never seen a home job that was durable. Also, for small lot charges of $75 I think I'll leave the acid to the pros. And they can make consistant colors pretty much so that your next parts will match your last ones.

I'm starting to use nickel plate alot. I'll have more pictures soon. It sticks to the castings, no problem and looks almost like polished. It also has a Rockwell hardness of about 50 making it an extremely durable surface. I would have loved to anodize but I've seen the results, ugly.

Sab

Sand blasting or bead blasting is abraisive. The way to go is CO2 blasting (Dry Ice Blasting) it also removes any grease or oil. Then you will have to powder coat, polish and plate or paint it. The bare aluminum will probably turn ugly fast if not treated.
regards,
Sab.

KBlair

So what finisheing process was used on the stock intake from the factory?

KBlair

This the one you were talking about?



Looks nice, imagine it in red!

Larry

What process is normally used to refinish the intake? And am I correct in remembering that the material makeup of the 87+ intakes is differnent that the earlier ones?

Larry
88 S4

Glenn Evans

All the 32-valve engines have magnesium intake manifolds. Unfinished, these are dark grey. The Porsche finish is silver paint.

NEVER use alkaline washes on the painted manifolds; this is what sends them yellow and, if bad enough, causes the finish to flake.

Dave Schaeffer, on the Rennlist 928 e-mail list (dunno about in here yet), is very knowledgeable about manifold coatings.

Larry

Thanks Glenn, that's the info I was looking for. I plan on refinishing mine this winter. Unfortunately, the akaline wash was already applied to my engine by a detailer who said he's owned 928's in past and knew how to clean it. Then he had his "help" do the work while he was out of the "office". We're in the process of "talking" about that now!

<img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" />

Larry

Randy V

Another relatively inexpensive alternative is to have the intake ceramic coated. I had mine done in silver ceramic - looks great and requires zero maintenance:

KBlair

Randy, that looks great! How much did it cost? And can they do it in red?

Drewster67

Hey Everyone - What about just good old fashion polishing?.

My intake had this nasty yellow color to it. So I went to AutoZone and bought some BLUE MAGIC metal polish cream. With a little elbow grease and time - It took the yellow out and I bet if I had a polisher I could make it shine like chrome.

Was this a bad thing or a good thing?. I stopped after removing the yellow but my inner voice says keep going, you can make it look like the intake on the 928 Specialist website. BTW - beautiful 928 - The Stuff dreams are made of !!.

D67 <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />