928 Forum
Sponsored by:
Sponsored by: 928 Specialists

Intake Refinishing Alternative to Powdercoat

Old 01-25-2012, 10:30 PM
Rennlist Member
Thread Starter
olmann's Avatar
Join Date: Oct 2010
Location: Oklahoma City
Posts: 640
Likes: 0
Received 6 Likes on 3 Posts
Default Intake Refinishing Alternative to Powdercoat

This is the process I used for refinishing my intake and cam covers. I researched the best process to refinish the aluminum/magnesium (Al/Mg) alloy and came up with this process. I wanted to have more of a variety to color schemes then offered through most powdercoaters. When inquiring around to all the local paint shops and metal finishing companies, no one was willing to touch magnesium to refinish with any type of guarantee it would work. The problem seemed to be that there was no good way to etch the Mg alloy so that you could get a good base for the primer to stick. Even the factory process could be improved upon as we see our current intakes paint peeling off. My searching lead me to a chemical company out of Chicago (Sanchem) that offers a converter for magnesium alloys. The conversion coating I used is the SafeGard CC-3400 RTU (Ready To Use) that runs $40 for a gal. I used about 12oz for the entire process. This converter essentially etches the metal alloy and allows for a primer to be applied that will result in excellent adhesion to the metal. I spoke with the lead chemist and he seemed to be familiar with the type of Al/Mg alloy that was used in the production of the intakes and cam covers. He then lined out the process I needed to follow for best results as the converter is time dependant.

First obvious step is to have the parts stripped. Chemical stripping is too harsh and sanding is too time consuming so I decided to have the parts blasted. I chose to go with aluminum oxide blasting. Aluminum oxide isnít too aggressive and I didnít need to worry about beads being left behind. Here are the parts after the blasting process. They come out a bit rough to the touch.

Name:  IMG_0101.JPG
Views: 4791
Size:  496.8 KB
Name:  IMG_0099.JPG
Views: 4699
Size:  551.3 KB

When I got these parts back I blew them clean with compressed air. Once I had that done I completely washed/immersed the parts in white vinegar. The parts will fizz and get real warm as the acid reacts with the Al/Mg. Continue to soak them for a few minutes and then wash them clean with distilled water and let dry. Here are some additional photos after that process. The vinegar acid bath seemed to smooth out the roughness from blasting and take care of any of the aluminum oxide blast media left behind.

Name:  IMG_0104.JPG
Views: 5185
Size:  571.4 KB
Name:  IMG_0105.JPG
Views: 4772
Size:  516.0 KB

Once that had dried completely I spray/coated the parts with the converter, let it soak for a few minutes and then wipe/air dry.

Name:  IMG_0108.JPG
Views: 4624
Size:  404.5 KB

Once the part is dry you have a 2 hour window to apply primer. If you donít get it sprayed in that time frame the primer will not make a good bond. You will have to go back to the vinegar step and start over. I chose to use Dupontís ChromaSeal urethane sealer. Since the converter acts the same as an etching primer, I went straight to the sealer. The sealer gives a nice level smooth surface that you can paint over with no sanding. Here again it is time dependent. Follow the manufacturerís recommendations but you can topcoat after about 1 hour and up to 16 hours. After that you will need to sand the primer to promote adhesion. This product has excellent leveling for the topcoat and EXCELLENT adhesion with the converter. If you would ever want to repaint it down the road you would just have to scuff sand it and repaint. It would not need to be striped again due to having the good base sealer in place.

Name:  IMG_0111.JPG
Views: 4748
Size:  456.4 KB

Name:  IMG_0112.JPG
Views: 4939
Size:  492.0 KB

I sprayed a factory Porsche color with Dupontís ChromaBase paint and a high temp engine clear over that. In hindsight I wish I would have used the ChromaBase high performance clear as the high temp clear has yellowed a bit but not too bad. The color has a pearl essence in it so it changes color a bit depending on the light. If you would prefer to skip the clear coat, you could just go with a single stage paint that would need nothing else once sprayed. Itís all personal preference. I did this approximately a year ago and have had no issues. When reassembling the intake I wanted to level off the surface area of the intake where the intake gasket goes for mounting to the engine. I had to aggressively sand it down to get it off. Even then the primer didn't want to come off easily. Its adhesion is excellent and you can see from the pic where I worked to get it off.

Name:  IMG_0225.JPG
Views: 4707
Size:  502.4 KB

Here is the final product. I hope that this helps others who would like an alternative to powder coating. Thanks
Attached Images      
olmann is offline  
Old 01-25-2012, 10:37 PM
Super User
pcar928fan's Avatar
Join Date: Apr 2008
Location: Austin, TX
Posts: 9,337
Likes: 0
Received 1 Like on 1 Post

Looks awesome!
pcar928fan is offline  
Old 01-25-2012, 10:38 PM
Rennlist Member
SMTCapeCod's Avatar
Join Date: Jul 2005
Location: Mechanochondriacism
Posts: 4,633
Received 0 Likes on 0 Posts

Wow ^^ New guy with the big win!
Just kidding, I can tell by your post and your sig that wouldn't be an apt characterization.

Beautiful outcome- you could have quite a cottage business on the side doing that, I expect.

I like the slight hue/patina that it has acquired too...Just, wow. Thanks for posting up the source info, process and results.
SMTCapeCod is offline  
Old 01-25-2012, 11:05 PM
jbrob007's Avatar
Join Date: Mar 2011
Location: Columbus, OH
Posts: 1,331
Likes: 0
Received 0 Likes on 0 Posts

WOW! That is beautiful! Someone needs to make a STICKY out of this post so I can find it once my painted intakes start peeling... I just finished my paint job last week - it looks great, but not sure how long it will hold up - we'll see

Thanks for the info and the step by step procedure!

jbrob007 is offline  
Old 01-25-2012, 11:15 PM
Rennlist Member
77tony's Avatar
Join Date: Aug 2010
Location: TucsonAZ/WlfdCT
Posts: 7,848
Received 11 Likes on 10 Posts

Saw these at 3rd Coast this past Nov and they did look great. Nice job Brian. 77Tony
77tony is offline  
Old 01-26-2012, 12:36 AM
jbrob007's Avatar
Join Date: Mar 2011
Location: Columbus, OH
Posts: 1,331
Likes: 0
Received 0 Likes on 0 Posts

See if I can post a pic or two... Paint works if you do the prep. And, I did a TON of prep. Wish I had known about this etching material a month ago! Oh well, maybe next time
Attached Images  
jbrob007 is offline  
Old 01-26-2012, 12:55 AM
Rennlist Member
MJ928's Avatar
Join Date: Aug 2005
Location: So Cal
Posts: 7,885
Likes: 0
Received 0 Likes on 0 Posts

That looks awesome. I wish this thread was started before I painted mine. Your beautiful work makes mine look like ***. Thank you for posting.
MJ928 is offline  
Old 01-26-2012, 11:24 AM
Join Date: Jan 2010
Location: Muriland
Posts: 1,382
Likes: 0
Received 0 Likes on 0 Posts

That looks really sweet. Nice job.
aaddpp is offline  
Old 01-26-2012, 11:30 AM
Rob Edwards
Archive Gatekeeper
Rennlist Member
Rob Edwards's Avatar
Join Date: Sep 2002
Location: Irvine, CA
Posts: 13,728
Likes: 0
Received 11 Likes on 5 Posts


When the chemist was 'familiar' with the Mg/Al alloy, did he specify a particular type or composition? Just curious.
Rob Edwards is offline  
Old 01-26-2012, 11:53 AM
Rennlist Member
NoVector's Avatar
Join Date: Oct 2004
Location: Central Texas
Posts: 2,412
Likes: 0
Received 5 Likes on 3 Posts

Outstanding--just bookmarked this page for my top end refresh. After it's stripped, is it possible to lightly sand and fill some of the pits to get a really smooth surface? If a filler can be used, what kind would I use that wouldn't mess up the rest of the process?? Again, great job! / Bruce
NoVector is offline  
Old 01-26-2012, 11:55 AM
Running up the Odo'
Rennlist Member
SeanR's Avatar
Join Date: Apr 2006
Location: DFW Texas
Posts: 34,629
Received 13 Likes on 11 Posts

That looks very very good. Well done.
SeanR is offline  
Old 01-26-2012, 02:19 PM
Herman K
Rennlist Member
Herman K's Avatar
Join Date: Jun 2005
Location: Rockport, TX
Posts: 1,684
Likes: 0
Received 0 Likes on 0 Posts
Default Looks great

PM send, thanks for posting
Herman K is offline  
Old 01-26-2012, 04:20 PM
jeff spahn
Rennlist Member
jeff spahn's Avatar
Join Date: Nov 2009
Location: Dubuque, IA
Posts: 7,498
Received 1 Like on 1 Post

I'll look at this route in several years when i re-do my intake again. I am not really happy with the silver color that got powder coated and will try to get something closer to what the OP shows.
jeff spahn is offline  
Old 01-26-2012, 05:59 PM
Bertrand Daoust
Rennlist Member
Bertrand Daoust's Avatar
Join Date: Oct 2005
Location: Gatineau, Quťbec, Canada
Posts: 4,198
Received 1 Like on 1 Post

Nice job.
Very well done.
Bertrand Daoust is offline  
Old 01-26-2012, 07:27 PM
Rennlist Member
JWise's Avatar
Join Date: Dec 2003
Location: Oklahoma
Posts: 2,568
Received 2 Likes on 2 Posts

Anyone who's had a chance to talk to Brian will come away impressed - he's very knowledgeable, thorough, and detail oriented. I had the pleasure of meeting him and seeing his car in person at 3rd Coast. His car was incredible and the intake looks better than factory.

About two years ago, I painted my intake and cam covers with Duplicolor Engine Enamel on top of their self-etching primer. It's held up well, although there are a few places where it has started to bubble, most notably in the cam cover lettering. Note: I did not throroughly strip mine, rather I removed everything that was loose then feathered the edges in with primer and sanding. As such, you could say my prep work was subpar.

I'm not a big fan of powdercoating and will bookmark this thread for use next time. I suspect Brian's method will hold up at least as good as the factory's did, and possibly better given modern materials and our own attention to detail. Thanks for the writeup!
JWise is offline  

Thread Tools
Search this Thread
Quick Reply: Intake Refinishing Alternative to Powdercoat

Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: