Ready, set, sand.

Ready, set, sand.

"In this Special Series about the E46 OE+ 1:1 Carbon Doors, I document the development, logistics of getting these doors to America. With the Atlantic bridged, I cover the unboxing, fitment adjustments, installation notes and final paint & body steps. 

In this entry, we set out our aesthetics objectives and I cover the preliminary preparation and adjustments to the exterior panel of the 1:1 OE+ carbon doors."
- Matt

You can't raw dog this. 

Aftermarket carbon body panels all need some level of preparation and adjustments before paint. The level and depth of the work required will vary depending on the original craftsmanship of the brand manufacturing the panel along with your quality and fitment expectations. 

As part of my complete restoration of the Phoenix, I sought an OE+ build across the board. Whatever we felt we could improve, we did, or will, eventually. 

We applied this framework to the doors by commissioning a new mold for carbon doors, seeking to drastically lower the weight. Our fitment expectations are OEM: everything should bolt, plug and align like the original doors. 

This implies some paint preparation work would be required. Consequently, I spec'ed my carbon doors in raw carbon. 

Carbon naturally has a literal weave to it, it's most apparent when left raw. It needs to be flattened to avoid the Ferrari F40 style checkered paint. 

Block sanding it raw.

Upon unboxing the carbon doors, we noticed a few dings in the panel. Those came from the junkyard doors that were used to create the mold.

This should have been caught by the manufacturer. They have since corrected the mold. You should expect a bit less preparation work. 

We isolated the dings by using block sanding techniques. I went in depth on the topic in my entry "Looking up, looking blue"

For a few, this is blasphemy: "You're ruining the carbon!". I guess - yea, if you ever had any intentions of rocking a 2002 Civic-like bare carbon door.  Leave this to the drift gang, no diss intended.  

The process does not affect the structural integrity of the door. 

The smaller, darker circles represent the few dings that were present on this door. 

Audrey went in depth in curvatures using smaller blocks to flatten out the door and find any imperfections. 

Primer coats. 

The next step was to apply primer coats. The primer acts as a flattening component in the process. ExclusivAutomotiv used 2 component primers to build up sufficient thickness to perform further block sanding. 

The amount of coats required here will depending on your target goal. We wanted it OEM+. We ended up having to apply 3x coats.  

The interior of the doors were taped and the first coat of primer was laid down. 

We could have taped off the mirror's mounting points. We decided against it. 

The first coat was not sufficient to fill in small imperfections by the lower section of the door. This was most likely subtle shipping damage. 

The bottom right corner of the driver side door was rough and would need more work.  

The small dark circles are sections that sit higher the sanding block relative to other sections of the door.

It highlights the sections that need further correction to achieve a perfectly flat panel

While in there, I lined up the door trims with the intended holes to clip into. The alignment was great. The holes would require slight trimming to get it to snuggly clip in. 

You actually want to have to slightly trim holes. With composites panels, it's most often better to be tighter than loose.

You cannot easily add material to composite panels. You end having to use adhesives.

The door trims are fitted slightly towards the rear as they sit over the rear quarter panel trims. 

Another round. 

We didn't expect a single coat of primer would be sufficient to flatten the panel - and we were correct. We went for another round of primer and block sanding. 

Out of the paint booth and onto the rack after some time to harden and dry. 

We ended up getting it acceptably flat on the second round.  You'll notice the large circles. Let's zoom in and explain. 

The raw exposed carbon indicates this section of the panel was sitting slightly higher, while the whitened section is filling agents we used to bring it up to level with the entire panel. 

Aww, wait! One last round. 

Nevermind, we went for another round to seal in the work and hide the exposed carbon for paint work. This was required as you do not want the weave exposed to color coats if you want a flat finish. 

Out of the paint booth after a third round of primer. 

While you may assume we're adding considerable thickness to the paint, we aren't adding much considering the extensive block sanding work performed. 

Here we go! We were paint ready. Back to the paint booth [...] mmm no, not yet. 

This carbon door set is the first ever created out of this mold. 

We had to test fit one last time before spraying color and clear coats. 

Up next: we cross our fingers and test fit the doors on the car. 

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