Can a carbon fiber body panel that has been painted, be stripped back down?

sand it, it will not damage the appearance when clear coated...

use the wrong materials for the clear coat and it will peel like the clear wrapper in a few months when exposed to UV... there can be a compatibility problem with adhesion to the resins in the CF... also insure that the clear coat has max amount of UV filters, otherwise it behaves like a bad varnish job on wood exposed to the son... using a color coat is the best way to protect CF and having a long term finish and may be the reason for your part being painted vs clear

best results are when we use a high fill two part epoxy primer followed by two part epoxy clear coat... plan on spending over $500+ for the finish materials...smallest sizes are quarts ( over kill for a small job like yours ) which run about $100 per part, plus thinners etc... it's materials that are professional grade and will not be found at the Home Depot / Lowes... get a technical bulletin from Akzo-Noble for the correct formulations ( there are several ) to use, as they are application specific ( the average car painter does not have a clue about long lasting clear finishes on CF )

UV failure from long term exposure ( daily ) is the major problem with using clear coats over CF....this also applies to the resins in the basic CF structure if not protected by a UV bearing finish coat... think of the behavior of finished wood when exposed to Sun, CF is not far behind

 

As Cheesey said, sanding it probably the best way to remove the finish. NEVER use aggressive paint strippers (like "Aircraft" brand stripper that PEP Boys sells). These strippers will eat into the epoxy and get down into the fiber and make mess of your piece. If you want to use a chemical stripper find one that is labeled as "safe for fiberglass" (Aircraft Brand makes one of those, and West Marine makes one too). These can be used, but need to be cleaned just after use and still can ruin the carbon fiber underneath if you aren't careful. For that reason it's better to carefully remove the finish by sanding, and don't take any more material off than you absolutely have to. You are correct in that if you go too far you will end up messing up the weave and it won't look right after that. Once you get the bottom layer of color off stop an don't go any further.

There are a number of automotive polyurethanes that have very good UV protection and you need to use one of them. If you sand down too far you might need to recoat with a layer of epoxy. If you do coat with some clear epoxy use an epoxy with UV protection, RAKA makes one that I've used with good results.

What you have to remember is that UV protection in a clear coating goes away with exposure and eventually recoating is going to be required to protect the carbon fiber. That's why solid coatings are really better in that they protect the epoxy matrix a lot better than clear coatings. Think of it as though the protection gets burned out of the clear coating over time. After it gets burned out of the topcoat it starts eating at the UV protection in the epoxy and then when that is gone it starts eating at what is under that.

Some automotive clear coatings have very very good UV protection and last a long time, so select you coating on that basis.

Finally make sure the previous owner didn't paint the top because it was starting to look bad and needed attention. If that's the case it may not be good candidate to redo in clear if there was some other damage like a heavy scratch into the carbon fiber or other damage that they were covering up with some filler and paint. If you get the old finish off and find filler you are hosed.

 

CF can be sanded as much as needed to get a fair / clean surface... the primer is what rebuilds the surface and makes it ready accept the finish clear finish...the primer creates the bond between the CF and the finish coat as well as filling/leveling the surface ... using finish coat alone will result in disaster

the resin used in the CF must be compatible with the finish coatings... just because it is clear does not mean it is compatible... untested, off the shelf, clear coatings over CF are the road to disaster... I worked with Akzo-Noble in refining their technical bulletin to coating CF for long term durability... removing failed finishes is time consuming and expensive... get it correct from the beginning... for a durable finish... finishes that are described as "automotive" means alsolutely nothing when coating CF.. UV stabilizers are additives and have nothing to do the underlying product... there is more to coating CF that applying random product... DO NOT USE RANDOM automotive coatings over CF