Does anyboby know where to purchase black bondo?
Buy regurlar Bondo (mostly PER and fillers) and add black pigment to it before adding the catalyst (red or blue stuff).
I buy mine at Pep boys for maybe $12 per gallon.
I recently expiramented with 3M’s Premium Body Filler. Its Vinyl Ester based.
Pretty wicked stuff, and can be used below the water line. Although for the hobbiest its probably not worth the extra cost.
Since you posted this idea, I have got to tell an adult student that made a Lotus CF lower front engine tray and while sanding the little imperfections (you know that type of a guy) he sanded thru the CF into the FG inner reinforcements. He experimented with black pigment (for per) in the Hawaiian Epoxy resin and will see if it will work!
http://www.expresscomposites.com
It’s not listed on there site, but Adtech has a black bondo called “P-17 Black”.
It’s a high temp Per based filler works well for blems in carbon and can be
used to repair high temp tool flaws up to 400 F. They normaly have a few
quarts on the shelf.
The problem with dye and making your own is the amount of dye that you need
severly effects the filler. And the best you can hope for is a shade of grey. As
most automotive filler is made mosly of talc and its very white.
Cheers
Jim
Yes, I tried using black pigment in bondo a few years ago and didn’t have much sucess either. I also used the Adtech black filler a few years ago. I don’t know if it was a bad batch, but it was very dark brown instead of black. I’m using a PTM&W product now, but I use such a small amount that it goes hard in the tin after a couple of years and I waste almost a gallon! It is jet black, though.
Thanks for the link
Just called Express Composites, they don’t have it in stock ,but can get it… in a quart tin. I think I’ll try the adtech again.
Thanks
Add some milled carbon fibers.
This will make it the same black color as the carbon fiber.
Thank you Cjoe for the correct PTM&W site link. 
I think, think UPOL make an expensive smc filler that is black
Can you recommend a retailer? I want to see if they sell it in a quart tin.
Call or E-mail them and ask for a retailer in your area or nearest one to you.
Please, just tell them you read about PTM&W on here from GGROP (Garden Grove Regional Occupational Program).
ad-tech makes a really good black polyester filler, its intended for mold repair and is stable up to 400 degreez, highly recommend this for carbon cosmetic and mold repair, I believe its called Ad-tech p-17, something like that, ill go to my storage and check tomorrow to make sure thats the correct name