Here is a few shots of some recent work on a new trunk we built for a convertible version of a specific vehicle platform.
^^ We did the exterior lip & license plate area in carbon/kevlar (blue) obviously…
^^ Silver one…
Anyways, all done in epoxy, VARTM 
Very Nice…!
Very nice! Do you wetsand and polish the entire inside frame?
Thanks
The whole trunk is wet sanded and polished…we don’t use any gelcoat, we run strictly on epoxy so surface quality is numero uno when running these things. Any pin holes add hours to the finishing process. We are frequently polishing the tool to ensure a smooth, glossy finish.
How do you prevent print through?! If I don’t use a gel coat I always notice a terrible print through :L(. I wish I can get away with out using any gel coat on our clear coated carbon fiber parts. My partner, (business partner) won’t let me though unless I prove him we get a better result. Which I believe we would! If it werent for print through :(.
I use a resin with a slower curing cycle and fast wet-out, never had issues with print through on epoxy, always seen print through on PE & VE mainly. I just hate using gel-coat because it takes away from the product in my opinion, it clouds the weave, you have a loss in depth of perception. Plus it stinks, it has it’s own issues, it requires a set-up time in the mould, it makes a mess during spraying (not a single time) but do it 20 times a day for 1 year and your booth looks like the inside of a yellow marshmellow.
We sometimes run clears in the mould, epifanes makes a nice poly-urethane for this function but we just pretty much run nothing but fabric and epoxy, provided the surface of the mould is pristine, you can get away with it. The key is keeping the mould surface freakin’ perfect and polished if doing in a composite mould. When we run aluminum tools T6-2024 which are polished it likes shooting parts off chrome, nothing else is needed. We just pull the parts, trim, wipe with acetone and ship…doesn’t even need polishing, they come out gleaming.
We do a lot of BMW parts and those owners are tweakers, more than 50% of the vehicle ownership seems to be Engineers, they accept only perfection and expect it, quick to criticize and fast to applaud, I know of other suppliers in this area who do run gelcoats on the parts, they sell less than those who don’t. People notice the difference.
Lol BMW owners are surely a breed of their own.
So I’m assuming you use a thin layer of fiberglass over the top of your carbon to add some depth?
I have to disagree about the gel coat taking away from depth though. I believe if you are able to tweek the gel coat to be as clear as possible, (which I’ve spent allot of money experimenting with) and you are able to spray it with the right tools, (again which I have spent hundreds on) then you get a great result. However, it is still somewhat cloudy.
If you are using a marine gel coat, its hazy. Duratec is too amber. Others are weak or poor. Its alway one thing or another with gel coats.
Now if you are saying that due to the fact of loss of clairty with gelcoats, you lose depth, then I agree.
I’m laying up an intake right now and I"ll be using two layers of 3/5th oz fibreglass woven coth over the carbon fiber. Hope that gives me a better finish than gel coat :).
Also, I’m asuming you don’t post cure your epoxy since it has alonger set time? Or a I wrong?
You also said your molds are Aluminum?
Hey John, actually we put no glass down, it is BGF 5.7oz plain or twill as first down, no gel coats, 90% of the time no clears, poly-urethane etc…
On the gel coats, the brilliance is higher without it but there is a higher risk of pin holes. The trunks aren’t pulled from aluminum tools, other parts we make are but I haven’t posted pics of them nor could I, those are industrial clients so NDA’s exist.
I will be in the future moving away from composite moulds for our own products and running 2024 polished.
Ahhhh ;-). Understood. Why 2024 aluminum? Why specifically hat kind of aluminum for mods?
6061 gums up on faster mills, basically it kinda melts. 2024 runs smoother and polishes out better. It is also 3 x the cost of T6-6061