Hi, about to make a CFRP part using a female mould and want to know the best coating to use for the part.
I see two diffrent gelcoats on the website which are sutible for an epoxy layup, the Epoxy gelcoat and the GC50. 
I read that the GC50 gelcoat is difficult to apply by brush and I do not have the means to spray it.
Is the regular expoxy gelcoat (https://www.easycomposites.co.uk/epoxy-bonding-polyester-gelcoat-clear) easier to apply by brush?
I read that the regular epoxy gelcoat is not as UV resistant as the GC50, the part I am making will be used outdoors but mostly stored indoors and only be outdoors for upto about 20 hours per week, will UV damage be a problem here if I was to use the epoxy gelcoat?
Are there other coatings available other than the epoxy gelcoat or GC50 which I could use or Is there anything available which I could spray into the mould without requiring a professinal spraybooth and air fed respirator (I only have a regular paint spraying gun and a cartridge respirator with A1 and P3 filters).

Yes, you can spray paint into the mold and then laminate your part on top of the paint layer. These paint systems are usually two component polyurethane paints. If you work outside with good ventilation you won't drop dead when spraying a mold, our parents and grandparents generation mostly survived and reached old age, some of them even made a living out of spray painting cars and furniture. Occasionally spraying a part or a mold will NOT kill you even if you use less-than-perfect personal protection equipment.

I really don't understand how people can endorse the use of these things without proper equipment. Sure it isn't going to kill you, but death is not the only health defect that one should be concerned about. Hexamethalyne di-isocyanate is not something that you want to expose yourself to EVER. Why even consider risking loss of eye-sight and respiratory problems, for the sake of producing a one off part? 

I'd make it without the gelcoat or GC50, pop it out once cured and take it to the local spray shop and get them to clear coat it with a 2k high build topcoat such as durpox for a durable finish or normal 2k clear for a decorative piece, much easier and safer plus you won't lose nearly 1mm of thickness to just the UV coating

I have made quite a few parts without gelcoat so far and I have had a few sprayed by a local spray shop however after I take the part out of the mould it normally has quite a few pinholes in it, between the weave of the CF.  I thus have to spread body filler on the parts and sand them back so they are smooth prior to spraying which is a step I'd rather avoid if I can, I have had parts sprayed without any further prep after removing from the mould and the result is less than ideal as the pin-holes show through.   Idealy I'd like to be able to create parts which are usable direct from the mould without the further finishing steps.  Is there anyway I can create a part which is smooth without any pinholes direct from the mould without gelcoat?

Oh and while isocyanates may not kill you straight away, they can cause respiratory problems such as iso-induced asthma.  I am making parts in order to to make my bicycle faster so if I screw up my lungs it would kinda defeat the purpose of making the parts in the first place.  I want to remain a fast cyclist (PB of 37 miles in one hour but want more), thus want to look after my lungs.

You can get a nearly pin hole free finish by using a longer working life resin, create a resin rich 1st layer and really work it in (and the bubbles out) then vac bag to compress, you could infuse but again you may get dry spots / pinholes etc depends on the layup, resin etc, or use an out of autoclave prepreg designed for the cosmetic layer.

If someone is that scared of bodily harm that they don't dare to spray three or four blasts of paint into a small mold, outside, with the wind blowing into the right direction and using some common sense then maybe these people should look for another hobby. Like woodworking *), but without using sharp tools and two component laquers... which happen to be exactly the same stuff.

I doubt most people here are using full moon suits when they work with polyester resins, or do they? Considering the metabolic fate of styrene, what your body does with it in other words, it's certainly not a bad idea.

*) Did you know that many wood dusts are proven to cause cancer? Do people use proper respirators every time they saw, sand or otherwise work with wood? And clean up afterwards using proper cleaning equipment? And no, a regular household or shop vacuum cleaner will NOT filter out the fine particles.
Others enjoy barbecues. Do I need to spell out what's wrong with heating meat over flames? Or acrylamide in potato chips/crisps. And so on.
Life is dangerous and usually fatal.

I don't mean to start an argument, each of us is going to stick to our own beliefs and practices. My point was that I am always a bit taken a back when someone with obvious experience posts on a public forum where people who don't know any better will read comments of "go ahead, use these chemicals without proper protective equipment, you'll be fine". I just think those of us that do know about these chemicals have a responsibility to communicate that these are incredibly harsh toxins rather than compare them to barbecuing, and some people may value their health above their composites project.

I think you need to use a gel coat or in mould coating to be sure your surface has no porosity.

Taking a composite part to painter and expecting them to deal with pin holes when doing a clear coat is something they are not used to doing. Car panels don't have porosity but composite parts are generally full of it.

Use a gel coat, an in mould coating, infuse your parts,,,,,,,,,,or buy an autoclave!