DO use green loctite on the valve AND on the antisyphon. DO use a torque wrench to fit the valve to the bottle, not a spanner and guess work. The torque setting will be that recommended by the maker of the valve. Too loose and yes you may well find that instead of unscrewing your bottle from your marker you end up screwing your valve from your bottle. Its happened in the UK at least twice this year that i know of and probably a lot more. It happened in the States this year too and killed a bystander because some plonker didn't install the valve properly. On the other hand, if it's too tight you may find that the valve sheers off from the bottle, if it were to be dropped for instance, as the over-torque causes stress fractures to the brass valve which is softer than the ally bottle. That's happened in the UK too. What the others havent told you is that you need to clean both the bottle and valve threads with a de-greaser, as during manufacture cutting fluid is used which can interfere with the curing (setting) of loctite. Also you need to put the loctite in the correct place on the valve so that it doesn't block the safety vent hole (in the inner valve thread) when assembled. Oh and another thing... are you sure the supplier has given you the correct o'ring on the valve for the neck of your bottle? There are two main sizes and it DOES make a difference. Supplying unassembled Co2 bottles to the general public is damn irresponsible IMO. Where did you buy it from?? We recently had a player turn up at a Delta Force site with his new marker and his new co2 bottle and his new co2 valve. Luckily someone spotted him as he screwed the valve into the bottle by hand. We have subsequently made it policy that no-one can bring their own gas bottle to a DF site, own gun fine (with managers consent) but you use a properly set-up DF bottle or don't play.
Also i'd disagree that a 90 degree bend in the antisyphon is correct... that would probably restrict the flow of co2 as the tube will be pinched at the bend. I use a 45 degree angle and a bend a longer piece of the tube up so that it still almost touches the 'top' of the bottle as it's held in firing position.
Please Play safe... it may not be you whose head gets blown off but the poor sod standing next to you. And paintball gets closed down as a result!
LJ. Red loctite comes in many forms. The 271 which i think youre talking about is stronger than the blue and is resistant to cracking from vibration or changes in temperature. There's also a red one no 545 which is a hydraulic sealant which we use on the gas line assembly of Site Infernos. I think 569 is another red one and there are bound to be others....