pete75 wrote:...Why would anyone with access to a proper spray gun use it for the undercoat but not the top coat?
good question; cost and convenience really, I suppose.
You can buy good quality primer for about £15 a litre but good quality topcoat costs a lot more than that, and if you buy a whole litre you have enough to do about five or ten framesets... if you want them all the same colour, that is. Topcoat needs more thinners of better quality too, and is intolerant of any defects in the sprayer setup, where by contrast in primer defects can be flatted off more easily.
So if you just want some nice colour as a one-off, it is often easier just to use a rattle can on a reasonable sized area. However I quite often decant a little from a rattle can into an airbrush, and then spray headtubes and lugs etc in contrasting colours using that. This way I can have dozens of different colours to hand, with no storage problems, and no cleanup problems past the airbrush itself.
Another benefit to using rattle cans for topcoat is that you can leave a part-full can on the shelf for years and come back to it knowing that you will have something you can use for touch-up. Other paints tend to dry out, or don't mix properly second time around.
cheers
