spraying is not a black art, but covering mdf is of course.
one of the important things to do is to stop the paint soaking into
the mdf, so many of us initially use a "dry coat" to get a coverage that
will reduce the soak, then build up.
having practiced in the car paint shop, and sprayed model cars which were
only about 4-6 inches long the major problems i found were. not thinned enough paint, not thinned with the right medium, distance from spray gun to workpiece, not moving the gun quickly enough, and too high air volume.
an additional problem is whether the panels are vertical, horizontal or
at an angle.
i was taught to start outside the to be sprayed piece, move slowly across it, and outside the other side, then move the gun down about half the thickness of the first layer, and go back the other way. frankly the first coat is always going to be a problem, but that is why we rub down and use more top coats.
many people think the layer will be too thick, but you are only talking microns.
orange peel is generally caused by paint which drys too soon, generally before actually touching the surface.
runs are generally due to either the gun being too close, so the paint does not dry quickly enough, or the paint being too thin so the same thing happens.
on a flat sheet, it is pretty easy to organise a good finish with about
4 layers in total, as long as you rub down between each coat. the first coat is just to evenly coat the wood/mdf, and get a less porous surface
for the balance of the coatings. but remember you can also cover a lot
of sins when you use a decent finishing lacquer.
personally i have found the rustins two part lacquer which is heat
resistant worked really well being brushed on to a re-finished gillows
veneered oak table, and you can chose deep gloss back to very flat.
finally, the ambient temperature of the spraying area, plus the
"paint" being at a decent temperature also. remember that it is suggested
that when you use a spray can, to get the best finish, you should put
it into a bowl of hot water, and then shake vigourously to get the
proper paint mixture.
you do have to mix the paint and the spraying medium, (thinners/water/etc) properly, and for this an electric paddle is valuable.
unfortunately the final thing is you need to practice.
then practice again.
paul :wink:
oh yes dont forget a GOOD mask :lol:
