Re: DIY Respray
Some out of a can primers react with real paint thinnned down from a spray gun.
I found this out the hard way a few weeks ago when respraying a numberplate surround for my XD.
I personally don't think spray putty is nessesary. Just leave as much of the original paint on as you can and put a good couple if coats of undercoat on. Do all the fine filling/scratch removal before you put undercoat on and try as hard as you possibly can not to cut through the undercoat, doubley if there is only bare metal under it.
Once the undercoat has dried do 2 things:
1. Go over the entire car and fine fill any pin holes, etc before you start sanding.
2. Get some really, really cheap black paint and spray a really fine coat over the fresh undercoat. This is called a guide coat if you not familiar with the concept, it allows you to see where you have already sanded the undercoat so you won't be sanding the same area too much.
With the top coat make sure you spend at least half a day making sure there is no pin holes/unsanded areas still on the car, your equipment is clean, and most importantly, the area your spraying in is absoloutly 100% clean. Even the smallest of crap settling in the paint will make it look crap. I have seen some fantastic backyard jobs in the past few years and the difference between the good ones and the dodgy ones are only a little more time and effort spent preparing the car and the spray area.
Last but not least practice your spray skills on something other than your car!
The way to spray with a gun is to keep the spray nossle at the same distance from the car at all times. When your spraying a panel you need to move your arm/legs/back but only move you wrist as a pivot point. Too many backyard painters move their wrists too much and end up with horribly uneven coats.
Practice on an old panel with crap paint before hand and keep going untill you can keep the nossle at the exact same distance wether it be pointing up, down, left to right, a quick blast under the door from underneath, etc as the only way to do it right is practice!
Well I hope all this helps, sorry for the long post!
Just like a Tsunami.