Originally Posted by 962porsche (Post 9478697)

JON it takes two .
i tend to just say it as i feel i'm willing to help any one with there projects .

ok so your looking to paint the underside of your car as you know i feel this is one of the biggest mistakes for a number of reasons . the biggest is no matter how or what you do over time down the road you will have the painted finish sandblast to hell .

i have had a few customers ask us to do this and this so far is the best way we have found .
we are going to get right back to the tinted chip guard but you would tint it to closely match the color of the paint color your looking to use . by doing this when the finish does get scratched , chipped and sand blasted you would not see a big difference in the colors from the top coat to the chip guard .
then you would also want to pick a sealer you can also tint to match the top coat color .
when it comes to the top coating you want to use a flex additive as you would use for rubber bumpers . this will add to the impact protection . it's not a cure all never to get damage on the finish but it's a big help .
as we all know the undercarriage takes the biggest beating from sandblasting of road debris .

prep becomes very important when your looking to paint the undercarriage .
spray your stone/chip guard then let it dry . i wouldn't try wet on wet from stone guard to top coats .
once the chip guard is dry sand it with a red pad . an easy way to sand some thing the size of the chassis is to use a DA sander with a hook and loop pad on it .
the red pad with stick to the hook and loop pad because the hooks grad the red pad .
this will get into the nooks of the chip guards texture and not sand the tops of the texture as sand paper will .
with an old pair of scissors you can cut the red pads round to match the DA backing pad .
once you sand every bit of the area blow the area off and clean with a prepaint cleaner .
from this point you can go wet on wet .

as i'm sure you can guess i think it's a very big mistake to paint the under side of the car like this unless you are only going to show the car and trailer it .
this is not to say i don't think it should ever be done i finished a deuce coupe not long ago and i painted the underside of it the same pearl color as the top side . the big difference is the owner is not really going to drive this car . we did all the suspension in chrome and the frame is a gloss black . as we can guess he is not going to drive this car . it's nothing more then a trailer queen ( now how sad is that ? )
porsche's are made to be driven take our loved 86 carrera's don't know about you all but i like that car should it not be driven ?
OMG NO !!!!! even my car with low miles and in very good shape it's meant to be driven and get driven .
it is such a drivers car ! think about its a exotic car you can take to work with great every day road manners and yet take the same car to the track and whoop up on bigger cars .

i have seen more times then i can remember people painting the undersides of there car or spraying rubberized undercoating on them .
any one ever trying to clean it off will tell you the hell job it is many times i have found it easier to fix it we would just end up stripping the chip/stone guard right off the car and just replace it (the chip guard ) .
when we do replace it we use the white chip guard and tint it to match the old 3M product that was used .

i maybe should have stated this from the start ????
you would have a better understanding of what i'm trying to get across and why i feel it's a very bad idea .