Motosys

What type of sand paper should I use to sand my car to bear metal and should I use a chemical paint remover first and if so what kind?

Thanks

81_TURBO

Hi Motosys----------if you have read Godzilla's post he is pretty close to being right on with what to do-------------the only thing I would like to add is --------Use an aircraft quality paint stripper only if you have to area to make the mess----------Paint strippers are generally messy-----so expect the mess if you are going to use one-----------the best aircraft quality paint strippers usually can be picked up at a auto paint supply store-------or if you live in CA pick one up at an auto swap meet I see them there all the time

I do have some problems with Kyle's response also----in regards to scratching the metal's surface---------fortunately with today's primers you can get away with murder-------yes today's primers are a pain in the backside to spray, but they do have great qualities------------I personal start when I strip a car to bear metal is a 16 grit 8" disc-----------talk about instanteous paint removal--------yes but at the same time you have to be quick and nimble not to stay in anyplace to long since it heats up the metal quickly and can remove metal at the same pace-----------once i have removed most of the stuff with the 16 grit disc I finalize it with 80 grit on a DA sander-------than straight to major metal repair-------if no metal repair is necessary than i goto spraying a metal-etching primer-------from there you will than mild sand with 220 grit on a block sander and than spray with a filler primer----------------than block sand again with 220 grit working your way up to 400 grit---------------if you plan on doing a base coat clear coat system 400 grit is as far as you will need to sand---------if you plan on doing a single stage paint than i would wet sand with 600 grit and than shoot the final paint---------sounds like i got sidetracked with my rebuttle to Kyle's response--------the whole thing in a nutshell is that if you have a good filler primer to use they normally on average can fill sanding scratches up to what a 40grit sanderpaper can cause with just one pass of the paint sprayer---------------I normally do multiple passes of spraying filler primer and sanding and filler primer and sanding ect............

Generally speaking---------------stripping a car to bear metal is not normally recommended--------------there are certain reasons to go this far-------------1--------you have bad rust and need to cure the car of its cancer------2--------you have a car with extremely incompatable paint( ie. it will react with the new paint or that it is un-workable when it comes to sanding -------which is the first sign of incompatable paint)--------3-------you have way too much time on your hands and need something to destroy---LOL

Reasons not to strip--------it is the factory paint job------which means it is of good quality paint----------it has a great etching primer in place-----------and is a quality base to start body work from(as long as you clean the surface first of both wax and grease-------an auto body paint supply place carries a wax and grease remover)

Good Luck

Motosys

Godzilla and 81Turbo you have both been great help. I have another question: both of you said not to sand to bear metal if necissary. well I would like to find out if it is neccsary in my case. I have a 73 with a hood and driverside door that dose not match the color of the rest of the car and I have some light surrface rust. should I just sand down to metal in the areas that have rust and primer the whole car? or just the areas that have been removed

Thanks

81_TURBO

Hi Motosys again---------this question is a toughy--------how big are the areas? If per se it is more than 30% of the given items surface area(i.e. door, hood, roof, hatch, ect) I would go with a complete strip of said item.........Another thing you have to consider is the placement of said surface rust---If on the edges I would just block sand out those areas--------However, If they were like on the door and they went along the elongated area of the door I would than strip the entire door...........The major thing you will have to consider when deciding on whether to sand off or completely strip is whether the partial sanding will cause a rippling/wavey effect.......It is extrelely common to think that if the bad area is extremely small that just fixing that one area will not become noticable........Even my car to the trained eye has multiple flaws, but I would have to point them out to most people---LOL

Just remember that placement is extremely critical when it comes to sanding to bare metal------------there is soo much more to think about than just the rust...........

Keep up the great questions

LaterZ, 81 TURBO

Motosys

Ok 81Turbo,

So the places that I won't sand to meatal I would just do some light sanding to "ruff" it up a bit like 180-220 grit and then primer over the existing paint? or would I just clean it realy good and primer it??

Thanks,

Brad

Motosys

81,

I've also got an additoinal question my 240 has an old pain job that was poorly don it is peeling (very thick chunks) in some areas what can I do to (or do i need to ) take this top layer of thick paint off before primering

Thanks again,

/\/\ {} T {} S Y S

81_TURBO

Hello Brad------------Well I am only going to respond to this question and not the one you posted prior--------The reason is if you are having the peeling problem this could mean bad things to come---------------"A paint job is only as good as to what is underneath it"---------You stated that you are have major peeling going on------------Well that is the worst thing that could be seen when it comes to painting a car----------To paint a car you must have a great base to start with and if it is peeling in some places and not others you should watch out-----------the places that are not peeling now shall peel in the future-------------I am guessing since you are digging this deeply into your Z that you plan on owning it for some time????----------Since this is the case you will want to do it right the first time and not kick yourself later..............Peeling is caused from-------either bad adhesion between painting coats or a chemical reaction between the paints-----------Solution--------------take it to metal and do it right the first time------------strip to metal---------------metal-etch primer-----------filler primer---------sealer primer---------base coat/clear coat paint--------Sorry to give you the either good news and bad news-------but if it is not done properly the paint job that you get ready to put on will not hold for more than one or two yrs----------paint jobs in general should last between 15 and 30yrs before they die----------yes they will fade from the sun---------but they should not peel or crack----------Hope this helped
LaterZ, Scott(aka 81 TURBO)

Motosys

Thank you 81,

It may not have been exactaly what I wanted to hear but I would rather have it done right the first time and not have to re visit it in the future. Because I am planing on keeping this car until I am unable to drive or die witch ever comes first unless I absolutly have to sell it.