For those of you that want to know more about bodywork/prep for painting here goes...I had someone send me this and thought those of you doing your own restore might enjoy reading this for reference.
For a good solid reference, there is an outdated publication that still holds true with metal shaping, but mind you everything else in the book is pretty dated. That book is Chilton's Body work manual.
Now as far as what kind of surface is best to use filler over, be it etching primer, build primer, or bare metal...
The best answer to that question is to put the filler over bare metal, because, the best most adhesive properties of the filler will be limited to the adhesion of the primers. therefore, filling over bare metal is best, but you can fill over primers, but remember that cutting the primer is crucial. 80 grit at the FINEST. the best is 24 or 35 grit paper, and the best means to do that is by hand sanding or using a high speed circular sander such as an abrasive grinding disk on a die grinder or a high speed circular sander. the key is low speed though. You don't want to go fast or high speed. give it some pressure, and grind slow. This will keep from heating up the metal and will give you more grip. You can experiment and try it at a couple different speeds and pressures, and then feel the difference with your fingers. You can actually feel the deep cuts.
That is what is needed for good adhesion, and adhesion, rust and water are the 3 main failure points of filler. IF you eliminate all 3, then your filler should last 30-40 years.
Now...
I have been thinking about how I want to do this without confusing you, and trying really hard not to assume you know nothing at all...
So, here goes...
I thought the first thing I would do is give you a list of simple important supplies that you might not have handy, but shoudl have.
all of these items can be bought at advance auto parts, and a good autobody store.
1. red rags and white terry towels. (come in packages of 40 rags and 12 towels) should cost about $15 for one of each
2. Dawn dishwashing soap liquid
3. Red and gray 3M scotch-brite scuff pads
4. sandpaper in follow grits
35 grit long board
80 grit long board
180-220 grit DA disks
400 grit full sheets
600 grit full sheets
1000 grit half sheets
1500 grit half sheets
2000 grit half sheets
5. Sanding blocks in 6 inch and 9 inch length, should be hard rigid rubber, not flexible at all, and a 14 inch long board or air board
6. soft sanding sponges 3M stick-it makes some nice ones
7. different shaped hard foam rubber sanding blocks in as many sizes as you can find
8. single edge razor blades(boxes of 100 are pretty reasonable), and a razor blade scraper
9. masking tape in 1/4", 3/4", 2" sizes. 3M pressure sensative tape is best. 3M green is ultimate, but costly.
10. air tools. the more the merrier...
i. high speed air sander
ii. air blow gun
iii. die grinder with 24 grit 4 inch disks and wire brushes
i
v. air board (nice but not nessesary)
v. primer paint gun. conventional gun is fine, hvlp is not necessary but very helpful.
11. assorted masking paper and (personal recommendation) Norton Blue Sheeting in 16x350 roll. it's cheap, expendable and works well for masking. paint won't flake off of it and it clings nicely to cars.
12. paint stir sticks
13. paint strainers
14. cardboard, and lots of it
15. fillers such as... (should have all of these) EverCoat Z-Grip, Metal-2-Metal, USC Icing (evercoat thin ice)
15A. filler spreaders. in 4" and 6". get a bunch of them... cut some down to 2" and 1 inch.
16. sharpie marker
17. Body hammer and dolly block set
18. Clean up thinner. laquer thinner you can get it in a 5 gallon can and a pump for it.
Steps:
1. The first thing you should always do, most importantly is center the car in your work area, so that you have full access to everything, and every panel on the car at the same time. You should have enough room available around your car so that you can step at least 10 feet back from any given point to observe body lines and areas on the car that you are working on. There are 2 very important tools you must have in any shop to get good results.
i. lots of light, preferably florescent
ii. Your hands
If you don't have either, then don't try doing the bodywork yourself.
Florescent lights are dirt cheap to buy and use, because the bulbs are usually only 15 or 25 watt bulbs, compared to 60 or 75 watt that you normally use. incandescent lighting isn't enough for good work, as florescent will show you everything.
2. Once you have your car in a good position, for work, wash the whole car with Dawn or Ajax or some kitchen liquid dishwashing soap, and then dry it THOROUGHLY. blow it out with air in every seem and crack and make sure it is 100% bone dry. A very important part of bodywork is constantly blowing surfaces clean of dust and dirt and sanding dust. The proper way to do so, is to get a red rag (any rag will do, I just choose the red ones from advance auto because they are guaranteed clean, with no grease on them, when you pull them out of the package) and with a rag in one hand and an air blow gun in the other, wipe and blow. wipe adn blow until yoru compressor is blue in the face, and there is no dust on the car, nothing but metal would be left. It should be noted at this point that having a good air dryer system is key to keeping oil and water off the car from the compressor. Sometimes it helps to wet down the floor a little bit to keep the dust from blowing back up on teh car, but not necessarily. Now you are ready to start bodywork.
3. Start by walking around the car, with a black marker or pencil. I use a piece of 80 grit sandpaper, folded to the size of my thumb... walk around the car, and look at the reflection of the lights on the surface where ever possible. look for dings, nicks or anything that distorts the shape of the fluorescent light bulb on the surface. (this is another reason fluorescent light bulbs are important, because they are almost perfect in shape, and they make a good clean reflection on paint or semigloss primer(like what is found on new sheet metal such as your new door shells and 1/4 panel)
...anything that looks remotely suspect, circle it...
for places that you can't "see" any reflection, then use your most important tool (clean hands) and make passionate love to your car. molest it everywhere. but it's not a girlfriend so move your hands fast. you will feel every thing. try feeling out a ding that you already circled. Feel how it feels in your hand... and then "look" for that feeling all over. Anything that you can feel, you will see in your finish later. ANYTHING...
With this in mind circle everything. if the thing is really dinged up, when you are done, it should look like a big polk-a-dotted beast. It's ok... because you will get these spots fixed eventually. and you don't want to get 1/2 of tem and say "to heck with this, this is hard work" BE thorough dammit. That's why you get paid the big bucks as a bodyman (or at least keep lying to yourself and thinking this in your head )
4. Now you should have a good starting point to go from... and you are ready to start cutting the steel. Before you think of putting any filler in the car, first take your hand and determine how it is dented. Right here I could go off on a 5 page tangent of how to read a dent and how to hammer it flush again, but I will hold off until later, and for now, just to get you started, simply say, try to get the ding or dent as smooth as possible without filler, and make sure there are no high spots. low spots can be filled, but high spots need to be pounded out, unless you feel like sanding a hole in your car to get rid of it.
5. When cutting for filler use at most 80 grit paper. anything less coarse than that won't give it enouch bite to hold filler in place. this is where a lot of people miss and end up giving filler hte bad name that it has. Remember, this is 2003, filler is not what it used to be in the 60's, it's a lot better, when used correctly.
Take your high speed sander, or die grinder with 24 grit disks or just a plain piece of 80 grit or 35 grit paper in your hand, and scuff up the dings that you circled, and then scuff 3" past the circle in all directions, for room to feather.
6. Once you have every ding scuffed, make sure you have memorized approx. what shape and size the dents all were, for reference later. and now you can start to fill your bad spots. Get a 12"x12" square of flat cardboard from a box or something, and lay it down flat on your bench, spoon out a 4 inch dia. puddle of filler relatively flat on to the cardboard center. Then kneed up the hardener tube. I like to use blue hardener for the initial filler and then red hardener for skim coat icing. then, after kneading, draw a straight line across your puddle with the hardener. This will give you an approx 50:1 ratio. keep that in mind, and don't draw a straight fat line, just nice, steady medium line. I like to use a paint stir stick. preferably 1/2 or 1/3 of one to save on stir sticks to mix the filler. The proper way to mix your filler is hold the stick end into the puddle flat on the bottom, and at about a45 degree angle, so you are not stirring on it like a 3 year old in a sauce pot. and keeping the bottom of the stir stick flat agains the cardboard, stir it quickly and steady in circles. Make sure the whole mixture is the exact same color throughout then toss the stir stick and pick up your spreader and fill all areas until they look full when viewed from the side. Filler is glossy and you can use that to your advantage. Fill it full. and remember you can always hog it back down off if you need to, but it takes a bit more effort to have to put a second coat on.
7. Within 5-10 mins you should start cutting down the filler high spots and rough shaping it. You can use a hard block with either 35 or 40 grit, or a body file, on a file holder or in your hand it doesn't matter, they are pretty rigid. use straight edges to guide you. and get everything close to flush, but not quite. then switch over to 80 grit paper and continue to sand it. There are a bunch of tips and tricks I could put in here, but I want to try to stay basic. I will use a few...
for example:
always use a sanding block long enough to reach over top of the entire filler area, so that both edges of the block are touching metal that is straight. This will let the block naturally sand out the filler to the same height as the metal.
Always use a low grit sand paper to start and keep it relatively low, there is no need to attack putty with a 120 or higher grit paper. You want to get as much of the filler out to level without tearing the metal out around it and the best way to do this is to use a low grit and hog it.
You can always sand out the scratches in the filler with a DA later, but it takes a lot more to add filler to correct a low spot or a wave caused by high grit paper.
"feather" that's a key word when sanding. The edges of your filler shoudl be feathered into the surrounding metal. no hard lines. only feather edges. the wider the feather the better.
Feel everything with your hands constantly. you can pick up a low spot or a flaw a lot easier and faster with your hand than with your eye. For 99% of all work your eyes just won't do, you need to use your hands.
And the last tip I will put in here that is pretty important. While you are sanding a filled area, watch for bright shiney bare metal spots to show up. if you see a small area that seams to keep getting hit more than other areas, it might be a high spot or bump. So if you keep getting caught on it, bang it down with a hammer.
Wipe and blow as you sand. The more you wipe and blow, the better. Dust fills holes, and blowing it out of the pinholes will let filler work right.
8. This is the point when you can get out your spray can of paint. and this is one of the only times I will ever recommend anything that comes from a spray can.
take your can of spray paint and lightly mist the repair area. This will be a guide coat to use for nit picking all the small little imperfections, not necessarily pinholes and scratches, but for very unsubstantial waves or low spots.
remember you are just filling you are not worried yet about small scratches, pinholes or nicks, those will be eliminated with your skim coat of polyester fill later.
Once the paint is dried out, take your block again, with 80 grit paper and sand out the whole area very lightly, and you will see the guide coat disappear. and low spots will stay painted. now you can "see" roughly what still needs to be filled. So fill again and get the whole surface smooth, keep repeating as needed. if you don't feel confident, then dig it all out and start over again. You can redo it as many times as it takes to get it right, and if you don't get it right, then you will have to live with it for the lifetime of the paint job.
WIPE AND BLOW! I can't say it enough. it is very important.
9. Now that you have a relatively smooth flat fill spots on your car. mix up some USC or Evercoat "Icing" or "thin ice" polyester skim coat. Mix it in the same manner as you did the filler, but mix a 2 inch or 3 inch puddle. skim coating doesn't take a lot of filler to do it. So mix up a spot and with a good crisp edge on your spreader, get a roll of icing on the edge of the spreader, and holding it tight to the car drag it across in smooth long strokes. hold it at a tight angle but don't put too much icing on at one time. You should have less than 1/16" inch at the thickest of this stuff. just try not to work it too much and get it to lay as flat as the surface of the car. when you are done the filled spot should be as smooth and flat as the car. once it is filled, stare down the side of the area. look at the gloss and you will be able to see if it is filled enough. Any waves or ripples that look too deep to sand out should get a second coating.
Block sand this in the same manner as you did the filler, but use only 80 grit paper. no pressure, keep the block flat, move around-don't stay in the same spot. make a circle pattern with the block. Like keep the block in the same position but sand in a circle (don't twist the block) then every 3 strokes give the block an 1/8 turn. then back to the original position. Just be sure that you are looking at your fill spot from 360 degrees and not just across one way. like feel up and down, and side to side, and at diagonals.
feather edge the spot. Don't worry about scratches, just don't press hard. it's the strokes that sand, not the pressure. pressure is destructive. Now you are ready for a DA sander.
10. Get your DA sander out and with 180 or 220. I prefer 220... lightly LIGHTLY sand out the scratches int eh putty. 5 or 6 strokes. that's all. You shouldn't have more than 20 mins invested in DA sanding an entire car. Also at this time, DA sand out any small chips or knicks that you might have in any of the remaining paint. just keep the sander moving, don't use pressure, but KEEP IT FLAT. and once again feather out chips and scratches that are in the paint.
Change your paper very often. very often. that is why it comes in rolls of 100 sheets. keep a good hard biting sheet on the sander at all times.
11. Now get a red scotch-brite pad and scuff up the entire car, over all of the body work too. This will be your final scuffing for primer. Make sure you get everything be thorough and don't skip anything. Get into every crack and get the black electricote primer dulled down. You shouldn't see any thing shiney at all except metal.
12. Now you should be ready for primer. prepsol everything of course. some people use a spray bottle and a rag for prepsol some people like to use 2 rags. I use 2 rags just incase there is some grease or wax that might be hard to remove, usign 2 rags should make it easier to remove it.
Mask as needed and spray.
here is a tricky situation.
There are many different types of primer and ways to do it. Some people like to put an etching primer down and then put a building primer over top of that. I like to use a single stage product. because it's cheaper, adn it works just the same now that they did away with the good self etching primers such as DP-90. now it's DP-90LF and that's crap. THe stuff I use is called PPG NCP-270 or NCP-271 depending on color. It is a 2 part epoxy primer that is high build enough to take care of small things, but remember that you want to do all your bodywork with filler not primer. high build primers should not be used in excess amounts, so as to prevent cracking and peeling and chipping.
Apply as directed by the manufacture. There are technical data sheets available for all paints adn primers, so if you follow their data sheet info, then you shouldn't have any problems.
After primering, let it dry and then before unmasking, get a can of guide coat or SEM trim black and give the whole car a nice even guide coat for wetsanding later.
I'll leave off here, this is plenty to digest or give you a good start...
For a good solid reference, there is an outdated publication that still holds true with metal shaping, but mind you everything else in the book is pretty dated. That book is Chilton's Body work manual.
Now as far as what kind of surface is best to use filler over, be it etching primer, build primer, or bare metal...
The best answer to that question is to put the filler over bare metal, because, the best most adhesive properties of the filler will be limited to the adhesion of the primers. therefore, filling over bare metal is best, but you can fill over primers, but remember that cutting the primer is crucial. 80 grit at the FINEST. the best is 24 or 35 grit paper, and the best means to do that is by hand sanding or using a high speed circular sander such as an abrasive grinding disk on a die grinder or a high speed circular sander. the key is low speed though. You don't want to go fast or high speed. give it some pressure, and grind slow. This will keep from heating up the metal and will give you more grip. You can experiment and try it at a couple different speeds and pressures, and then feel the difference with your fingers. You can actually feel the deep cuts.
That is what is needed for good adhesion, and adhesion, rust and water are the 3 main failure points of filler. IF you eliminate all 3, then your filler should last 30-40 years.
Now...
I have been thinking about how I want to do this without confusing you, and trying really hard not to assume you know nothing at all...
So, here goes...
I thought the first thing I would do is give you a list of simple important supplies that you might not have handy, but shoudl have.
all of these items can be bought at advance auto parts, and a good autobody store.
1. red rags and white terry towels. (come in packages of 40 rags and 12 towels) should cost about $15 for one of each
2. Dawn dishwashing soap liquid
3. Red and gray 3M scotch-brite scuff pads
4. sandpaper in follow grits
35 grit long board
80 grit long board
180-220 grit DA disks
400 grit full sheets
600 grit full sheets
1000 grit half sheets
1500 grit half sheets
2000 grit half sheets
5. Sanding blocks in 6 inch and 9 inch length, should be hard rigid rubber, not flexible at all, and a 14 inch long board or air board
6. soft sanding sponges 3M stick-it makes some nice ones
7. different shaped hard foam rubber sanding blocks in as many sizes as you can find
8. single edge razor blades(boxes of 100 are pretty reasonable), and a razor blade scraper
9. masking tape in 1/4", 3/4", 2" sizes. 3M pressure sensative tape is best. 3M green is ultimate, but costly.
10. air tools. the more the merrier...
i. high speed air sander
ii. air blow gun
iii. die grinder with 24 grit 4 inch disks and wire brushes
i
v. air board (nice but not nessesary)
v. primer paint gun. conventional gun is fine, hvlp is not necessary but very helpful.
11. assorted masking paper and (personal recommendation) Norton Blue Sheeting in 16x350 roll. it's cheap, expendable and works well for masking. paint won't flake off of it and it clings nicely to cars.
12. paint stir sticks
13. paint strainers
14. cardboard, and lots of it
15. fillers such as... (should have all of these) EverCoat Z-Grip, Metal-2-Metal, USC Icing (evercoat thin ice)
15A. filler spreaders. in 4" and 6". get a bunch of them... cut some down to 2" and 1 inch.
16. sharpie marker
17. Body hammer and dolly block set
18. Clean up thinner. laquer thinner you can get it in a 5 gallon can and a pump for it.
Steps:
1. The first thing you should always do, most importantly is center the car in your work area, so that you have full access to everything, and every panel on the car at the same time. You should have enough room available around your car so that you can step at least 10 feet back from any given point to observe body lines and areas on the car that you are working on. There are 2 very important tools you must have in any shop to get good results.
i. lots of light, preferably florescent
ii. Your hands
If you don't have either, then don't try doing the bodywork yourself.
Florescent lights are dirt cheap to buy and use, because the bulbs are usually only 15 or 25 watt bulbs, compared to 60 or 75 watt that you normally use. incandescent lighting isn't enough for good work, as florescent will show you everything.
2. Once you have your car in a good position, for work, wash the whole car with Dawn or Ajax or some kitchen liquid dishwashing soap, and then dry it THOROUGHLY. blow it out with air in every seem and crack and make sure it is 100% bone dry. A very important part of bodywork is constantly blowing surfaces clean of dust and dirt and sanding dust. The proper way to do so, is to get a red rag (any rag will do, I just choose the red ones from advance auto because they are guaranteed clean, with no grease on them, when you pull them out of the package) and with a rag in one hand and an air blow gun in the other, wipe and blow. wipe adn blow until yoru compressor is blue in the face, and there is no dust on the car, nothing but metal would be left. It should be noted at this point that having a good air dryer system is key to keeping oil and water off the car from the compressor. Sometimes it helps to wet down the floor a little bit to keep the dust from blowing back up on teh car, but not necessarily. Now you are ready to start bodywork.
3. Start by walking around the car, with a black marker or pencil. I use a piece of 80 grit sandpaper, folded to the size of my thumb... walk around the car, and look at the reflection of the lights on the surface where ever possible. look for dings, nicks or anything that distorts the shape of the fluorescent light bulb on the surface. (this is another reason fluorescent light bulbs are important, because they are almost perfect in shape, and they make a good clean reflection on paint or semigloss primer(like what is found on new sheet metal such as your new door shells and 1/4 panel)
...anything that looks remotely suspect, circle it...
for places that you can't "see" any reflection, then use your most important tool (clean hands) and make passionate love to your car. molest it everywhere. but it's not a girlfriend so move your hands fast. you will feel every thing. try feeling out a ding that you already circled. Feel how it feels in your hand... and then "look" for that feeling all over. Anything that you can feel, you will see in your finish later. ANYTHING...
With this in mind circle everything. if the thing is really dinged up, when you are done, it should look like a big polk-a-dotted beast. It's ok... because you will get these spots fixed eventually. and you don't want to get 1/2 of tem and say "to heck with this, this is hard work" BE thorough dammit. That's why you get paid the big bucks as a bodyman (or at least keep lying to yourself and thinking this in your head )
4. Now you should have a good starting point to go from... and you are ready to start cutting the steel. Before you think of putting any filler in the car, first take your hand and determine how it is dented. Right here I could go off on a 5 page tangent of how to read a dent and how to hammer it flush again, but I will hold off until later, and for now, just to get you started, simply say, try to get the ding or dent as smooth as possible without filler, and make sure there are no high spots. low spots can be filled, but high spots need to be pounded out, unless you feel like sanding a hole in your car to get rid of it.
5. When cutting for filler use at most 80 grit paper. anything less coarse than that won't give it enouch bite to hold filler in place. this is where a lot of people miss and end up giving filler hte bad name that it has. Remember, this is 2003, filler is not what it used to be in the 60's, it's a lot better, when used correctly.
Take your high speed sander, or die grinder with 24 grit disks or just a plain piece of 80 grit or 35 grit paper in your hand, and scuff up the dings that you circled, and then scuff 3" past the circle in all directions, for room to feather.
6. Once you have every ding scuffed, make sure you have memorized approx. what shape and size the dents all were, for reference later. and now you can start to fill your bad spots. Get a 12"x12" square of flat cardboard from a box or something, and lay it down flat on your bench, spoon out a 4 inch dia. puddle of filler relatively flat on to the cardboard center. Then kneed up the hardener tube. I like to use blue hardener for the initial filler and then red hardener for skim coat icing. then, after kneading, draw a straight line across your puddle with the hardener. This will give you an approx 50:1 ratio. keep that in mind, and don't draw a straight fat line, just nice, steady medium line. I like to use a paint stir stick. preferably 1/2 or 1/3 of one to save on stir sticks to mix the filler. The proper way to mix your filler is hold the stick end into the puddle flat on the bottom, and at about a45 degree angle, so you are not stirring on it like a 3 year old in a sauce pot. and keeping the bottom of the stir stick flat agains the cardboard, stir it quickly and steady in circles. Make sure the whole mixture is the exact same color throughout then toss the stir stick and pick up your spreader and fill all areas until they look full when viewed from the side. Filler is glossy and you can use that to your advantage. Fill it full. and remember you can always hog it back down off if you need to, but it takes a bit more effort to have to put a second coat on.
7. Within 5-10 mins you should start cutting down the filler high spots and rough shaping it. You can use a hard block with either 35 or 40 grit, or a body file, on a file holder or in your hand it doesn't matter, they are pretty rigid. use straight edges to guide you. and get everything close to flush, but not quite. then switch over to 80 grit paper and continue to sand it. There are a bunch of tips and tricks I could put in here, but I want to try to stay basic. I will use a few...
for example:
always use a sanding block long enough to reach over top of the entire filler area, so that both edges of the block are touching metal that is straight. This will let the block naturally sand out the filler to the same height as the metal.
Always use a low grit sand paper to start and keep it relatively low, there is no need to attack putty with a 120 or higher grit paper. You want to get as much of the filler out to level without tearing the metal out around it and the best way to do this is to use a low grit and hog it.
You can always sand out the scratches in the filler with a DA later, but it takes a lot more to add filler to correct a low spot or a wave caused by high grit paper.
"feather" that's a key word when sanding. The edges of your filler shoudl be feathered into the surrounding metal. no hard lines. only feather edges. the wider the feather the better.
Feel everything with your hands constantly. you can pick up a low spot or a flaw a lot easier and faster with your hand than with your eye. For 99% of all work your eyes just won't do, you need to use your hands.
And the last tip I will put in here that is pretty important. While you are sanding a filled area, watch for bright shiney bare metal spots to show up. if you see a small area that seams to keep getting hit more than other areas, it might be a high spot or bump. So if you keep getting caught on it, bang it down with a hammer.
Wipe and blow as you sand. The more you wipe and blow, the better. Dust fills holes, and blowing it out of the pinholes will let filler work right.
8. This is the point when you can get out your spray can of paint. and this is one of the only times I will ever recommend anything that comes from a spray can.
remember you are just filling you are not worried yet about small scratches, pinholes or nicks, those will be eliminated with your skim coat of polyester fill later.
Once the paint is dried out, take your block again, with 80 grit paper and sand out the whole area very lightly, and you will see the guide coat disappear. and low spots will stay painted. now you can "see" roughly what still needs to be filled. So fill again and get the whole surface smooth, keep repeating as needed. if you don't feel confident, then dig it all out and start over again. You can redo it as many times as it takes to get it right, and if you don't get it right, then you will have to live with it for the lifetime of the paint job.
WIPE AND BLOW! I can't say it enough. it is very important.
9. Now that you have a relatively smooth flat fill spots on your car. mix up some USC or Evercoat "Icing" or "thin ice" polyester skim coat. Mix it in the same manner as you did the filler, but mix a 2 inch or 3 inch puddle. skim coating doesn't take a lot of filler to do it. So mix up a spot and with a good crisp edge on your spreader, get a roll of icing on the edge of the spreader, and holding it tight to the car drag it across in smooth long strokes. hold it at a tight angle but don't put too much icing on at one time. You should have less than 1/16" inch at the thickest of this stuff. just try not to work it too much and get it to lay as flat as the surface of the car. when you are done the filled spot should be as smooth and flat as the car. once it is filled, stare down the side of the area. look at the gloss and you will be able to see if it is filled enough. Any waves or ripples that look too deep to sand out should get a second coating.
Block sand this in the same manner as you did the filler, but use only 80 grit paper. no pressure, keep the block flat, move around-don't stay in the same spot. make a circle pattern with the block. Like keep the block in the same position but sand in a circle (don't twist the block) then every 3 strokes give the block an 1/8 turn. then back to the original position. Just be sure that you are looking at your fill spot from 360 degrees and not just across one way. like feel up and down, and side to side, and at diagonals.
feather edge the spot. Don't worry about scratches, just don't press hard. it's the strokes that sand, not the pressure. pressure is destructive. Now you are ready for a DA sander.
10. Get your DA sander out and with 180 or 220. I prefer 220... lightly LIGHTLY sand out the scratches int eh putty. 5 or 6 strokes. that's all. You shouldn't have more than 20 mins invested in DA sanding an entire car. Also at this time, DA sand out any small chips or knicks that you might have in any of the remaining paint. just keep the sander moving, don't use pressure, but KEEP IT FLAT. and once again feather out chips and scratches that are in the paint.
Change your paper very often. very often. that is why it comes in rolls of 100 sheets. keep a good hard biting sheet on the sander at all times.
11. Now get a red scotch-brite pad and scuff up the entire car, over all of the body work too. This will be your final scuffing for primer. Make sure you get everything be thorough and don't skip anything. Get into every crack and get the black electricote primer dulled down. You shouldn't see any thing shiney at all except metal.
12. Now you should be ready for primer. prepsol everything of course. some people use a spray bottle and a rag for prepsol some people like to use 2 rags. I use 2 rags just incase there is some grease or wax that might be hard to remove, usign 2 rags should make it easier to remove it.
Mask as needed and spray.
here is a tricky situation.
There are many different types of primer and ways to do it. Some people like to put an etching primer down and then put a building primer over top of that. I like to use a single stage product. because it's cheaper, adn it works just the same now that they did away with the good self etching primers such as DP-90. now it's DP-90LF and that's crap. THe stuff I use is called PPG NCP-270 or NCP-271 depending on color. It is a 2 part epoxy primer that is high build enough to take care of small things, but remember that you want to do all your bodywork with filler not primer. high build primers should not be used in excess amounts, so as to prevent cracking and peeling and chipping.
Apply as directed by the manufacture. There are technical data sheets available for all paints adn primers, so if you follow their data sheet info, then you shouldn't have any problems.
After primering, let it dry and then before unmasking, get a can of guide coat or SEM trim black and give the whole car a nice even guide coat for wetsanding later.
I'll leave off here, this is plenty to digest or give you a good start...
Time will tell. So much info online, so many "experts", this is giving me a headache!
I am extremely happy that I did not have you do any work for me.
