Understanding body work

40fordpu

40fordpu

Well-known member
Hello barners....

The next step of my project is "body work". There are issues with the body. The paint is old, there is surface rust, there is cancer rust in the floor boards, there are dents. With that said, I understand that certain things need to be done is a certain order. Here is the order I believe and have heard is "correct".

1. Sand down/media blast the entire body.
2. Prime (with cheap spray) the body to prevent surface rust.
3. Work the body with hammer/dolly set
4. Repair cancer in floor boards
5. "body fill" needed areas (body fill as in....)
6. Sand down areas and "smooth/straight" for paint
7. Paint by others.

Any advice? Is this correct? Close? I am on a budget and need to get this right before paint and "final" body. Thanks for your help.
 
Do NOT use cheap primer as second step - use two coats of good epoxy primer like PPG DP-90 or equivalent, then any filler on top of epoxy. Be sure to read all pertinent safety info on these hazardous materials and adhere to them or send the work to someplace that is equipped to do so. Your life is worth more than an old car...Bob L
 
Don't use cheap body filler, buy the good stuff. Rage Extreme is the best. Self leveling and easy to sand,feathers real nice. Ken
 
I would recommend using an etch primer in step 2....napa auto parts sells a good primer....which is your first coat after removing all paint....it's called finish 1 made by ACME....have some fun!
 
Do not use cheap anything. This is not the time to try to save a few pennies. Also, get an assortment of sanding blocks including a long one. You will never regret going the extra mile for bodywork. If you do not...I guarantee you will regret it for as long as you own your ride.
Find a good body person close to home and get some advice. Hopefully they will demonstrate some of it for you.
Surely someone on this forum would be willing to stop by for a couple of hours to get you started. Body work is called that for a reason. It is hard work. It's also extremely frustrating if done incorrectly.
Good Luck!
Everyone strarts somewhere.
 
I am not sure whether you should sand blast early ?? It depends on how bad it is I would tend to repair as much as possible eg patch panels then when you are close to filling sand blast ,fill ,Then epoxy ,But if you have heavy rust in floors etc then you may need to do that first,The main thing is to put the epoxy on freshly cleaned metal .Degrease , possible, phosphorus ,then etch ,then prime ,
 
FlatheadTed said:
I am not sure whether you should sand blast early ?? It depends on how bad it is I would tend to repair as much as possible eg patch panels then when you are close to filling sand blast ,fill ,Then epoxy ,But if you have heavy rust in floors etc then you may need to do that first,The main thing is to put the epoxy on freshly cleaned metal .Degrease , possible, phosphorus ,then etch ,then prime ,
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Good advise right there!
 
we usually sand blast first...then use good epoxy i would use ppg or if you have heavy pitting use Z-chrome Rust Defender its self etching high build primer with rust inhibitor(build almost 11mils percoat 86%solids almost sprayable body filler) ...then do your rust repair....sand blasting can sometimes find other areas that need done old paint can hide a lot of filler or bad repairs....once you have all rust repair done then handle the hammer and dolly work...make sure u get everthingas close to perfect as possible less filler you have to use...after that its body filler time...block your primer first with a guide coat allows to see your highs and lows...use a good quality filler....rage extreme is good....the best on the market is evercoat quantum 1...its a polyester and epoxy compound...unlike regular fillers it sands every easy...youhave to let it kick completely first then start sanding with 80-grit(this is quantum only) 80 grit with quantum sands like 40 grit with regular filler...its nice because you can let areas for a week and itll always sand the same also the beauty of quantum is its 95% pin hole free and you can use it as glazing putty as well...after initial filler work fill prime and again block it out do any glazing you need to block and fill prime one last time...by nowyou shouldbe ready for paint
 
Blasting before repair shows all the thin metal that needs to be replaced which can be easily missed by patching the obvious stuff. I've found some etching primers bleed through and are susceptible to surface rust and are not always compatible with some brands of fillers. I prefer using epoxy primers as they seal the metal from the atmosphere preventing that surface rust from appearing.
 
I definitely would not spray cheap primer on it. You do not want to paint over it and its going to be a lot of work to take it off.
If your going to keep playing with old cars you can take a auto body class at a local college. I did it thirty years ago and it has saved me thousands of dollars over the years

As a beginner I would leave the old paint on to help you locate all the dents. I would do the roughing out of the metal with the paint on the panel. Bump up the low spots with a dolly or body hammer. Gently move the metal so you are not stretching it, think about every strike of the hammer and dolly. I really suggest you get an old fender and beat some dents into it and practice with a hammer and dolly on it first so you learn how hard to hit the metal so it moves but not so hard that it stretches, if you stretch it then you get to learn all about metal shrinking. Check your work with the palm of your hand by running it over the panel, when you get it really close you can check it for low spots with a body file. Being a beginner, when you get everything leveled out to where a skim coat of filler (by skim coat I mean 1/16 of an inch or less) will finish it I would stop screwing with it before you stretch the metal or make the metal too thin. Then weld all you patch panels in the floor. Now I would take it to the media blaster, bring it immediately home and wipe it down with wax and grease removal and spray it with a good etching primer or epoxy primer (It will start rusting over night if you don’t) If your on a budget you can skip the etching primer. The epoxy primer will get plenty of bite on that freshly media blasted metal.

I like to initially wet sand the first coat of primer with 400 grit paper and then wipe it down with wax and grease removal and step back while its still wet and look for waves in the metal. I circle them with a marker and then make a decision if they will need a skim coat of filler or if another coat of primer will make the waves go away. If you can feel the low spot with the palm of you hand then its going to take filler to make it go away. If the low spot needs filler then I grind all the primer off down to the bare metal, I grind it back about 1 ½ times bigger than I think the low spot is, its always bigger than I think. Apply your filler and sand it with 36 grit speed file paper until you just start to see the shadow of the metal coming through around the edges of the low spot and stop. At this point your about two strokes away from creating a low spot. Lightly hit it with some 80 grit paper. If you can see a hard line between the filler and the metal you have sanded too far and now have a low spot that will take another coat of filler.If it looks good prime it immediately so the bare metal around the repair does not rust.

If you can find it, there was super good thread on the H.A.M.B. site on block sanding, it has a lot of good tips. There is so much more to this stuff but you got to start somewhere. The most important thing is to be patient, there are no short cuts. Your probably going to have a few setbacks. I’ll give you an example of just one of my many disasters. About thirty years ago when I first started painting I was working on a ’66 Mini Cooper S. The cup fell off the gun, I tried to save my quart of lacquer but as I reached for the cup it hit the ground and the paint shot straight up. (see photo)
 

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Z-chrome rust defender is self etching and has a rust inhibitor it never bleeds through espicially once several layers of primer and ssealer are on it

Dave72dt said:
Blasting before repair shows all the thin metal that needs to be replaced which can be easily missed by patching the obvious stuff. I've found some etching primers bleed through and are susceptible to surface rust and are not always compatible with some brands of fillers. I prefer using epoxy primers as they seal the metal from the atmosphere preventing that surface rust from appearing.
Click to expand...
 
kwmpa said:
Z-chrome rust defender is self etching and has a rust inhibitor it never bleeds through espicially once several layers of primer and ssealer are on it
Click to expand...




That's what the sealer does, prevents atmospheric moisture from bleeding through the etching primer and not all etching primers have rust inhibitors. Todays epoxy primers adhere well to bare metal and seal and it's one less type a material to keep on hand.
 
yeah i know not all self etch does that i was specifically talking about the Z-chrome brand Rust defender...its a hig build high solids designed for sealing bear steel and filling pitting...im well aware of all the steps im in the restoration business i work for a shop and have my own shop...also a buddy is in the development department at ppg...im up on all the new happenings

Dave72dt said:
That's what the sealer does, prevents atmospheric moisture from bleeding through the etching primer and not all etching primers have rust inhibitors. Todays epoxy primers adhere well to bare metal and seal and it's one less type a material to keep on hand.
Click to expand...
 
Some good advice here I do agree with most of what's said , I am two minds about the etch primer its is just that ,a etch !,Its most likly not needed ,The sand blasting does the same thing (pits the surface ),then a good coat of epoxy ,The decision on blasting first is yours but you don't want to get into the situation were the raw steel is exposed to the atmosphere .and rusts .
 
agreed 99% of the time etch primer is not needed....the only time we use the z-chrome rust defender is when the surface is badly pitted....rust defender is basically sprayable body filler... it saves time and money....

FlatheadTed said:
Some good advice here I do agree with most of what's said , I am two minds about the etch primer its is just that ,a etch !,Its most likly not needed ,The sand blasting does the same thing (pits the surface ),then a good coat of epoxy ,The decision on blasting first is yours but you don't want to get into the situation were the raw steel is exposed to the atmosphere .and rusts .
Click to expand...
 
It sounds like that you are not experienced in body work and if so, do not start pounding with a hammer on the body. Get some experience somewhere. See if a friend at a body shop will let you see how things are done with metal or go to a class somewhere. Just starting out with no knowledge will not give good results.
 
Like has been said, DO NOT use the cheap primer. But it is also important to start with the paint system of your choice and use all products of the same brand and type, enamel, lacquer, etc. Of course lacquer products almost gone now. I personally prefer to use a paint remover such as Tal Strip to remove the paint and only sand blast the rusty areas. Sand blasting work hardens metal. But with paint remover it is very important to get it very clean and out of all the seams. Plastic media blasting will remove all the paint W/O the work harding but will not remove rust. I use all DuPont paint products and have been doing so in my collision repair shop for over 40 years. DuPont products are very good and work very well. I also use Vari Prime self etching primmer as a first coat.
 
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