• Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Is there a bodywork for dummies post?

johnpsz

Member
I'm new to the forums, and just about to get started disassembling and stripping multiple (crappy) paint jobs. So once I get to bare metal, and still evaluating if things need repair and ordering parts, what do I do to prevent rust? Is this the time for a self etch primer, or something else?

Sent from my SAMSUNG-SM-G930A using Tapatalk
 
Last edited:
Ospho (found at Home Depot) can be used for a short time to prevent rust, but typically, you want to paint the panel with an epoxy primer which both seals and primes the panel. Most use a DPxxLF where xx is a choice of colors (DuPont primer). You can topcoat after the primer within 24-48 hours, or let the primer sit for however long you want. In the latter case, you can do your body work, filler, etc., on top of it. When ready to paint, re-apply the primer after scuffing the surface then apply topcoat. Going back to ospho, IIRC, you hand wash the panel with water, then apply a good wax/grease remover. Then scuff the panel and shoot primer.

I should say you need to weld any metals before primer, or at least remove the primer around the welding area before welding.
 
Ospho (found at Home Depot) can be used for a short time to prevent rust, but typically, you want to paint the panel with an epoxy primer which both seals and primes the panel. Most use a DPxxLF where xx is a choice of colors (DuPont primer). You can topcoat after the primer within 24-48 hours, or let the primer sit for however long you want. In the latter case, you can do your body work, filler, etc., on top of it. When ready to paint, re-apply the primer after scuffing the surface then apply topcoat. Going back to ospho, IIRC, you hand wash the panel with water, then apply a good wax/grease remover. Then scuff the panel and shoot primer.

I should say you need to weld any metals before primer, or at least remove the primer around the welding area before welding.

Thanks, I’m not sure I want to try and wash with water in the garage, thanks for the info though.


Sent from my iPhone using Tapatalk
 
I have used an Eastwood 2K Epoxy Primer that is available in an aerosol can. Its expensive, but looks great and seems to hold up really well.
 
Mid is right on with the 2K primer. That's by far your best course of action. The DP is the most commonly used but there are other products by other manufacturers that could be just as good.
I would stick to mixing it yourself and spraying with a gun. I've used the 2K can stuff myself on small parts and such with mixed results that were not based on my part prep, etc. Not knocking the Eastwood (or others) rattle can product but my experience with it would prevent me from using it on a body panel that would eventually be top coated as a final paint application. Save that stuff for the small bits, etc and you can't go wrong.
 
Well, I am going to start hitting panels with the grinder this week to bare the metal and see how bad some panels really are. I don't have a paint sprayer, or super dry air (it's dry enough for my plasma cutter) for spraying paint/primer yet. Therefore, from the posts above, are my only choices Ospho or something similar or 2K spray bombs? Would it be a waste of money to spray the 2K on the bare metals of panels that may be replaced or patched? If any of you have seen the vids or pics of my car, you may know that I will probably need to replace the quarters. I am planning to bare the metal there just to investigate how bad things are, would generic spray bomb primer from the auto parts store be sufficient for this stage of the game, or is that just a bad idea?

Like I said in my other posts, I am a decent mechanic and fab guy, I just have never done auto body work, thanks for any help.
 
Spray bomb primer may protect the metal for a few months at best. Regardless, you'll need to strip it off fully because it will not adhere as the first coat against the metal when you get to the real painting stage. Ospho is really easy: use a spray bottle and wipe with a clean rag to ensure every part of the metal gets exposed to it; no need to wipe it off. It dries fairly quickly. Don't be alarmed if you see a whitish powder when dry.
 
Spray bomb primer may protect the metal for a few months at best. Regardless, you'll need to strip it off fully because it will not adhere as the first coat against the metal when you get to the real painting stage. Ospho is really easy: use a spray bottle and wipe with a clean rag to ensure every part of the metal gets exposed to it; no need to wipe it off. It dries fairly quickly. Don't be alarmed if you see a whitish powder when dry.
OK that sounds like the best bet at this stage of the game. I have also recently (since your suggestion the other day) been youtubing Ospho. It should be pretty easy to clean up and get off the panels before real finish paint time...
 
If you have the financial means I second the thought of having the whole thing media blasted. Cost has come down and it is really the easiest/best way to get to the bottom on things. You will have a hell of a time cleaning some areas anywhere near as well. Not to mention the mess is in someone else's place! I had mine done to start my project and was clearly the best choice I made looking back.

Depending on the environment I would leave plain bare metal as opposed to rattle can. Like Mid wrote, if you did use it you need to remove it completely before the real bodywork/paint process starts. I have no experience with the stuff (Ospho) he suggests so can't comment on it.
 
If you have the financial means I second the thought of having the whole thing media blasted. Cost has come down and it is really the easiest/best way to get to the bottom on things. You will have a hell of a time cleaning some areas anywhere near as well. Not to mention the mess is in someone else's place! I had mine done to start my project and was clearly the best choice I made looking back.

Depending on the environment I would leave plain bare metal as opposed to rattle can. Like Mid wrote, if you did use it you need to remove it completely before the real bodywork/paint process starts. I have no experience with the stuff (Ospho) he suggests so can't comment on it.
Thanks for the advice, I have gotten quotes for blasting, and they are not out of the question. However, my curiosity of how bad these quarter panels are I was thinking of breaking out my grinders with some stripping pads and hit the quarters. As for weather/environment, we are in wet country, the pacific northwest, and even the media blasters that I have talked to warn that panels will start to rust (flash/surface rust) before I get the car back home, and they are only a 10 minute drive away.
 
I'm the type who refuses to hire out any work on not just my car but anything, period. Why pass up the chance to buy a new tool, right? Anyway, I broke that steadfast rule only once and that was to get my car completely blasted to plain metal upon dragging it home. I thought about doing it myself but the equipment cost and the mess just didn't make sense. By far the best thing I ever did. The guy I used sprayed the whole thing in 2K after he cleaned it. Wasn't cheap. Seem to recall it cost in the neighborhood of $2500 all done. But I had a clean and protected canvas with which to start. I recommend doing the same to everyone. The time spent trying to strip a car by hand and the material expense involved start to add up fast. And honestly, there are some areas you will be hard pressed to even be able to get in and clean well (think inside door shells, for example).
Anyway, that's my typical long winded thoughts on the subject.
 
Wow, I wish the places around here that would prime following blasting, and guys if you know of a good company about 20 miles south of Portland Oregon, pass it on. Most of the places that I have found are mobile blasters that also have a shop, and all they do is blasting. I have been quoted $800 for the exterior, $200 for the interior, and if I had the car on a rotisserie already it would be about $500 to blast the underside. Since most of the business models (that I have found locally) are mobile blaster they also have mess cleanup and charges on top of that unless I trailer it to their shop. However, like I said if I found a place that stripped and primed, I'd definitely call for a quote.
 
You mentioned 2K primer... be careful how you use that term. Epoxy is a 2K primer that generally can be sprayed direct to metal but not all 2K primers are intended to be sprayed on large metal areas. 2K urethanes for instance are usually intended to be sprayed over epoxy or filler. To strip paint to bare metal, avoid using a grinder. I was considering one of those eastwood rotary drum strippers 'til I figured out I'd need about $200 worth of sanding drums along with the $200 tool. I ended up buying some 7" diameter sanding disks from home depot and mounted them on a harbor freight 7" sander polisher ($29-$39). I used 60 grit to rip the multiple layers of paint off, then as I got close to the last primer layer, switch to either 80 or 100 grit. Those 7" sanding disks are usually in the Tool Rental department right next to the Floor Sanding equipment. Panel stripping is pretty quick with this method. Fastest I've tried yet. To protect the metal from flash rusting, I too use "Prep & Etch" from home depot. Even if the metal turns white or even rusty colored, it scrubs right off with another treatment of prep & etch and a scotchbrite pad. If the underside of the car is sound and your only looking for family driver quality, don't bother with media blasting. My suggestion would be to purchase some Epoxy primer, the 7 grinder and disks, strip a panel down, and immediately spray a coat of epoxy. Once the epoxy is on, you can wait til you are ready to continue bodywork. Spraying small batches of epoxy shouldn't generate too much moisture, but still be sure to install a water trap on your air line.
 
I ended up buying some 7" diameter sanding disks from home depot and mounted them on a harbor freight 7" sander polisher ($29-$39). I used 60 grit to rip the multiple layers of paint off, then as I got close to the last primer layer, switch to either 80 or 100 grit. Those 7" sanding disks are usually in the Tool Rental department right next to the Floor Sanding equipment. Panel stripping is pretty quick with this method. Fastest I've tried yet. To protect the metal from flash rusting, I too use "Prep & Etch" from home depot. Even if the metal turns white or even rusty colored, it scrubs right off with another treatment of prep & etch and a scotchbrite pad. If the underside of the car is sound and your only looking for family driver quality, don't bother with media blasting. My suggestion would be to purchase some Epoxy primer, the 7 grinder and disks, strip a panel down, and immediately spray a coat of epoxy. Once the epoxy is on, you can wait til you are ready to continue bodywork. Spraying small batches of epoxy shouldn't generate too much moisture, but still be sure to install a water trap on your air line.

Oddly enough that was what I was planning to use, one of those 7" sander/polisher with 60 grit for the top coats as well as 80 grit to get it to bare metal. Actually in the time since you had posted this, we have already done some of that, my son went to bare metal in a few places with the 60 grit though. I am heading to Home Depot later today for the "Phosphoric Prep and Etch" solution, as nobody carried the Opsho stuff and this was the closest I could find.

Here is the start of the sanding work from over the weekend.
 
Oddly enough that was what I was planning to use, one of those 7" sander/polisher with 60 grit for the top coats as well as 80 grit to get it to bare metal. Actually in the time since you had posted this, we have already done some of that, my son went to bare metal in a few places with the 60 grit though. I am heading to Home Depot later today for the "Phosphoric Prep and Etch" solution, as nobody carried the Opsho stuff and this was the closest I could find.

Here is the start of the sanding work from over the weekend.

Good for you getting the boy involved! My son helped with every process on our car, albeit the power tools scared him a bit.
 
Ok, so after taking the rear window out and cleaning up a little. I finally got a chance to see the lower corners that were leaking. It looks like those sail panels are not reproduced, so I may have to fab a few patch panels.

e5eff378e24cb475abc28ce9e309dd23.jpg
a0daa217b0deb71953f45a4d19f3686c.jpg
1c88899bc6b0c91395a42aba251268d5.jpg
0c34223d7be48526cb563b292a0da694.jpg
4f61bcd7f185428241edcff80471ed4b.jpg
9f8530ed7c43b5a4d9235e853bbccfe9.jpg
cb10372e9e433c7f347714556e5a1bf7.jpg
dd832940d64ee6ebb9bf86910c49259d.jpg
a92c405777b6ef0e198c7ac65d28df15.jpg


Sent from my SAMSUNG-SM-G930A using Tapatalk
 
bummer... but it is a place covered by trim so it doesn't have to be pretty, just solid. It could be fun making sure you get it all out so it won't come back but you seam like you are not afraid to tackle it.
 
It could be fun making sure you get it all out so it won't come back
This. This is why I harp on about media blasting. Hell, when things get to this point dipping in chemical is the absolute best way to go. You can't get down and into some of the crevices, etc. any other way. People think they do but a few short years down the road guess what rears its ugly head again.
 
Back
Top