Final Rust Removal Methods

[Texas82GP]

I'm no pro but I can't see doing damage to the car with a DA sander and 80 grit paper. I may well be wrong but if it were my car, I would DA sand it with 80 grit, wipe it down with Prep Sol or equivalent and then epoxy prime it. I would consider doing one or two panels at a time so the freshly sanded metal isn't exposed to the elements for very long. Use common sense with the sander. Keep moving and don't dig in. I've gotten pretty aggressive with a DA sander and 80 grit paper before and didn't do any damage that I could perceive. Again, I'm no pro. This is just how I was taught and based on my own experience.

 

[Opie Knievel]

So the 2 body guys who do this for a living said blasting is the best method for this particular situation.

What's the simplest, most cost effective way to get this car blasted?

I have to agree with the guys who've said that taking shortcuts will be a bad idea and will cause more problems later.

 

[fleming442]

Clutch, honestly, I wasn't even considering the paint warranty. It was addressed from a frugality standpoint. Maybe, POR15 could be done as a temporary measure (thinned and sprayed, not globbed on) after sanding to at least get the surfaces sealed to prevent further damage. Then get some urethane sealer/primer on, and let it thoroughly cure. Could you explain why it voids paint warranties? I'm new to this paint stuff (slowly learning).
I didn't realize it was a low mileage car worth saving. Whoever stripped it,and left it unsealed should have their pee-pee smacked! It really needs to be completely blown apart and blasted (sand, soda, or whatever).
I was also speaking from novice experience. I had some rust similar to that on the rear quarters of Operation Pig Lipstick. I sanded it all down, cleaned it, and tried to use a Permatex rust converter. I got some spray bomb touch up, filled, primed, and painted it. Guess what happened... 2 years later, there are gaping holes because it kept rusting, and I am putting patch panels in. Granted, it's no show car, and I just want it to look a little better until the MD salt kills the frame. 🙁

 

[H/O84]

I'm no pro but I can't see doing damage to the car with a DA sander and 80 grit paper. I may well be wrong but if it were my car, I would DA sand it with 80 grit, wipe it down with Prep Sol or equivalent and then epoxy prime it. I would consider doing one or two panels at a time so the freshly sanded metal isn't exposed to the elements for very long. Use common sense with the sander. Keep moving and don't dig in. I've gotten pretty aggressive with a DA sander and 80 grit paper before and didn't do any damage that I could perceive. Again, I'm no pro. This is just how I was taught and based on my own experience.

that is my plan I just haven't been able to find a good product to use after sanding. The picture where I sanded a small spot that was a few seconds of sanding with some 180 grit The deep pits are fairly minimal. What others have told me is one I get the panel looking like that I use a rust neutralizer that does make the rust disappear but changes it to a black substance that won't pop back through. Doesn't sound like snake oil sounds like science, I believe the products use phosphoric acid to turn the rust into iron oxide. Blasting is 2k and I'm trying to be a cheapskate on this cause that's what I planned to spend to be done with priming the car. The only rust issues are the surface rust

 

[Texas82GP]

that is my plan I just haven't been able to find a good product to use after sanding. The picture where I sanded a small spot that was a few seconds of sanding with some 180 grit The deep pits are fairly minimal. What others have told me is one I get the panel looking like that I use a rust neutralizer that does make the rust disappear but changes it to a black substance that won't pop back through. Doesn't sound like snake oil sounds like science, I believe the products use phosphoric acid to turn the rust into iron oxide. Blasting is 2k and I'm trying to be a cheapskate on this cause that's what I planned to spend to be done with priming the car. The only rust issues are the surface rust

The product you are talking about is OSPHO or similar. It is Phosphoric acid. It converts the Iron Oxide (rust) into Iron Phosphate. It is said to be an ideal substrate to lay primer over. We used it on my brother's Camaro. I can't say that we used it on any of the exterior skin of the car. What little surface rust there was on the car got DA sanded and primed. This may sound dumb, or ignorant, or both, but I don't see how the rust can continue to react (oxidize) with the absence of moisture (H2O). Once you epoxy prime, any tiny rust pits, as long as they don't go through are sealed away from the elements. My understanding is Epoxy is impervious to water. I'm happy to be corrected if I'm wrong. I know that we used OSPHO on my brother's car on places like the core support, the battery tray, suspension pieces, etc. Our normal process was to treat that after sanding or wire wheeling, we treated the surface with OSPHO and let it react. Later we wiped down a few times, changing the microfiber cloth, with Prep Sol or equivalent, then epoxy primed. Some of it got rattle can primed and painted. We haven't had any adverse reactions to date. Some of that stuff has been painted for eight or nine years now so I look at it as a viable refinishing process. I don't see anything wrong with using it on the skin of your car, I just don't want to see you have a negative experience with your epoxy primer reacting to the phosphoric acid. I suggest you do your homework and maybe even do a test piece. Find something else rusty and treat it the same way and see how it goes before you try it on the car. Again, if it were me, I would sand it and epoxy prime it. Perhaps I'm wrong. It's just the way I was taught and the way I've done it before with no issues.

 

[Texas82GP]

As far as what epoxy to use, look at the Shop Line Epoxy. It is PPG's value line. I have used it. It is a good product. I doubt there is much difference between it and PPG, save the label. Since you are going to paint the car silver, go with the grey primer (JP371). Here is a link to the tech sheet.....
http://archpdfs.lps.org/Chemicals/Epoxy_primer_Shop-Line.pdf

 

[Clutch]

Clutch, honestly, I wasn't even considering the paint warranty. It was addressed from a frugality standpoint. Maybe, POR15 could be done as a temporary measure (thinned and sprayed, not globbed on) after sanding to at least get the surfaces sealed to prevent further damage. Then get some urethane sealer/primer on, and let it thoroughly cure. Could you explain why it voids paint warranties? I'm new to this paint stuff (slowly learning).
I didn't realize it was a low mileage car worth saving. Whoever stripped it,and left it unsealed should have their pee-pee smacked! It really needs to be completely blown apart and blasted (sand, soda, or whatever).
I was also speaking from novice experience. I had some rust similar to that on the rear quarters of Operation Pig Lipstick. I sanded it all down, cleaned it, and tried to use a Permatex rust converter. I got some spray bomb touch up, filled, primed, and painted it. Guess what happened... 2 years later, there are gaping holes because it kept rusting, and I am putting patch panels in. Granted, it's no show car, and I just want it to look a little better until the MD salt kills the frame. 🙁

I'll explain later after work unless someone else does first

 

[fleming442]

As far as what epoxy to use, look at the Shop Line Epoxy. It is PPG's value line. I have used it. It is a good product. I doubt there is much difference between it and PPG, save the label. Since you are going to paint the car silver, go with the grey primer (JP371). Here is a link to the tech sheet.....
http://archpdfs.lps.org/Chemicals/Epoxy_primer_Shop-Line.pdf

I'm currently using that product for my project. I am less than knowledgeable on paint, BUT my experience was echoed across some threads I've found: that crap takes FOREVER to dry! My mix ratios could by off as I'm using mixing cups from the shop I bought the paint from. I've got $800 tied up in paint, and MAACO would have done the job with Sherwin Williams for $600. Guess where I'm going next time....

 

[Clutch]

Ok so you want rime and reason. This thread touches on a extremely large area of the automotive industry so this could get long winded and I may make mistakes as I'm exhausted from doing body work all day with the whip crackers up my rear to work faster! So I'll try to keep to the car in question
If you look at the picture of I believe the top of the fender were it looks to have been sanded with 36 or 40 grit to show the cleaned off rust you can just barely see the tiny black spots in the clean area that is rust as ribbedroof was kinda saying only blasting will remove it properly if you are looking to just clean it up on prime it the seed will be planted so to speak so no matter what you treat it with it will come back the only true cure for rust is to remove it. All the treatments (snake oil) lol just slow it down so even if you sand it down nicely and prime it you will still need to blast it later so the product you put on will have to come off later so what ribbedroof is saying is just do it one time yes it is extremely expensive but body work is so do you want to do it more than once? I think not if you want to know the right thing to do call MLJ in Texas they make dustless blasting equipment they will tell you where the nearest blaster is tell that blaster you want the car done with (hold tight 102) it is an inhibitor good for24 hours on bare metal and ALL the paint manufacturers accept it as a bace what I'm talking about is a slurry blaster it will not warp panels because it dose not make friction heat in fact it cools the mettle also tell them not to use the corse glass if you are worried about it being rough
When the blaster is finished he will rince the car with hold tight and water blow it dry and it is ready for epoxy
Choosing product really is up to the painter so choose a painter and ask what paint he or she uses if it's PPG use PPG if it's basf use basf the days of cocktailing box mixing and guessing are over unless your a used car dealer that doesn't care what happens down the road
Someone asked why not use different companies products well every company formulates differently some product lines rely on a mechanical bond others rely on a chemical bond what do you think can happen?
I'm sorry if ribbedroof and I may seem to be a little harsh this bisness dose that to us and for is it's all cut and dry we do what we do because well that's the correct way body men are a special kind of *ss hole and there's good reason for it not a lot of people really understand it so I guess we don't tell you why we just tell you how I'll work on that I'm a work in progress lol
So I guess we were trying to say just sanding and priming is really a half measure and the money and time spent is a wast in the long run because it will come back so that said
1. Call MLJ to find someone with the equipment
2. Be a car dealer and work him on the price trust me he needs the money
3. Call your painter for his product line
4. Buy the epoxy and have it on hand for when the blaster is finished
5. Don't touch the bare the oil and acid from your hands will contaminate the steel and cause rust we're rubber gloves
6. Epoxy primer it don't worry about body work the beautiful thing doing it this way is you can do your body work on top of the etch primer good fillers bond mechanically and chemically so when your ready to do plastic work rough it up with 80 and do it
7.use a high build 2k primer over your body work when you do your body work it should be 80 to 180 to 320 then a red scotch bright then primer do not prime passed were you scotch bright
8. Once the body work is all primed go back and block it ...oh yeah guide coat your primer to help block out in perfections
9 reprime and guide coat the hole car and give it to the preper at the paint shop to block it again before the painter seals it baces it and clears it

I hope this helps you

 

[H/O84]

Thanks clutch I've been getting real sick of people telling me to do it a certain way and giving a really bad explanation of why or not really having an answer of why. I tend not to get along with body guys very well especially when they quote me 15k to paint it. I just have a bad history with body guys for some reason. I plan to spray the car myself but due to my crappy air compressor i think I can only do one panel at a time. Guessing that will take me about a week to get done. Do you think that will be an issue once it's blasted to wait that long? And what about needing to sand near the edges that got taped off, isn't there the possibility of the rust causing problems similar to if I just sanded the whole car