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Discussion Starter #1
I have been doing auto body repair for nearly 35 years. During that time I have repaired numerous cars with some small round surface rust spots on the body panels from flying stones etc. I have for years simply sanded these spots, wiped them clean with DX 330, primed, blocked and painted them, and I have never had a problem with rust in these spots again. Enter the twenty first century and I keep reading that rust must me "neutralized" with some expensive three part liquid, because if you don't you will be driving your car someday and you will hit a bump and it will evaporate into thin air.

Have I been extremely lucky for 35 years, (no) or are these guys trying to sell us a bunch of good sounding but useless stuff? (I fear the answer is yes.) What do you think?

Benji
 

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Benji its a half and half situation really. The folks that sell these chemicals are telling the truth, but are leaving out the exceptions for "good business". It is best to nutralize rust if any is left behind under the future paint, BUT if you sand away the serface rust (like I and many others do) you don't need that stuff. Remember also that your in the 21st century where everything is get it done fast and get it out. These rust nutralizers appeal to the younger guy in the trade because they can just spray this magic stuff on and kill the rust in a few minutes without the sanding time and effort Its all about time, effort and the people who want to use less of both. Rust is best dead and gone no matter what you do. So sanding away the metal or treating it with chemicals and saving the metal is two ways that work fine, its just all up to the person doing it and how much time and effort they want to put into the job.

HK
 

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Hey Benji- don't change what you're doing just 'cuz somebody found something new to sell!! Like HK says, your method is BEST!!! Why cover something with a chemical when you can completely remove it?? You've been doing work on these fun things we call cars longer than most of us- stick with what has worked!!! Good work always takes a little perspiration and to me that's what makes it fun!! I do mine the same way and never had problems in over 28 years... I tried to learn leading from an 'old Master' and even though he was a GREAT teacher- I like the new fillers better. I did one car his way and it is cool and fun to be nostalgic, but I like to do things the way I'm comfortable!! Keep on keeping on!
 

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This hits dead on my problem,that is surface rust with no rust through.I have sand blasted the surface with low pressure to prevent panel warp but I can not seem to get the rust pits 100% clean. After asking here a few days ago,I decided to use POR-15 metal-ready and epoxy primer. Am I on the right track? If I use a good epoxy primer do I not have to worry about tiny rust specks that the sand will not remove?
 

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Discussion Starter #5
Hey Olred,

Don't worry about the little specks of orange colored metal. Just like coffee will stain cloth but not affect the strength of the cloth, rust on the surface of steel will stain metal but not affect its strength. Just sand it, clean it, prime it, block it and paint it. Priming it will fill in the little indentations, so you may need to prime and block several times to get the affected area back up to the level of the surrounding surface.

Benji
 

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Wow!! Finally some knowledgeable people about this subject. Every one I seem to talk to has a different opinion about this. Let me get this straight. After sanding down rusty area (of course w/out overheating surface) clean with dx 330, prime and paint. OK do you use metal prep on the bare metal? sealer after the primer? I'm using Nason 421-18 primer, then PPG 2 stage. Is that ok. My Commando has surface rust, more serious rust (into the metal), and some rust thru. Do you treat them all the same?
 

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(just my $.02...) Sand surface rust smooth- sandblast pitted areas till as clean as you can get- cut out and replace ANY rust through and clean welds well- then prime as usual. I've used sealers and have been pleased but have also painted w/out sealers and the job still looks great today (16 years later)... I personnaly don't use much for metal prep- just Kleenz-Easy, a NAPA product for cleaning the surface before primer- a kind of 'wax and gease remover' to get rid of fingerprints, bug dook and such. If you have a really clean surface that has 'tooth' primer will stick and the paint films will seal- especially if you use a two-stage and especially with a catalyst. Happy painting!!! :cool:
 

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Discussion Starter #8
Hey Manytoyz,

You asked "Do you use metal prep on the bare metal?" Yes.
"Sealer after the primer?" Only if painting the entire panel.
"I'm using Nason 421-18 primer, then PPG 2 stage. Is that ok?" Yes.
"My Commando has surface rust, more serious rust (into the metal), and some rust thru. Do you treat them all the same?" I suggest on the "rusted through" panel that you cut out the area or replace the entire panel and weld in, or glued in the replacement. The glue works amazingly well. It is however quite expensive and the special gun needed to apply it is about $100.00! I've used it a couple of times over the past several months, really holds well, no chance of setting the car (or yourself) on fire, no warpage due to heat. BUT it take 24 hours to cure.

Benji
 
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