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Discussion Starter #1
I couldn't find anything addressing my question, so I'll ask about it :p

I was thinking of using a Rust-Coat as a primer. My car will be painted red, so if I used a red rust-coat it should be ok. I just want to know if this is a good idea or would this just peel off.

Would an epoxy primer be a better primer to use on bare metal than rust-coat?

Thanks in advance,
Later.
 

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One of the things most people fail to realize is that modern paints are miracles of chemical engineering and they're not at all what most people think of when the term "paint" is mentioned. Modern automotive paints dry more from chemical reactions than evaporation. The fact is they really harden more than they dry.

When contemplating painting a car, you need to pick a particular paint line and then stick with that line. A primer that is formulated to work with a particular PPG line of paints, may not work well or at all with a top coat from DuPont or House of Color. It may not even work with a top coat from PPG if it's a different product line. Bottom line is that mixing brands and types of paint is like gambling. You never know whats going to happen and what the finished product will look like. What looks good when sprayed may not look good tomorrow, next week or next year for that matter.

The best treatment for bare metal is an epoxy primer. All major paint lines have them so do a little research and find out what lines are available locally, pick one and then stick with that line. Additionally, always read and follow the specific instructions on the product "P" sheet for the paint you're using. It will tell you what primers, top coats, and clears are compatible with the product you're spraying as well as exactly how to mix and spray it.

Good luck.

Centerline
 

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What he said.................

Rust paints are generally an enamal base, and not a real durable one at that. A laquer based primer, which most people use would cause it to react real bad. Don't do it.
 

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When contemplating painting a car, you need to pick a particular paint line and then stick with that line. A primer that is formulated to work with a particular PPG line of paints, may not work well or at all with a top coat from DuPont or House of Color. It may not even work with a top coat from PPG if it's a different product line. Bottom line is that mixing brands and types of paint is like gambling. You never know whats going to happen and what the finished product will look like. What looks good when sprayed may not look good tomorrow, next week or next year for that matter.

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Question?
If the the Pontiac came from a plant with PPG on it, does that mean Dupont or basf cannot be used in the body shop for incapability?

A 77 ford with enamel from factory, can we use base coat over it or would it be incompatible? Or single stage urethane? Or a Polyurethane? Waterborne base from ICI?

78-80 vette- waterborne paint from factory, nothing we can use?

That new replacement fender from Nissan with Nikkon epoxy,
no Dupont, ppg or spies or Basf on it?

UV cured primer from BASF and PPG, Their using this to get in doors of shops that don't use their products, are they wrong?

Just curious but big difference between wet and dry, compatibility.
 

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Brian Martin,Freelance adviser
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Barry, I see both sides of this issue. First, I understand that mixing brands of undercoats with a product like SPI epoxy primer and PPG Delta over the top is going to be a super system. I understand that when we repair a car at work with S-W it is being applied over another brand of paint and it works.

I also know that if you were to not do that and ONLY use the complete system from one manufacture following the tech sheets the ODDS are in your favor you will end up with a better finished product.

The key is the "ODDS" when following the tech sheets. I know that if you were to follow the tech sheets of PPG for recoating DP epoxy with that SPI it WILL work just the same being they are "similar" technologies.

But when I see something like a guy wanted to use a product like "Rust coat" and plan on following it up with an automotive finish like PPG I just can't agree.

What recommendations does a home hobbyist follow when doing such a thing? Follow the PPG recommendations for a synthetic enamal sealer? I doubt there is such a recommedation for Delta, here may be, but how is the home hobbyist to know what PPG product is similar? What if he follows the DP recommendations and shoots the Delta over the Rust-coat wet on wet? What will happen, I don't know, but I do know it would be a gamble. If he doesn't know the technologies and how recoat it, sand with what? How long is he recoat window? The ODDS are he is going to end up with a mess.

When there is an "unknown", I just have to recommend following a system recommended by the manufacture.

Does this sound fair?
 
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As I am sure you guys know, I am not a paint expert. I do have to agree with Centerline on this one. One thing that has to be considered is the drying/curing of the products. When we do a repair in the collision industry, the original paint in the vehicle is cured. We do not refinish a vehicle within hours, or even days of the original paint being applied. The original finish, being cured is going to be less likely to cause problems from chemical reactions of non-compatible paints. The average DIY, at home, is not likely to let the paints completely cure before the next step. This would possibly increase the chances of paint failure from non-compatible paints.
 

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Brian Martin,Freelance adviser
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That is of course the very most important point to make. If you look at a tech sheet for most any product there will be a "suitable substrate" list. This list will have "OEM cured Enamels" or similar discription of an OEM finish. DuPont, PPG and the like in other words have a recommendation in the tech sheets (backed by a warrantee in many cases) to apply their product over another brand of paint. That cured finish is not even another "paint" if you look at it as a "film" of what "use to be" liquid paint.

It is however a whole different ball game when you are talking about another product that is not fully cured. I agree, as I said, that these brand names are very similar in make up. PPG urethane primer is extremely close to DuPonts, S-W or whom evers urethane primer.

If you were to use a Dupont urethane primer or Transtar or what ever with your S-W Ultra/BASE system, it is going to work as long as you follow the same recommendations S-W has for top coating over the S-W urethane primer. AGAIN, the "ODDS" are in your favor if you were to use the S-W. But these "odds" are still VERY, VERY good using the other brands as long as you treat it the same as you would the S-W as far as sanding, recoating and such.

It is "almost" like you are using a "system" recommended by S-W. "ALMOST" I say because of the similarity of the X brand urethane primer to the S-W primer that is in the "system".

All that goes out the window when you are talking about a "ZeroRust" or "Rust Coat" or something like that. These products are unlike anything in the system DuPont, PPG, or whom ever has. There isn't a product in the system you can "copy" recommendations as you apply your products.

At that point you are guessing, plain and simple. Now, someone like Barry KNOWS his technologies and could get away with murder mixing these technologies. So could many painters who do this every day. That is not your typical home hobbyist who would find himself thinking about doing such a thing.

That is why I recommend to use a system from metal to clear. If you are going to drift from the system, use similar products. But you just can't use bell pepper instead of tomato and expect it to taste like a BLT. :welcome:
 

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&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
I totally agree about the Rust coat.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Point I'm, trying to make is if your in the same "family System"
Such as base clear is a system, its not Even an issue.

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Yes enamels (a system) Being painted with Lacquer (a system)
Is a problem.
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The fact of the matter is if you look at every company they all have strong areas and weak areas.
Example- for years PPG has had great undercoats and weak clears.
Basf has always had great clears and weak undercoats.
Dupont, weak undercoats and strong clears.

"Once a primer has dried enough to sand, Does it know or care what brand of base is applied"?
Once the primer is dried, what if you decided to spray a single stage instead? Will the primer know the difference? Should we have used another primer for compatibility?
Basecoats solvent dry with a ladder scale effect, so with flash why would it care what clear was used?
How can that effect the "said" dieback or problems down the road?
For years shops have shot a base in one company and it don't match and get a base from another company and put over the other base, why would that cause a problem? Even if you put a polyester base over an enamel converted base? Problem? Solvent dry on ladder scale.


So you can never make a blank statement that one full system is going to be the best!

NO one answered my question about compatibility, Some strong statements were made about this and he an engineer , I'm not and I want to know how and why?
I want to learn.

Footnote:
If I was going to write a book, I would not write it on paint itself as by time it came out, a lot would be out of date as fast as things change in this industry.
I would write a book on the relationship of Contracts for the mega shops and its relationship to the brainwashing of you can't mix systems-- its all related and for very good reasons. They take advantage of the small shops and the people who don't know the processes. bk
 

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Brian Martin,Freelance adviser
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Barry, you are totally right on all comments, I agree. I didn't say that a system from DuPont,PPG or the like is "Best". What I said is if someone not expericanced in paint were to follow the tech sheets of a system from one of these manufactures, by the ODDS they would have less problems.

They wouldn't have to think, they wouldn't have to ask the questions like "should I use RustCoat". If they didn't ask this, as many don't, by the ODDS they will have problems when they apply that PPG, DuPont or what ever over it.


Guys, understand why a company "brainwashes" it's custom into thinking they MUST use all the same products. It is simple, they want you to buy all their stuff right? Well, that is the reason, but it isn't that easy. There are those ODDS if you follow their guidelines in the tech sheets you will have better results with THEIR products, thus BUY MORE. If you become a junior chemist and start mixing products, you will open the door for problems with THEIR products as well. They want you to come back and buy THEIR products, right? Well, if you mix and match where you don't know what the heck you are doing and there is a failure, you may (and many times will) blame it on the products and not buy it anymore. It wasn't the any of the companies products faults, but they are who you will blame.

That doesn't mean you can't use primer from one company and paint from another. I am telling you why they do what they do, not what you should do.

Sure it is an instant "out" for the manufacturers liablity. "What?, you painted DuPont base and S-W clear and now you want S-W to pay when the clear fails, sorry, no warrantee", so says the S-W rep. I agree they take advanatage of that "out", I did myself (following company guidelines). However, how else can they make it? They can't have every single person employed be a chemist. You would have to be to understand every circumstance imaginable (or unimaginable, I have seen people do the DARNEST things). It makes total sense that if you apply the product in a different way than the chemists who developed it say, "you done did wrong". If they didn't do that, every single rep, or who ever had the power to yeah or nay on the claim of product failure would have to not only know the chemistry of every product availble, his brand and all the others. He would have to know the solvent and hardener "speeds", and everything else about the competitions products as well as his own. That would be impossible, so the "follow the tech sheets" starts making a lot more sense.


Ok, I know Barry knows this, but for those who don't, I will toss a wrench into the transmission here.

So, just what IS recommended paint system? Would it be Evercoat primer and S-W paint (Life time warrantee!)? How about S-W etch primer, PCL primer, S-W paint and Five Star clear? Well, those are both Sherwin Williams recommended systems. You won't see those names on the cans, all you will see is S-W, but they buy the primers and the clears (I made up the FiveStar name for the clear, I never did find who made that one) from other companies, and relabel them with the S-W name.

How about things like a TOP of the line paint that is also sold by the same company in a "value line" for a third of the cost with a third of the warrantee? How about a top of the line primer that is also sold in the "value line" at a half the price? How about a clear marketed under one name and number for cars and another name and number for truck fleets for more money? How about a toner marketed under the top of the line name as well as the "value line" name and the "value line" number costs MORE? :) These are all FACTS, I did not hypothesize.

The marketing departments play us like string puppets. :)

So, it is "ok" to mix brand names that is true. There is one BIG difference from this and some guy becoming a Junior chemist that is they were RECOMMENED by S-W. You don't have to ask on an internet forum if it is ok, you know it is because it says so in the tech sheets. I would be curious to see what the tech sheet says from RustCoat on this subject. Or, for that matter, call the RustCoat tech line (?) and tell them you want to PPG DBU or DuPont Chromabase over it, see what they say.

If one were to ask the company tech department of the products he is using they will tell him if it will be a good choice. Call RustCoat and ask. If you are using SPI primer, call them and ask, they will tell you if what you have planned is ok.

Barry, you can bet your bottom when I write the chapters about paint in my book I will be using VERY broad, generic information. I know there is no way I could put much detail, first being I would certainly screw something up :) Second just as you said, there are too many changes that would come along and make the info in th book useless.
 

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BarryK said:
Just curious but big difference between wet and dry, compatibility.
Quite correct. When someone who, by the nature of his question, is most likely a shade-tree mechanic asks about painting I can only suggest what I feel would be best course for an amateur to follow. I don't claim to be a pro and I'll yield to you guys with years of painting under your belt, but it's been my personal experience that most often the simple solution is the best when a person's experience is somewhat limited.

Naturally when a paint is fully cured it can usually be successfully top-coated by any number of other products but the ultimate success depends on the quality of the sub-strait. With one of the "rust coat" paints I'm not sure there is any way to know how well it will adhere to the surface and using it would seem to be somewhat of a gamble. Especially when you consider the amount of work and expense that usually goes into even an average paint job.

Pros with tons of experience can make educated judgments based on their product knowledge but for the average shade-tree in my opinion the safe way to go is to pick one line and stick with it.

Centerline
 

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Me too.

Troy
 

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Discussion Starter #14
Thanks guys, I'll do some looking around and see what I can get from the local shops. Then I'll research them a bit and find the best line to use, and I'll stick with it. This seems to be the easiest way to do it.

Later.
 
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