2k clearcoat

General Discussion. Make yourself at home...read, ask and answer!



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PostPosted: Mon Nov 22, 2004 10:04 pm
Hey guys, keep in mind that most of the factory paint is nothing like what we see for refinish work Different chemical makeup, different application, and different curing (Do you cure your jobs at over 300 degrees? Many factories do.)
I've read some on factory failures and it seems to boil down to two things - the factory screwed up the application - outside recoat window, contamination, whatever or the accountants made the factory buy cheap paint and UV just eats it alive.

For anybody that does ask about sanding base, that list above makes good reading.



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PostPosted: Tue Nov 23, 2004 10:42 pm
Parafin wax is in all Dupont base coat and is used for mettalic control, the wax is in the Balancer and Binder so it is present in solid colors and not needed, sanding is a no-no because the resin that inhibits clear adheasion floats to the top and sanding removes it and exposes the wax.
Make sense?



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PostPosted: Tue Nov 23, 2004 11:22 pm
This is interesting Frank....Now...Let's say that you have to repair your basecoat...Maybe you got a huge BUG in it, or a run...the base is cured so you can sand it...You are out of the recoat window and have to sand all of the exposed base....which has cured enough that it won't re-activate when you put fresh base on it......They say to recoat with base...BUT there's WAX in the sanded places you need to recoat with base......(Wax is a release agent) What do you do now? Did I mention that wax is a release agent?......



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PostPosted: Tue Nov 23, 2004 11:47 pm
Ah, one of the applications for wax is as a release agent. To be effective in that job, it needs a relatively thick, unbroken coat. If there was that much wax in the paint, I suspect it would, indeed, fall off all by itself. I imagine we are talking about small quantities of microscopic particles dispersed throught the paint. It does it's special job and is totally encapsulated in the dried film. Sand and don't repair properly and you have it out in the open to mess with your other paint. Base on base, the base has the chemestry built in to handle the wax.

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PostPosted: Wed Nov 24, 2004 1:12 am
right on, Jim :)

GST not to be offensive but how many times have you painted something with bc/cc. You really should try it because it sounds and reads like you haven't done much of it. I can assure you the paint manufacturers have some very talented and well educated chemist/scientist working on the paint formulas. Multi-Billion Dollar Industry.

Of course there are going to be some failures in the NEW Auto Manufacturers side because they are really pushing the BLEEDING EDGE for new developments, cost, and such. The OEM finishes are usually thin. EPA requirements are also forcing changes with the way paints are made and applied. Some Manufacturers are using a Powder Clear Coat Process now and actually some Manufacturers have been using that process sine the mid 1990's.

Some of the base coats are water base and water borne. These were tried and failed in the early 1990's with a return to solvent bases. What is old is new again except hopefuly this time for the better with changes. A lot of these changes and developments are due to EPA and LOW VOC requirements.

In case you have never been made aware of it CHEMICAL AFFINITY is the best reasons to stay within one brand and family of paints. Again the people in the labs do a lot of testing to insure the Major Name Brand paints work within their respective systems. THEY ARE DESIGNED TO WORK TOGETHER AS A SYSTEM. It is never a good idea to mix and match paints but yet people do it all the time. Even the NEW Auto Manufacturers will do that from time to time. Maybe why some people have problems with failures.

I have had some chemical classes in college many years ago and didn't care for them. CHEMIST have my respect.

To answer your other question do not have any links: try using your Internet search engine to look up Polymeric Binders, Acrylic Binders, Acrylic Driers, Acrylic Enamel Driers, and so forth. There are also things known as esters and so forth. Think those are some of the things to look up but my memory is slipping. Look at the MSDS then look up the components. :)

As I have tried to tell you fellas MOST ALL BASE COATS are like this for a re-coat. I don't know of any that are not like that for solvent base coats. -Jim THANKS Again.

It is important that we follow the Paint Product Sheets for most if not all things.

Don
P.S. When I replied to this post was initially focusing on the inital poster, mickyg100. I did get a bit side tracked too. Guess no harm and everyone probably learned something. I even learned something. :)

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PostPosted: Wed Nov 24, 2004 4:24 am
All info is taken on board, I have already re-sanded the pannel that had no CC on it ready to shoot another base coat, but I have another question now about decal application but I will post a new topic for that.

Thanks to all for info, greatly appreciated.
muchios gratias



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PostPosted: Wed Nov 24, 2004 9:00 am
Hi D71 no..you're not offensive, however, you are making assumtions...:)

If you wish, I can give you a rundown of the little bit of paint I have sprayed.....but it could get long...Suffice it to say that I've sprayed most of the resins that are used including many that aren't used in auto. ..and have been at it for more than .......maybe you don't wanna know......Lemme re-phrase that ..Maybe I don't wanna kow...:)
As to the chemistry thing...I have had many occasions in the past where the job required unorthodox application of coatings. This requires intense research into the chemistry of these coatings...I had to make things work that weren't "compatible". I have learned some interesting things about what happens in the "research" area, and what may or may NOT be "New" technology. (In spite of what you are told) You may not want to know the reality of this either.

Jim, the wax thing...Frank stated that if you sand base, you will expose the wax and won't get adhesion to the clear. (His exact words said that there are adhesion inhibitors that get sanded off...I will assume that he meant adhesion promoters. ) NOW. If the base doesn't re-activate with fresh base....And if they are hardened they don't..... and you sand the run or bug out of the base (which is done after it cures enough to sand ..so it wont get the chemical bond) now clear won't stick...Frank said so Well neither will base....(there is no chemical bond) Oh...You say that the window is still open?...I have found that the window is narrower than stated in many cases...(Through adhesion tests). You may be correct about the chemistry of the base making it work ok, but this system becomes very critical, and leaves the industry open to more failures. (Murphy's law) Adhesion can fail due to a VERY small amount of release agent.

From Frank's answer..( he is the only one that explained the reason for wax) It appears that the wax is used as a dispearsal agent for the metal powder in metallics. This is not a very good solution since metallics have been used without wax for the past 50 some years....(So swirl the gun from time to time it's not hard..) Frank also posted elsewhere that at least one version of clear coat contains TEFLON and cannot be painted over. D71...Do you want the job of repairing paint that cannot be repainted? What if you owned the car that had this and you had to touch up a minor ding? Not fun...Very expensive for what could have been a minor fix......

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PostPosted: Wed Nov 24, 2004 12:01 pm
GST,

Think you are making a Mountain Out of a Mole Hill.
MOST of these ESTABLISHED REFINISH SYSTEM Base Coat Paints come with a LIFETIME GUARANTEE when applied by a CERTIFIED TRAINED PAINTER/FACILITY but they must be used as a COMPLETE MAtched System from primer to final top coat just as the Manufactuer recommends and intended.

That clear coat with the teflon is being used on Aircraft and other heavy Industry or least ways that was the original intent. It is suppose to be very tough paint (moreso then IMRON) and yes it was suppose to be very difficult to repair. It has been out of the LABS for a few years now. I don't think it will show up in the automotive industry but could be wrong. I don't have the link to this specific paint development any longer but like most things it is available on the internet. :)

Again Dry Powder Clear Coat seems to becoming the Favorite Method for Auto Manufacturers along with Water Borne Base Coats. It does cost a lot to convert over to this application method so Paint Manuifactuers such as DuPont are developing LOW VOC - 80% HS Clear Coats that can still be used in traditional equipment.

You have mentioned something about WINDOWS for the different materials being open. It must be realized that the TEMPERATURES need to be taken into account when looking at these specifics for products being open. Most product sheets address 70 degrees. When the temp increases those open times are shortened dramatically. For instance and this an off hand example a paint product that is reported to be open for 24 hours at 70 degrees might only be open for 6 hours or so at 90 degrees. That is not an exact - only an off hand example and a chemical reaction is in progress. Heat is an accelerant and Cold is a retarder for most of the modern paint chemical make up properties. At under 60 degrees some urethane products can be extremely slow to setup and below that some may even stop. Just the reverse/opposite is true for heat being increased. Maybe Frank can add more to that one for "open windows" for products but need to be specific instead of the FLY SWATTER.

Again these current TOP END - BEST QUALITY BC/CC systems as previously listed can get a LIFETIME WARRANTY if applied by an approved / trained shop. I think that says it all for the REFINISH INDUSTRY and the faith they have in these modern urethane bc/cc materials. ALL of the TRAINED PAINTERS are taught to follow the PRODUCT SHEETS and the TROUBLE SHOOTING GUIDES like can be found on the Internet.

I think you are trying to use a FLY SWATTER where Tweezers should be used for a fine focus. Realize that paint failures are not just the fault of the base coats with wax in them. This post was originally about REFINISHING-Repairing BASE COAT and it got ALL mixed up with New Manufacturering processes and such - and then failures - so it is Garbley Goo now.

I am doing my best not to confuse any new hobbyist that might be reading this post. Remember there is a silent majority that are reading these post to understand and learn too.

There will probably come a time when The Govt under the guise of EPA Restricts Paints from Hobbyist. So wouldn't get to worried about much of it except doing what you do for now. Unless you have a job requirement where you must and in that case the Manufactuers will work with you in most cases to offer technical advise.

In the FUTURE application procedures may very well change too. Given there are new UV bondos, primers, and such out already out. Imagine a new primer that dries in 20 seconds and ready to move on to the next step with the aid of a UV Flash. Hobbyist are unlikely to have access to the new application tools required for these materials - due to high expense.

Say this again for the AUTO REFINISH Industry and it is an example for the HOBBY painters to follow the PRODUCT SHEETS. If the Product Sheets are followed then Hobbyist can expect ABOUT the same LifeTime paint job that can be achieved in a Professional Shop where the same complete package of materials might be Warrantied for a LIFETIME.

I know this is not what you wanted but it is my part of the SOUP for the people to which you might have frightened away from using BC/CC as a package. "You want the Base Coat without WAX comment." AGAIN these products are designed to be used as a package and when done will last a long long time. That even applies to the Modern Urethane Economy Products too.

Later,

Don
P.S. If you get to far out of the window or have a sand through with fresh bc/cc that is not activated then you can end up with a non-edible fruit roll up. :) or :( whichever the case may be. Think most manufacturers recommend an activated base coat for the LifeTime Warranty ReFinish. Again wil leave that to Frank and the Specific Manufactuers to clarify.



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PostPosted: Wed Nov 24, 2004 10:07 pm
I hate to keep this going for fear of turning into a heated debate, but I did want to address a couple of items. Understand the wax used is a liquid made reversible with solvent, if not it would never incorperate in the film ( Sherwin has its wax in the base reducer called base coat stabilizer) it does not resemble candle wax we think of when we hear the word wax. If you sand and expose wax you would o nly need to reapply base and the base solvents would remelt and reincorperate the wax, besides the base should be catalized and you would get adheasion that way, so without catalist you would have no recaot window since the base would rewet itself and with catalist you have 24 hour window.
We now use wax when we have not in the past because we have new mettallics and paerls, we now have round mettalics which are very spray sensitive and hard to control which did not have until a few years ago, we also have Xyrallic pearls which are only 16 months old. This is why we need this ingredient now and not in the past.
I'm not sure that wax is used as a release agent, I have not heard that and can't think what you need to release with it.
The OEM's use a base and clear refinish will never see, if it's not water based it is Melamine based, BMW does use a powder clear on some of there cars, the Meamine uses no catalist and by design crosslinks at about 300 degrees.
You will not see the 3460 EZ clear with Teflon in auto refinsh, it was put out to market bus and subway business who had troulble with Grafitti.
Today the highest solid content available for auto refinish is Spies Hecker 8030 or Standox VOC clear at 75% solids which is of course a 1 coat clear, it is also my favorite clear and the only one I use on my personal stuff.
Agan, sorry to keep this going, it is great to see everyone really thinking and offering freely there thoughts, lets just keep it a discussion not challenges and debates.



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PostPosted: Wed Nov 24, 2004 11:32 pm
Hi D71. first let me say that we could have a lot of fun if we kept this up....However I'll just note a couple of things.

Windows...I don't know anything about that temperature stuff...But I have designed and built several heating AND cooling systems for controlling the cure time of various resins to meet client's needs in years past.

Lifetime warrenty...Compared to what?

Mountains.......molehills.....one fits inside the other ...you should try it sometime...

Flyswatter...I went to one of my autobody suppliers and they didn't have any...I haven't used one of those yet...(remember..My experience is limitted..so I gotta learn about that new tool)

You have posted some in depth information here I thank you for that, however you still haven't answered my simple question ...Why do they put wax in base coat?...NOW if you look at the post right after your last one ..You'lle see that Frank just answered it. This time the answer works because knowing what I know about coatings...His recent info fits...Where the previous info didn't make sense. BTW Frank...Thanks for doing the homework and posting that. Wax by the way IS most definately a release agent that has been used for generations in casting and mold making. The composite casting industry has now switched to different refinements of that and other chemistry. I use wax here for mold release all the time. Again thanks for the info about the basecoat.
G
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