Help enrique !!!! paint question ?

[fuzze]

Afternoon all , I've removed and stripped and prepped my front end parts , hood ,cowl fenders , and valence .I used aircraft remover and then d\a and hand sanded all to bare metal .Once done everything has been treated with ospho , slight sanding again , then metal ready . I painted por 15 on the inner fenders and stopped there . My ? is can I, should I por the outer steel then use the tie bond primer and then epoxy prime on top of that, and then proceed with filler where needed or am I way off base .I'm thinking that I should just do the inner portions with the por and call it done .I've read over 25 pages of opinions and I am now a little overwhelmed . Bty ,all the metal is in excellent shape to start with . I know long question and respectfully await the answers and flames .

Thanxz

Chris

[fuzze]

No love yet I see . The reason I ask is I read about people painting por-15 in the engine bay with excellent results ,then top coating with a final coat of color of choice.Also correction with the primer name , it is tie coat primer made by por . I see geezer uses zero rust and from all indications it may be the better product for ease of use . Please pipe in without e-flaming , I just need some solid advice .

Chris

[JimmyZ]

My best advice would be to seek advice from your local paint jobber and the person who will be applying the topcoat.

Here's a page I made for this sort of thing...http://warbuddies.homestead.com/restohelp.html

In short apply some epoxy primer after the metal has been chemically treated to nix rust. The POR undercoat is unecessary and will not give you any gains in longevity over a properly applied series of primers. (as mentioned in the link above) You DO want to avoid having too much overall paint thickness. (Primer -> topcoat total thickness)

I'm not a giant fan of POR. POR's paint film is just shy of indestructable and it's very simple for the average Joe to apply. This would seem to make using it a no-brainer. The question then is why aren't more people/body shops using it? POR has done an excellent job of advertising and sells itself as being a one time fix all.

To me, POR could be used on underbody work as you have done. A more "normal" approach such as using primer/topcoat and body shutz would be better in the end. Of course you could coat the POR with shutz for a near meteor impact proof undercoating.

Shutz helps cut down road noise which is nicer than hearing every single pebble you hit.

2c

Jim

Edited November 22, 2008 by JimmyZ

[EScanlon]

You've definitely done some research, and I can understand why some of this gets confusing and even duplicitous.

I'll do my darndest to boil it down to smaller chunks. Don't worry about the flames, they'll probably be directed at me, but that's ok.

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If you've already treated with Ospho, in my opinion Metal Ready won't be adding much to the mix. Both Ospho and Metal Ready are acid baths that etch the metal and leave a surface preparation to help prevent further rust and promote primer or POR adhesion. They should be the last step before applying POR or Epoxy Primer.

Some folks even abide by the adage that Epoxy Primer does it's own "etch" and therefore does not need a prior metal prep.

Doing Ospho or Metal Ready before Epoxy Primer wouldn't necessarily be "over-kill", but doing both would be. In your case you did some sanding between. Anytime you "break" that prior surface finish a touch-up or re-coat is not a bad idea, and in this case since you did do some sanding, recommended.

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Painting POR on the underside of the fenders is an excellent idea as that will help avoid and hold off rust from forming there. That is what I've done to my cars.

If you wanted to further protect the POR from rock chips etc, a good tar based undercoating will help eliminate any "chips" (as unlikely as that may be) from happening to the POR.

Using POR, you don't need to top coat it both with Tie Coat and then with Epoxy Primer. The Tie-Coat primer allows you to top coat (paint) directly. When using it on the underside, you could coat the POR with the undercoating without using the Tie-Coat primer at all.

===

As far as using POR on the EXTERIOR... in my opinion it wouldn't be worth the expense, in labor, time or money, for the small benefit gained. As good as POR's self-levelling and rust protection properties are, I don't think they're good enough for an exterior finish.

IMO, it would take way too much time AFTERWARDS to smooth the final base BEFORE you could apply your color. The rust protection qualities are good, but the EXTRA work involved, (not to mention the curing time), IMO make this prohibitive.

If you absolutely insisted on using POR on the exterior, the surface prep for POR is sufficient for the POR to apply directly to the metal, and the Tie Coat primer then allows you to "prime" over the POR for top-coating with your choice of top coat. There is also enough fill material in the Tie-Coat to allow you to block or wet sand it. There is also another version of the Tie-Coat that does not have any fill material.

It should be noted though, that since both POR and Tie-Coat are quite thick, it is almost impossible to spray them. As a result, you end up brushing them on. This is where the problem of using the POR as an exterior rust treatment begins. POR by itself is extremely difficult to sand. Tie-Coat Primer is very easy, but it can take a day or so to cure, depending on how thick it is applied (remember, it gets brushed on). Then even after "curing" it can stay "soft" for another few days or so, all depending on humidity, temperature and how thick it was applied.

To me all that extra "juggling" of variables is too problematic. A proper application of Epoxy, Fill and Top-Coat of standard paints will protect the exterior metal well enough.

The rust protection that the POR would provide for the rock-chips that will inevitably happen isn't enough to off-set the additional work now and also when the rock chip would be repaired.

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Epoxy primer is primarily for use onto bare metal and generally has little or no "fill" capabilities. You can also use the Epoxy as a "sealer" (i.e. over prior paint, bondo or primer) as long as the surface has been properly prepared to accept it. That is, either scuffed / sanded or degreased / etched.

Follow the Epoxy with your choice of Fill primer (i.e. Light or High Fill) to build up the surface with enough material that you can then wet-sand it or block sand it smooth.

Depending on how smooth your car's sheet metal is, you can shoot it with light fill primer, mist-coat it with a different color of primer and sand off the mist-coat. Once you've sanded evenly you will have removed all of the mist-coat and you should be ready for color, or, my preference, a final coat of epoxy primer (remember it's low to non-fill property?), then to final color. (Don't forget to keep within the no-sand time-frame for the epoxy primer.)

If on the other hand you know you DO have some bodywork to do, then you get to choose between the two "thoughts" on the matter, that is, whether to epoxy prime and then apply your filler (bondo) or apply the filler directly to the metal after proper scratch-grinding the surface.

I personally do a complete scratch-grind and then apply the bondo. Granted, the bondo is pressured into the scratches very hard to eliminate any air after ensuring there are no cracks or holes in the metal. (Bondo IS porous! Don't use drill holes to "improve" adhesion... those spell guaranteed rust.)

After the bodywork is done, I top it with some medium fill primer and wet-sand it smooth before a final coat of Epoxy primer followed by final paint. (I'm using Epoxy Primer as a Sealer. Sometimes your final paint can call for a specific Sealer as a base coat, check the label.)

This gives you the BEST possible finish, for the best possible "fall-back" scenario.

The "Fall-Back" scenario allows you to "retreat" a small step, before pressing forward again.

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A final note on using chemical paint removers:

Aircraft Remover, Paint-Stripper, Kleen-Strip, to name a few; all use various forms of paint solvents and emulsifiers. Some of these can inflict serious chemical burns on unprotected skin and EVEN ON PROTECTED SKIN if it soaks through your clothes. (I won't say how I know, other than keep your arms, sleeves, shirts and pants-front away from this stuff.)

There is also the additional problem of re-activating the stripper hours, even DAYS later and not being aware of it, except that now it's underneath your fresh epoxy primer.

So, make sure you completely rinse, and neutralize the stuff.

In your case you've Ospho'd and Metal Ready (and rinsed after each of those) already, you should be fine. The extra note is for future readers.

This ended up being long... so flame away...

HTH

E

[geezer]

I have had great results with POR 15 and have learned when to use it and when not to.

I am using Zero Rust for the first time on this restoration and have no reason not to believe the claims made by them. We have gone into this before. The two products are totally different in their composition. I think I explained before that I do not use either of these products on any areas that would be considered a finish panel or even in the engine compartment. For these areas you should be looking at a complete paint system from the metal up. Like Jimmy says, consult your paint supplier or whoever is going to do the spraying for their advise. Myself I prefer PPG's DP90 Epoxy Primer for my buildable base and it's only common sense then to follow up with a surefire compatible basecoat/clearcoat by PPG also. Not that I'm saying you have to go with PPG products but do yourself a favor and use a total compatible system.

Back to the POR 15. I have some examples of suspension & underbody components on other restorations that are at least 8-9 years old, still protecting but turning a bit milky in color. Of course that can or could have been avoided by topcoating. I also used it in many areas that will never been seen, but that I still wanted to protect from future rust. Does the job, but I wouldn't use it and try to built a finish paint system overtop.

Same goes for the Zero Rust. I am using it in all the hidden unseen areas. This car like no other I have done was severely rusted, needing outer rockers, rear quarters, floor pans, supports, front frame rails, outer wheel housings and several other pieces. I more or less turned it inside out which exposed most every unseen area on one of these cars. This is where I'm using the Zero Rust. I had been told by friends that if there were areas of overlap where my PPG DP90 Epoxy Primer was applied over the Zero Rust there would not be any problems down the road. As a precaution I lightly sand any Zero Rust that will be covered with the epoxy primer. So far Zero Rust has been a pleasure to use with zero problems.

PS - I forgot to mention the difficulty of getting Zero Rust in Canada. I had the help of Bruce Palmer but still had to pick it up in Michigan myself. Nobody will/can ship it over the border.

Edited November 22, 2008 by geezer

[CrossroadsZ]

I have been a consultant for the largest paint company in the world for 20 yrs (Akzo Nobel). My recommendation is to get a high quality Epoxy primer like (CIP Epoxy from Akzo) and apply 2 wet coats. Allow the primer to air cure for at least 3 days and then start your bodywork. Scuff the area to be worked with 80 grit and apply the bodyfiller directly over the cured and scuffed Epoxy. Block the body work areas with 80 grit followed by 180 grit, then 220 grit. After the body work is complete apply 3 wet coats of a high quality urethane filler primer. Then start the blocking process. I would do the initial blocking with dry 320 grit and then apply a guide coat and wet sand with 400-600. If you want a super slick straight finish you could apply at least 1 more double wet coat of filler primer and block with 600 wet after applying a guide coat. This will give you a super slick bullet-proof surface for topcoat.

I hope this helped.

[fuzze]

Thank you to everyone for the awesome advice . Jim I refer to your site all the time for help,it taught me how to stitchweld and understand home body work and Ron and Enrique confirmed what I believed to be true . The por and zero rust are really meant for the hidden areas as you both mentioned . My neighbor will be painting my car in his booth and he spoke of using ppg products for this project . Crossroads , I am not familer with the line you talked about , but will do some research on it . Ron , there is a company in Coquitlam BC , that supplies Zero rust in spray cans and qts and I believe gallons and in colors as well . They are called KMS Tools , maybe they can ship to you or pm me and I could help you out .

As I've said before , Great site , Great people !

Thanxz

chris

[geezer]

Thanks for the offer Chris but I have enough now. Bruce did connect me with a supply house that advertized it in Ontario that I called but they didn't have any in stock and couldn't tell me when they would, so the Michigan source was my best bet. Not too problematic if I order it ahead of time when I have a cross border trip planned anyhow. I didn't get into any actual paint prep tips because I knew Enrique would chime in and his methods have produced some excellent results. Solid tips from CrossroadsZ also, no matter the product line. The reason for using Zero Rust instead of just starting with the epoxy primer is this. It is a lot easier & cheaper to cover these unseen areas as you get to them with a product like Zero Rust. I use a variety of methods to reach these areas. Some spots you can brush, others I use a wand with an old lawn sprinkler nozzle on my shutz gun...whatever it takes. During a restoration it can be a long time between spurts of work, but you still need it protected when that particular portion is completed. Point being, I don't open my expensive epoxy primer until I'm ready to cover finish panels or large visible areas. Good Luck!

[racebird1]

One quick note here is I did not see anybody that if using POR15 you should spray the primer on the POR when it has just started to flash off. This is because it is like a rock and as stated it is hard to sand. Either way always use a self etching primer or be sure to etch metal before priming. I personally would not por the whole engine bay. Too much work and not worth it.

[geezer]

One quick note here is I did not see anybody that if using POR15 you should spray the primer on the POR when it has just started to flash off. This is because it is like a rock and as stated it is hard to sand.

That is the point I have been making, for the reason of my using Zero Rust instead of POR 15 where a buildable base has to be established or overlap occurs from the transition of hidden areas. After a prolonged period of time, all you need is an easy light scuff, then you can prime or epoxy prime over it with good adhesion, unlike POR 15, that you have to be much more wary, where you put it.

Edited December 11, 2008 by geezer

[five&dime]

I have always been told by the pros I consult with that you should use etching primer on bare metal followed by epoxy primer for best rust prevention and adhesion for the base/clear. That is how I have always painted bare metal.

[geezer]

I have always been told by the pros I consult with that you should use etching primer on bare metal followed by epoxy primer for best rust prevention and adhesion for the base/clear. That is how I have always painted bare metal.

There are many methods of etching metal. There is nothing wrong with your method of using an etching primer followed up with an epoxy primer and very well could be the better way of doing it, but I am a creature of habit and if something works for me, I'll stick with it. On bare untreated metal I have always used Alchem Metal Prep to etch the metal. If the metal has been sandblasted, which I think is the ultimate etch, I usually bypass the Metal Prep and just insure that it is perfectly clean before priming. I prefer PPGs DP90 epoxy primer and do not keep a second type on hand. One thing I have found over the years is that pros and hobbiests alike can achieve excellent results even if their methods vary. If I was to experience an adhesion problem, then I would consider using an etching primer.

Edit: After entering this post I googled a few things and found out that PPGs DP90 is not available in the US any longer, but is available for the time being in Canada. Apparently the formula is heavy in zinc chromates and also contains lead. It has been replaced by DP90LF (lead free).

Edited December 11, 2008 by geezer
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