Por 15 Help

[homes1030]

waz up everyone. ok heres my problem. im puting new floor pans in the z and want to paint them black with por 15. but i also wanted to paint the rest of the inside to match and the under carige. but i didnt want to remove all the old paint just clean it off so its smooth. so im not going to use the marine clean and metal ready i just wanted to use the acual paint. i was wondering if it will still bond well and not peal or chip off. or should i use some other product scence im not going to go down to bare metal just paint over old paint. let me know what u guys think.

[ktm]

No, it will not bond very well. POR is meant to be painted directly over rust. If you have new metal, the metal must be etched before painting it with POR.

Just use a chemical stripper to take the paint off. Jasco is a phenomenal stripper that you can buy at Home Depot. Paint it on, wait 15 minutes, and use steel wool to take it off.

[EScanlon]

Any kind of paint requires adhesion via one of two methods: Chemical or Mechanical.

Chemical is where the paint can bond to the surface via some form of chemical reaction. Whether it's Epoxy Primer bonding to metal due to the self-etch properties in it's composition, or a second layer of paint on top of a previous and still "wet" (meaning fresh) coat of paint.

Mechanical is where the paint can bond to the previous surface via irregularities in the surface that allow the paint to flow into those surface scratches and irregularities such that when it dries (sets) part of the new paint is imbedded inside those scratches and the rest is outside.

POR requires the use of Marine Clean to ensure that the surface to be treated is free of grease, and other oils that would prevent proper surface contact. The Metal Ready is the portion of the preparation process that etches the metal to accept the POR.

While the Metal Ready would probably not be of much use on the paint, the Marine Clean would at least ensure that the surface is free from grease.

So in order to ensure that the POR adheres to the prior paint, you'll find that you are left with only one option....mechanical adhesion. That means you'll have to scuff up the paint, and scuff it up enough for the POR to "bite" into it well enough to stick.

The few times that I've had POR drip onto a previously painted surface that was NOT prepared....it didn't stick. In fact, you could PEEL it off like if it were a sticker.

FWIW

E

[ktm]

Metal Ready is just phosphoric acid. Marine Clean is just a degreaser. You do not necessarily have to buy them as long as you get their equivalents and do the same steps.

Remember, if you are going to do something, do it right (especially the first time). A few extra hours stripping the old paint will be worthwhile.

[madkaw]

I will have to say that the marine clean is some of the best degreaser I have ever used. I think if you spend the dough on good paint like por-15 you should follow their instructions . Like it's been said you need to rough up the paint for por-15 to stick, if you want to utilize it's rust preventative properties you need to paint it on the bare metal.

[beandip]

Metal Ready is just phosphoric acid. Marine Clean is just a degreaser. You do not necessarily have to buy them as long as you get their equivalents and do the same steps.

Remember, if you are going to do something, do it right (especially the first time). A few extra hours stripping the old paint will be worthwhile.

I must disagree with the statement that the Marine Clean is just a degreaser. It is more than that , in fact if you use it on polished aluminum it will etch the shine off. I know from experience. I contacted the dealer with the question of using the Marine Clean and the Metal ready on a painted surface and they DID RECOMMEND IT. I did and have no problem . 1030 , Like you I painted the under as well as the interior of my Z with POR-15. I have also experienced the same thing Scanlon said with POR on a NON TREATED surface and it did peal just like a sticker. Fortunately it was on a premiered fender that didn't matter if it stuck . Use gloves when using this stuff and plenty of ventilation , it is nasty. My neighbor is a kidney specialist and he said to drink lots of water to flush out your system after using this stuff and breathing the fumes. It really loves skin too , don't let it dry on you .

[ktm]

Hmmm, I may have to try Marine Clean then. I have used a lot of POR with great success. Since it was called out as a degreaser, I figured it was just a re-branded product.

Don't let it TOUCH your skin. You will have a nanosecond to remove it before it drys it seems. I got a bit on my forearms and did not know it. When I finally saw the stains, it was too late.

As Gary stated, you want to work in a well ventilated area. Wear a long sleeve shirt, long pants and gloves. I used a high density foam roller to apply the POR over most of the area. It goes MUCH faster than a brush

[EScanlon]

Actually, if you get POR on your skin, or on an area you don't want it on, use plain old Lacquer Thinner (even the cheap stuff from Home Depot) and it will remove it as long as it hasn't set.

Now, MOISTURE causes POR to set very quickly (This is one of the key items they quote in their instructions...it draws moisture out of the surface and air). So if you're sweating it will set up lickedy split on your skin or if you drip some sweat onto the surface, you'll literally watch it "boil".

As far as Marine Clean, it is a VERY STRONG degreaser. Strong enough to literally leach the oils out of your fingers and hand. DO NOT USE THIS WITHOUT WATERPROOF GLOVES.

When Gary mentions using lots of ventilation...ALSO USE A PAINT RESPIRATOR. This is not to sound dramatic, but rather to have you avoid getting massive dizzy spells, vertigo, and headaches....been there and have the doctor bills to prove it.

Don't forget to shoot POR with the syphon gun into the rocker panels and fenders.

E¢

[Bruce Palmer]

... use POR?

[=Resurected280=]

In my experience with POR-15 if you dont use metal ready before you paint it will not adhere to the metal at all or provides very poor coverage. POR is a great product but you have use their methods to apply it or it doesnt work as well as it should.

[hls30.com]

Think of POR15 as a specialized tool. Using it other than as directed is much akin to using a unisyn for a hammer. It is made for a specific use, and the directions were refined through trial and error before they were packaged with it. This is not your roll of duct tape...

Will

[ktm]

I would love to know how I gained the reputation of having no knowledge of the material (POR-15). I have only used it to cover the interior of my wheel wells, cross-member, and frame rails.

Using POR-15 requires careful surface preparation. You must start with a clean surface first and foremost. How you get there does not matter. As long as the surface is clean and free of grease, etc. that is all that matters. They recommend using their water-based Marine Clean and say that kerosene or solvent-based degreasers should not be used as they may leave an invisible film. However, they do NOT come out and say you MUST use Marine Clean. Do any of you disagree?

Once the surface is clean, you must etch the metal. They do not say you MUST etch, but we all know that you should etch the metal, especially a new metal. You can use either Metal Ready or phosphoric acid. Do any of you disagree?

After etching, you need to clean the surface again to remove the excess Metal Ready or phosphoric acid. You do this by wiping it down with a wet cloth.

Once the excess is removed and the surface is dry you can then paint using POR.

Now, where am I wrong in any of that?

It is recommended that you use Marine Clean to remove any grease on the surface, but the intent is to make sure you have a clean surface. It does not matter HOW.

Edit: I am trying to give back to this wonderful community by sharing the knowledge that I have gained. I am not the type to post something if I have any doubt, as I know that it will show up in a search.