Greetings again,
Looking for recommendations on finishing newly replaced bare metal floor pans, rockers, sandblasted center consul etc. to achieve maximum corrosion resistance.
Thank you in advance
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Multiple sprayed on coats of two stage primer. Rustoleum primer is also good sprayed to structural steel but is very, very slow to dry and needs to be applied thick and let drip and run.
I like the 2 stage primer the best. Don't worry about being neat with it. Let it run and drip under the floor pans.
Then on the inside panels like inside the doors and rockers shoot the waxy cosmolene rustproofing. Let it sit as long as you can before reassembling. It is supposed to creep into the nooks and crannies on the seams and seal out the air.
It gets sprayed on with an undercoater type wand.
3m body shoots is a high quality dark charcoal gray undercoating better then the rest. It dries looking civil rather then looking like the original undercoating from the LaBrae tar pits that the factory sprayed in the engine compartment.
The 3m rocker shoots also works well to minimize the stone chips behind the wheels and under the rockers. It dries tan and is intended to be painted body color over it.
I have found that construction "flashing cement" dries hard like a plastic and works well inside of the fenders to absorb the stone thrown by the tires.
It needs to be troweled on and you can get it to look bumpy like a travertine if you work it a little.
I like the 2 stage primer the best. Don't worry about being neat with it. Let it run and drip under the floor pans.
Then on the inside panels like inside the doors and rockers shoot the waxy cosmolene rustproofing. Let it sit as long as you can before reassembling. It is supposed to creep into the nooks and crannies on the seams and seal out the air.
It gets sprayed on with an undercoater type wand.
3m body shoots is a high quality dark charcoal gray undercoating better then the rest. It dries looking civil rather then looking like the original undercoating from the LaBrae tar pits that the factory sprayed in the engine compartment.
The 3m rocker shoots also works well to minimize the stone chips behind the wheels and under the rockers. It dries tan and is intended to be painted body color over it.
I have found that construction "flashing cement" dries hard like a plastic and works well inside of the fenders to absorb the stone thrown by the tires.
It needs to be troweled on and you can get it to look bumpy like a travertine if you work it a little.
The best bare metal coating for non-exterior finished areas is "POR-15". It is available in a number of basic primary colours including black and silver. It dries epoxy hard. Ask "Google" about it. This would be ideal for your floor pans, inner rockers etc.
Secondly for corrosion resistance, use an oil spray like "Rust-Check". You need to get corrosion protection to go into the metal lap-joints.
HTH
BG
BG
Secondly for corrosion resistance, use an oil spray like "Rust-Check". You need to get corrosion protection to go into the metal lap-joints.
HTH
BG
BG
I sent my car off to have soda blasting. It got much of the paint off but did not touch rust, bondo nor did it prepare the metal for paint.
Subsequently I spent the summer blasting every corner with a pressurized blaster then coating all non body panel with POR15:
http://www.rc-tech.net/pantera1/strip/strip.htm
Here is my hind sight.
Having gone through this process I have learned more about coatings. First, the POR15 loves a sand blasted surface so adhesion is fantastic.
Coating POR15 with a paint-able primer is another mater and requires a lot of work roughing it up with sand paper.
People refer to POR 15 as very hard but it really is not accurate. It is very hard on the surface but still somewhat malleable in thickness almost like an undercoating. This combination is good or reflecting the impacts of rocks.
POR15 is not UV resistant and does need to be top coated.
Having to do it over, I have come to accept the industry standard is really to coat with an epoxy primer which is tough in of itself. The epoxy primers of today are fantastic in providing a vapor barrier and they are as well very tough. If the epoxy is primer is coated with eurethane primer within a window (see instructions, (48hrs-week) it does not need to be roughed up. If it is past the window it still has to be sanded or roughed up.
I have good adhesion on the POR15; we'll see over time if it is as good as going over epoxy primer. If I were to do it again though, I am sure I would just use epoxy primer.
Gary
Subsequently I spent the summer blasting every corner with a pressurized blaster then coating all non body panel with POR15:
http://www.rc-tech.net/pantera1/strip/strip.htm
Here is my hind sight.
Having gone through this process I have learned more about coatings. First, the POR15 loves a sand blasted surface so adhesion is fantastic.
Coating POR15 with a paint-able primer is another mater and requires a lot of work roughing it up with sand paper.
People refer to POR 15 as very hard but it really is not accurate. It is very hard on the surface but still somewhat malleable in thickness almost like an undercoating. This combination is good or reflecting the impacts of rocks.
POR15 is not UV resistant and does need to be top coated.
Having to do it over, I have come to accept the industry standard is really to coat with an epoxy primer which is tough in of itself. The epoxy primers of today are fantastic in providing a vapor barrier and they are as well very tough. If the epoxy is primer is coated with eurethane primer within a window (see instructions, (48hrs-week) it does not need to be roughed up. If it is past the window it still has to be sanded or roughed up.
I have good adhesion on the POR15; we'll see over time if it is as good as going over epoxy primer. If I were to do it again though, I am sure I would just use epoxy primer.
Gary
Thanks for all your responses! Have had first hand experiences with both POR15 and Eastwoods Encapsulator products with mixed results. Ideally would like to have the complete car E-Coated but that venue is not geographically user friendly for me. Eastwood has a product called Zinc rich galvanizing compound #13243zp. The finish film is stated to have 95% zinc in its surface. Was debating on using this and possibly top coating with some thing else or not. Any one here tried this product.
Thanks again!
Thanks again!
I have achieved the best results by using the following methods:
After blasting I apply self etching primer. As soon as I have finished shooting the primer I apply two pack (urethane) in body colour or black, solvent based not water based. It's very important to overcoat the primer within a few hours, the sooner the better for maximum adhesion. If I am spraying a small part I overcoat the etching primer as soon as it has flashed off. If you leave it until the next day it would be necessary to Scotchbrite the primer and even then it would not be nearly as well stuck as if you had done it immediately after shooting the primer and would chip off much easier.
I then overcoat that with Wurth body schutz (or equivalent product from 3M).
I would not use Por 15 at all. From what I understand it was developed to paint over rust and does that very well but does not adhere to clean metal nearly as well as self etching primer.
Always call the tech line number on the side of the tin to make sure you get the drying windows right, this is the key to maximum adhesion. Dont use anything that comes out of a rattle can unless it's small unimportant parts that are not worth cleaning you gun out for.
Wear an air fed respirator for anything containing isocyanate.
Johnny
After blasting I apply self etching primer. As soon as I have finished shooting the primer I apply two pack (urethane) in body colour or black, solvent based not water based. It's very important to overcoat the primer within a few hours, the sooner the better for maximum adhesion. If I am spraying a small part I overcoat the etching primer as soon as it has flashed off. If you leave it until the next day it would be necessary to Scotchbrite the primer and even then it would not be nearly as well stuck as if you had done it immediately after shooting the primer and would chip off much easier.
I then overcoat that with Wurth body schutz (or equivalent product from 3M).
I would not use Por 15 at all. From what I understand it was developed to paint over rust and does that very well but does not adhere to clean metal nearly as well as self etching primer.
Always call the tech line number on the side of the tin to make sure you get the drying windows right, this is the key to maximum adhesion. Dont use anything that comes out of a rattle can unless it's small unimportant parts that are not worth cleaning you gun out for.
Wear an air fed respirator for anything containing isocyanate.
Johnny
quote:Originally posted by Johnny Woods:
I have achieved the best results by using the following methods:
After blasting I apply self etching primer. As soon as I have finished shooting the primer I apply two pack (urethane) in body colour or black, solvent based not water based. It's very important to overcoat the primer within a few hours, the sooner the better for maximum adhesion. If I am spraying a small part I overcoat the etching primer as soon as it has flashed off. If you leave it until the next day it would be necessary to Scotchbrite the primer and even then it would not be nearly as well stuck as if you had done it immediately after shooting the primer and would chip off much easier.
I then overcoat that with Wurth body schutz (or equivalent product from 3M).
I would not use Por 15 at all. From what I understand it was developed to paint over rust and does that very well but does not adhere to clean metal nearly as well as self etching primer.
Always call the tech line number on the side of the tin to make sure you get the drying windows right, this is the key to maximum adhesion. Dont use anything that comes out of a rattle can unless it's small unimportant parts that are not worth cleaning you gun out for.
Wear an air fed respirator for anything containing isocyanate.
Johnny
Actually it adhered fantastic to sand blasted metal which is in there spec sheet. hey push for their product "Metal Ready" which etches it and increases the mechanical adhesion but that sand blasting is really optimum.
I etched primed parts of mine but epoxy does adhere better. Modern epoxies are head and shoulders above what they used to be and provide a moisture barrier.
Thanks Johnny!
This two pack product sounds pretty rugged. Is thisit,http://oicoatings.com/pdf/pds/Twopackpolyurethane_PaintPDS.pdf?
In the event one needs to address post blasting flash rust and also wants to use one of the various acid based rust conversion products to infiltrate the obscure seams/joints, what would you recommend and how would it interact with the two pack process?
Thanks again
This two pack product sounds pretty rugged. Is thisit,http://oicoatings.com/pdf/pds/Twopackpolyurethane_PaintPDS.pdf?
In the event one needs to address post blasting flash rust and also wants to use one of the various acid based rust conversion products to infiltrate the obscure seams/joints, what would you recommend and how would it interact with the two pack process?
Thanks again
These are all great suggestions and I am not arguing with anyone or against them,
The term "best" was asked.
In my opinion the best is what Ford did to the production line Mustangs from 1965 on.
1)The exterior rocker panels were heavily galvanized 2)The boxed chassis was vat dipped in electrostatic enamel primer.
In many cases after more then 40 years, it is still in place.
Where corrosion has occured is in places on the car that were never treated to this process.
On the Mustangs there is nothing but this primer as the final finish under the car.
The term "best" was asked.
In my opinion the best is what Ford did to the production line Mustangs from 1965 on.
1)The exterior rocker panels were heavily galvanized 2)The boxed chassis was vat dipped in electrostatic enamel primer.
In many cases after more then 40 years, it is still in place.
Where corrosion has occured is in places on the car that were never treated to this process.
On the Mustangs there is nothing but this primer as the final finish under the car.
quote:Originally posted by PanteraDoug:
These are all great suggestions and I am not arguing with anyone or against them,
The term "best" was asked.
In my opinion the best is what Ford did to the production line Mustangs from 1965 on.
1)The exterior rocker panels were heavily galvanized 2)The boxed chassis was vat dipped in electrostatic enamel primer.
In many cases after more then 40 years, it is still in place.
Where corrosion has occured is in places on the car that were never treated to this process.
On the Mustangs there is nothing but this primer as the final finish under the car.
When I got married years ago I bought my wife a clean run around car....Little 4 door Japanese car and I cannot even remember the brand.
At one point I put a big gouge in the rear fender from a tool or something. It was a bout an inch long and dug into the metal. I always said I needed to paint it so it would not rust. We had the car for years and not only was there not a drop of rust on the car but even the bare metal gouge was clean as if it was freshly gouged.
I know there were a few years the iron ore was so bad in MGB steel they rusted form the inside out and there was nothing you could do to stop it.
Kitchenguy,
If you get your car blasted you need to pick a nice dry day and get the car home as soon as possible. Make sure your airline is producing totally dry air before you start blowing out the sand/soda or whatever, because this will cause it to flash rust before your very eyes. Paint the car the same day.
Dont worry about the surface rust in the seams there is nothing you can do about that. If the seams are buldging with rust you need to completely cut them out and make new. Do this before blasting. Seal seams with overcoatable seam sealer. This is the best way to keep the moister out.
I no longer use rust converters. I am not saying they dont work I just dont like them.
when I say two pack I am referring to any paint that is mixed with a catalyst. In the USA it would generally be referred to as urethane. I am not even sure if you can buy it any more now it's all gone water based.
Paint talk has always been confusing between the British and Americans.
What you call lacquer we call cellulose (full name nitro cellulose lacquer)
What you call enamel we call synthetic (full name synthetic enamel)
What you call urethane we call two pack (full name polyurethane)
What you call clear coat we have always called lacquer, although the term clear coat is now more popular.
Gary, is it your experience that epoxy primer adheres better than self etching (acid etch) primer?
Johnny
If you get your car blasted you need to pick a nice dry day and get the car home as soon as possible. Make sure your airline is producing totally dry air before you start blowing out the sand/soda or whatever, because this will cause it to flash rust before your very eyes. Paint the car the same day.
Dont worry about the surface rust in the seams there is nothing you can do about that. If the seams are buldging with rust you need to completely cut them out and make new. Do this before blasting. Seal seams with overcoatable seam sealer. This is the best way to keep the moister out.
I no longer use rust converters. I am not saying they dont work I just dont like them.
when I say two pack I am referring to any paint that is mixed with a catalyst. In the USA it would generally be referred to as urethane. I am not even sure if you can buy it any more now it's all gone water based.
Paint talk has always been confusing between the British and Americans.
What you call lacquer we call cellulose (full name nitro cellulose lacquer)
What you call enamel we call synthetic (full name synthetic enamel)
What you call urethane we call two pack (full name polyurethane)
What you call clear coat we have always called lacquer, although the term clear coat is now more popular.
Gary, is it your experience that epoxy primer adheres better than self etching (acid etch) primer?
Johnny
I have used POR15 and epoxy primer.
To make a long story short, I would use epoxy primer. Its bullet proof, sticks to everything (bare metal, paint, bondo, etc) and also provides a vapour barrier (as Comp said).
In my experience it also adheres way better than self etching primer and you dont have to worry about the moisture getting into it.
Will
To make a long story short, I would use epoxy primer. Its bullet proof, sticks to everything (bare metal, paint, bondo, etc) and also provides a vapour barrier (as Comp said).
In my experience it also adheres way better than self etching primer and you dont have to worry about the moisture getting into it.
Will
This is great info except that no one commenting here lives in communist California where all the paint products that are allowed are crap. I'm having to take my Acura back to the body shop to have the clear coat redone for the third time form a fender bender repair done three years ago. The owner of the shop tells me the California Air Quality Standards have killed even the paint he shoots in a filtered booth.
I'm probably going to have to drive out of state and buy some good paint for my engine compartment painting in the next few months.
I'm probably going to have to drive out of state and buy some good paint for my engine compartment painting in the next few months.
I paint every day for my living and the best thing in my opinion for sandblasted metal it epoxy primer. I get a 4 to 1 mix gallon and a quart from carolina auto supply for right at 100 bucks. Like Gary says you can topcoat without sanding during a 24 hour window. In humid environments the clean metal will rust quickly. Johnny hit it right to paint it straight away, and wear gloves to keep your salty fingers off the bare metal!
That is one of my pet peves. I blast a car to bare metal and someone comes in and lays their hand straigt on the body to take look. It is the same with primer. I want a sign which says keep your grubby paws off.
Then I watch all these old hot rod shows and everyone is touching bare metal cars and freshly primered cars. I think, am I living in a vacuum?
Then I watch all these old hot rod shows and everyone is touching bare metal cars and freshly primered cars. I think, am I living in a vacuum?
I can only speak for my myself, but I live 3 blocks from the Atlantic ocean on a small island outside of Charleston, where everything outside rusts and usually rusts quickly. When I starting removing the paint from my engine compartment and the rear wheelwells using heat, scrapers and wire wheels. I then treated the bare metal with Eastwoods Fast Etch, a zinc phosphate coating according to directions and did nothing else until I took it to the body shop 2 years later and not a spot of surface rust was present. This stuff worked for me and I will use it whenever I can.
quote:keep your grubby paws off.
I had a sign on my cars at all times during builds...
"Please do not touch
Parts may not be secure"
Works every time....
Here is what I do based on my own experience.
If I am spraying a car in PPG paint then I use the DP LF series of epoxy primers over blasted and sanded metal. The data sheet does not call for using a etch first on steel so I don't use one. It does call for one on aluminum or galvanized metal.
If I am Spraying BASF(Glasurit, RM) then I use RM's EP series of epoxy primers. The data sheet also does not call for a etch so I don't use one.
The blasting company I use uses a sand/plastic mix so I can have all exterior body panels done with no warping. The downside is the finish doesn't have much tooth and the plastic leaves a residue. I have to go over the entire car with 80 grit when I get it back.
I have the cars blasted on rotisserie, inside , outside and underside so it is not possible to clean and blow the car out (which takes a day) sand the whole thing and epoxy in a day. The process takes about a week. Once it is covered with epoxy then I start grinding and welding. If done before spark slag/welding spatter sticks to the bare metal and has to be sanded off.
I have never used POR 15 and cant comment on that but I will say that as long as I have known Gary, he is not one to shortcut things so I would trust his evaluation on that product.
I also agree with Gary, it drives me crazy to watch bare metal groped on tv shows, same with bare hands running over sanded primer.
Where you live does have a lot to do with it. My dad blasted his mustang a year ago with out coating it and there is no visible rust on the car yet.
Good luck with your project!
If I am spraying a car in PPG paint then I use the DP LF series of epoxy primers over blasted and sanded metal. The data sheet does not call for using a etch first on steel so I don't use one. It does call for one on aluminum or galvanized metal.
If I am Spraying BASF(Glasurit, RM) then I use RM's EP series of epoxy primers. The data sheet also does not call for a etch so I don't use one.
The blasting company I use uses a sand/plastic mix so I can have all exterior body panels done with no warping. The downside is the finish doesn't have much tooth and the plastic leaves a residue. I have to go over the entire car with 80 grit when I get it back.
I have the cars blasted on rotisserie, inside , outside and underside so it is not possible to clean and blow the car out (which takes a day) sand the whole thing and epoxy in a day. The process takes about a week. Once it is covered with epoxy then I start grinding and welding. If done before spark slag/welding spatter sticks to the bare metal and has to be sanded off.
I have never used POR 15 and cant comment on that but I will say that as long as I have known Gary, he is not one to shortcut things so I would trust his evaluation on that product.
I also agree with Gary, it drives me crazy to watch bare metal groped on tv shows, same with bare hands running over sanded primer.
Where you live does have a lot to do with it. My dad blasted his mustang a year ago with out coating it and there is no visible rust on the car yet.
Good luck with your project!
quote:I then treated the bare metal with Eastwoods Fast Etch, a zinc phosphate coating according to directions and did nothing else until I took it to the body shop 2 years later and not a spot of surface rust was present. This stuff worked for me and I will use it whenever I can.
Basically, it's Phosphoric Acid, available under various names/brands at drastically different prices, but all the same. Wipe down any freshly blasted metal with one of these products immediately after blasting to prevent flash rust. Then you'll be ready to coat with an epoxy primer (urethane, or whatever your paint mfgr recommends).
quote:Originally posted by JOEB:
I can only speak for my myself, but I live 3 blocks from the Atlantic ocean on a small island outside of Charleston, where everything outside rusts and usually rusts quickly. When I starting removing the paint from my engine compartment and the rear wheelwells using heat, scrapers and wire wheels. I then treated the bare metal with Eastwoods Fast Etch, a zinc phosphate coating according to directions and did nothing else until I took it to the body shop 2 years later and not a spot of surface rust was present. This stuff worked for me and I will use it whenever I can.
Hello Joeb,
When you used the Fast Etch product did it blacken the metal or just remove the flash rust and leave the metal looking like fresh clean metal. Also did you have to neutralize the fast etched metal before applying the epoxy primer.
Thanks again