Primer...

[Tango]

Some (not all) self etching primers are intended only as a reactive base for metals such as galvanized and aluminum and require a bonding primer on top before the final coat of paint. Some can be painted over directly. Definitely check the labels.



Conventional paint (including ordinary primers) will NOT adhere to galvanized or aluminum.

[Brewerbob]

Originally Posted by Tango

Some (not all) self etching primers are intended only as a reactive base for metals such as galvanized and aluminum and require a bonding primer on top before the final coat of paint. Some can be painted over directly. Definitely check the labels.



Conventional paint (including ordinary primers) will NOT adhere to galvanized or aluminum.

Damn it man, give me names!!! You old crusty farts that have been in the business for two and three quarters forevers are supposed to know these things. I don't want to have read the entire paint aisle of Home Depot only to find out I should have been at Advanced Auto in the first damn place,

[PNW_Steve]

Originally Posted by Brewerbob

Damn it man, give me names!!! You old crusty farts that have been in the business for two and three quarters forevers are supposed to know these things. I don't want to have read the entire paint aisle of Home Depot only to find out I should have been at Advanced Auto in the first damn place,

I am way off in the weeds with the priming process. Not really sure that I made a good choice on the SEM and I am clueless as to what kind of primer to cover it with before I paint with Rustolium Implement paint.

Hopefully we can get this figured out.......

[Brewerbob]

Originally Posted by PNW_Steve

I am way off in the weeds with the priming process. Not really sure that I made a good choice on the SEM and I am clueless as to what kind of primer to cover it with before I paint with Rustolium Implement paint.

Hopefully we can get this figured out.......

Wrong old fart this time.

[Ninjakitty]

I've decided I'm just using rusty metal primer since I can't find gallon cans of rustoleum clean metal primer

[Brewerbob]

Originally Posted by Ninjakitty

I've decided I'm just using rusty metal primer since I can't find gallon cans of rustoleum clean metal primer

You found this place so you can probably find the rest of the internets.
Can't find anything on Amazon or local paint/body shops? Brevard county ain't exactly deep in the woods.

[Ninjakitty]

Originally Posted by Brewerbob

You found this place so you can probably find the rest of the internets.
Can't find anything on Amazon or local paint/body shops? Brevard county ain't exactly deep in the woods.

[emoji849] Ehhh... I didn't look online...

I'll go back to my corner now...

[Brewerbob]

Originally Posted by Ninjakitty

[emoji849] Ehhh... I didn't look online...

Before I buy, I'm looking everywhere including online. $100 a gallon insults my wallet like you wouldn't believe. I'm old and cheap. Paint ain't supposed to cost anywhere near that much.

[HappyInTN]

Originally Posted by PNW_Steve

Still looking for the best choice for primer.

I have found Rustolium Self Etching but only in rattle cans.

I found Rustolium Industrial Primer in gallons: https://www.zoro.com/rust-oleum-prim...02/i/G2255513/ but it is not self etching.

I found SEM Self Etching Primer in gallons: https://www.amazon.com/39681-Self-Et.../dp/B000K27IG2

Not very pleased with how the Rustolium rattle can primer that I have used so far. It is not sticking well.

Suggestions??

BTW: I plan on (mostly) spraying the finish.

Most of the skoolie people in my circle didn't use primer. We sanded the bus to roughen the original paint and rolled rustoleum professional enamel right over top. We are all seeing great success. I added paint hardener to mine but only time will tell if that helps its durability at all. If you have rust spots.. you can get the rustoleum in the aerosol can that is for rust covering. Mist those few places then you're back in ready to do the final paint. Good luck.

[Brewerbob]

Originally Posted by HappyInTN

Most of the skoolie people in my circle didn't use primer. We sanded the bus to roughen the original paint and rolled rustoleum professional enamel right over top. We are all seeing great success. I added paint hardener to mine but only time will tell if that helps its durability at all. If you have rust spots.. you can get the rustoleum in the aerosol can that is for rust covering. Mist those few places then you're back in ready to do the final paint. Good luck.

We are painting bare sheet metal, not painted bus parts. No idea if that make a difference or not. I'm guessing it does?

[PNW_Steve]

Originally Posted by Brewerbob

We are painting bare sheet metal, not painted bus parts. No idea if that make a difference or not. I'm guessing it does?

My best understanding is that bare metal should definitely be primed properly for optimal adhesion.

On a surface that already has a solid paint surface, priming is optional. You would want to stuff the surface with a scotchbright pad or fine sandpaper to give it "teeth".

On my new, bare metal surfaces I did the following:

Washed the bus with soap and water.

Rinsed thoroughly.

Sanded with 320 grit on a random orbital sander.

Wiped down with acetone twice.

Sprayed three light-medium coats of SEM self etching primer.


It was not until I received the SEM primer that I found out that they don't recommend applying color directly over this primer.

I want a long lasting and good looking finish. I need to figure out what a choice of primer will perform well in this application.

[Njsurf73]

There are several options for painting bare metal. And it will depend on the top coat as well. If you are doing automotive paint, then a self etching primer followed by a fill and sand primer then top coat.
If you are doing an oil based (alkyd) paint, a good metal primer (just about any brand) will work. I personally prefer an industrial primer called kem-kromic. It is durable and coatable by just about any non-automotive paint or coating. It's expensive compared to regular red oxide primers, but it is the first layer if protection on your metal.
That brings me to my next favorite primer for metal. Red oxide. It sprays better than it brush and rolls, but if you roll it on and knock the high spots down with 300 grit or finer sandpaper it can really work well.
That brings me to number 3... Spray if at all possible. A $20.00 hvlp gun from harbor freight will give better results than an airless sprayer and that will be better (more uniform) than brushing and rolling.
Point the 4th... If you have bare metal you have built in practice... Practice on the reverse side.. prime and paint the reverse side to dial in your technique... Your level of reducer... And to see I the results are what you are expecting.
If you are going to use automotive paint... You will have to talk to someone who knows more about that than I do... I have primed out an entire car using the self etching primer and a fill and sand primer... But I left the top coat to an automotive painter.
A really good resource this can find a commercial Sherwin Williams paint store.. they have them in most major areas and they are quite knowledgeable on different products that work well in any environment and on any surface. You may think I work for Sherwin-Williams by the way I push their paint but in 20 plus years of painting I used their commercial products more than anyone else's with ICI a close second.
Feel free to pm me with any questions.. I am happy to help any way I can

Originally Posted by Brewerbob

We are painting bare sheet metal, not painted bus parts. No idea if that make a difference or not. I'm guessing it does?

That's what my bus looks like.
Sherwin Williams industrial enamel hs
Light sanding of the original paint and a solvent wipe with xylene.

[Ninjakitty]

I used galvanealed sheet metal (paint ready) so I probably don't need to prime but I will feel better about it if I do.

[Njsurf73]

In my many years of painting anytime we had to paint anything galvanized we had to pickle it first. Not as we had to wipe it with an acid solution in order to have anything bond to it. There may be paint ready galvanized Coatings but I have never seen it so I would double check to make sure it is paintable and what it is paintable with.

[PNW_Steve]

Originally Posted by Njsurf73

There are several options for painting bare metal. And it will depend on the top coat as well. If you are doing automotive paint, then a self etching primer followed by a fill and sand primer then top coat.
If you are doing an oil based (alkyd) paint, a good metal primer (just about any brand) will work. I personally prefer an industrial primer called kem-kromic. It is durable and coatable by just about any non-automotive paint or coating. It's expensive compared to regular red oxide primers, but it is the first layer if protection on your metal.
That brings me to my next favorite primer for metal. Red oxide. It sprays better than it brush and rolls, but if you roll it on and knock the high spots down with 300 grit or finer sandpaper it can really work well.
That brings me to number 3... Spray if at all possible. A $20.00 hvlp gun from harbor freight will give better results than an airless sprayer and that will be better (more uniform) than brushing and rolling.
Point the 4th... If you have bare metal you have built in practice... Practice on the reverse side.. prime and paint the reverse side to dial in your technique... Your level of reducer... And to see I the results are what you are expecting.
If you are going to use automotive paint... You will have to talk to someone who knows more about that than I do... I have primed out an entire car using the self etching primer and a fill and sand primer... But I left the top coat to an automotive painter.
A really good resource this can find a commercial Sherwin Williams paint store.. they have them in most major areas and they are quite knowledgeable on different products that work well in any environment and on any surface. You may think I work for Sherwin-Williams by the way I push their paint but in 20 plus years of painting I used their commercial products more than anyone else's with ICI a close second.
Feel free to pm me with any questions.. I am happy to help any way I can
That's what my bus looks like.
Sherwin Williams industrial enamel hs
Light sanding of the original paint and a solvent wipe with xylene. Attachment 26794

Thank you for the tips.!!

I am spraying with the HF HVLP.

could you offer any suggestions of specific primer and which Sherwin Williams paint would you recommend?

Color selection is not a big deal. We are planning on going white on the whole bus and add accents later.

Thanks again.

S.

Edit: I missed your reference to kem-kromic. Will check it out.

[Ninjakitty]

Originally Posted by Njsurf73

In my many years of painting anytime we had to paint anything galvanized we had to pickle it first. Not as we had to wipe it with an acid solution in order to have anything bond to it. There may be paint ready galvanized Coatings but I have never seen it so I would double check to make sure it is paintable and what it is paintable with.

I'm sure it's galvanealed and not galvanized. It's the paint ready steel

[Njsurf73]

Any sprayable primer. There will be instructions on the label on how much to reduce it. The HVLP gun should have come with a meter... you put a predetermined amount of paint in that meter and time how long it takes to run out... As I said my favorite primer is chemchromic.. kem-kromic (sw name) and there are dozens of good top coats that can be sprayed with an HVLP. I used the industrial enamel High solids because it is a solid mix of performance for price. I haven't been in the painting business for over 5 years and there has been quite a bit of advancement in waterborne enamels. They have a direct to metal or D TM that has improved immeasurably. There are also several water-borne enamels and waterborne epoxies that are every bit as durable and maybe even better than oil based paints. But in my old school way of thinking a good solvent based coding is going to give you the best protection. and as far as colors go even if you do basic white they can tint anything these days. So if you were going to do as I am going to do which is Paint The Bottom third of the Bodywork a darker shade... You can paint exactly what you need to weigh and just buy another gallon of the darker paint. I always recommend using industrial enamel HS.. one word of caution use in a well-ventilated area and wear gloves as it is reduced with xylene and that stuff is no good for you soaking into your skin or breathing into your lungs.

[Njsurf73]

As far as Rust-Oleum goes.. Rust-Oleum is a residential paint. They claim to be commercial grade or industrial grade... But there paint is no better fan the bottom of a line oil-based paints you would get from any major paint manufacturer that you would use to paint metal door frames on an interior job. The higher-priced Rust-Oleum is just that higher-priced Rust-Oleum. They're rusty metal primer is no more than anyone else's metal primer. And I don't care what the label says you still have to prepare the surface if you want a good finish. If you are looking to paint directly over heavy rust and don't care about the Finish... Macropoxy (2 part) primer and hundred percent solid urethane for a top coat.. will outlive all of us... But it sure won't be pretty [emoji23] and it's pricey.
A good industrial primer, (red oxide) on properly prepared metal with a top coat of a good enamel or even a good alkyd enamel will last five to ten years easily... I know that doesn't sound like a lot compared to automotive paint but this isn't automotive paint.
To my original point about Rust-Oleum... It's expensive for what you're getting.
some of their Specialty Products were crate around the house but I wouldn't use them in an industrial setting

[EastCoastCB]

Originally Posted by Brewerbob

Damn it man, give me names!!! You old crusty farts that have been in the business for two and three quarters forevers are supposed to know these things. I don't want to have read the entire paint aisle of Home Depot only to find out I should have been at Advanced Auto in the first damn place,

If you want REALLY good paint/primer just abandon the Home Depot now.

[EastCoastCB]

Originally Posted by PNW_Steve

I am way off in the weeds with the priming process. Not really sure that I made a good choice on the SEM and I am clueless as to what kind of primer to cover it with before I paint with Rustolium Implement paint.

Hopefully we can get this figured out.......

If its compatible with oil based enamels you could just use rusto primer.