Advice on metal sign painting........

[Runs With Scissors]

Well my "metal sign" skills are getting better, (not great, just "better") and I am at the point where I would like to start painting them.

I "transformed" my old "gaming room" into a makeshift spray booth with a homemade "spray rack".

I was using rattle cans, but the results are not very good, so I decided to buy an "El Cheapo" HVLP spray gun to try and "up my game"

Anyone have some advice on what types/brands of paint to use/begin with?

This one is for my grandson Colt.

 

[GreensvilleJay]

99.44% of a great paint job is the PREP !!! The actual painting part is easy.
The steel needs to be totally degreased. You'll KNOW it's clean when you can wipe a papertowel over all of it and NOT have ANY 'black' on it.
For best( long life) results, use an epoxy primer, allow to properly dry, sand, wipe with cleaner, then paint on 'colour coat'.

 

[Hugo Habicht]

If you want the paint to last the dark gray skin from the steel mill has to be removed. Not sure if your sign has that, on the pictures it looks clean.

Then sharp corners should be removed for better paint coverage, probably difficult in your case. Also depends, for indoor use this is not so critical.

Degreasing was mentioned already and silicone remover. The latter is required when you get those little spots where the paint does not cover. And of course a water / oil separator between compressor and spray gun.

And to make my life easy I would lay the sign flat. Much easier to avoid runners.

The paint you choose is not critical, important is that primer (if any) is compatible with the top coat. With rattle cans you can also achieve good results. As with a spray gun it is important to start the motion outside the spraying area and press the button at the edge of the spraying area. Keep the spray direction constant / parallel while spraying, do not use your wrist to change the angle. This way the speed while spraying is constant and you get even paint coverage.

Also with your sign which is really 3D due to the material thickness I would start by spraying all the edges from the cutouts at an 45 degree angle from all directions and at the end the bigger flat areas at the top. A bit difficult to explain all that in words.

Very nice sign by the way, and not easy, I am sure I would have forgotton the odd connection so that pieces would have fallen out

 

[Hugo Habicht]

Forgot one thing: excellent light is essential when spray painting.

 

[Tughill Tom]

I'd look into finding a Powder coater near you. Spraying inside your house with a HPLV and solvents is risky to say the least, to your health and the property.
After the nice job on the cut out of the sign it will be a much better finish than paint without the proper ventilation and filtration.
Good luck with it.

 

[Hugo Habicht]

I'd look into finding a Powder coater near you. Spraying inside your house with a HPLV and solvents is risky to say the least, to your health and the property.

Forgot to say: I spray outside. So that limits spraying activities for me to about 8 months of the year. You need the right temperature, somewhere close to 20°C (68F).

 

[Runs With Scissors]

Yes I agree, the most important of any paint job, is the prep.

I will take my time with that for sure.

I also agree my "spray booth" is far from "state of the art", and I am betting my "cigar ventilation fan" is not "OSHA approved" , but I did buy a new respirator that is.

However; It will all have to do for now, for these small projects.

My question is more of a "Oil based vs water based" or "Rustoleum vs One Shot" or " Phil Suckmeoff's paint store has the best deals on paint" types of advice.

I'm going to go out and see what Home Depot has to offer a little later, but I know exactly how that is going to go when I ask the 17 year old kid, a "mind bending" questions like...

"Should I use a catalyst with this"

or

"Can I use acetone to thin it?"

or God forbid a math question like "What is the best 'paint to thinner' ratio for spraying?"

Awwww Hell, just typing this is pissing me off, cause I know exactly how this story ends.......with this kid.

 

[Hugo Habicht]

I try to stay away from water based paints. Water + steel = corrosion. I am not a paint expert though, so I could be wrong. Automotive industry had a lot of problems with corrosion when introducing water based paints but as far as I know this had more to do with less coverage than solvent based paints around a tight radius.

If you use the spray gun get acrylic or polyurethane paint plus the matching hardener and matching thinner. The paint to hardener ratio should be on the tin, possibly the thinner ratio as well. If not ask the sales guy, every manufacturer has their own mix ratio. As a rule of thumb I add about 10-15% thinner for spraying if not specified.

When temperatures are acceptable and you spray something flat I would go for normal hardener, sometimes fast hardener is being offered for colder temperatures or slow hardener for higher temperatures. You want the paint to flow to get a smooth surface.

You should consider satin or maybe even matt for the sign. Reflections on glossy surfaces may be a disturbance.

When spraying mix the paint and set the correct amount of paint flow in the gun. Try on a piece of cardboard or newspaper. You want enough to get good coverage and the paint to flow to a nice surface and in a reasonable amount of time but you do not want too much to avoid drips when you do small intricate corners. Again, a bit difficult to describe, but a bit of experimenting on the cardboard you will see quickly what you are happy with.

If you have vertical surfaces as well it helps spraying a thin coat, not fully covering first, and then wait 10 minutes or so before the final coat. This helps a lot to reduce drips.

 

[Russell King]

Be careful with the polyurethane and other high end paints. The fumes are dangerous so you need a really good mask that covers your face and eyes. I like Epoxy primers and polyurethane top coats for exterior items. Buy the same brand primer as top coat. Get all the parts of the paint you need (Sometimes 2 sometimes 3).

For an interior steel sign I would probably go acrylic paint over a good primer. You can get a good sand able primer and remove any runs or blemishes before top coating.

Have fun and don’t be afraid to sand and polish the finish coating but be gentle with the sanding.

 

[North Idaho Wolfman]

I can tell you this, spraying any solvent based paint indoors is INCREDIBLY DANGEROUS.
You are making the perfect conditions for any spark to turn your place into a debris field with a crater!

I use a ton of DTM (direct to metal) water based paints.
They have come along way over the years.
They work incredibly well on steel and last.
You can get them in any color.
They are much cheaper than solvent based paints.
You can have them mailed / shipped to you because they are not considered hazardous materials.
They are safe for an indoor paint room, as they are not flammable.
Clean, prime, paint, simple as that.
If you really want to make them a tough finish use a Poly top coat.
And yes you can do a water based poly too.

One other thing is clean up is a breeze, and all of it is so much cheaper.

Ratio on a paint gun varies on the tips and on the pattern and the paint.
I typically thin it to a light creamer consistency.

 

[GeoHorn]

I have had excellent results with a Home Depot rattle-can paint that sells for 97-cents (before tarriffs)…in Gloss Black, Flat Black, Gloss White, Flat White. (Painted an all steel home made trailer which was floored with C-purlins…with their Flat Black…stored outdoors in weather for the last 12 years…. and it has done well. I probably will pressure-wash and paint again this year as the paint is just now begining to rust again in spits.

Otherwise, My favorite rattle-can paint is Rustoleum. They always do a good job.

It is indeed important that the steel be crystal-clean. No primer needed with Rustoleum.

 

[North Idaho Wolfman]

I have had excellent results with a Home Depot rattle-can paint that sells for 97-cents (before tarriffs)…in Gloss Black, Flat Black, Gloss White, Flat White. (Painted an all steel home made trailer which was floored with C-purlins…with their Flat Black…stored outdoors in weather for the last 12 years…. and it has done well. I probably will pressure-wash and paint again this year as the paint is just now begining to rust again in spits.

Otherwise, My favorite rattle-can paint is Rustoleum. They always do a good job.

It is indeed important that the steel be crystal-clean. No primer needed with Rustoleum.

When in the heck was the last time you shopped for spray paint for $.97?
The cheapest HD paint (and its junk) it's $2.78.

 

[GeoHorn]

When in the heck was the last time you shopped for spray paint for $.97?
The cheapest HD paint (and its junk) it's $2.78.

If you shop online…Yes…they do not display the product.

But I’ve used so much of it that I last bought an entire box of it. No discount offered for the bulk purchase tho’….. LOL.

I’ll try to post a pic tomorrow of the actual product…. at the moment…it’s 3:32 AM and I’m going back to sleep.

 

[Runs With Scissors]

I agree that there are different quality levels of "rattle can" paint.

My favorite is the Rusoleum 2X. It is definitely a "cut above".

That 97 cent paint is terrible IMHO. I get more of it on the floor than on the project.

Regardless of which one I use, the results are typically from "barely OK" to "poor" , so it's time to "up my game".

I decided to save myself the aggravation of fighting traffic, and going to HD.

I will find an online retailer and give a "water-based" paint a whirl.

 

[Hoserman]

RWS You did an awesome job on that Colt sign. I've never attempted anything like that but it sure looks great. As far as paint goes Rustoleum is all I use on anything ferrous.

 

[BBFarmer]

I'm going to go out and see what Home Depot has to offer a little later, but I know exactly how that is going to go when I ask the 17 year old kid, a "mind bending" questions like...

"Should I use a catalyst with this"

or

"Can I use acetone to thin it?"

or God forbid a math question like "What is the best 'paint to thinner' ratio for spraying?"

Awwww Hell, just typing this is pissing me off, cause I know exactly how this story ends.......with this kid.

View attachment 154474

 

[Sidekick]

When blowing the residue outside with a fan, put a filter on it so the outside of your house or neighbors cars don't wind up with a light mist of paint that you find has hardened by the time it is noticed. Wind direction can distribute paint droplets far. That paint will outgass for days if not baked. An airbrush and several different colors can give a nice aged look to a sign like that. I like to glass bead plasma cut items before painting to remove sharp corners and mill finishes that don't cover well. Big stuff gets sand blasted outside. Can't wait to see the finished sign.

 

[Runs With Scissors]

RWS You did an awesome job on that Colt sign. I've never attempted anything like that but it sure looks great. As far as paint goes Rustoleum is all I use on anything ferrous.

Thanks for the kind words.

It was/is the most challenging sign that I have attempted so far.

It took quite a while to draw it on the computer, but I am happy with the result.