Painting options

[rons]

hm, thats interesting, because every time i tried spraying a water based paint there was no coverage. iv had pitting in the fresh paint on two occasions, obviously because of "wrong" surface prep. i dont touch it any more, but i dont have to.

Watch a youtube video about Ferrari or Porsche manufacturing. The automatic paint rigs make it look easy. Looks like the paint heads are
sprinkling sugar on the panels. There are also manual paint ops.

Those setups have exhaust air carrying the fog away from the painter. In a booth without a down draft the place fogs up and you can't see
what you are doing. Seeing how the paint is getting laid down can allow for some manual corrections during the process. Like if a corner is not
done yet.

Powder coat is like coating any object with porcelain. Try removing some with sandpaper. Very tough.

 

[Spud]

hm, thats interesting, because every time i tried spraying a water based paint there was no coverage. iv had pitting in the fresh paint on two occasions, obviously because of "wrong" surface prep. i dont touch it any more, but i dont have to.

Are you someone that sprays fast or are you a slow and methodical sprayer? I bought a new Sata 4000 digital HVLP with a 1.3 tip for my college Automotive program, and it was what I used for the solvent paints. It always required a lot of fussing about with the pressure and fan spray, and even then most times there was orange peel for the clearcoat. The Sata is a fast gun. When I used an Iwata Supernova for the waterborne paint, I got it right on the first attempt. The Iwata is a slow gun, for people who move slowly and methodically, which suits my style of spraying.

 

[memphisjed]

Take your parts to an auto body shop to get painted. They have the equipment and skill. Powder coating is a lot cheaper- likely faster option. I wouldn't put one over the other in the durability range.

 

[eKretz]

Take your parts to an auto body shop to get painted. They have the equipment and skill. Powder coating is a lot cheaper- likely faster option. I wouldn't put one over the other in the durability range.

I would. Almost all the paint I've stripped from steel removes easily with a sanding disc. Conversely, almost all powdercoat is a *@!%×#*@ to get off even with a sanding disc.

 

[dian]

Are you someone that sprays fast or are you a slow and methodical sprayer? I bought a new Sata 4000 digital HVLP with a 1.3 tip for my college Automotive program, and it was what I used for the solvent paints. It always required a lot of fussing about with the pressure and fan spray, and even then most times there was orange peel for the clearcoat. The Sata is a fast gun. When I used an Iwata Supernova for the waterborne paint, I got it right on the first attempt. The Iwata is a slow gun, for people who move slowly and methodically, which suits my style of spraying.

this is way above my head. i often just use an air brush. the last time i tried water based paint was when wife bent her bumper. after three coats the base coat was still shining through. i got tired after an other two and the spot is clearly visible even if dirty. i dont doubt that in a production environment where everything is figured out water based paint works. it obviously does.

 

[kb0thn]

I am surprised at the universal love for powder coat durability in this thread.

I find it to be anything but durable on edges of parts. We've made thousands of different weldments over the last 15 years. And all of them loose the powder off the thin edge. Peels right off. Won't stick to the laser cut edge. Hit it once and the whole thing goes. So we've had the vendors sandblast before powder coating. Slightly better, but basically the same thing. The edges always fail. The big flat areas do better, but if they have a problem then multiple square inch chips come off.

The thing powder coat has going for it, in my opinion, is that it is cheap. Pressure wash off the parts with slightly acidic cleaner. Air dry. Put on rack. Puff powder on. Into the oven. Done. You get an attractive looking finish for cheap. There is a shop in my industrial park that powder coats. I can drop off a skid of stuff in the morning and have it back in time to ship in the afternoon.

But if it is anything we care about durability, especially edge durability, we go to wet paint. Industrial epoxy paint, primarily.

And if it something we actually want to be protected outside, we go full hot dip galvanize.

FWIW

 

[eKretz]

I am surprised at the universal love for powder coat durability in this thread.

I find it to be anything but durable on edges of parts. We've made thousands of different weldments over the last 15 years. And all of them loose the powder off the thin edge. Peels right off. Won't stick to the laser cut edge. Hit it once and the whole thing goes. So we've had the vendors sandblast before powder coating. Slightly better, but basically the same thing. The edges always fail. The big flat areas do better, but if they have a problem then multiple square inch chips come off.

The thing powder coat has going for it, in my opinion, is that it is cheap. Pressure wash off the parts with slightly acidic cleaner. Air dry. Put on rack. Puff powder on. Into the oven. Done. You get an attractive looking finish for cheap. There is a shop in my industrial park that powder coats. I can drop off a skid of stuff in the morning and have it back in time to ship in the afternoon.

But if it is anything we care about durability, especially edge durability, we go to wet paint. Industrial epoxy paint, primarily.

And if it something we actually want to be protected outside, we go full hot dip galvanize.

FWIW

Can you radius the edge? It can be hard to get the edges right with powdercoat because of the way the electrical fields that attract the powder are oriented at corners. That makes it a bit difficult to get a thick coat on sharpish corners. I've not had the peeling problem myself.

 

[rons]

I ordered 2 quarts of hardener and 2 quarts of black. Imron 2.1. Sounds like a small order and I'm not painting cars right. Made no difference to this guy I was talking to.
I would buy from them again. Even the shipping cans were in thick plastic bags with nylon ties at the top.

Welcome to Johnson Supply Company - 218-722-1717

 

[dian]

are the prices they put there per quart, gallon?

 

[rons]

The prices are mostly for gallons. But the quantity in the gallon can is sometimes measured out as 3 quarts for mixing with 1 quart of activator.
Since the mix ratio is 3 to 1. Sometimes the quantity is measure as 4 quarts. When you order you can specify.

Go to the "Industrial" section, that paint is cheaper than the car paint.

The current prices on the website probably are not current. The black cost me a little more than listed.
The activator is priced as a pint, slightly less than a quart (80%), and a full quart. I don't know the reason for the 80% quantity can
but the price is 80% of the full quart.

Search Results for: 9T00

I bought two full quarts of black - $104.77
Two quarts of activator (80%) - $112.98
Shipping - $29 (from MN.)

No tax charged.

 

[dian]

so you got 2 2/3 quarts of paint for $142? $53 per quart? if we are talking such prices maybe a look a cerakote would be appropriate.

 

[rons]

If I bought a gallon of black the price would less. I still bought double what I normally use.

Using a 3 to 1 mixing ratio and considering that the activator is more money:

The actual cost for a mixed quart of black is $56.94. A mere pittance compared with:
paint gun cost.
fresh air system
paint booth
prep time
re-do time
cleanup
lacquer thinner or acetone ($22.97 and $20.97) at Home Depot.
waiting for the stuff to cure. (can be a week in 50-60 temp range)

See if anybody knows if PPG is any way better/cheaper. Never tried the stuff.

 

[rons]

One way I use to save paint is not to mix the paint and hardener in a container.

Use the paint cup. Fill the cup first with a bit of thinner, just so that the level is above the intake hole.
Then add paint with spoon 1. Add hardener with spoon 2. Use spoon 3 for the reducer. Transfer an amount from spoon 3
to either spoon 1 or 2. The spoon 1 or 2 is dumped into the cup. Automatic pre-clean operation while adding reducer.
Each spoonful (Cream anybody) can be filtered. So my cheapo idea is to drain as much stuff into the paint cup
with minimal waste and cleanup. I don't see any reason why I can't use the reducer as a cleaner at the same time.

The first blast of the gun is usually for checking the spray pattern. So the residuals down below the paint gun bottom hole
will be ejected at that time. For me it didn't make any difference during a flash coat

 

[Bill D]

I remember years ago reading that the cheap way to get a good paint job was to take you small project already prepped and masked to a auto body paint shop. Ask them to paint it next time they did a full car of a color similar to what you want.
Bill D

 

[Tobias-B]

Thirded for finding an auto body shop that will take your money.

They'll have all the chemicals and processes worked out, and you can
see if it actually works.

You'd want a smaller, independent shop- often, the owner will just set you up
with his painter, and the two of you can figure out prep, timing, etc.

t

 

[rons]

Are you someone that sprays fast or are you a slow and methodical sprayer? I bought a new Sata 4000 digital HVLP with a 1.3 tip for my college Automotive program, and it was what I used for the solvent paints. It always required a lot of fussing about with the pressure and fan spray, and even then most times there was orange peel for the clearcoat. The Sata is a fast gun. When I used an Iwata Supernova for the waterborne paint, I got it right on the first attempt. The Iwata is a slow gun, for people who move slowly and methodically, which suits my style of spraying.

I was looking to buy an Iwata or a Sata gun. I was looking at a Tekna too. A paint technician recommended a Sata 3000 HVLP RP with a 1.2 tip.
He said that a standard 1.3 tip would be on the fast side and a 1.2 would be good for clears and everything else.

When I get orange peel I don't blame the gun.

I am not a fast gunner. But if it's only good if the work is mostly flat and you can sweep back and forth.
With something like an electrical box the inside takes more time to cover. A fast approach will not get the
same coverage in the corners compared to the flats.

 

[rons]

I have two applications in mind: custom one-off jobs I'm going to give to machine shops, and manufactured electronic cases similar in form to a rack server (think pizza box, maybe thicker). The latter would be aluminum (probably a 606x alloy), and the former maybe 1018 or 1045 steel.

I would like to see a micro size case built without using a bending machine. This size is in between the full size cpu and the mini size boards.