What is a 'coat of paint'?

[badabec]

Hello, when spraying car panels, what is a coat of paint?
I'm spraying cellulose in the engine bay. I spray the bulkhead until it looks wet, then move to the sides and then the front. Once I've sprayed the front, I go back to the bulkhead and get it wet again. I go back and forth like this maybe three ir four times.
Is this one coat, or three or four?

I never know when to stop!

I'm having trouble with inside corners. The air pressure prevents the paint from wetting the corner. Is there a trick to this?

Thanks

 

[Screwdriver]

Ah, is this one of those "how long is a piece of string" conundrums.

Regards corners, I assume there will be a technique similar to "cutting in" where you concentrate more on that area before giving it the full monty.

 

[Kram]

A coat is the complete item, wetted once, and allowed the solvents to flash off before doing another coat .. as I understand it.

 

[tigdlo]

Data sheets often give a wet film thickness per coat but I have no idea how to measure, I tend to build coats as thin as I can but fully wetted out and have acheived some very good finishes like that.

I'm having trouble with inside corners. The air pressure prevents the paint from wetting the corner. Is there a trick to this?

Spray the areas that will be missed by the main passes of the spray gun first, inside corners, edges, awkard shapes, etc

 

[brightspark]

Data sheets often give a wet film thickness per coat but I have no idea how to measure, I tend to build coats as thin as I can but fully wetted out and have acheived some very good finishes like that.

Spray the areas that will be missed by the main passes of the spray gun first, inside corners, edges, awkard shapes, etc

yep thats what you normally do on resprays

 

[Ross365]

Paint companies often quote times for the paint to be 'touch dry', and also, for the paint to be ready for the next coat. I guess that for the latter, you want all the solvent to be gone, and some of the 'chemistry' to have started. Perhaps you could make an argument about what is a coat based on the time between applications?

 

[Morrisman]

Whatever you're happy with.
Or just keep going until the spray gun is empty.

 

[Turbo]

For inside corners, etc use the guns settings to get a narrow spray & use that (reduce the paint flow accordingly)

 

[beeRS]

Hello, when spraying car panels, what is a coat of paint?
I'm spraying cellulose in the engine bay. I spray the bulkhead until it looks wet, then move to the sides and then the front. Once I've sprayed the front, I go back to the bulkhead and get it wet again. I go back and forth like this maybe three ir four times.
Is this one coat, or three or four?

I never know when to stop!

I'm having trouble with inside corners. The air pressure prevents the paint from wetting the corner. Is there a trick to this?

Thanks

Doing what you describe here is what I would call three or four coats. This is not one coat. The actual paint film thickness achieved will vary from painter to painter.
For the inside corner try lowering the air pressure slightly and spraying these areas first.

 

[frank horton]

I paint inside corners at least twice before painting the rest.....
that way the corners stay wet...

 

[Burdekin]

One full coat I reckon is a wet coat so when you do one pass it looks fluid and then with 50% overlap with each pass. First coat is normally a lighter coat as you don't want runs and then second a full coat as it now has something to stick to. Just my take on it.

 

[Burdekin]

Hello, when spraying car panels, what is a coat of paint?
I'm spraying cellulose in the engine bay. I spray the bulkhead until it looks wet, then move to the sides and then the front. Once I've sprayed the front, I go back to the bulkhead and get it wet again. I go back and forth like this maybe three ir four times.
Is this one coat, or three or four?

I never know when to stop!

I'm having trouble with inside corners. The air pressure prevents the paint from wetting the corner. Is there a trick to this?

Thanks

You need to stop and let the paint flash off to properly and evenly build layers. Don't worry if first coat is not perfect and not fully covering.

Try a narrower fan for the inside corner and turn the pattern to horizontal.

 

[Smallfry]

In corners I have always given them a flit first. If the corner is vertical, flash up (or down) with a vertical fan, and a horizontal fan for horizontal corners.

Be careful not to put on too much paint or it will run, and let it flash off before doing the main panels.

You are doing several coats at once, which is OK as long as it doesn't run, but remember that the more coats you apply, the easier the finished job will chip.

 

[badabec]

Whatever you're happy with.
Or just keep going until the spray gun is empty.

Hello, that is exactly what I do!
I made a schoolboy mistake with the plastic sheet I am using to mask the rest of the car. I saw it said 'paint this side'. I started masking up taking that notice into account. Then found the sheet was doubled and the message was on the wrong side.
Of course I kept going. OK for first day. Next day, a quick blast with the air gun and hundreds of tiny paint flakes filled the air.
I masked over the top, the correct way round.
Stupid boy...

 

[badabec]

This is the engine bay. It doesn't include the wheel arches. So far I sprayed on 400ml paint diluted to 800ml with anti-bloom thinners

 

[badabec]

That picture was taken after a couple of coats of Jotun 87 applied with a brush and roller.

 

[ajlelectronics]

Painting starts with all the intricate areas. Remember that you can reduce the fan width and paint flow for those where needed. Either use the gun cocked or turn the fan around to do vertical passes. First coat should be just a light one, followed by normal paint flow for the rest. Start at the top of one panel and give one sweep to the other end, holding the distance and speed constant. You may need to adjust sweep speed to give you the correct application. Follow down the panel with 50% overlap until complete. That is one coat. Allow to flash and then apply the next coat. With 1K thin coats are essential as is proper flashing time. Final coat should be 75% thinners and take care with how much is being applied to the panel to avoid runs. You should end up with a reasonable finish straight from the gun.

 

[Smallfry]

Hello, that is exactly what I do!
I made a schoolboy mistake with the plastic sheet I am using to mask the rest of the car. I saw it said 'paint this side'. I started masking up taking that notice into account. Then found the sheet was doubled and the message was on the wrong side.
Of course I kept going. OK for first day. Next day, a quick blast with the air gun and hundreds of tiny paint flakes filled the air.
I masked over the top, the correct way round.
Stupid boy...

Of course I have never done this.........

Years ago when I lived at home, I sprayed mums Hillman Imp. She didnt want the nice white walls covered with overspray, so I hung curtains of polythene sheet all round and over the doors, plus stapled it to the underside of the rafters. It was all fine until I came back it ten minutes later to admire my work

 

[badabec]

Tadaa....

 

[beeRS]

Looks like a job done well