FYI about painting with spray bombs

[ray66v]

"Step: 4 Try to apply the paint so that you don't have to sand it at all. worst case, you only have to sand the last coat. Sand with 600 grit, (by hand). "

This confuses me a bit, why would I sand my finish coat at all?


Also if you don't mind what are your thoughts on the quality of spray cans? you think they can be just as effective if applied properly?

I'm confused too, here is the quote:

"4th, I sprayed 1 really light coat of the regal red and let dry, sanded with 800 grit and applied 2nd coat at medium coverage, let dry then sanded again with 800 grit, finally I finished the 3rd coat at medium/heavy coverage and let dry."

Ideally you don't sand the color coats at all, But you can sand either the next to last coat, apply a final coat, and clear. Or, sand the last coat and clear, the latter only works with solid colors, no metallics, and works well on dark colors, especially black.

The quality of the paint in spray cans is limited. First because, they cannot use hardener in them, (the shelf life is only about 2 days with hardener). The hardener makes the paint adhere better, and helps with gloss holdout.
They are also limited because the material has a lot of thinner to be able to spray well. High amounts of solvents mean low amounts of actual paint. And this thinner/reducer is not always the right one for your project or of high quality. It is usually medium dry, poor quality, so it can be used in cool and hot temperatures universally, and sold at a low price. To be able to control the drying with the solvents that match your conditions is the advantage of mixing and spraying your own paint.
Spray can primers are much lower quality then top shelf automotive primers. Again no hardener, and no way to get a true "etching" primer in a spray can. I know some are marketed as "etching" it is not really an etch that is going to be effective. The primer is the most important part of the finish.

This is not to say you cannot do beautiful work with spray cans. For me, it would be like making me do the job with my hands tied.

 

[Papasmith]

First, that Rustoleum rusty metal primer is great. I had a piece of equipment exposed to the elements for years with only a good coat of this on it and it endured. It also seems to hold the paint really well.

Secondly, the comment about spray cans coming with mostly solvents and little actual paint is dead on along with the detriment of not having the opportunity to add a hardener.

If you already have an air compressor, you might have been economically better off buying an inexpensive spray gun and then buying the paint including the rusty metal primer in bulk. Ebay has HVLP guns from $60.00 for a Devillbliss. There is even have a cheaper model for 20 some bucks. A spray gun would make it a lot easier to do a good job with the ability to include additives and the better spray pattern. Plus, as a bonus, you'll stilll have the gun for other projects later on down the road.

Anyway, it sounds like you're doing a great job on it and hope you will post some pictures of the finished job.

 

[Skyco]

Ditto on the cheap spray gun. I find even the most inexpensive POS HarborFreight spray gun is far superior to a spray can. I now only use spray cans for quick touch up or painting of a small piece. Any work that needs more than about one or two cans- you've already spent, and thrown away, almost what an actual HF spray gun on sale costs I also find what seems to be the exact same brand and color paint in a quart can rather than the diluted spray can version is a much, much better more durable paint.