The Stovebolt Site Forums The Shop Area Paint and Body Shop Rattle Can Paint

Just wondering if anyone else has issues trying to spray a decent paint job from a can. I've used spray paint for years with very good results, but lately it seems like all the can wants to do is spit out paint instead of spray it. I'm not spraying a whole vehicle, just parts and pieces. Read here in the forum about using "Rustoleum" Canvas White for a good color match for the inner bars on the 47-53 AD grilles. I bought a can, tried it on some scrap metal, and yes the color is a wonderful match. However, the can does more spitting than spraying, and lots of little specs of I don't know what come out and become part of the finished paint (all from a brand new can). I have had the same issue with other color's and brands recently too. So I'm wondering it's just me or if others notice this also. Maybe the paints are just made poorly, or the can and/or nozzles aren't what they used to be. Any comments are welcome.

Tom

I had good luck with the Canvas White I bought, but rattle cans are hit or miss. I've had cans that wouldn't spray at all when brand new, and some that have clogged about halfway thru a job. I've removed the nozzles to soak them in thinner only to have them not seal (but still spray OK) around the base of the nozzle making a big mess. FWIW, Rustoleum will refund your money on cans that don't perform (although they may not on a can that did when new, but not later.) They recommend just wiping the nozzle after use to be able to reuse it. I think that's hit or miss on having it clog.

I think the spitting is because the can has lost pressure sitting on the shelf. I'd recommend buying them from a place that has good turnover of their products so you don't get an old one. I've seen lots of store displays where people have sprayed paint on them (to test them) and then likely put the can back on the shelf.

Paint which sits around on the shelf for a while will do that...and it doesn't take that long. Especially today. I've posted here before that today's "enamel" is actually a closer kin to yesterday's lacquer if you analyze the ingredients. The manufacturers do that to make it dry faster I suspect. My suggestion: when you get it home, set it upside down in the sun and leave it there for a day. Then turn it upright and shake it for several minutes...5 or so at least. Then set it on one side and repeat the process. Bake in sun a while and then shake the tar out of it. Do this again if you feel like it. What is happening when paint clogs and starts spitting is very simple. The paint has been sitting there and it has separated. The heavy bits settle to the bottom and coagulate. They don't get mixed well enough before you start to spray and then you suck some of them up into the feed tube...where they stay forever. From there some globs will make it all the way up to the release valve and if that happens the only option is to try to get the paint out of there. Here is one very dangerous and generally ill-advised way: Hold the can upside down, let all the paint run down and very very carefully use a pointed tip can opener to make a tiny hole in the bottom of the can where the air can be released completely. Hold a junk towel over the bottom so you don't get a bath or get injured...but please just make a tiny hole. Then you can drain the paint out, mix it well and pour it into a PreVal jar (https://preval.com/) and have a chance at spraying it. You may have to study the maker's ingredient list to see what the main solvent used was. You may add a tiny bit of that to help thin the paint a bit if needed. Good luck!

PS neither your mother, your father, any of your sensible and semi-grade-school educated friends or even people who may not like you very much are likely to suggest my paint draining method. So yes, it could injure you badly or something. It could leave you painted canvas white. It could blind you or cause all your children to be born naked and all sorts of things. I can't take responsibility for anything at all pretty much in the entire world, so you're on your own. Once upon a time paint was made so that if you turned the can upside down and pressed the spray button only the air would come out but those days are gone now.

Edit: just checked and acetone seems to be the main solvent.

I have a "trim paint gun" with about a 1 pint cup I bought from "Harbor Fright" many years ago. After having a lot of the same rattle can woes that have been described here, I've just about given up on buying those things. Like Jon, I've salvaged a lot of usable paint from cans that don't want to spray when I need a specific color, and the trim gun works well to apply it. The paint volume control and the fan spray knob makes it apply much more smoothly. Once the residual pressure is vented, poke a hole near the top of the rattle can to help the paint drain out of the bottom hole. Ditto on the acetone, but Mineral Spirits also works as a reducer on some types of paint. Various different drying time enamel reducers can be bought from automotive paint supply stores, too. Be sure to use a good pressure regulator, and an inline oil/moisture trap when using air from a hobby type air compressor- - - -that air can be pretty dirty at times.
Jerry

Like Jerry, I have a set of 6 oz paint cups for my 3M Accuspray paint gun.

I can attest to getting paint out of a clogged rattle can being dangerous. The paint will tend to boil and escape the hole punched in the bottom. See the attached pic - most of the paint missed me. This was Rustoleum primer - probably not worth the effort to try and salvage it, but this was the can the failed to spray from the get go.

A good pair of industrial-grade safety glasses and/or a face shield are just about essential to any job with hazardous liquids or grinder sparks involved. Several years ago I tripped over an air hose in the shop, with both hands full, and did a face plant onto a vehicle lift pad 4 inches off the floor. No chance to try to cushion the fall at all. I fractured my left eve orbit in four places and needed over a dozen stitches to close up the cuts on my cheek, but my polycarbonate lens safety glasses saved my eye. The shape of the bruises and contusions exactly matched the shape of the glasses. The lens was badly scuffed up, but it didn't break.

When venting pressure from a spray can it's a good idea to wrap a couple of layers of shop towel around it, and [censored] a TINY vent hole in it with an ice pick
Jerry
.

You can make the tiny hole I mentioned if you carefully file an old style beer can opener to a fine point and press only until you hear something. As I said, I hold a junk shop cloth around the thing down there and turn my head away from it. Fortunately I haven't had the sort of bad luck Kevin had (sorry Kevin), but it could happen I suppose. Just be careful, please. I give everyone here credit for having a healthy dose of common sense and some here are pretty well educated to boot. Really interesting and impressive group.

The can I punctured had the tinyiest hole in it. I used a GI can opener that's pretty sharp, but as I mentioned, the paint started to boil from having the pressure released. I did have my glasses on, which probably saved me from getting paint in my eyes, which would have been pretty ugly. I had a rag over it, but that apparently wasn't enough.

Gosh, one time I was carrying a can of primer through the house. A brand new can of Rust-O-Leum red. I don't remember how, but I dropped it-onto a carpeted floor!! I don't know if it hit a Lego or a corner of cabinet or what, but it landed just right to make a tiny pinhole-that thing let loose and spun around and around shooting a stream of red primer from hell to breakfast! I was younger then so I had fast reflexes and caught it in a second, holding my hand over where the paint was coming out the pinhole so at least it wouldn't spray all over the house anymore. Then ran it outside and let it finish.

What a mess!! At least it was the old alkyd kind that dries slow, so I was able to clean most of it up pretty easy, enough for my long suffering spouse to forgive me. Eventually :-D

Other times, I've thrown a full can of paint at a pile of sharp metal things out of frustration when it won't spray. Thrown it full force.. not a puncture!!

Meanwhile, I now always shake a new can of spray paint for at least five full minutes, let it sit upside down for a while, then do it again. Because it really sucks to find that full can of high solids content zinc primer you bought yourself as a spare just six months ago, then push the button and have about a second of sputter come out before it clams up and never sprays again. $11 worth of never sprays again, and it was six months ago so you can't take it back.

This is what I could find quick as an example. They make them to adjust to fit 3 sizes similar to this one. I haven't tried it on paint though it could be made to work real safely if a valve was installed on one of the ports. Just an idea that came to mind reading all this.

https://www.nationaltoolwarehouse.com/3-in-1-Side-Mount-Can-Tap-Valve-P26332.aspx

I usually take the cans and put them in a sink of warm/hot water for 10-15 minutes, even for new cans that may have sat on the shelf for a long time. I always wipe nozzles with thinner after use and some time just go ahead and pull the nozzle and put it in my bottle of thinner.....after use I keep used nozzles in thinner as spares.

Harbor freight sells a paint can shaker that I've used with rattle cans. It's like the difference between an electric toothbrush and a regular one. You can't shake a rattle can up anywhere close to what a paint shaker can. It really comes out smooth that way.

Here’s another option that some folks swear by…..

Product Description
Discover the efficiency of the MixKwik Aerosol Can Mixer and Spray Paint Can Shaker, an American-made innovation that attaches to any standard reciprocating saw to mix aerosol cans effortlessly. Eliminate manual shaking and reduce waste by up to 20% while ensuring perfect consistency in paint and other products. Designed to handle various can sizes, MixKwik is a time-saving, eco-friendly tool that enhances project quality and reduces gas emissions, making it an essential addition to your toolkit.

Does that thing click into a Sawzall?

Yep

Hmmm guess paint supply may have one. I'll have to check....i have a brand new sawsall.