rattle cans

Clogged nozzles and clogged valves (the part in the can) are indeed a problem with spray cans.  While you can clean or replace the nozzle, you cannot clean the valve.  Most newer style spray cans use a cap with a fancy inner shield that fits air-tight.  You must replace the cap promptly after cleaning the nozzle.  In fact, the instructions on some cans no longer even say to clean the nozzle (inverting can and spraying for a few seconds), relying on that cap to even keep the nozzle clean.  I clean the nozzle anyway, but have found if I did not replace cap after spraying, that can and nozzle become junk.

Since we are on the subject of rattle cans.

When a rattle can will no longer spray or spray correctly (assuming the can isn't empty) where does the problem exist?

Here are three common problems:

The paint will spray but its sputtering, spitting, etc.

The paint just gurgles out like water from a faucet.

 Nothing at all comes out.

Rarely have I been able to fix these problems by cleaning (as best I can) the nozzle or replacing the nozzle with one from even an identical brand new can. BTW, I understand not all nozzles are interchangeable.

My cleaning method has involved soaking (at least overnight) the nozzle in a variety of solvents (not all at the same time) and using a very fine wire to ream out the nozzle on the end that goes into the can, not where the paint comes out. I scrub the area where the paint comes out with a toothbrush or 3m pad. I've passed compressed air through the openings. I've even use an ultra sonic cleaner.  I've also use an eye dropper to place solvents into the little hole in the can where the nozzle goes and cleaned it out with a variety of fine tools. None of this really works for me.

Is there something that breaks off down inside when you pull a nozzle off?

Is the problem down in the release valve inside the top of the can?

thanks for everyone's input.,it's given me something to think about.

I used to use hardware store rattle can primers.  They are much more costly due to overspray than bottled hobby primers like Tamiya liquid primers, AK primers & Vallejo primers.  Worse, they are grainy.  A Tamiya primer bottle sells for about $3.50 and can prime 10+ 1/35 models.  An AK primer bottle costs around $8 and can prime about 20 models.  To me, the cost of using high quality bottled primers is negligible.

They work fine but most of them finish too grainy. The big problem is the fact that they are coming out of spray cans. Spraying that stuff is a pain, and it's easy to screw up, and there's a lot of waste.

If you're going to use them it's best to decant and airbrush. However, I'm all for cutting cost with household products where possible, but primer isn't one of them. A bottle of liquid Tamiya Surface Primer and some lacquer thinner is a small investment to make to ensure great results.

The best primer I have found is Gunze Mr. Surfacer 1200 in a rattle can.  Can be sprayed on lightly and leaves a nice, uniform, flat finish while filling in minor imperfections nicely.  It's not cheap, but I am looking at quality, not cost, for all my modeling supplies.

Can you swap the hobby paint nozzles onto a hardware/Auto/department store spray can?

That might help get a finer spray. (if they fit, that is)

I find some of the hobby shop brands have a finer nozzle than the normal hardware store stuff. It can be hard to put down a really light coat with those.  But as long as there is not a lot of surface detail to cover up, they can produce a nice result.  I find a good compromise are auto paints in spray cans, if you want a gloss finish.

I've used Krylon primer as well with good results. I usually spray on a couple light coats.

One thing about using rattlecans to remember. Those cans might be cheaper to buy at the time of purchase, but, they are not the cheapest way to paint once you start spraying them. You had to pay for all the paint in that overspray cloud.

Rex

Most of the time they are OK, but you don't want to hit those 5% of cases where they ruin your model or at best cause you lots of unnecessary work to strip the paint that went bad... So always do a test run on a piece of scrap plastic. It's also a good idea not to mix brands - like primer comes from brand X, colour from brand Y and clear from brand Z - that's like invitation for trouble. It's good to put the first layer very light on the plastic - in case the thinner is agressive and melts the plastic, the light first coat lets you see the problem and kinda insulates the model from the next layers. Hope it helps, good luck with your projects

Paweł

A lot of guys in this forum swear by them.ived used them with good results. They seem to take a bit longer to dry,but cost savings makes it worth it. Krylon is one brand that comes to mind.