jimilee
Well-known member
I will admit, I'm impatient.
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Rattle can venting….
- Thread starter Locrian99
- Start date
Alan W
Well-known member
I have 1000s of hours of spray paint experience, but only 10s of using cans. When I finally start painting and decorating some pedal boxes, I thought I’d do a pictorial of the steps my shop uses for spraying lacquers. But, I also taught at a few schools that had spraybooths, but students needed to use rattle cans—so I got to see many of the potential failure modes for rattle can painting.
Here’s some brief thoughts:
1. Aluminum does not take paint well. After thouroughly cleaning with a good solvent, stick the box on top of an object that will hold it away from any surfaces. You need to have airflow around it, that’s what conveys the paint mist. We use double stick tape, and in this case, just some short sticks.
Use an etch primer. This is the trick to having a secure paint coat. I know these are available in rattle cans, but I don’t quite understand that, as what we used was always a 2 part mixture, that activated as an etchant when mixed together, and then had a shelf life of a few days… In any case, use an etch primer if you can.
2. Try to stick with one brand, and if it’s a big brand, like Rustoleum or Krylon, the same “product family” from that company. If you use paints from different companies, you may experience weird interactions between the coats. These might be never fully curing, or bubbles, or wrinkles, or? And the killer is, it may take a few weeks to happen. So, if you have to mix brands, test everything, give it a chance to cure, and see what’s up.
3. Spray cans spray very thick (by a professional painter’s standards) coats—by the time you fully wet a surface, you’ve got a few times as much paint there as a good spray gun user. This makes the whole curing issue really critical. A major difference between solvent based paints and poly or water based paints is that each coat slightly melts the coat below it. Softens it, due to the thinner in the new coat.
A thick coat will very often skim over across the top, and while the solvent vapors do make their way through, as that skin gets thicker and thicker, the gas release slows down.
If your surface is much warmer or colder than where you’ll be storing it to air it out while curing, you may get issues. We had a drying cabinet for small parts, usually ran it somewhere between 100 and 125 oF. If you’re getting good results with 300 oF in a toaster oven, I’m surprised, but that’s great. Just make sure most of the offgassing has happened; otherwise you‘re sending out highly flammable gas into a small enclosed space with glowing wires…
Here’s some brief thoughts:
1. Aluminum does not take paint well. After thouroughly cleaning with a good solvent, stick the box on top of an object that will hold it away from any surfaces. You need to have airflow around it, that’s what conveys the paint mist. We use double stick tape, and in this case, just some short sticks.
Use an etch primer. This is the trick to having a secure paint coat. I know these are available in rattle cans, but I don’t quite understand that, as what we used was always a 2 part mixture, that activated as an etchant when mixed together, and then had a shelf life of a few days… In any case, use an etch primer if you can.
2. Try to stick with one brand, and if it’s a big brand, like Rustoleum or Krylon, the same “product family” from that company. If you use paints from different companies, you may experience weird interactions between the coats. These might be never fully curing, or bubbles, or wrinkles, or? And the killer is, it may take a few weeks to happen. So, if you have to mix brands, test everything, give it a chance to cure, and see what’s up.
3. Spray cans spray very thick (by a professional painter’s standards) coats—by the time you fully wet a surface, you’ve got a few times as much paint there as a good spray gun user. This makes the whole curing issue really critical. A major difference between solvent based paints and poly or water based paints is that each coat slightly melts the coat below it. Softens it, due to the thinner in the new coat.
A thick coat will very often skim over across the top, and while the solvent vapors do make their way through, as that skin gets thicker and thicker, the gas release slows down.
If your surface is much warmer or colder than where you’ll be storing it to air it out while curing, you may get issues. We had a drying cabinet for small parts, usually ran it somewhere between 100 and 125 oF. If you’re getting good results with 300 oF in a toaster oven, I’m surprised, but that’s great. Just make sure most of the offgassing has happened; otherwise you‘re sending out highly flammable gas into a small enclosed space with glowing wires…
RetiredUnit1
Well-known member
This helps tremendously in minimizing the amount delivered while using rattle cans. I start my motion at least a foot before I get to the object I'm painting, then time the trigger to just before I get there so the can is going pretty fast and my total time of spraying is probably less than a second. Takes longer to paint this way but results in a thinner more professional application. I've done a ton of bicycles, starting around 56 years ago. I've used a gun to spray my house before, but nothing flammable.....
Locrian99
Well-known member
I think this may be part of my issue. I have noticed that the rustoleum “stops rust” products are much more likely to do the wrinkling after applying the the rustoleum painters touch 2x clear gloss than the painters touch 2x paint when I’ve used it. I guess I won’t be buying anymore of the stops rust.
Feral Feline
Well-known member
KR Sound
Well-known member
Yep. I was moving one after it was half-dry and ended up dropping it on the dirty garage floor. Had to let it dry, sanded it down real quick with the belt sander, then started all over again.
Locrian99
Well-known member
I’ve done this more than once. I took an Amazon removed the lid. Then took a smaller sized gatorade bottle set it in the middle and glued it down. Perfect for a 125b/1590b. The bb sizes are a little more of a balancing act. But you can move the enclosure pretty well after as well by just moving the box.Yep. I was moving one after it was half-dry and ended up dropping it on the dirty garage floor. Had to let it dry, sanded it down real quick with the belt sander, then started all over again.
Locrian99
Well-known member
So I ran a bit of an experiment. Using my usual method using these two paint types and this clear coat.
I found when using the rustoleum stops
Rust and letting it sit for 24 hours after the last cost. When applying the clear coat I would still get some wrinkling, while I do not on the 2x product. Which is the same lone obviously. Guess I just won’t buy the stops rust anymore, though there’s a few colors I like that I haven’t seen in the other line.
I found when using the rustoleum stops
Rust and letting it sit for 24 hours after the last cost. When applying the clear coat I would still get some wrinkling, while I do not on the 2x product. Which is the same lone obviously. Guess I just won’t buy the stops rust anymore, though there’s a few colors I like that I haven’t seen in the other line.
jjjimi84
Well-known member
This is a really good idea! Rattle cans are a pain in the ass but for me I haven't found a primer and clear coat i liked that wasn't out of a rattle can.
I live in Wisconsin, we just had 12 inches of snow dumped yesterday and now today will be 40 degrees.....
What I do is spend a day drilling 20 ish enclosures and as soon as the temp is within those parameters on the rattle can I blast them 10 at a time with primer and let them cure in the garage for an hour or so and then leave them in my airbrush area in the basement until I get to hitting them with paint. There is no real science to it, I have just had to come up with trial and error to find what works for my area.
A lot of acetone was used in the process of cleaning of paints and starting over.
