Paint Chips Grrrrr!

[Snare227]

I've made several circuits that I need to box up, but doing the paint kills me.  It seems like every paint I try to use chips or scratches off my bare enclosures.  I'll get the box looking exactly how I like it, decals are straight, clearcoat applied smoothly... then I go to box it up and something slips and SCRATCH.  I've tried extending the dry times, but I haven't tried the toaster oven yet... does that help with durability?  What sprays are the best for durability?  So far the Rustoleum stuff seems to hold up the best.  If I can't find a better paint or the fault of my own that's making them scratch up so easily, I'm going to have to start springing for the powder coated finishes... though the clear coat will still scratch up after I put on the waterslide.   Maybe I'm just being anal, but if I spend time and money making these and putting my name on them I want them to look good for awhile you know?  Thanks!

[Geiri]

Do you sand the enclosures before you spray them? That makes a huge difference. I also sand between layers, sometimes, with a very fine sandpaper and that works quite well also.

[Pipes]

I've found that using an etch primer as a base coat works well. A couple of coats of that on a nicely sanded enclosure and the paint sticks like glue.

[Vince]

Some zero grade wire wool works a treat for between coat sanding too. And the oven helps a lot with mine. Let them cool off in the oven too, they seem to dry harder that way.

The worst paints I've used are Plastkote, absolute shit, clogged up on nearly every can..

[Geiri]

I only use Motip/Duplicolor (same manufacturer) which is the leading brand in Europe. I've tried some Krylon cans but they were ALL faulty. Once I started with one can, I had to empty it because it wouldn't stop spraying. Piece of shit!

I'm trying to acquire a small oven to experiment with baking.

[Snare227]

I haven't been sanding the bare enclosure before painting them, so I'm going to give that a go.  I'm also going to keep my eyes opened for a second hand toaster oven to try out.  I'm going to hunt up some clear coat cans that are intended for automobile use, hopefully they will cure better and be a bit more durable.  I've got 17 125bs coming in the mail tomorrow, so I'll be drilling and painting by the end of the week.  

[Vince]

Just don't set the oven too hot as I did the first time... it burnt the paint.. actually quite a nice smoky effect on white paint. I have a small toaster oven and it's barely on a quarter as it's so small it gets very hot, very quickly.

I had the same issues with Plastikote cans, Geiri. Jammed up!... I've used Hycote stuff in the past and never had any issues with them.. nice, fine spray too...

[Snare227]

After you paint your boxes if you flip the can upside down and spray it for a few seconds it'll just shoot air out and clean the paint from the nozzle.  You guys probably do that, but just in case someone else comes through here and doesn't.  Some paint just sucks and ends up being one use no matter what you do though.

[Geiri]

Yeah I tried that but the problem wasn't that the nozzle was clogging, the nozzle just wouldn't stop spraying, no matter what I did. I pressed, pulled, turned and twisted with no luck. Also, the Krylon nozzles SUCK! The Motip/Duplicolor ones are really nice.

I'm gonna have a look at Hycote!

[Dave]

I use Holts automotive paint and get pretty nice results. Its good quality stuff and is fairly cheap in the UK, I've found a website that do it for £4.99 per 300ml can, occasionally the Range do it slightly cheaper in store but they tend to be pretty hit and miss as to whether they have it or not.
Thanks
Dave

[Snare227]

Well I looked for yard sales on my way to the city and didn't see any, and the cheapest oven I could find at the stores were $35 which I felt was a bit steep for something to bake paint in.  I decided to try the Goodwill thrift store and sure enough they had one for $10.  

My first attempt was decent, but I had the heat just a little bit too high.  After a little adjustment of the temp knob I won't be going back to air drying that's for sure.  If you haven't tried baking at a low temp give it a shot.  I've heard people say "it doesn't make your paint harder it just makes it dry faster".  This may be true scientifically, but I have pedals that I've painted with the same paint over a month ago that I can scratch up with my fingernail, and one that I painted and baked for an hour that I have to really get after with something metal to get it to scratch up.  

Get an old second hand oven with a wide range temp knob and give it a shot... it cuts down on time required to make a box and it makes a more durable smooth finish.