I refinish a lot of small parts, using either paint or powder coat. Powder coating is kind of a POA to set up, so I get lazy and just paint a bunch of stuff. When I was a kid, a lot of stuff was advertised as "Baked Enamel", which I thought was a way to improve the durability of the finish. Lately, After I paint some parts with rattle can enamel, I put them in my powder coating oven for a couple of hours at about 200 degrees. It doesn't seem to hurt anything, but I don't know if it helps or not. Any experts on this out there that can give me some information on whether this is a good idea or not?
I've done the same thing.......just used the toaster oven for small parts. Kinda stunk up the house. LOL
I usually use a heat gun, i think it helps adhesion but..... i think 6 cylinders and four doors are cool so i may be a little full of excrement. lol
Poking around on the websnet, it seems there are enamels meant to air dry cure and enamels meant to cure by baking. But do all enamels benefit by baking is the question, or other type paints, for that matter? My search was short but it didn't seem like that answer was a black and white fact one way or the other. Baking doesn't seem to hurt, though. I spent 10+ minutes and I'm no smarter than before I started. Here's one link with some info........ http://www.wurdack.com/enamel.html
Baking at 200 degrees will dry the paint and harden it faster. This is more forced drying than baked enamel. The real old baked enamel was a special type of paint used in industry. The process involved giving the article 2 coats of paint then baking in an oven. When baked, the enamel would melt and flow out to a smooth glossy finish and come out of the oven dead hard. In a way it was more similar to powder coating than regular painting, in that the heat was necessary to smooth out and harden the paint.
Some years ago I had a sideline repairing boat props, which requiring paint removal and repaint after finishing the straightening metal work/welding/ grinding and finish sanding on the aluminum props. Routinely baked them after a spray bomb paint job in a homemade box oven of plywood and a heat lamp. Doubt the baking hardened the paint, but it did dry it faster!
This.... Although some 'baked enamel' was merely an advertising ploy when in reality it was done simply to speed up the manufacturing process.
I'd kind of like to pursue this a little more, because one of my sidelines is rescuing old aluminum manifolds. Sometimes the aluminum is so old and of such poor quality that welding is out of the picture, so I use epoxy, which usually works very well. (It is also better for patching small dings, etc.) I would like to powder coat the manifolds I do, but the powder won't stick to the epoxy, because it is non-conductive. I have tried metalized epoxy with some success, but I usually end up painting these manifolds. A harder than normal "flowed" coating like "Rusty O'Toole" mentions sounds ideal for my purposes. Anybody with any knowledge of the "old-time" baked enamel "Rusty" was talking about, feel free to chime in.
You can still powdercoat the manifolds, you just need to change the process a bit. I've also found that JBWeld works better than just plain epoxy as it'll withstand the cure heat better. I've tried the special 'lab metal' that is recommended for powdercoating, but it's not any better than JBWeld IMO and considerably more expensive. The problem with cast aluminum is it's porous. Corrosion can be more than surface deep, and it can literally soak up oil and other contaminants. Sandblast the piece first, then bake it at 450 degrees to 'boil' all the 'stuff' out of the metal. You may have to do this more than once. Once you're satisfied than no more 'stuff' is going to appear, do your repairs with the JBWeld. Use the JBWeld that is rated for 650 degrees, and heat cure that by baking one more time at 450. Failure to get all the 'stuff' out of the casting will cause issues in the final finish if it's a heat cure. To get the powder to stick evenly, pre-heat the part to about 225 degrees and immediately coat it without using the 'ground' wire. The powder will start to melt on contact. The trick here is coating thickness; it's very easy to get a extremely thick coating, so some practice will help. Once coated, proceed with standard cure heat/time. This method also works well if you want a super-thick coating; I also use this method on battery trays/holddowns to apply multiple coats. You can get a 'dipped' coating appearance that's very durable this way.
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