super velcroboy wrote:
R.G. wrote:There is no substitute for actually knowing the details.
you know those paint cans don't come with detail instruction for baking and temperature settings
"Knowing" is much more difficult that "reading the can".
There are three major classes of paints; enamels, lacquers, and catalyzed paints, which are really forms of chemically hardening resins.
Enamels benefit most from baking. Mild baking of enamels can give you a clean, self leveling gloss surface that's had the solvents driven off almost entirely so they are as hard as they can get.
Lacquers and shellacs benefit least from baking. They don't depend on temperature for leveling and dry so fast that all baking does is get more of the solvent out faster.
Catalyzed paints benefit little if any from baking. Mild temperature elevation may speed up the hardening reaction.
In all cases, baking too hot in hopes of speeding it up really quickly will cause chemical changes in the paints that are not good, and may cause charring or browning.
By the way, consumer grade paints in spray cans from the home improvement store often contain major amounts of plasticizers that prevent them from ever getting really hard. You want hard paint? Go to the stores that sell auto paints to the auto body repair shops. Or even harder? Go to the shops that sell topside paints to the boat and marine industries.
Interlux "Brightsides" paint is an air-initiated self catalyzed paint that dries to a layer that's hard enough chip, but tough enough that you'll need a metal tool to make it do that. It can be brushed on and it self levels to a high gloss so it looks sprayed. It's only defect is its price: US$32 per quart/liter.
How do I know these things? I make a lot of mistakes.
In fact, I generally TRY to make mistakes, but I try to make them in a disciplined fashion. Before committing to a paint process, I'll get several blank boxes and abuse them by painting with whatever I'm wanting to use and then using/not using primer on the box, baking one, not baking one, low temps, high temps, etc. Once that messing around is done, I have a variable number of successes and failures in the batch. And I then know what works and what does not, in the conditions in my garage.
There seems to be an idea that one can do some new thing and get it right the first time. WALOHCS. Go ruin a few test pieces. Then you know. There's none of this "but the instructions said to ..."
As I say, education is ALWAYS expensive. Sometimes you pay for education with different things than money: time, test pieces, expendable supplies, etc.
I highly recommend you read a copy of "The Sensuous Gadgeteer" if you can find one. It presents a really, really good view of how to think about building things of all kinds, including the view that the finished product is just the garbage left over from the work.