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Sunday, April 18, 2010

Learning by doing

The Rustoleum can of yellow spray paint said that the paint is supposed to be applied at temperatures above 50F (10C). I had some things to attend to today; so I decided to give my AA0ZZ Keyer housing its last coat of paint this morning before I left. I checked the thermometer; and at the time it was 48F (8.9C) outside. Close enough - right?

Thankfully, the top half of the enclosure (which is the side the world will see) was already done after two coats, and I didn't need to apply a third coat. The bottom had some drips that I wanted to cover over, so ..........

The paint went on smooth as glass; or so I thought. When I came back home this afternoon, I went to check to see if the paint was dry enough to handle and I saw that the very bottom surface of the housing now has a pebbled finish. Not unpleasant by any stretch of the imagination; but not what I was looking for either. But since this is the very bottom and no one will see it, I am going to let it go. In fact, I intend to make a label (not a decal) with a summary of the keyer's command codes to attach to the bottom, anyway. So it will be covered.

I didn't think a degree or two would make that much of a difference; but facts prove otherwise. It's not like my old black and white darkroom days, where the film or paper developer could be one or two degrees off from what Kodak recommended; and you would still get optimal results anyway. I guess paint is a little more unforgiving.

One thing I have noticed, though. From here on out, I am going to use Krylon paint exclusively. Whenever I have used Krylon in the past, I never had to worry about drip marks in the painted finish. They even make that a part of their advertising. Rustoleum is not as forgiving. I had to put the third coat on the bottom finish to hide a few drip marks.

Now I know why they have robots paint cars in the assembly lines. Besides the fact that auto paint is extremely dangerous to inhale. I have a friend who hand makes racing bicycles from start to finish. Inhaling too many Dupont Imron paint fumes damaged his vocal chords and permanently altered his voice. But that's another story.

72 de Larry W2LJ

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