So I forgot to drill a hole for the LED before I painted and decaled my enclosure. I was going to enviro tomorrow. When it cures, can I drill another hole with a strapless bit, or should I trash the decal, drill the hole and decal again before enviro?
After my last experience I would trash / drill / re-decal.
I usually leave the decal film over the holes, envirotex, then carefully re-drill the holes after the ET sets. I did that last week, and for the first time the decal lifted a bit around the holes. So it looks a little filmy around the holes - air between the decal and the enclosure. I decided to live with it. The washer, nut and knob make it hard to see. But that would make me think drilling all the way through the ET, decal and enclosure might cause a problem.
If it's a bare LED, I always drill after enviro as it looks cleaner. I use the right size bit in a pin vise and hand drill it. I've never had any luck doing it any way other than slowly by hand, but it works out cleanly if done carefully.
Note that I do it the next day. I don't know if it would work as well a week later when the epoxy is better cured.
Perfect opportunity for a lightplate perhaps ;)
Drill very, very carefully and you might get away with it.
FWIW.
We drill the enclosures, fit the decal and cut out all holes bigger than 3mm. Tape the back of the holes, then fill them with Envirotex when the top it coated. It's easy to drill through them this way.
3mm holes we don't cut the decal and just coat. We use 3mm LEDs under the decal. 5mm are drilled using the above technique.