... do you use any sort of debubblizer on your waxes before you
invest? I've been using denatured alcohol and still get bubbles in
the crevices, been thinking about painting on investment in those
areas to avoid that....
Modern commercial investments already include wetting agents, so
additional debubblizers usually don’t do much additional good. What
you really need to get rid of bubbles, is a good vacuum pump setup.
Painting investment carefully onto the models can be a decent stopgap
if you can’t justify getting a proper setup, but there are problems
with this. You have to then fully invest the painted model before the
painted on layer fully cures, or it won’t properly bond with the
rest, resulting perhaps in bits breaking away from the mold
interior. Worse than a bubble. However, you also have to be sure that
pouring the investment into the flask with the painted model doesn’t
displace that painted layer and allow more bubbles… Not a major
problem usually, but still a possibility. Takes a bit of practice to
get it right. But it can work.