Homebrew PCBs

So I've been doing some (more) experimenting with UV cure soldermask 
ink, I wondered if anybody had any tips to add.

Photos:
   Copper 
Side:http://www.flickr.com/photos/93638530@N08/8601556485/in/photostream
   Component 
Side:http://www.flickr.com/photos/93638530@N08/8602656700/in/photostream
   (no copper on the component side, I inked it just to get a more 
reflective surface, it's a board full of LEDs).

There are effectively a couple of individually cured coats on both sides 
since I tried various ideas.

Technique:  spread thin layer ink, smooth a piece of polyethylene 
plastic bag over it with a cardboard squeegee, expose, peel off plastic, 
wipe pads clean.

Apart from the alignment (which Is just a matter of better practice or 
mechanical technique), the really hard part is getting a SMOOTH coating 
without air pockets on top, the stuff is really sticky, and spreading an 
even thin layer under the plastic I'm finding very difficult.

I've tried thinning it with acetone, mineral turpentine, and kerosene 
with various results, even the tiniest drop (literally, a drop) of 
acetone makes it like water, it still cures OK and it's mostly smooth, 
but it's a bit too watery I think and may be the cause of the chipping 
shown in the photos.  Turps and kero  don't really combine with the ink 
at all, but seems to make it a smoother.

I've tried rolling the ink on using a foam art roller, and it just sort 
of stipples (a very uniform and thin coat, but stippled) and applying 
the plastic on top is no easier.

I'm thinking maybe if I rolled it on, then sprayed the plastic with 
turps, or maybe acetone, and applied that, it might work better.

I also drilled it after I had applied the mask, as you can see on the 
bottom (which was just a straight coat, no pad masking, single sided 
board) where the drill went through the soldermask sometimes chipped 
off, I think this is probably due to thinning the mask ink down which 
affected it's adherence.  It also made it a bit tricky to drill in 
general, due to the slight misalignment the mask on a couple of 
occasions mis-directed the drill bit, I'm thinking about drilling it 
first then applying the solder mask, although I'm concerned about 
cleaning out the holes adequately.

Also considering getting some perhaps thicker polyethylene plastic.

Any other suggestions?