Drilling resin!

It is possible. But, not very pleasant. I don't own a dremel either and it makes doing a lot of pretty basic things with resin difficult-- but again, not impossible. Just make sure you wear a respirator and possibly use cut-resistance gloves (I've had knives slip off of resin and into my hands pretty often.)

 

to the best of my knowledge you can drill resin. But I'd be careful about it and yes definitely wear a mask.

 

resin is easier to cut with a blade right after it is removed from the molds. I like to trim my gates off as soon as I can and I also will cut some of the slots and channels right away before the resin gets to its final hardness. Definitely use a good mask and safety glasses. I also like to have a shallow plastic bowl of water when I drill. this helps catch the resin dust and keeps more out of the air.

 

I have been working with really tiny parts so they are easy to handle. I will dunk them just under the surface of the water to wet them as I start drilling so it makes resin mud and then swish them to keep the dust in the water. The dust from diamond style bits will sink to the bottom but the curly stands from a standard drill bit will float. I have some plastic pieces I use as splash guards around my work area.