Drilling holes in foam

[siberianhusky]

Anybody have any good ways of drilling clean holes in blue of pink foam?
Even with a brand new bit it seems to be tearing out on me, tried fast and slow speeds on the drill press, about the same results both ways.
Thanks

[scoota]

How thick ? Hole punch ..

[Diegoboy]

I run the drill in reverse so it doesn't "bite"

[siberianhusky]

Ok I'll try that, it's 1" foam.
For once I'd like nice clean tight fitting holes through sponsons, Although the rough surface does give some good irregularities for the epoxy microballons mix to "bite" into. The sides of the sponson are what is actually holding them in alignment anyway until the epoxy cures.
LOL just me being anal about a place in the boat nobody ever sees!

[NativePaul]

I use a sharpened piece of brass tube, a small slit in the end makes it cut easier, insert a dowel into the other end or plug with tape and part fill with epoxy to stop the chuck crushing the tube if you want to use it over and over for a long time or just wrap the outside with electrical tape for grip and be careful not to tighten the chuck too tight for a quick and easy single use.

This method works well at any speed in my pistol drill and my dads pillar drill but will burn the foam leaving an irregular and hard skin if spun at very high speeds in a Dremmel type device.

pic here, shown cutting skins but the same thing is used for the foam.

[siberianhusky]

Cool! drilling holes and making a new "tool"!
I now see why my attempt with an x-acto punch probably failed, they are sharpened on the outside!

[lipdaddy]

I have a spare tip for my soldering iron just for foam. It works great for carving and making perfect holes.

Ryan

[Diegoboy]

I have a spare tip for my soldering iron just for foam. It works great for carving and making perfect holes.

Ryan

That is a good suggestion. I have done that before, but it hasmade the holes too big because my iron tip is a deep cone shaped. It does work well if careful.