Question about drilling a hole in plastic.........

[CathyA]

Wasn't sure where to put this, since I couldn't find the "drilling holes in plastic stock tanks" forum. :)

I used a drill with a hole-cutting attachment. It has wings on it. The round hole cutters don't work.
So.....I drill a hole with a 1" hole cutting thing, but the 3/4" bushing that I'm putting through it doesn't fit. ?? Well, it fits if I turn it really, really hard.......which I don't want to do. I'd rather have that hole just a smidgen bigger, so the pvc bushing easily drops through it. Then I tighten it underneath with a threaded cap. This is my new system on all my veggie garden stock tanks, in dealing with weather that goes from monsoon, to drought. I can let it drain too much water, or plug it up so it retains all the water.
The 1" hole saw is the biggest one I have. How do I make that 1" hole......just a teeny bit bigger? Would a rasp of some sort work? Or would sand paper work better? (just thought of sand paper....which I have, but since I wrote all this, I'll still post it, unless you have a better idea.

Thanks!

[Dhiana]

A round or half-round hand file should work fine. You could also use most any of the sanding bits with a dremel type tool, also.

Be careful of the fact the friction could start melting the plastic vs. scraping the plastic away. Just take it slow and if you see it start to melt a bit,
give it a short break.

Of course, the sandpaper should work also :)

[kib]

I've taken a regular small drill bit - maybe 1/8" - and used the side of it in a way similar to using a dremel, i.e. not punching a hole with it but rather rubbing it up against the side of the hole. This may work better on wood, if the tank material is very flexible the drill will chatter a lot.

[CathyA]

Thanks Dhiana and kib........both good suggestions! I'll give them a try. :)