Backyard Aquaponics
A place to discuss aquaponics

OK, before I start destroying these expensive plastic tubs we've bought, has anyone got any tips on how to cut holes in them?

What sort of tools? are you putting anything behind them to drill thru to? all hints and tips gratefully received!

Thanks

Andrew

depends on how accurate you want the hole. I'd advise a holesaw.

Here in aus a decent hole saw set is about $20.00 [thats for about 10 different sizes]

ok, cool - anything to watch out for when using it? I guess I'm worried about splitting the tank?

Hi Andrew

Depending on the size you require - up to 28 mm we use a cone drill (your local hardware store has them or Screwfix sell a set of three cones from small to 28 mm and they are invaluable, will cut metal as well as plastic). If we are cutting into larger stuff we use solid hole cutters as they are better than those multiple cutters which are cheap, cheerful and NAFF. If you feel that your drill will go too deep then put a piece of wood behind the drill hole, we do this when drilling out polar gullies. Get back if you want more info.
WD and OH

Whats the tank look like. And how big. I had to resize some holes later after going too small to start with. Also good to work out what you want before you start drilling.

HOW GOOD IS SCREWFIX!!! focus or jewsons would be able to help you out at well... or ceck out ebay. I found that some holesaws, will give you a super snug fit on your pipe which will not leak... but i put slaz around the outside anyway.

If your worried go half way through then turn the tank around and finnish it on the other side, worked for me cutting hard plastics oh and not to fast

Tips.

1- Don't put the hole through across a ripple, curve etc. Makes it impossible to get most bulkhead fittings to seal properly.

2- Don't push too hard on the drill, if the plastic is brittle, you are more likely to make a crack that way and having the point of the hole saw suddenly punch through with force may cause the rest of the hole saw to hit and bite unevenly causing you to twist your wrists or hit yourself with the handle of the drill as it swings around.
Slow and steady is the best way to deal with hole saws. Do some practice cuts on scrap materials if you are not comfortable with the tools at first.

3- Double check the position of the hole a few extra times before cutting. Make sure you will have room to install whatever fitting you intend to use. too close to corners or bracing tends to be a problem for some types of fittings. If you install a bulkhead fitting and are going to screw an elbow into it, make sure there is room for the elbow to spin. That sort of thing.

Thanks for the tips guys - I have bought a holesaw, and will let you know how I go (gently!)

long time since we've seen you... .what's up ... did you manage to make some holes and set your system up?

If the plastic is brittle and flat, you can clamp a small piece of plywood on both side of the hole. You won't have to worry about cracking at all then.

the main thing I have experienced, is I drilled the hole 1 mm too small, and then cracked the tub when forcing the pipe through.

MAKE sure to be tight, but not TOO tight...

Oh ya - make sure you plan the size better then me. On my IBC, I planned for two 1" overflows and drilled and plumbed them up. Turns out I should have used at leat two inch (or more) instead of one as the pump is way over powered. I am now diverting about 90 percent of the pumped water back into the sump as to not overflow the FT. Big waste of power!

thanks guys... appreciate it.