Originally posted by TCLynx on AGC, June 13, 2010
A nice whole saw kit plus a few larger whole saws (of the appropriate size for bulkhead fittings or uniseal fittings of whatever two primary large sizes you are going to use if doing a large system) are definitely a must in the Aquaponics Tool kit
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 and/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.
I find that drilling holes in plastic works better if you let up on the drill trigger and push as the drill slows down. If the drill is going fast into thin plastic it can tear it up a lot. Then once the drill is through you can clean it up with a faster speed.
Yes be careful as you get through the pilot hole so the drill doesn’t suddenly jump and bite into the edge on the hole saw since it is likely to twist bad and can chew up the plastic. And yes as you first bite in around the outer part of the hole with the hole saw you want to be running slow and controlled until a good track is in place then you can speed up a bit carefully.
I did some holes for Bulkheads in a Rubbermaid – and the wall was so thick the threads would not meet up! Had to sink a bigger “well” on the outside side so the female’s shoulders could get closer to the male and catch the threads.
If you have to do this, drill the countersink hole first with the larger hole saw, stopping often so you don’t shave off TOO much. Then it’s a simple matter to drill the smaller hole (all the way thru) using the same pilot hole.
Ugh, I just added another video to my to-do list!!
Rick