Gerald wrote:
I need to cut a 50mm (slightly less than 2") hole in the floor of my '90
Westy to
install a gas furnace. I looked at holesaws yesterday, and besides being
expensive to buy
one for just this job, I am wondering how well they would work on the
uneven, ribbed
surface of the van floor. And the hole will come out 1/8" away from the main
side
beam.
Any hints, tips, suggestions on how to do this?

------- reply --------

I've used holes saws for that purpose and location.
Tricky part is when the teeth catch and bind and then the saw stops.  Then
the drill twists in your hands because you cannot release the power fast
enough.  Then the teeth tear off the saw. You have to balance the rpm and
downforce to keep the saw moving.  Not too slow.  Maybe some coolant/cutting
fluid to ease things up a bit.
I can't think of another way to make a nice round hole, so it is your only
choice.

The teeth are torn off the holesaw from chattering and off angle torquing.
This happens long before the teeth get dull.  Unfortunately you cannot hold
a holesaw rigid enough in a hand drill.  Even if you wreck the holesaw after
one hole, it's only $8.00.  And it is likely that you may ruin the saw.

I use holesaws to cut manifold flanges in 1/2" plate steel and get many many
holes out of one saw.  It's fixtured in a bridgeport style mill - rigid.

Gary Lee
Calgary, Canada
http://www.telusplanet.net/public/gary2a/vw.htm