The contractor’s hole that was cut for the vents was fine for the inexpensive, beige-painted, short little Home Depot vents, but not for the fabulous bronze vents we purchased – so material had to be removed.
With the MultiMaster and a wood-metal saw-blade attached, the super-easy ability to do a sideways plunge-cut and then a vertical cut removed enough material and allowed the grate to drop right-in.
The blade/tool also doesn’t have a jerky, instant-on start-up. It begins gradually and comes up to speed, and then once you make the plunge-cut, you can pretty easily move the blade laterally/sideways to keep cutting. Nifty tool, works in tight spaces.
SIDE EFFECTS: During this process the whole vent sheet-metal and 4-inch ducting-hose fell off with an Oops! It dropped away into the basement and disappeared, so I had to go down there with a flashlight and get up on a ladder, and push it back-up into place. I secured the tin from below with a long sheet-rock screw. Back On the upstairs side I anchored one end of the ducting with another screw and then adjusting for height, did the other side.
The action of falling released two pieces of hitherto unknown yellow fiberglass insulation batting that were lodged in the duct-hose, clogging it. Now what was once a hot room in Summer and a cold one in Winter flows A/C and heat freely. YAY two-fer!