enlarging hole in patio doors

hiace_drifter · Post by **hiace_drifter** » Mon Sep 25, 2023 10:56 am

I need to fit a new loch mechanism on my patio doors, and the new mech is slightly bigger than the old one*. I have shown in the pic one of the old holes, and where the new mech extends to (green line). What's the best tool to use? Multi tool with a small blade?

I'm thinking something like this:

https://www.saxtonblades.co.uk/fein-mul ... wood-blade

* I have been liaising with UPVC spares who have been guiding me with the replacement, they have confirmed the new mech is the correct part.

Someone-Else · Post by **Someone-Else** » Mon Sep 25, 2023 11:34 am

What picture?

and the multitool blade is for timber.

This is one job I would get a locksmith in for, or look for a different supplier of locks.

big-all · Post by **big-all** » Mon Sep 25, 2023 1:36 pm

general points
ossilating saw blades will only cut around 50mm deep
the swing cuts around 3-5mm into each side off the arc you need a chisel and perhaps a spade bit

hiace_drifter · Post by **hiace_drifter** » Mon Sep 25, 2023 3:08 pm

Sorry, didn't attach pic in original post:

According to the link for that blade, it cuts "wood, plastics, plasterboard and more"

dewaltdisney · Post by **dewaltdisney** » Mon Sep 25, 2023 4:29 pm

I would put a bit of narrow wood in the slot and slide it up under the plastic and past the green mark. Using a spade bit of the right diameter drill through the plastic into the wood to ensure accuracy and stability. Remove the wood and fit the lock.

DWD

Someone-Else · Post by **Someone-Else** » Mon Sep 25, 2023 4:47 pm

I would get one of these.

: hs.jpg (9.68 KiB) Viewed 354 times

Not necessarily this brand, but a hole saw. No timber needed and it will cut its way through nicely. I assume the gap is 20mm wide. You can get bigger cutters. Or you could go the old fashioned way, drill lots of tiny holes.

dewaltdisney · Post by **dewaltdisney** » Mon Sep 25, 2023 4:54 pm

SE, It would be too hard to get the cut using that without wood under to take and guide the pilot bit. A flat bit would do it easily, or a forstner bit with a centre punched as a guide.

DWD

wine~o · Post by **wine~o** » Mon Sep 25, 2023 5:32 pm

hiace_drifter wrote: ↑Mon Sep 25, 2023 10:56 am I have been liaising with UPVC spares who have been guiding me with the replacement, they have confirmed the new mech is the correct part.

IF it was the correct part then it would just fit straight outta the box. Any markings on the part/s that you removed ???

big-all · Post by **big-all** » Mon Sep 25, 2023 9:08 pm

Ahh ok plastic not deeper mortise in wood ??