Best tool to remove window frame return?

[Flaps]

Got a hardwood double opener window that I’m going to change to a fixed window.

The plan is to remove the existing return and then trim the new piece of insulated glass in either side with matching strips of wood and then silicone in.

I’m thinking of the best way to remove the existing return, I’ve got a multitool and flush cut blade but as I’ll be cutting in parallel to the grain I know it can be difficult. When I’ve used the multi tool for this kind of cut in the past it’s almost burnt through the wood and been difficult. Cross grain cuts are a lot easier and I can’t afford to make a mess of the frame!

Is there a better tool for the job?

Also bonus points for identifying this hardwood (so I can match the trim pieces), im thinking sapele or mahogany but would be great to have it match!

 

[woodieallen]

I'm afraid my Go-To for this type of job is also a multi-tool. Lots of new blades perhaps. Or do what I do ...paint over it.

At the risk of teaching my mother's mother to suck ova, any requirements re building control? access to the room? fire egress...that sort of thing ?

Welcome to the forum, BTW

 

[Flaps]

I'm afraid my Go-To for this type of job is also a multi-tool. Lots of new blades perhaps. Or do what I do ...paint over it.

At the risk of teaching my mother's mother to suck ova, any requirements re building control? access to the room? fire egress...that sort of thing ?

Welcome to the forum, BTW

Hey!

Good point on the building regs, although it’s a bathroom so can’t see anything about opening window being required, just a form of ventilation which it will have. Happy to be educated otherwise though!

 

[deema]

I’m not sure what you mean by a return. It doesn’t appear to have a muntin in the frame. Anyway, why don’t you just remove the two sashes, plonk in your double glazed unit, make or buy some beading and you’re all good?

 

[Doug71]

By the return do you mean the rebate? You should be able to glaze straight into it or maybe add a small bead on top if you want a bigger rebate?

I wouldn't be trying to cut it off, it will make a right mess.

Edit to add at a guess the wood is probably Meranti but Sapele would be better for the external beads.

 

[Flaps]

By the return do you mean the rebate? You should be able to glaze straight into it or maybe add a small bead on top if you want a bigger rebate?

I wouldn't be trying to cut it off, it will make a right mess.

Edit to add at a guess the wood is probably Meranti but Sapele would be better for the external beads.

Ah yes I mean the rebate. The new piece of glass is 28mm thick so if I set it with the rebate still there I’ll have no space to use any sort of trim peice/beading on the outside. It would be a lot easier if I could leave it as is!

Alternatively I could just try to cut the rebate back a bit but I think that will be even more challenging!

 

[Flaps]

I’m not sure what you mean by a return. It doesn’t appear to have a muntin in the frame. Anyway, why don’t you just remove the two sashes, plonk in your double glazed unit, make or buy some beading and you’re all good?

It’s due to the thickness of the glass that’s going in (28mm) there isn’t enough depth for it with the existing return

 

[Flaps]

oops double post

 

[HOJ]

Why not get a thinner glass unit 24, 20, 16, 14, 12 even down to 10mm

 

[Doug71]

If you really want to trim it you could use a router? Would it be enough if you took off the flat section (guessing 12mm)?

You want at least a 15mm high rebate for DG units so you could add a bead (probably 9 degrees) to the bevelled section at the back and then run round on top of this with a flush trim bit finishing the corners with a multi tool.

Personally I'd just be getting thinner units, worst case it's okay if the glazing beads stand forward of the window frame.

 

[Flaps]

Why not get a thinner glass unit 24, 20, 16, 14, 12 even down to 10mm

That side of the room is being converted into a sauna so needs a thick insulated glass

 

[Flaps]

If you really want to trim it you could use a router? Would it be enough if you took off the flat section (guessing 12mm)?

You want at least a 15mm high rebate for DG units so you could add a bead (probably 9 degrees) to the bevelled section at the back and then run round on top of this with a flush trim bit finishing the corners with a multi tool.

View attachment 152422

Personally I'd just be getting thinner units, worst case it's okay if the glazing beads stand forward of the window frame.

Thanks for taking the time for a well thought out response, the diagram is much appreciated!

You’re right, it’s a 12mm high rebate and I could do as suggested, but in my mind this is more work than removing the rebate entirely and fixing a new piece in?

Thickness of the unit has got to be 28mm as he room is going to be a sauna!

 

[Doug71]

You could do as my diagram but cut the waste out with your multi tool instead of a router, it just helps having something to work to. I picture if you try to cut it all off it might not be very tidy, multi tools are hard to keep straight.

 

[Phil Pascoe]

Make a new frame and triple glaze it.

 

[deema]

If you try and take the rebate out you will make a complete Horlicks, it will look a complete mess! It would be far easier to just make a new frame and pop that in.
What is the depth / thickness of the openers (sashes)?

 

[Flaps]

If you try and take the rebate out you will make a complete Horlicks, it will look a complete mess! It would be far easier to just make a new frame and pop that in.
What is the depth / thickness of the openers (sashes)?

Glass has already been ordered, in my head it’s wouldn’t be too bad with a multi tool but I suppose it’s a relatively large depth for it to get through. I was hoping a flush cut blade would remain pretty straight. Maybe I could test it on something else first.

I could keep the current rebate and build it up with some beading so it’s over 15mm on the inside. The part where the glass will then sit is 30mm wide which would mean the glass will be 2mm short of filling this space entirely. I could then built up some sort of beading on the outside if that makes sense. There is enough space externally around the window I would just have the slope of the sill to contend with.

 

[Phil Pascoe]

The problem with multi tool blades is they are not designed with any facility for clearing the sawdust - you need to clear them literally every few seconds or they burn badly.

 

[Flaps]

The problem with multi tool blades is they are not designed with any facility for clearing the sawdust - you need to clear them literally every few seconds or they burn badly.

Perhaps there’s another tool out there that could do it?

I could maybe trim it almost flush by using the multi tool on top of a spacer where it’s doesn’t matter if it’s burning and then clear out the last bit a little neater and hit it with a sander to finish off

 

[skeetstar]

My first thought would be for a router with a chisel for the corners. Might need to fabricate some sort of carriage to keep the router at the correct angle.

 

[aet1]

I have heard of people getting a double glazed unit "stepped" - with the outside pane larger than the inner one. Then the larger part fits in the rebate for the outside and the smaller one ON the rebate for the inside - then just some beading in and out and the job's done. Would be worth asking the glass people if they can do it.