Cooker hood modification

[artie]

I don't get into metal work much, but I need to modify my cooker hood.

As per attached pics I need to make an opening to facilitate the recirculation gubbins.

It's less than a mm thick.

It would be handy if I could use my router with a metal cutting bit, or is there a better way?

 

[Dee J]

The slots already there are what's normally used for recirculation mode. Are you fitting non-standard works? Best way I've cut stainless cooker hood chimneys is with a thin cutting disk (for stainless type) in a small angle grinder - but it can grab if you're anything other than delicate and precise.

 

[artie]

The slots already there are what's normally used for recirculation mode. Are you fitting non-standard works? Best way I've cut stainless cooker hood chimneys is with a thin cutting disk (for stainless type) in a small angle grinder - but it can grab if you're anything other than delicate and precise.

Yes I'm fitting none standard parts. The out put is approximately the same size as the black line on pic 2

 

[Fergie 307]

Metal cutting blade in a jigsaw will do that easily.

 

[clogs]

using a jigsaw unless very exp will results in kinks/sharp bends at the cut edge.....
the grinder is best if u use a block of wood / ply to back up the cut....
take extra care to secure the panel....wobbly panals are a no no...
and try on something else first.....

 

[Lons]

Grinder with a thin slitting disk and/or Dremel.
As said clamp it to a support block and wedge the whole thing carefully in case of snatches. A full face mask and thick gloves are a must

 

[flying haggis]

Would old school tin snips cut that?

 

[MarkAW]

If you're just cutting a single hole, and not continuing the vents I'd use a jigsaw and metal blade. Clean up the edges afterwards with a file.

 

[Sideways]

I'm in the camp that says a jigsaw, sabre saw, tin snips, hacksaw will all bend the thin sheet.
Only a slitting disk in an angle grinder or dremel, or a nibbler will make the cut without bending the metal.
I would make the straight cuts just slightly short and finish the corners with a file.
If I needed to tidy the edges of the cut, I'd try a fine flap disk in the grinder.

 

[TRITON]

Metal cutting blade in a jigsaw will do that easily.

Thats going to leave a hell of a jagged edge though. Something like a dremel would clean it up but you probably arent going to get a clean finish.

 

[Fergie 307]

Not sure what people are doing with their jigsaws. If you use a proper metal cutting wavy blade and a fairly slow speed it will do it very neatly. Yes you will need to run a file over the edges afterwards, but that applies equally if you use a disc. A disc will introduce a lot of heat, especially in stainless, and you will probably blue the metal around the cut. Just drill a suitable sized hole for the blade at diagonally opposite corners and away you go.

 

[Fergie 307]

If you're just cutting a single hole, and not continuing the vents I'd use a jigsaw and metal blade. Clean up the edges afterwards with a file.

Good idea to put masking tape over the area to cut. Makes it easier to see the lines to cut to. Use a variable speed saw set slow, and make sure you keep the sole plate firmly in contact.

 

[XTiffy]

I had to cut the "chimney" part of my cooker hood to match the slope of the ceiling. I used a thin cutting disc in an angle grinder. If you do it steadily there will not be any "blueing". Mark it out with masking tape as suggested.

 

[Adam W.]

Drill then file.

 

[MikeJhn]

I would use tin snips, cut inside the line and fold over the edge, angle the corners and file the rough bits, use something like the wide jaw welding mole grips to fold the edge's.

 

[artie]

That job was on the back burner for a while but I eventually got around to it.

I used a thin cutting disk in my antique B&D Grindette. Which appeared to be the most apt tool in my possession.
I was pretty careful but I wasn't entirely happy with the outcome so I put a black bead around the edge.
It's not noticeable since the new gubbins fitted is black also.

Thank you all for your advice.