Cutting extractor chimney

If cutting a extractor chimney or anything else made of sheet steel I clamp a piece of scrap wood (e.g 9mm ply) to the inside and then clamp that to the bench. Mark the line with wide masking tape and then draw line on that. Cut into the sandwich using a brand new blade. The wood helps to dampen out a lot of the vibration (and the awful noise!). Hacksaw is easiest but you will need to bend the offcut piece away to make room for the saw frame. You'll also need to move and reclamp the workpiece frequently to keep the cutting angle right - a hacksaw works best at a low angle so several teetth are in contact with the metal ant any time. Any rough edges clean up with a file.

I have had mixed results using a metal cutting blade on an angle grinder - some steels will 'blue' very easily and then you have a nasty looking patch that you can't do anything to get rid of. You have no idea how a particular piece will react until you try it so do trial cut first on a piece that will go in the bin anyway. Again, I always clamp it to a substrate that can be cut into.

As for the height of the mechanics - no idea .... give DIY a call and ask. They're generally pretty helpful.

 

tin snips best thing to cut with. disc cutter will blue the steel. Mechanical part of fan not too high most of "chimmney" is hollow to cover ducting. regards nigel

 

I've always cut the stainless steel with an angle grinder, there are thin blades available so less heat will be generated.

Also it is advisable to remove the outer protecting film otherwise it will melt and be really difficult to remove, peel back about 100mm.