Cutting Sheet Metal

[Big_bazza99]

What's the best way of cutting the sheet metal? - I have attacked sheet metal with a jigsaw, but it tends to bend it, a dremmel and it wears the cutting disc out really quickly, hacksaw and I have reach problems and cant cut holes. I have even used an angle grinder.....

Any help appreciated as I would like to try to make a flat pack stove/firebox, thanks Paul

 

[shaggystu]

what thickness? what kind of metal?

stuart

 

[Retired Member southey]

Is it to thick for tin snips Paul?

 

[Dave Budd]

lotsof ways to cut sheet metal. Mostly it comes down to what you are trying to cut out and the tools you have. Some tools like nibblers, shears andold fashioned chisels will cut any shape you like but will distort the metal meaning you will need to flatten it afterwards (won't always come out perfect after either). Plasma cutter or gas torch will do any shapes you want if you have access to them. Angle grinderwith thin disc, or good jigsaw are good, chain drilling works too. If the sheet is too flexible then try sitting it on a sheet of ply and cutting close to the wooden edge (so it has support),or even sandwhich between two bits near the cut.

give us a clue what you are trying to do and I'm sure we can provide a better suggestion

 

[Big_bazza99]

I saw this thread:

http://www.bushcraftuk.com/forum/showthread.php?t=63160

I was hoping I had missed a really easy way of cutting sheet metal with basic tools but I guess there are certain techniques and perhaps a little bit of pactice and patience to put in to the mix too.

Southey - I forgot tin snips, but again the problem is when cutting longer sections, the remaining metal "gets in the way".

Dave - a lot of good suggestions, thank you - based on the stove in the link, do you have any other suggestions?

Regards, Paul

 

[Dave Budd]

I would go for an angle grinder with a thin cutting disc. Lay the sheet metal on a flat firm surface you don't mind cutting into (like scrap ply) and cut as close to size as you feel capable of, then tidy up with grinder/files. That would be the easiest, fastest and clenest way I would think.

for the slots I woujld chain drill and then file them out.

 

[nuggets]

you could drill out the slots then file them square -same with the hooks !! to cut the sheet into pieces your better of with an angle grinder or find some one with a guillotine or plasma cutter !!

 

[shaggystu]

i'd be going for dave's suggestion of laying the sheet flat on a piece of scrap ply to get over issues of flexing and going at it with an angle grinder....... just looked at the plans again, 2.5mm thick sheet (plate at that thickness, can't remember the cut off point?) is pretty sturdy stuff, i think i'd probably just get busy with the hacksaw to be honest, the angle grinder's going to go through ally sheet of that sort of guage like a knife through butter, mistakes would be really easy to make. hacksaw and a file and some elbow grease would be my approach to this.

stuart

 

[Mojoracinguk]

If you are doing lots of holes and want neat jobs bite the bulet and purchase tools like this

Back when i was a spanner monkey we used tools similar to these....think we got ours from RS.....they are quick to use if you compare it to chaindrilling and filing the edges afterwards.

not sure it will be of any use to you but like i say it's good for multiple holes (and square/rectangle/hexagonal holes as they sell shaped cutters to)

Mojo

 

[Big_bazza99]

Thank you all for your advice.....will give it a go with the angle grinder - need some thinner discs first.....

Just been thinking (and perhaps no real point in this as I dont have one) would a band saw be any good? The problem I have had with my jigsaw is the fact that the blade goes up and down and as such causes the metal to move about / tear.

 

[alan whelan]

If you put a very fine blade into the Jig saw with the speed slowed down and if it has a cam adjustment ( a little lever on the side near the blade) set to the lowest you should be able to cut without any damage, the sandwich between two bits near the cut would also help. Jig saws come with a range of prices and they are one tool where you get what you pay for, the most expensive cut the best.

Alan.

P.S. Let the blade do the cutting don't force it it will take a little time.

 

[FGYT]

Laser.....................:borgsmile

 

[bilmo-p5]

Thank you all for your advice.....will give it a go with the angle grinder - need some thinner discs first.....

I've been using these lately. Bit pricey but 0.8mm and a dream to cut with. Mojo is spot on with the Holecutter he suggests - well worth the expense & knocks spots off step- or cone drills.

 

[nenook]

hey up Paul, In my former life i was a fabricator for 20 years, its simple mate take your sheet down to a fab shop that has a guiletine, with your measurements, give the lads a beer and presto one straight cut, we used to do it in our dinner time for folk, it pays to ask . the slitter disks your after arent cheep . its up to you but its another way

Nenook

 

[Scots_Charles_River]

Second Nenook, guileotine is best. We have one that has a table about 1m by 0.5m and a huge lever for cutting. The lever is padlocked up when not in use (saves fingers). It Shears the sheet and slightly raises one edge. Luckily we also have a Folder too, which allows for angles to be accurately bent too. A cold chisel may struggle at 2.5mm, unless it's alu. alloy. One of the benefits of being a CDT teacher.......

Nick

 

[DaveBromley]

I've got a tool box full of these and they are great, dont use them much but when i do they deff cut down the labour

Dave

 

[WeThePeoplexfbm]

tip snips, or grinder? when useing a grinder dont have petrol near by....

 

[spoony]

Heres mine

 

[Big_bazza99]

Heres mine

That looks so good - is that all your own work.....? (dont mean that to sound patronising or imply you are not capable....!)

 

[Ronnie]

Try a set of aviation tin snips. They come in straight cut, left curve and right curve - for example:

http://www.screwfix.com/prods/15364/Hand-Tools/Pliers-Cutters/Sets/Aviation-Tin-Snips-Set-3Pc

People scratch-build planes with these as their primary tool:

HTH