Cutting Metal....

[BogMonster]

This might seem like a silly question but ... how thick a bit of steel can you get away with cutting with a jigsaw, given a few spare blades and a reasonable amount of patience?

I'm looking at doing something that requires some curves, don't have any access to any lovely kit like a plasma cutter it needs to be neater than a gas axe, and cutting bendy things with a grinder or hacksaw doesn't really work ... so I'm wondering if a jigsaw would cope, never really tried anything thicker than about 1mm. I know they are only really supposed to do thin stuff but would it cope with 4mm? I have never tried it and I only have 1 bit of metal the size I need so don't want to start and then find it doesn't work and I have F'ed it up! The only other stuff I have lying around is either a lot thicker or a lot thinner so no good for experimentation and if I can't find a way of doing what I want to do I'll have to fiddle with the design a bit. If it'll do 6mm that would be even better

Ta

[roguevogue]

Should be able to cut 4mm no problem, use a decent jigsaw, one with a pendulum action and variable speed set to slow.

As with all the fun things in life a little lube will help enormously.

[landrover598]

anything over 2mm is a grinder job in my garage.

you can cut quite tight radii with a 4.5" grinder mind, you'd be surprised

[Les Henson]

I've cut 3mil cold pressed steel with a B&D pendulum jigsaw. Spray occasionally with WD40 or similar type of oil, take it easy and don't let the blade get hot or the tips of the teeth will quickly blunt. You need a good quality blade as well, you get what you pay for when doing this type of work. If you are cutting a curve, then one that's tight will heat up the blade very quickly, and may cause it to seize or break.

I wouldn't try to go to 6mm though.

Les.

[rtbarton]

I've cut holes in 4mm mild steel with a hole-saw without any problems, a jigsaw is just a hole-saw straightened out.

Use the correct lube, I like Rocol cutting oil.

[Hybrid_From_Hell]

I've used a jigsaw to cut 6mm steel (yes, I know a "Repair section )

Its best to give it short 'bursts' and use a fine balde and cutting fluid,

Oh and you'll be F deaf too at the end of it, and the vibration (oooer ) will make you hands go numb....

Basically a great days fun

Nige

[BogMonster]

Thanks ... when I get that far I'll give it a whirl with the jigsaw and see what happens

At the moment I am fiddling with the KittyGripper design, oh and doing a damage assessment on stuff like how round most of the bolt holes aren't

What I have in mind is that when I build the winch bumper I have the support leg off the side of a Portakabin (90x90x4mm box section) which is going to form the main part of the bumper with an 8 or 10mm plate let into it for the winch mounting, but I don't want to just hack the ends off square so I thought I would try and cut it from the back edge into a curve like on a std LR bumper, leaving the front face intact, then flatten the front face round and weld it to give a completely sealed box ... should be waterproof (no internal corrosion) and nice and strong for popping a tow rope onto. I'll probably do the ends first as it will be easier to work with just the box section than after I've added 1/2 ton of steel plate to it! What I really need is the front off an old chassis to use as a template for the mounts ... I don't want to take the MM off until the bumper is almost finished and ready for a test fit, and stuff usually changes size between when I measure it and when I later go to fit it so being able to build it "on a chassis" (even if only the front 2ft!) would be a bonus!

I hope I'll be able to cut everything else in straight lines with the grinder... otherwise I will be up a certain creek without a certain instrument

[LR90]

Steve,

for the level of accuracy that requires, and given you'd be welding it after, surely gas axe woudl be quite adequate?

Also consider tapering the ends?

Tonk did this to mine. Gas axe along the front face to remove a thin wedge, bend up the bottom face and reweld. I'm dead chuffed with it

[BogMonster]

I did think of that but I want it nice and strong and I figured with it only being 4mm if I tapered it the end would be likely to bend, which is something I want to get away from.

Might change my mind yet though

I don't have oxyacetylene either (though I could use the one at work)

[geoffg]

Hi

You could cut it straight with a cutting disc and then grind the curve in with a grinding disc. I use those flapper discs you get for the grinder, they are a bit more accurate than a grinding disc. just leave enough material on the end to ensure you can get the curve you want

Geoff

[western]

Stephen, a mate of mine bulit his own winch mount for a X9, he built it to fit between the chassis rails with 2 agri drawbar 3/4 inch pin mounts in line with the rails and re-used the outer parts of the standard front bumper to finish it off I haven't got any decent pics of the finished bumper

[BogMonster]

I am going to make the outer bits stronger though, I have bent the std outer bumper ends a few times on the old 90, and box section should be much stronger than C-section like the ordinary bumper

A couple of proper towing hitches are also on the "maybe" list though they are 'kin expensive!

[Tonk]

I did think of that but I want it nice and strong and I figured with it only being 4mm if I tapered it the end would be likely to bend, which is something I want to get away from.

internally brace the bumper with summat nice and thick

[siggy]

aye 20mm steel everthing else is just a repair section

[JST]

i cut 5mm mild steel with bosch 750W pendulum jigsaw with relative ease. good eye and ear protection essential though.

nice slow speed and lubricate........................

[Tonk]

i use a guilly and a cnc punch press