Air Nibbler - best way to cut sheet metal?

[ISUZUROVER]

Not really 4x4 tech, but not that far off...

I am cladding a shed, and want to know what the best way to cut the colorbond sheeting is - mostly straight and diagonal cuts.

Is an air nibbler the way to go? And any reccomended brands or places to buy?

[chimpboy]

An air nibbler is fantastic but it's not easy to get long, neat, straight cuts unless you make up some kind of jig.

[big lux]

grinder with cutting disc workd well 4 me

[ISUZUROVER]

grinder with cutting disc workd well 4 me

Thanks for that guys - but won't the grinder burn the paint - and be just as uneven???

Most of the cuts will be covered by flashing, except for the sheeting on 2 sides (under the eaves). And these I will only need to cut myself if the supplier cuts them too long.

[Daisy]

get a piece of 25x5 flat or whatever piece of flat you have.... clamp it to the job via vise grips or the like.. and run the grinder along it.. you'll have the straightest cut.

[CWBYUP]

First of all when you say colourbond sheeting do you mean standard CGI or Flat Deck etc ?

If its CGI tin snips or any of the above will work.

If its not then i wouldn't use anything but tinsnips.
Go to bunnings and buy your self a set of IRWIN left and right tins snips and you'll do it easy.

Nick

[Dees]

Try using pferd 1 mm cut off wheel's on a 5" grinder will cut it with
very little heat effect

[ISUZUROVER]

First of all when you say colourbond sheeting do you mean standard CGI or Flat Deck etc ?

If its CGI tin snips or any of the above will work.

If its not then i wouldn't use anything but tinsnips.
Go to bunnings and buy your self a set of IRWIN left and right tins snips and you'll do it easy.

Nick

It is Trimdek. I have a set of left and right handed (wiss?) snips, and they suck at cutting this stuff (take ages and hard to get over the rubs). There is NO WAY I am cutting 30 metres of sheeting using tin snips.

[Daisy]

Try using pferd 1 mm cut off wheel's on a 5" grinder will cut it with
very little heat effect

yup and with what i said before as well... piece of flat works wonders in straight cuts and the sheeting would be fairly thin... so you'd go through it fairly quickly.

[chunderlicious]

grinder with cutting disc workd well 4 me

Thanks for that guys - but won't the grinder burn the paint - and be just as uneven???

Most of the cuts will be covered by flashing, except for the sheeting on 2 sides (under the eaves). And these I will only need to cut myself if the supplier cuts them too long.

ok i am a sheetmetal roofer. NEVER use a grinder it will stop the zincalume being able to recoat or sacrifice itself over the iron underneath. air nibblers with a peice of flat or even better air shears. straigtness doesnt matter as the wall will be covered by a barge cap up top and a corner flashing on the sides.

grinder WILL cause the sheet to rust in about 2 years. i always reroof where people have made there own and it is always rusty from grinders.

if the sheets are too long and you just need to shorten the whole sheet then use aviation sheers. get the red handled ones they are for right handed people but are for cutting left hand corners. the greens work best for lefties or for cutting right hand corners. yellow handled or straight cut snips just suck, dont bother.

[scuba steve 22]

Try using pferd 1 mm cut off wheel's on a 5" grinder will cut it with
very little heat effect

[/quote]get a piece of 25x5 flat or whatever piece of flat you have.... clamp it to the job via vise grips or the like.. and run the grinder along it.. you'll have the straightest cut.[/quote]



this is the way i have done it before works fine

[ISUZUROVER]

if the sheets are too long and you just need to shorten the whole sheet then use aviation sheers. get the red handled ones they are for right handed people but are for cutting left hand corners. the greens work best for lefties or for cutting right hand corners. yellow handled or straight cut snips just suck, dont bother.

So you also reckon that something like this (which I have):

is a better way to shorten sheets than an air nibbler or air shears?

The 2 sides of the shed have to be cut neatly, as they won't be covered by barge capping (timber frame with overhanging eaves).

[shakes]

if the sheets are too long and you just need to shorten the whole sheet then use aviation sheers. get the red handled ones they are for right handed people but are for cutting left hand corners. the greens work best for lefties or for cutting right hand corners. yellow handled or straight cut snips just suck, dont bother.

So you also reckon that something like this (which I have):

is a better way to shorten sheets than an air nibbler or air shears?

The 2 sides of the shed have to be cut neatly, as they won't be covered by barge capping (timber frame with overhanging eaves).

Hate to bring you down but generally yes. I've never had much success doing smooth cut's with nibbler's of any sort no matter the technique. Snips there is definatly a lil bit of an art, and you will get mega arm pump but you'll be sweet.

If the actually cut your doing is going to be covered by a flashing once you've cut 2 ribs out you can generally "tear" the rest of the sheet, take's a bit of practice to get it to tear perfectly straight how ever.

NO GRINDING!!!!!!!!!!!!

[MART]

If all the sheets are cut at the same height , when you get the pack of sheets cut them in 1 go using a 1mm 9 inch blade , very little heat , but be careful , I too am building a shed and this is how I am going to do it , Cheers Paul.

[chunderlicious]

yeah wiss snips are what i always use. if you do it for long enough your arm will actually clench up. its pretty cool for the first time if it is in sight then cut it close to the line with the nibblers and cut the line with the snips after, the smaller the width of sheet running down the sheet the easier it is to cut with snips. as for shortening by tearing. it is actually easy if you know how to tear anything else, pull to the left it goes there etc. just make sure you have a firm grip on the sheet as it will cut through you like .4mm steel wont even feel it untill you see blood pissing out


oh also, there is a thing called a screamer blade for a circular saw that will cut through sheets very easily. but it screams, you need plugs and muffs as it is a loud bad noise.

i also recomend actually fixing the sheets to the wall and cutting them up there as this will get the lengths perfect and the cut as straight as the frame.

anything else?

[ISUZUROVER]

Thanks for all the advice guys.

Oh and Chunderlicious - you need to change your avatar - the pyramids were built by well-paid tradies!!!

[toaddog]

http://www.pneumaticproducts.com.au/saws.htm

[Jaffa]

Another vote for the snips, just practice a little bit first and you will be cutting dead straight in no time (and have very sore lower arms)

[ssfabricator]

if using corrugated cut in one inch with snips place a foot on the the tin grab the off cut end and pull it up hard and fast only good for sqaure cuts
doesnt sound like it would work but trust me it does try it on some scrap as for angle cuts nine inch is the go but using the 1mm wheels on nine inch is a nightmare as they flex a lot normal cutting wheel will breeze through it

[Shadow]

wiss snips or get a set of power shears that the roofers use. Probably a big cost for something youl never use again tho.

When your cutting with snips, remember to pull the waste away from the cut, like pull up toward you or push it away (depends iof your cutting left or right. If you have the waste at say 60degrees to the cut, its alot easier to cut anything, including the ribs in the trimdeck.

[chunderlicious]

ok since everyone is saying use a grinder ill say this

tin has a warranty, cut it with a grinder and you have no warranty. use snips and nibblers or excalibur cutters (electro shears) if you can spare 400 bucks. but dont for any reason cut purlins, battens, roof sheets, wall clad, flashings, caps, aprons or anything else associated with zincalume roofing or framing with a grinder. it will corode very fast and screw up warranty claims or even any chance of an insurance company if it gets hail damaged. if they see rust they normally refuse to redo it. use a hacksaw if its all you have, a powersaw, jigsaw anything but a grinder.

if you can a water jet works well and so does those air jet things. but plasma wrecks it. even if painted over after it doesnt matter its screwed if its hot cut.

[super jeep]

chunderlicious is spot on only cut sheets with tinsnips i'm a shed builder and if i catch any of my workers useing a grinder on sheets they get a one way ticket to dole office. i use wiss snips for cutting around flashings and trim work but i found gilbows are the best for a straight line cut across the sheet even when on a angle. gilbows take alot of getting used to but i will challange anyone with there air/grinders tools that i could cut my sheet quicker and neater with my gilbows than the other guys.
also alot of sheet metal bluescope included voids there warrenty if been cut with grinder

[Shadow]

we cut our purlins with a grinder when we have to, but we have to paint the cuts with a high zinc paint.

The rust will travel for a good 1cm around the cut if its not cold galled.

[super jeep]

we cut our purlins and battens with a makita cold saw it has a tungsten tip blade and clean cuts leaving no heat to burn paint but yes we still cold gal our cuts

[blackmav]

Yep. Go to your local hire shop and rent a cold saw for half a day. Earplugs and muffs.
Rip into it.
They are HEAPS FAST.
30 meters will be cut as fast as you can push the saw.
Angle cuts are easy.

[chimpboy]

Wow, I'd never seen these.

Written up here: http://en.wikipedia.org/wiki/Cold_Metal_Cutting_Saw

Sounds perfect for the job.

[WRXZook]

We use a Makita metal circular saw... but only as a last resort, they are the most annoying sounding tool I've heard. Anything covered with flashing we cut with a nibbler, very quick and it can be surprisingly accurate with a bit of practice. Snips for flashing and trim.

[bazzle]

Put a tungsten tipped blade in your circular saw, backwards..

Bazzle

[Guy]

I have some little "rotary hacksaw" blades for my 5 inch grinder .. noisy as all fark .. but quick, clean and very neat (no swarf at all)

[Guy]

ok since everyone is saying use a grinder ill say this

tin has a warranty, cut it with a grinder and you have no warranty. use snips and nibblers or excalibur cutters (electro shears) if you can spare 400 bucks. but dont for any reason cut purlins, battens, roof sheets, wall clad, flashings, caps, aprons or anything else associated with zincalume roofing or framing with a grinder. it will corode very fast and screw up warranty claims or even any chance of an insurance company if it gets hail damaged. if they see rust they normally refuse to redo it. use a hacksaw if its all you have, a powersaw, jigsaw anything but a grinder.

if you can a water jet works well and so does those air jet things. but plasma wrecks it. even if painted over after it doesnt matter its screwed if its hot cut.

If it is painted over with an approved "colorbond" brand paint that seals out external contaminants .. how can it still be screwed ? ( I am not doubting what your saying about insurance companies looking for any reason to get out of coughing up the $$ .. but I bet a court case would beat em .. as the damage is in no way related to the cutting of the metal with an abrasive disk .. if it was rusted to all fark well thats another story unless you have new for old)