I need to cut some vent holes in a steel water tank I’m using as a wood store.

I cut the end out with a 9 inch angle grinder, it took a while.

Is there a quicker more efficient tool I could use.

I’m off to Screwfix tomorrow, if there is anything they’d stock, that would be a plus.

[video]http://www.youtube.com/watch?v=q6j9wEF1sf8[/video]

were you using a specific steel cutting disc in the grinder?

I’d use hole saws. The type that fit in an electric/cordless drill. Page 879/880 in the current screw fix catalogue. There is also a set for £40.

with that 9″ grinder and the right disc, Id plunge cut square holes in it.

Depending on how many holes and the thickness of the steels you may be better off with a HSS nibbler Brandon Hire nibbler

Oxy-Acetylene cutting torch would be the business, but if you had access to one, I guess you’d be using it 🙁

Hire a plasma cutter, you’ll be there all day with grinding discs! 😆

…or cut a long rectangle, say, 9″ deep out of each side and weld it back as a rain louvre….

Hire a plasma cutter, you’ll be there all day with grinding discs!

Does a plasma cutter need a compressed air source?

As Stoner says just cut slots with the angle grinder

Thermite!

Does a plasma cutter need a compressed air source?

Don’t know, sorry. All I know is the fabricators/welders where I used to work were always after one…
…thinking about it due to portability, grinder might be the best (albeit slowest) option.

you’ll not get through 5mm plate with a nibbler I would have thought (not my hitachi one anyway, that won’t do much more than 1.6mm) you also won’t get a nibbler from screwfix (and for much less than £300 – £400 anywhere else)

If you go down the hole saw route get the bosch bi-metal ones. they need their own style of arbor, but they’ll outlast the cheaper ones by a massive margin, in fact I don’t think I’ve ever blunted one. If there are a lot of holes to do they’ll still be a ball ache and the noise will drive you mental, and working with a drill driver will result in lots of wrist-spraney moments. A 9 inch grinder and good disks would give a faster, clumsier looking result. Neater work could be done with a 4.5″ grinder and a good supply of 1mm disks and a gentle, patient hand.

An evolution TCT saw would have made a better job of cutting the end of the tank of, you can’t really plunge cut with them really. If you used a grinder to start things off you could use an evolution saw to cut sets of long slots rather than small holes. Shop around as there was some pretty heavy discounting going on recently. B&Q might have them

Does a plasma cutter need a compressed air source?

yes they need a really pretty powerful air compressor. Rather than hire all that I’d drag the tank to someone with a plasma cutter or the gas gear. It’d take them 10 mins

Thanks, I think I’ll get a load of cutting discs and just grind them out. I think the hole saw route wouldnt make holes big enough.

If you bought the pack of “metal” discs they had in Lidl recently it’ll be a long slow job (Lidl stuff is normally good but the disc are utterly useless). However, if you were using a quality cutting disc (stainless compatible if in doubt) I doubt you’d have started the thread.

If your going to screwfix try to get some of the thin profile (2mm) 9inch discs, as Edukator says there stainless steel blades but cut mild steel beautifully, look for INOX on the blade.

5mm steel plate is not something to do with discs unless you’re into making life hard for yourself. Get it oxy cut by a local eng place, far quicker and easier.

like stoner said only cut two sides and the bottom. then bend outwards to form the louvre to keep the rain out

Plasma cutter or arc air gouger.

I loved the cordless and holesaw suggestion… can we get to see the movie afterwards?? 😆

If your going to screwfix try to get some of the thin profile (2mm) 9inch discs, as Edukator says there stainless steel blades but cut mild steel beautifully, look for INOX on the blade.

These are 1.9mm thick discs, I dont see any stainless specific cutting discs.

http://www.screwfix.com/p/norton-thin-metal-cutting-disc-230-x-1-9-x-22-2mm-pack-of-5/56089

I’m also not certain I could uniformly bend the two sided cut triangles, 5mm plate is pretty hard to work. I’m thinking I could just cut out a full triangle. It might look quite decorative when you see the logs through the cutouts.

We use this at work http://www.petrogen.com/

i have drilled holes in 10 mm steel [ boat for vents] with a hole saw it will blunt it will burn it will require a massive massive drill and you risk breaking your wrists when it snags especially as it gets through the metal. It will take at least 30 mins per hole if not longer with cutting oil and patience – hence the need for a serious drill or you will just burn it out

A battery one would take a lifetime.

At home a 9 inch grinder and good discs should do it fairly quickly and it would be my choice – should not take that long tbh. I did a bulk head with just one disc but cant recall how long it took but I dont recall it being a massive struggle and that involved cutting about 12 feet…burning will take a few minutes if you have access to oxy-acetelene

A rocket powered sled?

[video]http://www.youtube.com/watch?v=GUkXDA2dtfQ&[/video]

Tie lots of nails to something high, like say the branches of a big tree, and let it fall on said tank?

🙂

Just use those aforementioned thin cutting discs, you may need a pack but boy they cut well, I use them most of the time when fabricating stuff for the farm and get on very well with them, our plasma cutter broke months ago and we’ve not bothered replacing it as these thin cutting discs are amazing!

As an example I cut a 5″ diameter circular hole in an old Nuffield nose cowl the other night, I found some of the smaller worn out blades and gently went round and ended up with a neat hole which just needed a little fettling with the Dremel to tidy up.

We’ve used them for cutting meters of 5mm steel for making cereal dryers and use them for repairing our boilers on our steam engines, they’ll cut your holes with precision if you mark up and wear your safety glasses.

Tie lots of nails to something high, like say the branches of a big tree, and let it fall on said tank?

😀

Oxy Gear or Plasma would be first choice, however big grinder with the right discs will probably get the job done.
If you do go with the grinder, can I suggest a face shield.. chap I used to work with had 16 stiches in his cheek after a big grinder jumped back and caught him… It isn’t a pretty scar either, as grinders just obliterate everything in their path.

If its a galvy tank I would watch the way I cut it,Not use grinders burning gear or plasma unless you have the correct breathing apparatus.

I just LOVE mcmoonter threads.

There must be a way to somehow combine the logsplitter and the hung tree to achieve a semi-satisfactory result 🙂

Some plasma cutters have a compressor built in for true portability.

**** around with drills and discs 🙄 gas axe all the way and at a push id fire up the stihl!!

Gas axes may lead to the world’s largest barbeque. I’ve started filling it with logs. 😕

Gas axes may lead to the world’s largest barbeque

Invitation accepted, I’ll bring a bottle and a bag of burgers

Aaahh 😐 however you’d get several pigs on there hor an almighty hog roast!!

I got myself a stock of those 2mm cutting discs, and chalked out a vent design on the tank. I will try and give it a go tomorrow.

So I guess you are not flipping it over to use the base for a roof!

What are your plans for that now?