drilling different holes in SS pot in imperial - best approach?

[buckerooni]

Hi All,

So I need to drill 2 different holes in my (cheekypeak) SS pot.

• 2 x hole for a 1.5 inch triclover ferrule: https://www.brewhardware.com/product_p/tc15rsf.htm. The hole needs to be between 34.9mm and 41.2mm.

• 3 x hole for pull through bulkhead: https://www.brewhardware.com/product_p/ptbulkhead.htm. The hole needs to be 20.9mm

I was thinking a decent imperial stepped bit might be the answer but am unable to find a bit that covers the range in size.

Any suggestions of what I should get? Already dropped a bundle of coin on the hardware so looking to minimise the spend on a one-off tool if possible.

Thanks.

 

[spog]

Best I can suggest is drilling the holes to nearest smallest size then slowly file the holes to suit using a round file.
Remember that when drilling into a rounded surface like the wall of your pots,if the drill isn't perfectly aligned the hole won't be perfectly round and cause issues,slowly slowly catchy monkey.

 

[Danscraftbeer]

Depends what tools and equipment you have. What I would do is literally drill or grind out the bulk, Some grinding bits that fit in a power drill and time with a dremel to finish it out.

 

[bevan]

Stainless is pretty tough stuff to drill through. I'd use something that's designed for it like this
http://www.ebay.com.au/itm/HSTR-Tungsten-Carbide-Tipped-Metal-Hole-Saw-20-25-30-32-35-40-50-64-65-75-100mm-/201271627211?var=&hash=item2edcb94dcb:m:mzoguhs7mW2edVZC5i6TPSg
http://www.ebay.com.au/itm/Tungsten-Carbide-Tipped-Hole-Saw-TCT-Stainless-Steel-/291824879020?var=&hash=item43f21e45ac:m:mUfym0M5flcqGeWLYZFkgEQ
Also you can smaller sizes from keg king or grain and grape
http://kegking.com.au/misc-plumbing-fittings/brewing-fittings/20mm-tct-holesaw-25mm-deep.html
Prices are not too expensive and they should do a nice job on your shiny pot from cheeky peak

 

[Lyrebird_Cycles]

Stainless is not difficult to cut if you are careful.

The key is that the stainless will work harden in the cutting zone under the tool if it gets a chance.

You need to go around this: keep the tool speed low to reduce the size of the work hardening zone and keep the depth of cut high so you go under the work hardened zone that does form.

Slow the tool down as far as possible. Use lots of lubricant and apply as much pressure as you can without stalling. If it does stall, back off completely and start again.

DO NOT leave the tool running on the surface with low cut depth, this will just create a large hardened zone which will be difficult to remove.

 

[Mardoo]

What about sheet metal punches? They'll make short work of holes in the CP pots. I love them. Dead easy to use. Greenlee are trade quality and Q Max are next best. I've always used Q Max. You can get them on eBay. eBay seller davethetools (in the U.K.) carries a wide range of imperial Q Max punches. I've been using them for years. They're manual tools, so easy to overlook in our search for Max Power, but they do a fantastic job. You'll still need to drill a pilot hole, and will need to take a close look at the Q Max sizing charts to make sure you get or have the right size bits for the pilot holes.

There are also hydraulic sheet metal punch sets from China on eBay that some people here have spoken well of. I haven't used those particular ones myself.

 

[nosco]

Ive heard they make the neatest hole but a few years back when i was looking they where very pricey. Maybe i was searching for the wrong thing?

 

[nosco]

I think Bobby NJ on Youtube ( brewers hardware?) Uses them. If we are talking about the same thing that is.

 

[feralbass]

If your worried get them laser cut

 

[Curly79]

Like you said. Step drill. Just stop one size down from the size your after then slowly go a bit more,measure, bit more, measure etc.

 

[Mardoo]

Ive heard they make the neatest hole but a few years back when i was looking they where very pricey. Maybe i was searching for the wrong thing?

The Greenlee ones are quite pricey, but will last a lifetime. The Q Max ones cost much less. I haven't yet worn one out, but I haven't gone more than six holes on any of them. For our purposes the Q Max ones are fine.

 

[n87]

I have a set of the chineese hydraulic punches, was about $90 for a range of sizes.
like this one: http://www.ebay.com.au/itm/10-Ton-Hydraulic-Hand-Pump-Knockout-Hole-Punch-Kit-Metal-6-Die-22-60-5mm-/121201233156?hash=item1c38280d04:g:BBEAAOSwMgdX1y2s
mine works fine, have done about 12 holes without signs of stopping.

 

[dblunn]

The larger, less precise hole could be cut with a hole saw. The smaller one could also be done with a hole saw but cut it undersize and use a carbide bur on a die grinder to open it out.

 

[user 31093]

Like you said. Step drill. Just stop one size down from the size your after then slowly go a bit more,measure, bit more, measure etc.

+1

I have a step drill which is perfect size for punching holes for 1/2" fittings.

They do have a tendency to suddenly cut very well so go slooowly. Use silicone lube.

 

[Mardoo]

You know Buckerooni, I'm 90% certain I have a 21mm punch you could use for your 20.9mm hole. Should you decide you want to give punches a go, it would mean you'd only have to buy the larger one. From what I've read about the pull-through fittings the extra 0.1mm wouldn't be an issue. I'm in Ferntree Gully, so It's a bit of a hike for you to pick up, but I'd be happy to post it to you as long as you promise to post it back to me. I'll double check to see whether it's the correct size.

 

[Matplat]

Sheet metal hole punches are definitely the way to go, dunno if it's the sort of tool you can hire or not? Second to that is a step drill.

If you go the hole saw route, as Lyrebird says, slow tool speed, high pressure. You also don't want teeth that are too large, otherwise they'll catch as you start to break through the other side, with it being a curved surface and all.

If you have the perfect conditions for drilling stainless, it isn't a problem. If you don't, it can be a real pain in the backside to work with, and end up with an untidy finish.

 

[bevan]

I didn't realise that you could get the hole punches so cheap, definitely the way to go!

 

[user 31093]

I didn't realise that you could get the hole punches so cheap, definitely the way to go!

**** nor did I. There you go.

 

[sp0rk]

+1

I have a step drill which is perfect size for punching holes for 1/2" fittings.

They do have a tendency to suddenly cut very well so go slooowly. Use silicone lube.

They're very worth buying the expensive option too, anything under $30 tends to be made of cheese

 

[Ducatiboy stu]

These work if you are careful and slow