# Attn Metal Workers: ideas for drilling 2.5" holes in shipping container



## FWBGBS

I'm looking for the most efficient way to drill 2.5" holes 20 times in my container.
Any and all suggestions welcome.

Both my professional electrician and plumber friends agree I'll be lucky if I can get maybe three holes drilled with a Milwaukee or Lenox hole saw blades before they dull(are they correct?). Also, with those larger teeth I'm concerned the bits might catch and rip my skinny little arms off.
or
Pay between 60-$100 and get one of these "Carbide Tipped Hole Cutter":








In these holes I'll be inserting 2.5" round louver soffit vents.
Eventually I'll have two 5"x5" vents both fore and aft.


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## Schroedc

Rent or borrow a plasma cutter?

Reactions: Agree 2


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## FWBGBS

Yeah, me with a plasma cutter.


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## DKMD

Plasma cutter sounds like fun. Amazon has one for under $300... wonder if Harbor Freight makes one?


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## rocky1

How bad you want holes in it? Spendy, but I've seen holes cut in red iron to run conduit with these. They weren't 2 1/2", but container walls aren't as thick as red iron either. Cordless impact it shouldn't be too terrible bad.

Reactions: Agree 1


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## FWBGBS

The holes are going to happen.
I was just fishing for any members that might be familiar with my situation.
The box must have adequate ventilation to avoid condensation in the winter and oven like conditions in the summer.

Reactions: Like 1


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## rocky1

2 1/2" Knockout Punch - In the event Amazon rerouted that link to a generic homepage for you too. Damn internet anyhow!

Reactions: Like 1


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## Schroedc

FWBGBS said:


> The holes are going to happen.
> I was just fishing for any members that might be familiar with my situation.
> The box must have adequate ventilation to avoid condensation in the winter and oven like conditions in the summer.



I've modified containers before, plasma cutter or torch was how we did it so that was my first thought.


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## FWBGBS

That's a great idea Rocky, but man, those punches aren't cheap.

I'm sorry Colin, I honestly thought you were kidding.
I've used said torch once... That is A LOT of power.
What does a plasma cutter do to the epoxy paint? 
I envision something akin to a third degree burn.


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## Schroedc

FWBGBS said:


> That's a great idea Rocky, but man, those punches aren't cheap.
> 
> I'm sorry Colin, I honestly thought you were kidding.
> I've used said torch once... That is A LOT of power.
> What does a plasma cutter do to the epoxy paint?
> I envision something akin to a third degree burn.



Plasma cutter is a much narrower heat area, cuts fast so a very narrow area of affected paint. You could light yourself on fire but you'd have to work harder at it than with a torch


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## Lou Currier

Plasma is probably your best bet...have you thought about installing an RV heat/air unit to control the air? That what we use on our container that is used for ammo storage.


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## FWBGBS

Yes Lou, I'll be running power next summer and install a blower with lighting.

All you gentlemen have given me a lot to think about.
The wife is curious why there's smoke wafting from my ears.

Reactions: Funny 2


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## rocky1

Been trying to determine what wall thickness is on those and coming up blank. Looking at specs on the knockout punch, it's only rated up to 10 gauge steel on the 2 1/2" Greenlee. Pretty sure it would do it, but... It isn't my $200. Plasma cutters are seriously cool devices! This might be a good excuse to buy one.


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## Mike1950

rocky1 said:


> 2 1/2" Knockout Punch - In the event Amazon rerouted that link to a generic homepage for you too. Damn internet anyhow!



I have a full set of those- Might have a little dust on them- dad bought them in 59 or 60. I will find a use for them one of these days....


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## ripjack13

Target practice with a 50cal?...those suckers will blow through anything. And you'd have a blast doing it.
Literally....hahahahaa

Reactions: Funny 2


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## rocky1

There's always Tannerite too!

Reactions: Agree 1


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## gman2431

3 holes With a hole saw?! Must not be using any cutting fluid... 

Even my cheap set of hole saws work good still but I dont skimp on good cutting oil and do NOT horse them.


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## Ray D

We use the Starret hole saw cutters where I work. We are primarily using them on stainless jackets on cryogenic valves. We cut hundreds of holes before we ditch one...using coolant of course.


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## woodtickgreg

The hole saws will work, the problem is holding it steady so they don"t catch and bind. Look into renting a mag drill and use some cutting oil on the hole saws. That carbide cutter will last longer but only with secure mounting like with a mag drill. A ridgid setup is the key. And there are cheaper carbide hole saws with narrower kerfs on the market. I think I just bought one for under 30 bucks from a local source.


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## rocky1

gman2431 said:


> 3 holes With a hole saw?! Must not be using any cutting fluid...
> 
> Even my cheap set of hole saws work good still but I dont skimp on good cutting oil and do NOT horse them.



Pretty sure their concern is based on the alloys used in the steel they're constructed out of. Containers are built out of Cor-Ten or Weathering Steel.

https://en.wikipedia.org/wiki/Weathering_steel 

Reading up on which begs the question... Why? Supposed to be corrosion resistant, then it turns around and says it doesn't fare well in humid environments, and/or constant exposure to salt air.


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## Mike1950

why not make a couple bigger holes and use a solar fan. seems like less work with available tools.

Reactions: Like 1 | Agree 1


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## sprucegum

Mike1950 said:


> why not make a couple bigger holes and use a solar fan. seems like less work with available tools.



I bet for larger rectangular holes a angle grinder with a cut off wheel or a saws all with a metal blade would work then just use some store bought louvers or grates of some sort.

Reactions: Agree 2


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## sprucegum

ripjack13 said:


> Target practice with a 50cal?...those suckers will blow through anything. And you'd have a blast doing it.
> Literally....hahahahaa




needed a burn barrel one time so I just took it to the range for the weekly pistol club shoot and taped targets to it.

Reactions: Like 1 | Funny 3 | Creative 1


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