Styrofoam Coolers?

I picked up six of these one gallon coolers @ Dollar Tree yesterday. I plan to use these for some clones while I get my big tents ready. Going to put air stones in each one. I’m just trying to figure out the best way to make the holes for my 3 in net pots.

Cheap Hot knife works well on Styrofoam but it stinks

3 inch hole saw? Might cost more than the coolers.

shnkrmn said:

3 inch hole saw? Might cost more than the coolers.

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Yeah I'd definitely go with the hole saw and it's great if you need to do a door replacement too! I made my original cloner from a Rubbermaid container and used a smaller hole saw to fit the clone rings and didn't bother with net pots. I think the styrofoam would help with keeping the reservoir cooler too. But net pots with rings would allow you to hold them and feed them for awhile. I think @doublejj did that.

I think I have a 3” hole saw. I just wasn’t sure how it would do on the styrofoam. Guess I’ll go for it. Thanks!

You probably don't need to be told, but run the saw in reverse, you'll get a much smoother cut in soft material like that.

shnkrmn said:

You probably don't need to be told, but run the saw in reverse, you'll get a much smoother cut in soft material like that.

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I was wondering about that doing styrofoam. Thanks!

Drop That Sound said:

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Haven’t got a 3d printer but cool idea.

One thing to consider before fully committing is that Styrofoam isn't necessarily watertight. I'd fill one up all the way and let it sit somewhere for a couple days to make sure it doesn't seep at all.

Drop a hot lid on it

Well, don't drop it on like that. Drill a hole in the center of your 3" metal disc, and put a handle on it. Use it like a brand to stamp out perfect holes every time!

A hot wire is often used to cut foam. It's fast, clean and precise. The amount of power through the wire controls the temperature. One use is making the foam cores for RC airplane wings.

Tuna helper.

You can buy a set of hole saws at Harbor Freight for $14..

I cut the bottoms out of the net pots and just use the top ring as a holder for the foam pucks. Otherwise the pucks will just fall thru

doublejj said:

You can buy a set of hole saws at Harbor Freight for $14..

1 in. - 2-1/2 in. Carbon Steel Hole Saw Set, 10 Pc.

Amazing deals on this 10Pc 1In - 2-1/2In Steel Hole Saw Set at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

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That set only go's up to 2-1/2", but they do have single 3" bi metal type ones at HF still.. Or also a 3, 4 & 4-1/2" three piece set, or something like that If I remember right.. Way cheaper than the other stores that's for sure.

You'll never get a perfect hole using regular hole saws with teeth into polystyrene foam btw.. Even in reverse, its still gonna chew it up a little bit, because its more like a bunch of small balls that will tear out, unlike rigid or other closed cell types of foam material that are more consistently mixed. Probably not a big deal though, and will be covered by the net cup lips anyway. You might even wanna cut with the next size down in case it does wanna tear out. Then heat it up inside the holes and push the netpot in for a good seal. Should be good enough even with the teeth if careful.. good luck!

Some guys grind the teeth off the hole saws if they have to cut a lot of clean holes in foam panels for net pots all the time, but I wouldn't waste a good hole saw for that. I would make a hot punch tool for sure, and heat it up red hot and punch through multiple lids/sheets at a time if I had a huge system to design..

Dont forget air that you put in the water is outside temp you will slowly heat it up.

Why not just heat up a wire and melt a perfect hole.

You can make your own foam cutters using some wire, alligator clips, a spring, and big enough battery. A smaller handheld knife, or even a table top unit for ripping blocks down into sheets, etc.

I made my own portable mini one from a ecig vape mod and atomizer head, that uses such a small wire you can plunge right in and cut perfect holes. Even has temp control if I use SS wire. Its even better than the ones they sell IMO.