Getting rid of dead space in MLT

I built an MLT a few weeks ago out of a 10 gallon rectangular Coleman cooler. So far it's worked alright, but it has a lot of dead space. The spigot is mounted high enough that there's about 2 gallons of dead space below it that I'm not able to drain from my copper tube manifold. The manifold is not soldered, so it's easily disassembled and cleaned, but that means I can't siphon with it. And I have no plans to solder it up; I don't have a torch and don't want to blow the $ to buy one just for a quick solder job.

What I would like to do is plug up the existing spigot hole and drill a new hole in the bottom of the cooler. I always set the MLT up on a table when I brew, so hanging it off the edge a few inches to accommodate the bottom-mounted spigot would be easy. I also store it up on a shelf where it'd be easy to just hang it off the edge a bit. I think that I could prop up the other end of the MLT with a half-inch thick piece of plywood, giving all the liquid a nice downhill path to the spigot. I figure if I do both of these things I will eliminate the dead space almost entirely.

I'm looking for tips and suggestions on this undertaking. I have in my tool arsenal an ordinary cordless drill and a small dremel. What tools/techniques would be best to cut a nice clean, round hole through the bottom of the cooler? I'm sure someone's already done this successfully.

As for drilling the hole a 1/2" drill bit should do the job well. Do you have any plumber friends near you could probably just borrow a propane torch some flux and silver solder from them to finish your manifold. I just accomplished mine with parts I had laying around the house (Minus the bulkhead and ball valve) after my MT sprung a leak. I'll link a pic of my setup but as it's soldered I only have a few ounces of wort left in the tun, besides what the grain soaks up with a simple gravity drain at around 2.5'

Hope that helps

I was thinking a smallish hole saw would probably be my best bet. I need to drill a hole big enough for a 1/2" pipe, so like 3/4" diameter. If I tried to use an ordinary drill bit for that it'd probably end up making a really gnarly hole that's damn near impossible to seal.

I kinda like having the manifold unsoldered because I can break it up and drop the pieces into a bucket of oxy-clean water and clean them really easily. Rinse with hot water and put it back together and it's ready to go.

How do you drain off the wort from the cooler? Do you attach a tube and have the kettle on the floor to create some pull?

How is the manifold connected to the spigot? If you can get an airtight seal from the manifold to the spigot, you can create enough of a vacuum to siphon out most of the wort. Even if your manifold is not soldered tight, you should still be able to get out all the wort above the top of the manifold just by making the hose connecting the manifold to the spigot airtight.

Are you using some sort of bulkhead in the cooler wall? That makes connecting hoses a lot easier.

Be sure to have the end of the hose on the outside of the cooler set below the bottom of the cooler to ensure the siphon gets as much as possible.

ReeseAllen said:

I was thinking a smallish hole saw would probably be my best bet. I need to drill a hole big enough for a 1/2" pipe, so like 3/4" diameter. If I tried to use an ordinary drill bit for that it'd probably end up making a really gnarly hole that's damn near impossible to seal.

I kinda like having the manifold unsoldered because I can break it up and drop the pieces into a bucket of oxy-clean water and clean them really easily. Rinse with hot water and put it back together and it's ready to go.

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You can always use a step-bit. I don't have a pic but it looks like a large triangle and will gradually increase the hole size to 3/4". It's more precise then a standard drill bit, but for drilling plastic I think it's overkill and you'd do fine with just a normal bit if you go slow and drill a pilot.

As for taking the manifold apart I can see your point, I just take mine out run hot water through it then use compressed air run through it the day of brew to blow out any remaining grain. I don't bother sanitizing anything pre-boil it's a waste of sanitizer. I do however sanatize anything used during the boil, IE stir spoon, and everything post boil, CFC, Fermentors, caps, airlocks, etc. That's just me though.

That's the Irwin one called Unibit.

You can find them in any hardware store...but I'll warn ya, they are like $50 a pop.


Great if you have the use for it though. I love mine.

JayInJersey said:

That's the Irwin one called Unibit.

You can find them in any hardware store...but I'll warn ya, they are like $50 a pop.


Great if you have the use for it though. I love mine.

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Or you could get one from Harbor Freight for $7.

I rue the day I first entered that damn orange overpriced hardware store...

JKoravos said:

Or you could get one from Harbor Freight for $7.

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And it may even last long enough to drill the one hole.

Scimmia said:

And it may even last long enough to drill the one hole.

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I wouldn't trust it to go through 1/4" steel (which I've done with a Unibit), but I'm sure a cooler or a keg is no issue.

You could also put a solid sheet of plastic underneath the manifold, effectively removing the deadspace.

hezagenius said:

How is the manifold connected to the spigot? If you can get an airtight seal from the manifold to the spigot, you can create enough of a vacuum to siphon out most of the wort. Even if your manifold is not soldered tight, you should still be able to get out all the wort above the top of the manifold just by making the hose connecting the manifold to the spigot airtight.

Are you using some sort of bulkhead in the cooler wall? That makes connecting hoses a lot easier.

Be sure to have the end of the hose on the outside of the cooler set below the bottom of the cooler to ensure the siphon gets as much as possible.

Click to expand...

I haven't bothered to set up a tube connected to the spigot so far, although I do have a barbed fitting installed on the spigot outlet. As the manifold is currently built, trying to siphon wouldn't help because the manifold tubes have holes in them all the way up to the height of the spigot. I attached a drawing of what the manifold looks like now.

JKoravos said:

You could also put a solid sheet of plastic underneath the manifold, effectively removing the deadspace.

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Yeah, but then I'd have to seal that sheet around the edges, and it'd reduce the overall volume of the MLT. I'd always be worried that liquid was leaking under the sheet, too.

Scimmia said:

And it may even last long enough to drill the one hole.

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+1

A good uni bit is one of those things where you get what you pay for. I use them almost daily, and Irwin is the ONLY way to go.


That copper drain is fantastic, i'm building my MLT currently, and may do something like that with spare soft copper tubing from work (free!!).

Thanks!

ReeseAllen said:

Yeah, but then I'd have to seal that sheet around the edges, and it'd reduce the overall volume of the MLT. I'd always be worried that liquid was leaking under the sheet, too.

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You don't have to seal it, it would just sit on the bottom and take up space. You'll lose volume, but your dead space would be gone.

It's probably easier just to move the valve. Don't bother with a Unibit, though. A spade bit is plenty to get through a cooler and you can get one for much cheaper than a Unibit.

Seeing your design and knowing your not soldered. Just angle the "Tee" in the middle leading to your drain upwards around 45 degrees or so and use soft vinyle tube to make the connection to your drain. IE this puts your manifold flat with the bottom of your cooler and a slight flex tube to the drain. Don't be shy of putting the Tee on the other side of the cooler and running the line. If you preffer copper for the entire thing you will get better results putting the Tee on the opposite side of the drain as the bend radius is not as sharp.

With a flat manifold you will get a more effective drain then your current setup. Your loss will only be the capacity of the manifold to drain segment, which will be minimal.

Hope that helps. If you relook at my pic post I run my manifold Tee on the opposite side of the drain and only have around 5" from the Tee arched to the drain.

Not to piss you off but I think your over engineering a very simple design that has been proven to work.

JKoravos said:

You don't have to seal it, it would just sit on the bottom and take up space. You'll lose volume, but your dead space would be gone.

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Marbles, buddy. Marbles.

I use a coleman 48 qt. w/ a braid. The drain fitting is also about an inch off the bottom. At first I found this disturbing feeling like I was leaving behind a lot of wort. Several times I ahe tipped the tun to try and drain more out and I sually get a cup or so additional. The dead space in the tun is occupied by the grain also, and on your last batch sparge, leaving a bit of runnings behind is not a huge deal.

Crazytwoknobs said:

Marbles, buddy. Marbles.

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Marbles will only take up slightly less than 2/3rds of the dead space. Random spherical packing efficiency is about 60-65%.

JKoravos said:

Marbles will only take up slightly less than 2/3rds of the dead space. Random spherical packing efficiency is about 60-65%.

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Yeah, but in a mash, if you had a bed of marbles above your manifold, like maybe 2 marbles thick across the whole of the bottom, wouldn't that make the system flow better?

I think marbles are where it's at.

I think you may have lost your marbles. j/k

wilserbrewer said:

I use a coleman 48 qt. w/ a braid. The drain fitting is also about an inch off the bottom. At first I found this disturbing feeling like I was leaving behind a lot of wort. Several times I ahe tipped the tun to try and drain more out and I sually get a cup or so additional. The dead space in the tun is occupied by the grain also, and on your last batch sparge, leaving a bit of runnings behind is not a huge deal.

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I have the same cooler, and had the same concerns. I put a brass 90 degree elbow on the inside so the braid is flat on the bottom all the way to the drain.

I haven't had any problems, but I've only done 2 batches, so what do I know.

Just lay the manifold flat and engineer the connection to the bulkhead.