building my first MLT

ok, I have a 30 quarts cooler that I want to convert to MLT. This cooler doesn't have a factory made valve, so I have to drill it, and this is my biggest concern.

It seems to me that it has double walls, and if this is true, than I believe it's going to be very difficult to make it leak-proof...

my first question: is it worth to do it with only 30 quarts cooler ( I make only 5 gallon batches), and my second question is, how to do it without destroying the cooler

thank you all!

How thick are the walls? As long as they're stiff enough, you should be able to get the gasket to clamp down on the inside wall and make a seal. That's the critical point, where the spigot seals against the inner wall.

A 30 quart cooler will work well for all but rather big beers. As for the double walls, how thick are they?

I drilled a cooler since it didn't have any valve. It was double walled, but they were close together at the point where I drilled. I just simply pinched them together when I was tightening, and there is no leaking.

Oh, and here is the page I was talking about: https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/

klyph said:

How thick are the walls? As long as they're stiff enough, you should be able to get the gasket to clamp down on the inside wall and make a seal. That's the critical point, where the spigot seals against the inner wall.

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two seperate plastic walls that are probably 3 milimeters thick. between them, I'm afraid there might be some insulating material, but I'm not sure.... the space between the walls is approx. 0,25 inch wide....

Another option is to not drill a hole for a valve. I just made a copper tube that comes off my manifold that goes above the water level. I then forces braided vinal hose on it while it was heated up. During the mash the hose and copper tube fold on top of the grain. When I want to take the wort off I just get a syphon going and all is well. I have done this for 3 batches with no problem, one of the batches being a pumpking ale.

I don't see the problem. You might have to get a slightly longer spigot piece, but other than that it should work.

you could always get some food-grad silicone adhesive and seal your inside fender washer against the cooler wall with it. Just a thought.

Good luck, and enjoy the process, I just finished my MLT today.

Most coolers are dble walled. if its under 5/8" thick all together where the fitting goes then a normal cooler fitting will work, if its more but not more then 1 1/4" then you need the extended version fitting, heres a link to a place to get either.
http://www.greatbargain.net/order/shop1.html

If there is a gap between the inside and outside, and you try to fit a bulkhead through both I think you will have problems. Over time, as you open and close the valve on the end of the bulkhead, unless it is solid it is going to "wiggle" and you will risk leaks.
I read a thread here sometime back about cutting the outside plastic and insulation larger than the inside plastic. Then mount your bulkhead to the inside plastic so there is no "wiggle". I think the thread I read also mentioned adding another layer of plastic to the exterior of the inside plastic to increase the structural integrity.

Good Luck
Ed

ok. I figured out how I'm gonna do it.

I just wanted to ask how long does the stainless steel mash braid have to be? I have a really long one, and I was thinking about putting it all on the bottom of the cooler, to cover as much of the bottom as possible...

by now I've seen only one straight mash braid going across the bottom...

I think it can be as long as you want it. Just know the water won't actually travel along it as it is completely open. It will basically only be coming out of the very end where it attaches to the spigot. I use copper tubes that have slits on the top and are placed as a rectangle with on cross piece to help drain the wort evenly.

mitch171 said:

I think it can be as long as you want it. Just know the water won't actually travel along it as it is completely open. It will basically only be coming out of the very end where it attaches to the spigot. I use copper tubes that have slits on the top and are placed as a rectangle with on cross piece to help drain the wort evenly.

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so you think I will not increase the speed of wort draining from the MLT if I have longer braided tube across the bottom?

400d said:

so you think I will not increase the speed of wort draining from the MLT if I have longer braided tube across the bottom?

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You should use a ball valve to control the flow rate.

Ed

Ohio-Ed said:

You should use a ball valve to control the flow rate.

Ed

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of course I will use the ball valve, but I'm asking am I going to increase overall draining potential from the MLT if I use longer braided tube?

400d said:

of course I will use the ball valve, but I'm asking am I going to increase overall draining potential from the MLT if I use longer braided tube?

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A longer braid will not be a problem.

You will have greater flow potential with a longer braid but that is not a problem because you can limit the output with the ball valve.

If you intend to batch sparge, there's really no benefit to a much longer braid. I'd keep it to about 12-16" max.

I agree with your concerns about getting a decent seal on a double wall. There have been a few different ways of dealing with it. One way is to drill a larger hole in the outside wall (and insulation) and make the seal only on the inside wall. Another way is to add rigidity between the walls. One way to do that is to hollow out a little insulation and pack it with epoxy. Another way is what I outline in my leak-free MLT bulkhead thread.. see my sig.

Ohio-Ed said:

A longer braid will not be a problem.

You will have greater flow potential with a longer braid but that is not a problem because you can limit the output with the ball valve.

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When draining, is there a reason to be able to control the flow? Is there a benefit to draining slower?

greeneyed said:

When draining, is there a reason to be able to control the flow? Is there a benefit to draining slower?

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If you are "batch sparging", the only advantage of controlling the flow rate is to prevent a "Stuck Sparge".

However, if you are "fly sparging" you do need to control the flow.

Ed

400d said:

so you think I will not increase the speed of wort draining from the MLT if I have longer braided tube across the bottom?

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I can't claim to actually know because I never did the braid thing because it seemed like a lot more work than just making a copper pipe one. I also found price wise the copper did not cost much more. And from reading it seemed like using copper tubes would create a more even extraction of wort. I don't remember reading much about flow rate.

ok, this is what I did and I have a problem....



the blue thing is the insulating material between two plastic walls of the cooler. I made bigger hole in the outside wall, and a smaller one in the inside wall.

when I attached everything, the thing is very weak because this inner wall is too thin. I really don't know what to do.

I was thinking of sealing everything with epoxy, but I'm not sure.....

maybe you have some suggestions?

the other problem is that much of this insulating material dropped out of there while I drilled....

400d said:

ok, this is what I did and I have a problem....

the blue thing is the insulating material between two plastic walls of the cooler. I made bigger hole in the outside wall, and a smaller one in the inside wall.

when I attached everything, the thing is very weak because this inner wall is too thin. I really don't know what to do.

I was thinking of sealing everything with epoxy, but I'm not sure.....

maybe you have some suggestions?

the other problem is that much of this insulating material dropped out of there while I drilled....

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My first thoughts if I were doing this...
I would find a thicker piece of rigid material (heavy plastic), that would barely fit through the outside hole and attach it to the outside of the cooler liner. I would put a hole in the new backer material I just added to line up with the hole you now have in the liner. I would glue/epoxy the backer to the liner. The point of this backer is to reinforce the liner and spread the force of moving the bulkhead while turning the valve over as much area as possible. Bobby M has a great no-leak design you can use for the bulkhead itself.
Not sure how much insulation you lost, but once you are sure you have the liner adequately supported, you could re-stuff the insulation and fill the void with LOW EXPANDING foam insulation.

Ed

I have one of those coolers with a lot of space between the inside and outside walls. I dont think I would have done what you did by taking out the front like that as you have discovered that this makes it very weak and the handle heavy on the outside.

Whatever you do to fix it now youll want to be able to remove that ball valve and tube for cleaning purposes so keep that in mind before you go filling that area.

As for a manifold I would use copper pipe with holes drilled in it. Youll get a more even extraction of the wort from the bottom of the cooler and reduce channeling, but that is my personal preference. I also would imagine it would be easier to clean due to the smooth sides but again...personal preference.

-Edit-
This assumes you switch to a copper manifold. It is how I set mine up.

If I was working with that particular cooler in its current condition I would go to Lowes or HD and pick up a 1/2" brass nipple about 1 1/2" long, a 1/2" ball valve, 1/2" FPT x 1/2" copper fitting and stainless steel washers that just fit around the brass nipple to be used as spacers and a square of 1/2" thick lexan (they may have free scraps they would give you) to stuff in that hole you made on the front. Glue the lexan in that hole after carving out the insulation and epoxy it to the front wall of the cooler then re-drill the hole through that.

Youll need to assemble the copper fitting to the brass nipple and slide on a washer, then a high temp o-ring (http://www.rebelbrewer.com/shoppingcart/products/Extra-O%2dRing-set-for-Kewler-Kitz.html). Insert the nipple through the hole from the inside. On the outside of the hole youll slide the other o-ring on and then keep adding washers until you are to the threads on the brass nipple. Then screw your ball valve on tight.

If you go the epoxy route, make sure it will stick to plastic. I've had good luck with a product called aqua mend

I used it on HDPE (plastic brew bucket) containers and it worked. I believe it will stick to PP and most ABS stuff from what I've read on the web.

I would use it only on non contact point such as to shore up where you cut out the exterior wall.

Another option is to get a bigger outer diameter washer to add some strength to the inner wall.

You can still use the method I show here:



The key is part #6 which is a piece of PVC that fits over your nipple and fits the diameter of your outside hole. It will add rigidity to the whole assembly.

ok people, I did it somehow. most of the space between the walls of the cooler is sealed with two component epoxy...

it is very firm and strong. I tested it with cold water, leaving it full over night, and there are no leaks...

I only wonder, how hot mash and sparge water would affect the epoxy? is it temperature resistant?

I don't think you will get any movement with the epoxy at higher temps. Most have starting in the 250 F range.

BargainFittings said:

I don't think you will get any movement with the epoxy at higher temps. Most have starting in the 250 F range.

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thanks man, you really helped me...