matc

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Hi folks !

Built a mlt out of a cooler last week and quite frankly, I don't like the idea of using plastic with 180F water so I got an idea and I'd like to get your opinion.

I'd like to simply put an aluminium pot inside of a plastic barrel (use for kayaking and rafting) and fill the void with spray foam. I might as well spray some foam on top of the lid too. That way, I would have a solid 1.5-2" of insulation which is a bit more than a cooler. What do you guys think ? The only parts missing for the project is the barrel which cost 34 $

gatorbite87

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Most coolers are food grade plastic, so you shouldn't have an issue with any chemicals leaking into your mash

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matc

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I don't want to start a debate about this but I doubt coolers were designed to handle very hot water in them. Anyway back on topic, my question was if my pot in a barrel setup be enough insulated to keep the temp stable ?

ChemE

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I would absolutely shoot the gap with insulation in order to help maintain mash temperatures but more importantly temperature homogeneity. The last thing you want is a 154F mash that is 130F on the edges because the MLT is poorly insulated. Much better would be a vessel capable of keeping the ENTIRE mash at or very near 154F. This is a point a lot of folks miss here.

Back off topic; there absolutely is a difference between some materials' performance in cold vs. hot water and what they leach at those temperatures. Check out ANSI/NSF Standard 61; one can test coating against cold water (73F or 86F), domestic hot water (140F), or commercial hot water (180F). In general things will leach out of plastics MUCH more readily at higher temperatures. Now whether or not this poses a health risk is a very different debate, but if the NSF tests materials in contact with potable water at different temperatures then clearly temperature does play a part in the safe/not safe call for a material. So too does wetted surface area relative to volume which is extremely high for our purposes.

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matc

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well I would think that my setup would be more efficient at keeping the temperature at 153 F than a cooler assuming the spray foam is as effective as the one used in coolers

JoshuaW

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There are coolers that are designed for hot liquid. As others have pointed out, food grade plastics wont leach, and people have been using coolers for a long time, if there was an issue I'm sure someone would know by now.

I'm not putting it down, I have a 7mm thick aluminum pot that can hold temp for over an hour already. Insulated it would be that much better.

Cpt_Kirks

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Didn't Bobby do this with a Keggle? I know I've seen it done here by somebody.

jcaudill

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Not to add more fuel to the fire - but I wouldn't use aluminum. Great conductor - but you can't use any of the oxygen or caustic based cleaners if you ever want to give it a thorough cleaning. Even if it is pre-boil.

Like others have said - there are plastics rated for temps. Good example is Colder HFC35 fittings - thermoplastics.

LandoLincoln

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I can't see why your idea wouldn't work. It's the same principle as wrapping a keg with insulating material, but your idea would probably be more efficient.

Before you go the spray foam route, you could try some insulation that could be removed just in case your idea doesn't work out.

Varroa

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I saw a thread by somebody who just took a round cooler and found a pot with the same diameter and slit the pot inside the round cooler. He then drilled holes in the pot which lined up with the valve hole in the cooler and put in a weldless fitting. Sound similar to your idea.

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