Lexan in the Mash Tun question

[stevebremer]

Hi all,

I'm thinking of building a mash tun out of an old Sprite cooler on casters; it's the kind you might see at an outdoor event or something, circular and filled with ice and cold soda. It's got a drain on the bottom, and is slightly larger than my existing 60 qt. Polar Ware MLT. It has a ledge about 2" from the bottom that would support a false bottom perfectly, and an outlet on the bottom to let out the yummy once I've finished converting...

My only concern is with the relative safety of using the various plastics I have in mind. I'm not too concerned about whatever the cooler is made of, as I imagine it's likely very similar to the standard Gott coolers so many of us use. However, in thinking about fabricating a false bottom, I've already ruled out any metal, as the circumference of this ledge is odd, something like 16 1/4", and getting a ready made false bottom is pretty much out of the question. So I was going to cut a sheet of 24 x 24" Lexan to fit on this ledge, and drill a buttload of holes in it. Does anyone know whether Lexan would be an appropriate resin to use for this application? I'm a bit concerned about its food-grade worthiness... I can find no obvious reason NOT to use it, but wanted to see if anyone here has any experience working with it in any sort of application where it has contact with consumable goods...

Thanks for any help!

 

[wildwest450]

Google is your friend.

Lexan is a food grade polycarbonate plastic that has gained a large following in the food service community. It is hard, durable, and resistant to reacting with oils resulting in a virtually stain and odor proof material. It is capable of handling a range of temperatures from below freezing to boiling.

 

[arturo7]

+1 polycarb is OK for this application.

Before you give up on a stainless steel false bottom, you may want to check with fellow HBT's Jaybird. He can probably make one to your specs.

 

[GreenMonti]

How would the rigidity be on that material?

Just curious to the amount of grain you plan on putting in the cooler/MLT, expecting the lexan to support it over the span. How big is the ledge? I ask cause if it is a small ledge then very little flex would be tolerated.

 

[arturo7]

The rigidity of the polycarb screen would depend on it's thickness.

 

[GreenMonti]

The rigidity of the polycarb screen would depend on it's thickness.

So, how pliable would it be at 170*? What would the life span be, after several brews? Plastics like to move slowly over time. Does Lexan absorb water like acrylic?

Please understand i am not trying to be an A$$ here at all. I am just asking questions about the material so anyone with knowledge can chime in. If this is a good material, then why in the he!! are we still fighting with SS? A new one could be made simply, or a couple made at one time. For the occasional tinker type, this may be a good option. They would get to play around and build stuff for their system and not need to change anything. The apartment dweller could do this with the rechargeable tools in the closet.

 

[arturo7]

Considering the heat deflection temperature of polycarb is over 250 F, I don't think 170 would be much of a problem. Polycarb does indeed absorb water but, at room temp it is pretty much saturated.

 

[Ohio-Ed]

I made a FB out of lexan and it worked great (It has since been retired).
I cut 5 or 6 supports out of 1.5" cpvc and stood them on the bottom of the cooler under the FB to keep it from flexing.
I notched the bottoms of the supports so the wort would not get trapped as it was draining.
The only problem I had was the time it took to drill all the holes... I printed a pattern, taped it down and drilled them on a drill press. (I wasn't trying to be perfect, just did the pattern so I didn't get lazy midway through drilling).
I brewed many batches with the lexan FB until my cooler wall cracked, then went all SS.

Ed

 

[scottlindner]

A few things about Lexan to consider.

Lexan is used to make bullet proof glass. It is extremely strong. Since a mid 90s Backpacker gear guide review that first placed the Lexan Nalgene bottles as the least plastic odor, I have been using them for all of my outdoor activities. After learning of how strong Lexan is I took a filled 1L bottle, walked to a cliff ridge, and threw it down as hard as I could toward a sharp boulder below. This was about a 50ft cliff. It got scratched and dinged up, but I'm still using that Lexan Nalgene bottle today.

The other thing to consider is that Lexan may contain BPA which is still consider safe for food purposes, but you really don't want that in anything you consume. I'm not sure if you recall, but BPA was big in the press two years ago regarding baby bottles. You should be able to verify if the Lexan you're buying contains BPA.

Scott

 

[GreenMonti]

Considering the heat deflection temperature of polycarb is over 250 F, I don't think 170 would be much of a problem. Polycarb does indeed absorb water but, at room temp it is pretty much saturated.

That's good to know. Thank you