Material for false bottom

[maltMonkey]

I'm trying to find a good CHEAP material for a false bottom for my rectangular MLT. After a little searching at Lowes last night I found two candidates: clear plastic sheeting and fiberglass mesh screening. I believe the plastic sheets are for window replacement and the fiberglass mesh is for screen doors. The downside to the plastic of course is that I would have to drill a few hundred holes in it.

I know nothing about either of these materials. Would either of these be both foodsafe and able to stand up to 200 degree temps?

 

[Lil' Sparky]

Are you set on having a FB? I think a better/easier solution for a rectangle cooler is a copper/CPVC manifold or a stainless steel braid. Lots of brewers have gone this route with excellent results.

Mesh screening is probably too fine and will clog easily. Drilling a few thousand holes doesn't sound like fun, either. I wouldn't use fiberglass, and unless you know what kind of plastic that is, you can't know if it's foodsafe and will hold up to the temps.

 

[maltMonkey]

Well, I already have a stainless braid but I'm wanting to try my hand at fly sparging. Has anyone had good efficiency with a pipe manifold and fly sparging?

Drilling the holes in a plastic sheet wouldn't be fun, but I really don't think it would take that long...I might swing by Lowes again and see what kind of plastic it is.

 

[Grimsawyer]

Just double up on the SS braids. Maybe triple up. it'll be easier than building something else. That being said... I did a search on perforated Stainless Steel and got THIS. Not sure if this is the best site to get that material off of but you could search around and get a better deal then cut it with a dremmel or angle grinder to fit exactly the inside of your MLT. spacing it from the bottom of the cooler would be a sinch. Just get some small SS bolts and nuts, drill some holes and tighten them up. Yuri_Rage has done this with a COOLER.

 

[Bobby_M]

Replacement window panels are either going to be Acrylic or Polycarbonate. According to this site: http://www.bisphenol-a.org/human/polyplastics.html it's fine for food use. I didn't find anything on acrylic.

I sure wouldn't want to drill the holes. You're looking at 1/8" holes on 3/16th centers. So if your cooler is say 12" x 24" it's going to take 60 x 120 = 7200 holes. Even if you back off to 1/4" centers, that's 48 x 96 = 4600 holes. Good luck.

I strongly urge you to try batch sparging first and then decide if your reason for wanting to fly still holds up.

 

[Lil' Sparky]

Has anyone had good efficiency with a pipe manifold and fly sparging?

You can fly sparge in a rectangle cooler and manifold with good results. You just have to be a little more concerned about manifold coverage and getting good even spread from the "sprinkler" (which will probably be a similar setup). This is a great reference. http://www.howtobrew.com/appendices/appendixD.html

 

[maltMonkey]

Thanks for the tips all....I'm either just going to extend the braid or build a manifold. I did a manifold sparge arm and it was pretty simple, so I'll probably just duplicate that.

 

[Jim Karr]

I had exactly the same thoughts as far as making a false bottom from fiberglass window screen cloth. I went as far as placing a sample in a pot of boiling water on the stove, and it passed with flying colors. It seemed to be completely unaffected by boiling temps.

My idea for a frame is to take two long sections of CPVC pipe, place one over the other with the fabric sandwiched in between, bolt the pipes together with SS bolts, and stretch the fabric over to the other side of the cooler, where you repeat the procedure for the other side.

To support the fabric in the middle, take some sections of pipe, and cut grooves that face downward toward the bottom of the cooler.

The only drawback with this type of system, is that the drain would need to come out of the bottom of the cooler, instead of the valve opening on the end.

 

[maltMonkey]

I had exactly the same thoughts as far as making a false bottom from fiberglass window screen cloth. I went as far as placing a sample in a pot of boiling water on the stove, and it passed with flying colors. It seemed to be completely unaffected by boiling temps.

My idea for a frame is to take two long sections of CPVC pipe, place one over the other with the fabric sandwiched in between, bolt the pipes together with SS bolts, and stretch the fabric over to the other side of the cooler, where you repeat the procedure for the other side.

To support the fabric in the middle, take some sections of pipe, and cut grooves that face downward toward the bottom of the cooler.

The only drawback with this type of system, is that the drain would need to come out of the bottom of the cooler, instead of the valve opening on the end.

Well, I went ahead and built a manifold last night.....if you get the mesh screen working let me know! Glad I'm not the only one who thought of this....did you check into the food "safetiness" of that material? Just curious.

 

[treemuncher]

I came across some landscape fabric in my shop during clean up. I purchased it at Lowes. Some of it is black and the other type is white. I believe the black is more for the garden to keep weeds from growing while the thinner white fabric is a silt cloth for keeping french drains free from silt.

Has anyone looked into these types of materials for building a super cheap false bottom?

There should certainly be more than enough flow through this type of fabric if the grain is not crushed to the consistency of flour.