Keggle MLT flase bottom number of holes

[mattd2]

One of the fabrication shops I deal with at work is doing me a favour building a few bits for my E-brewery. I'm looking at getting a false bottom for the MLT and sugested the usual perferated sheet. The shop foremans reply was that that S**t is expensive and sugested a few other options... the last being using one of the apprentices to drill 100x 2.5mm diamter holes in some 20 gauge ss sheet.
My question is will 100 be enough, it sounds like a lot but if you add up the total area it is the same as a 25mm hole. And on a 300mm (12") false bottom it is less than 1% open. The normal 3/32" hole - 5/32" centre is about 32% open.
Another way to ask it is are all the false bottoms mad out of 3/32" - 5/32" centre perferated sheet becaue it won't work with anything smaller than that or is it because it is the most commonly available perferated shet with the right hole sizes?
Cheers

The other thing to mention is this will count towards the apprentices apprenticeship, not because it's fun to be mean to apprentices

 

[OneHoppyGuy]

Your false bottom should have every hole you put in it...
I'm full of answers...

 

[mattd2]

Your false bottom should have every hole you put in it...
I'm full of answers...

Or full of holes
The only problem with your theory is I'm not the one putting the holes in it.

I think I have worked it out that with 100 holes it would be one every ~1" (26mm). 200 holes would be one every 3/4" (19mm).
Is this enough????

 

[outside92129]

drilling that many holes is a PITA. Hit it with an angle grinder and it'll be done in 5min. Or get some perforated sheet for cheap on ebay...

 

[mattd2]

drilling that many holes is a PITA. Hit it with an angle grinder and it'll be done in 5min. Or get some perforated sheet for cheap on ebay...

It might be cheap on ebay but shipping to NZ cost more than the sheet itself!

I'm not going to be the one drilling it, and the apprentice needs the practice for his marking out and drilling (and will get signed of on it from this probably), it's a win-win (sort of)

 

[diS]

I read somewhere that "minimum" open% is ~15%.
With that in mind, you can cut slots with angle grinder and get somewhere between 15-20% open area without any problem.

Check this:

With SS sheet, angle grinder, one blade, few hours of work and some patience you can cut it by yourself.

 

[mattd2]

I read somewhere that "minimum" open% is ~15%.
With that in mind, you can cut slots with angle grinder and get somewhere between 15-20% open area without any problem.

Check this:

With SS sheet, angle grinder, one blade, few hours of work and some patience you can cut it by yourself.

Yeah I saw that sanke lid FB on here. Hmmm 15%, damn I hate it when you remember reading something just not where
I suppose worst comes to worst I get them to drill it, try it out (maybe just with water first ) and if there is not enough flow connect the dots with an angle grinder

 

[diS]

.. damn I hate it when you remember reading something just not where

Check link @my sig.

You"ll get decent flow with water even on really small open area like 5-10% so i don't think that water is applicable for testing it.
Suppose that you will (like me, if you intend to DIY) have to build it and then test it on real mash. I know that is pretty PITA but as you know that it is how things works on DIY side..

 

[mattd2]

Check link @my sig.

You"ll get decent flow with water even on really small open area like 5-10% so i don't think that water is applicable for testing it.
Suppose that you will (like me, if you intend to DIY) have to build it and then test it on real mash. I know that is pretty PITA but as you know that it is how things works on DIY side..

Yeah I know what you mean, got to suck it and see
Just got a call that the guys finished putting 200 holes in a sheet and they just need the diameter to cut the circle to. These guys are too quick

My thinking with the water test was I thought the mash would slow the wort down more than the FB. Oh well I might just tell them 300mm and get it tonight

 

[diS]

Wow.. the ARE quick.
Hope it will serve you well.

 

[mattd2]

Wow.. the ARE quick.
Hope it will serve you well.

I hope so too, I'll try get some info up on here ASAP

 

[diS]

And pictures too.. no pics, no FB

 

[mattd2]

Just got the FB and keg back from the shop tonight, the water test went amazingly. Full stream out of the MLT drain no problems at all. Will need to test with a mash next week to see if that creats any issues.
Ended up with 288x 2mm holes in a diameter 310mm FB, I'll get pics up as soon as I can steal the wife's camera

 

[D3Brewing]

Yes, pics please. I just picked up a 16 ga sheet of stainless and I don't have a shop to drill the holes for me. I don't want to cut corners but 300+ holes will take an idiot like me while to drill.
They gave me extra stainless so if anyone in San Diego has a lot of free time and needs a false bottom PM me.

 

[mattd2]

Just an update with a picture. Oh ignore the element, just needed something to block up the socket someone else welded to my MLT (in future this will end up being my BK)
Might need to wait until the shop gets back to me with a price for a whole lot of fittings/valves/etc. to to a actual test. Well either that or build an awesome sculpture out of the outdoor furniture and end up standing on my table to stir the mash. Might do that, either with buckets or no sparge!

 

[JRems]

My only concern is it might collapse from the weight of the grain. It's only 20 ga, that's pretty thin. I think jaybird false bottoms are 16 gauge.

 

[mattd2]

My only concern is it might collapse from the weight of the grain. It's only 20 ga, that's pretty thin. I think jaybird false bottoms are 16 gauge.

It is pretty stiff, you have to actually press down pretty hard to get it low enough to get the nut on there. If it does have an issue I can always put a short piece of SS tube over the bolt to support it in the center. I don't see it ever having a issue though, remember that with the bought FBs they are a lot more "flexible" because they have many many many more holes in them

 

[mattd2]

Use the MLT for the first time last night with no issues at all... with the MLT! Wort drained smoothly and did not stick one bit. No cavitation problems with my pump or the suction hose collapsing.
Ended up with 60% effeciency but I reckon this could have been higher if I had of stirred the mash before,or perhaps after, adding the "sparge" water (only have a MLT BK at the moment so I heated the sparge water in the BK, then pumped it ontop of the mash and then the whole lot drained back to the BK) or possibly being a few degrees low on my numbers
Made an Irish red, and it looked damn tasty. Bit low on the sytle guidlines at 1.040 (1.044 low end to style) but should make a good session ale... I hope! I did have issues with using the kit for the first time - missed temps due to not know the equipment at all and the pump blocked with hops (need to use a hop stopper/bag next time). But all up it was a great brewnight, much easier with a pump and control panel, I'll just have to wait a few weeks to see what the final verdict is