Shiny false bottom V plastic

[cnelsonplumber]

My HLT and mashtun are almost complete save for a false bottom in each. I have decided to go down this route due to previous problems with stuck wort and sparges. The layout of holes is identical except the HLT is larger diameter and therefore has an additional two ring sof holes, this way I can drill most of the holes with one sheet above the other.

I have approached a couple of local laser cutters and come back with prices around £100 each from both suppliers for 316 which isn't too bad given set up and material costs, but it's a lot more than i want to spend. Drilling 500 or 600 1.5mm holes in 1.5mm 316 is not likely to be cost effective based on how many drills I break.

I have looked at plastics of which there are many types approved for use in direct contact with food, HDP, polyethylene, polypropylene, and PVC. I'm still looking at these but PVC seems to be coming out favourite as it will stand 100 degrees C indefinitely. Manufacturers have to heat is to 147 degrees before it can be bent. it is also easily machined and relatively cheap. :grin:

I have found a local supplier who is offering 8' X 4' sheets 4.5mm thick for any of these products around £45 ea. This is enough to make 8 false bottoms although at 4.5mm it may need two circles of 3 equally spaced support posts diametrically opposed at say 25% and 75% full diameter.

Before I get carried away just thought I would ask if anyone else has experience if using plastics in this application, I think my greatest concern is whether or not I will need to anchor it to prevent floating in the copper.

:

CNP

 

[keith1664]

I might be missing something, but I used this for my mash tun.

http://cgi.ebay.co.uk/Perforated-304-St ... 19bb77f2a3

 

[cnelsonplumber]

I might be missing something, but I used this for my mash tun.

http://cgi.ebay.co.uk/Perforated-304-St ... 19bb77f2a3

I found perforated sheet but not the offcut site, which makes the idea much more attractive, so cheers for that.

I will need to check up on 304 as my understanding is that it is approved for use in the food industry but not recommended for direct contact although a quick trawl shows that is used in the manufacture of beer barrels. :wha: So I might have got that wrong :shock: g

How do you get on with the 2mm holes do they filter the mass effectively?

:drink:
CNP

 

[keith1664]

It works fine, no problems at all, I've not had a stuck mash yet!. I believe it's quite safe for food use as well (I'm still here )

 

[Runwell-Steve]

Why would you need a false bottom in an HLT?

 

[cnelsonplumber]

Why would you need a false bottom in an HLT?

Very good question that

My HLT and copper are identical :rofl:

 

[graysalchemy]

I would use stainless steel. I have a false bottom made out of 5mm acrylic sheet, and over about 4 uses it has distorted with the weight and heat, which is causing problems with drainage. So when I build my new brewery I will make a stainless steel one.

 

[cnelsonplumber]

I would use stainless steel. I have a false bottom made out of 5mm acrylic sheet, and over about 4 uses it has distorted with the weight and heat, which is causing problems with drainage. So when I build my new brewery I will make a stainless steel one.

Thank you for the feed back. :thumb:

The off cut perforated sheet is looking like the easiest cost effective solution at the moment :

 

[steveT]

Does anyone have any opinions on 2mm v 1mm holes in the perforated sheets?

According to the ebay supplier, 2mm holes gives a 40% open area, compared to 23% for the 1mm holes. Obviously 1mm will allow less debris to escape than 2mm, but I'm worried about flow-rate and stuck mash's. Is grain getting through the false bottom likely with 2mm?

 

[Aleman]

I think the optimum is 1.5 mm :whistle: . I have one FB at 1.2mm holes and the others at 2mm . . .they all let debris though, but it clears fairly quickly