10 Gallon tun upgrade

Guys,

I'm new to the forum but have been brewing on and off for a few years. I've got a 5 gallon rubbermaid water cooler type (round) mash tun and other than the capacity have been pretty happy with it. I want to upgrade to 10 gallon capacity and can get a similar 10 gallon IGLOO from Walmart for $40 and just use the hardware (false bottom and valve) from my 5 gallon unit. Do you think this will work? Will I have issues with the smaller false bottom sized for the 5 gallon tun? Thoughts?

There are a few variables you're not explaining. Is it a false bottom, or some kind of mesh or drilled tube for lautering? If its a false bottom, and it doesn't taper downwards to the bottom and touch, you risk way too much grain slipping by and never getting a stable grain bed for the wort to run clean. If you can explain that better, we may be able to help more.

It's a false bottom that tapers at the edges and fits pretty close to the edge of my 5 gallon set up. I imagine there will be at least a few inches to the edge of a ten gallon cooler but I'm trying to be budget concious and don't want to buy a new false bottom if I can avoid it...
Thanks for the help!

Then it should likely work. It will reduce the overall area that you can drain through on the bottom, but if it touches the bottom on the edges, then no grain can get past and it should work fine. With more grains means possibility for a stuck sparge though, so make sure you use rice hulls if you're doing a mash with a lot of sticky things like oats etc.

You can use the valve, but not the false bottom.

-a.

So you think the false bottom has to go right to the edge of the tun?

No not necessarily... like I said, if it touches the bottom, and grains won't get past it, it will work... so long as wort can drain out the valve just fine. It really depends on if it fits right or not. False bottoms aren't a necessity, some people use a mesh tube or drill holes in cpvc or copper manifolds... so long as grains can't get past them, it works. You need to check and see if the false bottom will still fit, let grains rest above it, and wort drain out the valve... that's it.

I upgraded from 5g to 10g several years ago. I tried one brew with the false bottom from the 5g MLT, and it was a total disaster. Grain got under the bottom and caused a stuck sparge. I ended up having to dump the grain into a paint strainer bag, cleaning everything out, and putting the bagged grain back on the false bottom to sparge. Next brew, I got the right size false bottom, and it's worked fine ever since.

-a.