Insulated Kettles

[Tombsy]

Has anyone ever welded a smaller pot inside a larger pot and insulated between? I have a 15 gallon kettle and 12 gallon kettle. I have a SS welder neighbour who would be able to weld in some ports for me.

So essentially, the 12 gallon sits inside the 15 gallon, with some type of insualtion between (spray foam?). Tri-clover fitting welded to inside pot.

The idea is to do biab on my gas stove and eventually move to a recirculating system (similar to brew boss).

 

[Bobby_M]

Sure it would work but you're not going to be able to direct fire it.

 

[Tombsy]

Why not? Is there not certain insulation that has a high temp rating? I don't need to use spray foam.

 

[WayFrae]

Why not? Is there not certain insulation that has a high temp rating? I don't need to use spray foam.

Insulation works both ways. It will keep heat in and keep heat out. I guess if you used some kind of high temperature insulation and had the bottoms of the two pots touching each other it could work. Your idea would be awesome for an electric set up though.

 

[Onkel_Udo]

Why not? Is there not certain insulation that has a high temp rating? I don't need to use spray foam.

They do exist but one or both of following apply:

You can't afford it
It should not be anywhere near food product

I work an industry that uses +230 f insulation and almost all of it is really nasty stuff.

Even if you could, the heat transfer from the outer to inner pot will be a challenge. Sounds like a good idea for an electrically heated item.

 

[Onkel_Udo]

Duplicate, please ignore...

 

[dwoods]

Vermiculite is a fire proof insulation used in furnaces. Don't see why you couldn't use it.

 

[Onkel_Udo]

Vermiculite is a fire proof insulation used in furnaces. Don't see why you couldn't use it.

Old-school Vermiculite had a lot of asbestos. Assuming they still make it, this would not be a modern issue...though they do occur naturally together.

 

[Tombsy]

I was definitely not going to insulate the bottom, just the sides. I was thinking of using this stuff.

http://www.roxul.com/products/residential/products/roxul+safe'n'sound

Fire rating of 1177°C (2150°F).

I was also going to include a port for a future heat element, but for now I would use the gas stove. The idea is to get something similar to the Brew Boss.

 

[Onkel_Udo]

Mineral wool is actually your best bet. Good call. It will settle/compact over time so some of the insulating properties will be lost for the top 1/4-1/3 of the pot.

I was not referring to insulating the bottom. There is rarely a good chance to "fuse" those two layers of metal continuously together without some sort of combination of heat/electric arc and pressure that is likely to destry the SS properties we desire so much...when we are talking 304 to 304 SS. You will inevitably end up with and air space however minute.

 

[TennBrewer]

On a related note, I just started using the BIAB method too and really like using the all-grain recipes. I was looking for a way to insulate the kettle while the grains are mashing without having to fire up the burner. I had a down-filled jacket that had mysteriously shrunk on me so I fitted it around the 10 gallon kettle and zipped it up. Perfect! Down is a good insulator and growing up in Wisconsin winters, you need all the insulation you can get. Anyway, over the 60 minute mash step, the kettle lost only 2 degrees. I was very happy. Maybe you have an old winter coat and you could try that. Welding two kettles sounds cool but I don't think it's all that practical. Maybe there's a good reason nobody has done it before (too pricey, like the big brewer's double wall mash tuns). I think dead air is an insulator, like double-pane windows.

 

[Tombsy]

I guess i could cut the bottom of the bigger kettle and slide the other one through. Weld the seam.

I live in Winnipeg. I have winter jackets to spare. I would be worried about the winter jacket catching fire though from the gas element. I tend to over indulge while I brew and this seems like something that would happen to me.

I was looking at the Grainfather, but I figured I could do something similar at half the cost by using some existing equipment.

 

[Onkel_Udo]

I was looking at the Grainfather, but I figured I could do something similar at half the cost by using some existing equipment.

That is a very confusing statement. The Grainfather is neither gas fired nor is it insulated.

 

[Tombsy]

I guess it sounded a bit confusing, though it made sense when I was writing.

When I first saw the grainfather, it peaked my interest as a somewhat affordable all in one system. I however didn't like the 1600w heating element. I then found the brew boss which wasn't any cheaper and figured I could start off small and piece it together over the next year.

 

[JohnSand]

I like the idea of cutting the outer pot bottom. But that opens the idea of using something else as a sleeve. If you don't insulate the bottom couple of inches exposed to high heat, you might just wrap the insulation with flashing. Secure it with wire wrap. Insulate your lid too, for heating to strike temp.

 

[Onkel_Udo]

When I first saw the grainfather, it peaked my interest as a somewhat affordable all in one system. I however didn't like the 1600w heating element. I then found the brew boss which wasn't any cheaper and figured I could start off small and piece it together over the next year.

In short, you want a stovetop BIAB system with a mesh "sleeve" instead of a bag and recirculating system with option of adding a RIMS tube at a later date.

Once you piece it together, it will end up cheaper (depending on your pump and fittings) until you start adding the RIMS tube, control box, etc. Then you are probably looking at break even or more expensive.

This is all conjecture as I have not priced all the items out recently.

 

[Tombsy]

In short, you want a stovetop BIAB system with a mesh "sleeve" instead of a bag and recirculating system with option of adding a RIMS tube at a later date.

Once you piece it together, it will end up cheaper (depending on your pump and fittings) until you start adding the RIMS tube, control box, etc. Then you are probably looking at break even or more expensive.

This is all conjecture as I have not priced all the items out recently.

Pretty much.

If I can get to the point of having recirculating system with a mesh sleeve I will consider it a victory, everything else would be bonus. Plus I love the DIY aspect. Having access to a SS welder who pretty much helps me out for free, I figure I should take advantage.

 

[Onkel_Udo]

Pretty much.

If I can get to the point of having recirculating system with a mesh sleeve I will consider it a victory, everything else would be bonus. Plus I love the DIY aspect. Having access to a SS welder who pretty much helps me out for free, I figure I should take advantage.

Focus on that.

You need a minimum of two SS 1/2" couplers or nipples on the pot. One high an one low

You need a way to get the wort to the pump that is either protected from the heat or the direct firing or impervious to it (SS tubing).

You need a pump, switch and tubing back to the top port.

You need a basket. The basket can be as simple as giant colander lined with SS window screen but I would shoot for something custom built by your guy.