Direct Fire MLT Insulation Project

It's a little expensive, but if you have any friends in construction there is usually left over or cut offs.

Hence the $5 sheet from Mcmaster.

If it were similarly priced I would have been interested (should I ever need to rebuild this) but I think that it really bends just fine on its own. Most of us are using Bobby's spec with the silicone chalk on the top, so it is not very removable. So long as you put it on only once it is not going to be damaged. Depending on the guage of aluminum it would be nice to have prebent aluminum, now that would have made the project a little easier, though it was not that hard really.

I used flashing for mine. I bought a 10' section, then folded it in half so it was doubled up. That gave a nice edge for teh top section that overlapped. I then cut a couple of small pieces of aluminum to put behind the flashing where the nuts are so that the bolts wouldnt pull through the flashing. Here is a crappy cell phone pic I took when I did it:

Anyone know if 24 gauge stainless steel would be appropriate for this? It's about half as thick as the stuff Bobby_M used (which he estimated to be 16 gauge). In one of these posts he suggested to use something half the size of his so that shaping it would be more reasonable. Paraphrasing here.

I just want to make sure it isn't gonna melt or something...might sound dumb but I don't know much about working with metal.

My concern stems from my recent attempt to make a heat shield for my burner using aluminum flashing from Home Depot. Basically, within about a minute of testing out my new heat shield, it literally caught fire and burned to nothing. I ended up going to a local metal shop and getting a small square of 16 gauge steel, which has worked great.

Anyway, please let me know...or if a cheaper material or gauge would be just as good. Lowering costs is always preferable!

Thanks.

I typically have a hard time visualizing sheet in terms of gauge so I got myself a sample pack. 24 gauge is .024" and from the 4" square piece I have seems like it would be pretty hard to bend into a 18" diameter tube. I also have a .018 which is 26 gauge and I THINK I could get the bent around a corny keg. I'd venture that even 28 gauge would still be sturdy enough but it's pretty hard to find. The 16 gauge aluminum I used was pretty hard to bend and aluminum is much more soft than stainless.

Bobby_M said:

I typically have a hard time visualizing sheet in terms of gauge so I got myself a sample pack. 24 gauge is .024" and from the 4" square piece I have seems like it would be pretty hard to bend into a 18" diameter tube. I also have a .018 which is 26 gauge and I THINK I could get the bent around a corny keg. I'd venture that even 28 gauge would still be sturdy enough but it's pretty hard to find. The 16 gauge aluminum I used was pretty hard to bend and aluminum is much more soft than stainless.

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Thanks for the info. Turns out aluminum is 1/3 the price of the stainless that I was looking at. That might be obvious to some, but I really had no idea. So anyway, I think I'll try that out. It's in the neighborhood of 10 bucks for an appropriately sized piece of Aluminum 3003-H14 on www.metalbytheinch.com.

I chose that site because it was mentioned by someone in an earlier post but if anyone knows of a better resource, then by all means, please share. The smallest gauge they have for aluminum is 22, which is 0.025" according to the chart they have...about half the size of 16 gauge (again, according to the chart on their site).

Bobby_M: is your sample pack aluminum or stainless steel? You said that 0.024 seems like it would be hard to bend; just trying to determine if you're referring to SS or aluminum. The aluminum I'm looking at is 0.025" (22 gauge), but I'll keep looking if that's gonna be too thick to reasonably work with. Thanks.

Oh, my sample pack is stainless 304.

22gauge aluminum should be just fine. Thin enough to bend, thicker than aluminum roof flashing. I think a 18" x 56" piece would be good. You want it to overlap a bit on the seam and not be butt-jointed.

Not exactly cheap, but man I'd be tempted to go with the aluminum tread plate. How badass would that look?

Bobby_M said:

Oh, my sample pack is stainless 304.

22gauge aluminum should be just fine. Thin enough to bend, thicker than aluminum roof flashing. I think a 18" x 56" piece would be good. You want it to overlap a bit on the seam and not be butt-jointed.

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Thanks again for the info!

Bobby_M said:

Not exactly cheap, but man I'd be tempted to go with the aluminum tread plate. How badass would that look?

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Ha...I'd be lying if I said I hadn't considered this as well. Still haven't completely ruled it out!

Do you guys know if anyone has attempted the Nuclear project of welding an air tight outer shell and creating a vacuum type insulation? I am felling inspired by my Thermos

I bought 22G aluminum for this. I just haven't put it on yet.

Bobby - how did you set thermal values for the MLT in Beersmith or whatever program you use? Not as efficient as a cooler, but better than an empty shell.

I have the values set in beer tools pro but I'm not at my home computer at the moment. I'll post them later. It was definitely better than a bare shell. Post #54 says:

The insulation definitely works. In my BTP calibration, the bare kettle lost 17 degrees in an hour while the insulated tun lost 7. The ambient temps were 42F. This was only tested with 8 gallons of water. Mash would lose a lot less, but I don't have that data yet.

Thank you kind Sir.

Has anyone ever thought of using "Durablanket S" for this application? It is a ceramic insulation blanket that is rated up to 2300 degrees and very flexible. I'm just wondering if your willing to pay the price would this be a good product for this application.

Here is a company that sells it. Mor Electric Heating Assoc., Inc.'s heaters, controls and accessories. detail&itemcode=INDFB10002

Next question, what kind of density are we looking for or what would be good for this application. I am assuming the density rating tells us how well the insulation will preform? What did the mineral wool have?

If you order from www.metalbytheinch.com, give them a call. They bent mine to desired circumference (which resulted in cheaper shipping) and were very helpful determining best thickness. I was very impressed with their services.

That insulation is probably fine, but I'd still want to protect it somehow and it's $35 vs $7.

I was asked about figuring out where to put the holes in the insulation and wrap to have them line up with existing ports.

If you don't have anything welded in yet and it's just holes in the vessel, It's best to wrap the whole thing and get the clamps on first. Then you can use an awl or punch from the inside to mark the centers on the wrap. Remove the wrap, cut the holes, put it all back together and then remove the plug of insulation between the layers.

It's harder when you already have couplings welded in and my suggestion is almost the same as above, but consider making the holes in the outside wrap a bit larger just in case you don't nail the centers perfectly.

Holding the insulation and wrap in place temporarily really does require those ratchet straps I show. Also, it would be cool to locate the seam/clamps on the side of the vessel opposite the location of the most bulkheads/accessories.

I just looked thru all 14 pages and I gotta ask:

Would it not be easier to just have a HERMS coil in the HLT like in the Electric Brewery HLT?

To save a lot of money you could just use copper instead of stainless.

Is direct fire RIMS better than HERMS as far as for making beer, keeping temps???

Just wondering since I plane on building a version of the electric brewery HLT to use with my setup except not electric. Seems a cleaner easier to maintain option than trying to insulate my MLT. Just making sure I am not missing something?

Hot Liquor Tank

I agree Akthor, but to each their own.

Here's my $40 solution to the same quandry:

^^ What do you use to automate the temperature of the HLT water for 60 minutes?

I don't think it's a question of whether to select a direct fire RIMS vs any other system but rather it was what I had and wanted to add insulation. Insulating your mash tun or any other vessel for that matter is a step in an efficient direction.

My system was a manual 3-burner system to begin with and I was experiencing temp drops where I'd have to light the burner every 15 minutes. Adding the insulation dropped that requirement to none during the summer and one heat makeup during the winter. Eventually when I convert to an automated RIMS or HERMs, the insulation doesn't hurt at all. It just saves me energy.

If I were ready to go with a HERMS from the start, I would have probably skipped the insulation. Who knows, there are so many ways to skin this cat.

akthor said:

I just looked thru all 14 pages and I gotta ask:

Would it not be easier to just have a HERMS coil in the HLT like in the Electric Brewery HLT?

To save a lot of money you could just use copper instead of stainless.

Is direct fire RIMS better than HERMS as far as for making beer, keeping temps???

Just wondering since I plane on building a version of the electric brewery HLT to use with my setup except not electric. Seems a cleaner easier to maintain option than trying to insulate my MLT. Just making sure I am not missing something?

Hot Liquor Tank

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The whole point of a HERMS is automation of temperature control..which requires a lot more than just the coil in the HLT. You need temperature probes and a control panel that is taking in their readings and turning on/off the heat source for the HLT. At least from what I understand, if you tried to do a HERMS without automation then you would be firing up the heat on the HLT to keep the water at your target temp throughout the mash, and since the mash with all the grains and larger volume of water would hold heat better than just a kettle of water, it would require more work to do that.

The insulated direct-fire MLT is just a glorified cooler-mash system that allows for manually applying heat when you need it to hold your temps instead of doing calculated infusions of more water if you need to raise the temp.

HERMS would be easier..but A LOT more expensive. I think it's safe to say that just about anyone on this site would prefer a HERMS system if cost and set-up wasn't an issue.

But isn't there a danger of scorching in the direct fire MLT?

To me I like the simplicity of the HERMS coil even without automation. Prefer firing up the HLT a few times to wrapping insulation or making covers. Also I like only to have two burners to worry about buying, installing, plumbing etc. But that's just me. Not saying any way is wrong or right.

No danger of scorching when you're recirculating with a full false bottom. You're just heating liquid mash and putting it back on top.

akthor said:

But isn't there a danger of scorching in the direct fire MLT?

To me I like the simplicity of the HERMS coil even without automation. Prefer firing up the HLT a few times to wrapping insulation or making covers. Also I like only to have two burners to worry about buying, installing, plumbing etc. But that's just me. Not saying any way is wrong or right.

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Most anyone who direct fires their mash tun will also recirculate while the heat is on..

The simplicity of HERMS is in it's automation...otherwise you're trying to manually control the temperature of a kettle of water for an hour instead of a kettle of water and grain (which would hold temps better). I have my Mash Tun insulated and so far in 3 brews it has held it's temp within 1 degree the whole 60 minutes without turning the burner on.

You're right there is definitely not a wrong or right way to do this...but I've personally never seen a HERMS system that wasn't automated to some degree, and IMO having a HERMS with no automation defeats the purpose of it to begin with.

One of the advantages to a direct fire tun is how quickly you can make temp moves. Herms relies on a single burner to apply heat to twice as much thermal mass so it's slower. The other advantage an insulated direct fire tun is that I don't have to run my pump for an hour. It runs 5 minutes during the heating and that's it.

I switched from a Herms to direct fire for the reason Bobby M states and to reduce the temperature stratification. I overcame scorching and hold the entire mash within <1 degree by using a motorized stirator.

Stankonia said:

^^ What do you use to automate the temperature of the HLT water for 60 minutes?

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My eyeballs. If my MLT is at 153, and the HERMS output is 153, then the mash is 153. The key is the size of your heat sink. The smaller the HERMS HLT the more it gets leached and therfore needs adjustment. I use a 26g HLT with a 15.5g MT so it's pretty damn rock stable with a pilot light. The only downfall is that when I ramp up temp I have to light the burner under the MTfor 5-10 mins, but if you're continouosly circulating/vorlaufing (herms) then it's a non issue. you're just raising the base of the MT the same rate as the HLT.

Stankonia said:

The whole point of a HERMS is automation of temperature control..which requires a lot more than just the coil in the HLT. You need temperature probes and a control panel that is taking in their readings and turning on/off the heat source for the HLT.

Click to expand...

Horse hooyey - I don't even use automation. The only vessel I need to monitor in the process is HLT. if it says 153, and the HERMS output says 153 (2 of the 3 thermometers I have) then the mash is at 153.

Stankonia said:

At least from what I understand, if you tried to do a HERMS without automation then you would be firing up the heat on the HLT to keep the water at your target temp throughout the mash, and since the mash with all the grains and larger volume of water would hold heat better than just a kettle of water, it would require more work to do that.

Click to expand...

Nope. If i'm maintaining temp, then basically I have a pilot light on the HLT. The only time adjustments are made is when I'm ramping up. in that case, i pilot light the MT as well as UP the burn on the HLT.

Stankonia said:

The insulated direct-fire MLT is just a glorified cooler-mash system that allows for manually applying heat when you need it to hold your temps instead of doing calculated infusions of more water if you need to raise the temp..

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And the problem with that is? It is less cumbersome for me, I apply only the energy I need, and I can change things at will.

Stankonia said:

HERMS would be easier..but A LOT more expensive. I think it's safe to say that just about anyone on this site would prefer a HERMS system if cost and set-up wasn't an issue.

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Cost is only an issue if you make it one. Deciding on a HERMS system from a basic All Grain system cost me about $50. Could I make it 100% stainless for $200 more? Absolutelty. Did I need to? no. Only you can refine your own processes and find out what works best for you.

For me? 3 burner copper coil HERMS was the way to go. YMMV.

Stankonia said:

You're right there is definitely not a wrong or right way to do this...but I've personally never seen a HERMS system that wasn't automated to some degree, and IMO having a HERMS with no automation defeats the purpose of it to begin with.

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We both agree. The difference is I'm dyslexic and suck at math. I can look at a thermometer and see it's low and turn a needle valve to ramp it up to where I want. 99% of the time, it's dialed in to wher I need it for the heat bleed off. Also a reason why I use a larger HLT.

luhrks said:

For me? 3 burner copper coil HERMS was the way to go. YMMV.

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Do you have a link to your build? Or, can you post up some photos of your system? I would like to see this, as I am still in the planning phase of my brew rack.

Man this thread got off topic in a hurry!

I have a automated RIMS system and I still plan to insulate my Mash Tun and HLT. A few months ago I did a experiment without even knowing it. I had a stuck mash and to fix the problem i had to stop everything. I had lost a lot of heat in the mash and to help it get back up to temp, i wrapped a thick moving blanket around the mash tun. Once I added the blanket I was getting temp ramps like never before (in a good way). So it doesn't matter if you have a automated system or not. The fact is if you have a insulated system then you will be better off.

boldham said:

If you order from www.metalbytheinch.com, give them a call. They bent mine to desired circumference (which resulted in cheaper shipping) and were very helpful determining best thickness. I was very impressed with their services.

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Out of curiosity what thickness did they suggest?

pola0502ds said:

Man this thread got off topic in a hurry!

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This is true but I'm all for a short off topic discussion of "why" as long as it doesn't completely derail a young thread (this one is not). My last word on this one is that IF you want to direct fire your tun and you want to get some assist with heat retention (whether you use an automated control system or not), a direct flame-capable blanket is the answer. This thread is about one option in that category. Everyone cool with that?

Tottally cool with it.

There's no "right" or "wrong" only what works best for you.

Huaco said:

Do you have a link to your build? Or, can you post up some photos of your system? I would like to see this, as I am still in the planning phase of my brew rack.

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There's a pic of both my HLT as well as my stand in this thread. I am moving to a single tier system this year though.

boldham said:

If you order from www.metalbytheinch.com, give them a call. They bent mine to desired circumference (which resulted in cheaper shipping) and were very helpful determining best thickness. I was very impressed with their services.

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Can you tell us what they charged you just to bend it?

Also, what vessel are you using? Maybe you can post this info and also post what dimensions you gave or used to get this piece of metal shipped to you. That way if members on this board have the same vessel they won't have to re-invent the wheel. That would be very cool.. Do you have pics?

I found I could get a sheet of aluminum diamond plate for around 10$ more than a similar sized sheet.

Discount Steel - 3003-H22 Aluminum Floor Plate - Buy Online - Cut to Size - No Minimum Order

Granted I live nearby the shop and can pick up to avoid shipping. The smallest gauge it comes in is 14 gauge. I'm not sure if they could bend it for me. They do have a full machine shop and capabilities etc so its a possibility.

Would this gauge be to hard to bend by hand? Could I do it with straps similarly to what you did Bobby?

14 gauge is really too thick to hand bend, especially with patterns which add rigidity.

Admit it...

... you just did this to avoid polishing this one, didn't you?