Insulating Keggles

What type of material do you use to insulate the mash tun keggle? I see the same type that is used for hot water heaters but want to know if there are any real dangers with that stuff.

Please post at will.

WW

Reflectix bubble insulation @ Home Depot - I did a twice around wrap with foil tape top/bottom/side.

No real danger, other than melting or rapidly deteriorating the insulation. The various insulation materials used by most homebrewers are NOT meant to handle 212F, including Reflectix which is only rated at 180F. Yes, the horror.

I installed and recommend Buna-N Closed Cell Foam Rubber. It has a higher insulation value than Reflectix, very easy to work with, and is rated to 220F.

lamarguy said:

No real danger, other than melting or rapidly deteriorating the insulation. The various insulation materials used by most homebrewers are NOT meant to handle 212F, including Reflectix which is only rated at 180F. Yes, the horror.

I installed and recommend Buna-N Closed Cell Foam Rubber. It has a higher insulation value than Reflectix, very easy to work with, and is rated to 220F.

Click to expand...

Genius! What a great idea. I only want to insulate my Mash Tun which is only heated by the RIMS heater.

After looking at Mc Master CarrI have found a number of foam rubber style insulations that are good to 200 degrees or over.

McMaster-Carr Flexible Low Temperature Polyethylene Foam Rubber Insulation Temperature Range: -160° to +200° F

McMaster-Carr Ultra Flexible Foam Rubber Insulation Temperature Range: -20° to +220° F

There are a number of adhesives that can be used with these products that have the same temperature ranges.

For propane/NG fired vessels, I'd recommend mineral wool. Electrically heated vessels are easier to insulate with foam. Either a wrapped rubber foam, or a sprayed/poured PU foam. The PU foam is a little more difficult to install, but has a much better insulation value.

I've had 3 layers of reflectix/foil tape on my keggle for 2 years now (I do direct-fired step-mashes too). It's warped a little, but no big deal. It finally started coming apart at the seams after a batch yesterday, so I just put another layer of reflectix on. Now I have 4 layers, so that sould keep my mash temp pretty well.

There isn't too much you can put on for a reasonable cost that will withstand heat from an open propane burner. The temps from that will go way over 220°F... especially when they shoot up through the drain holes. The way I solved this was to put foil tape over the drain holes. That's why my reflectix has lasted so long. The only thing to be mindful of is that those drain holes helped ventilate under the keg skirt. So, I'm careful not to let propane gas build up under there before lighting it.

menschmaschine said:

I've had 3 layers of reflectix/foil tape on my keggle for 2 years now (I do direct-fired step-mashes too). It's warped a little, but no big deal. It finally started coming apart at the seams after a batch yesterday, so I just put another layer of reflectix on. Now I have 4 layers, so that sould keep my mash temp pretty well.

There isn't too much you can put on for a reasonable cost that will withstand heat from an open propane burner. The temps from that will go way over 220°F... especially when they shoot up through the drain holes. The way I solved this was to put foil tape over the drain holes. That's why my reflectix has lasted so long. The only thing to be mindful of is that those drain holes helped ventilate under the keg skirt. So, I'm careful not to let propane gas build up under there before lighting it.

Click to expand...

I could be wrong but I don't think the original poster is direct firing his mash tun. If he is not direct firing, I would guess that the foam rubber would be a better insulator. If he does direct fire his mash tun he should take your advice and use reflectix tape.

lamarguy said:

No real danger, other than melting or rapidly deteriorating the insulation. The various insulation materials used by most homebrewers are NOT meant to handle 212F, including Reflectix which is only rated at 180F. Yes, the horror.

I installed and recommend Buna-N Closed Cell Foam Rubber. It has a higher insulation value than Reflectix, very easy to work with, and is rated to 220F.

Click to expand...

how thick would you recommend, 1/2" or more? i'm referring to the buna.

thanks

Ya, 1/2" is sufficient.

Do you get the adhesive backed or use some time of tape wrap for the Buna N?

lamarguy said:

No real danger, other than melting or rapidly deteriorating the insulation. The various insulation materials used by most homebrewers are NOT meant to handle 212F, including Reflectix which is only rated at 180F. Yes, the horror.

I installed and recommend Buna-N Closed Cell Foam Rubber. It has a higher insulation value than Reflectix, very easy to work with, and is rated to 220F.

Click to expand...

I did my mash tun like that. I used the 1/2" sheet with some industrial adhesive. Since I don't direct fire, I'm not worried about whether or not it's rated to 220. I also took it down to the Line-X place were I had my truck bed sprayed and had them tape off the keg and Line-X the insulation. Looks and works good. I've got a picture somewhere. If I can find it I'll get it posted.

Here's a shot of my insulated MLT with Line-X:

That's pretty sweet. How much was the Line X? And you said you used industrial adhesive. Is that necessary if you were going to Line X over top of it? I ask because on that order form for the 1/2" foam it's almost twice as much to get it with adhesive already on it. Thanks!

spittinrivers said:

That's pretty sweet. How much was the Line X? And you said you used industrial adhesive. Is that necessary if you were going to Line X over top of it? I ask because on that order form for the 1/2" foam it's almost twice as much to get it with adhesive already on it. Thanks!

Click to expand...

Just put on my Closed Cell Foam last night with the adhesive. Super easy, took me about 10 minutes. Then I wrapped it all up with black Gorilla Tape. We'll see how it works with heat (electric).

spittinrivers said:

That's pretty sweet. How much was the Line X? And you said you used industrial adhesive. Is that necessary if you were going to Line X over top of it? I ask because on that order form for the 1/2" foam it's almost twice as much to get it with adhesive already on it. Thanks!

Click to expand...

The Line-X guy charged me about $55. He taped it up and used the overspray from a truck bed he was doing. I used some contact adhesive that I had in the garage. I rolled it on to the keg than on to the buna rubber and mated the two. Contact adhesive that they use for formica tops would work just as well.

Does anyone know if using just Line-X on a keg mash tun, with direct fire/RIMS, is safe? I called up the local guy today and he's checking with corporate to see if it's designed for the temperatures we're talking about. If it's not, then I'll be looking for some kind of insulation combination that I can simply put onto the mash tun keggle and not worry about. I like how Line-X would be waterproof, very resistant to damage and so much more. I have prices on an 1/8" layer, so if you've done it, please post up how thick of a coating you had applied.

I'm thinking of stopping at the lower skirt (so only covering the keg body down to that weld point), but up to the opening cut in the top (leaving about a 1/2" edge without any Line-X around the opening). Although I could just do the outside and use Reflectix over the lid to keep heat from escaping there.

Keep in mind, I'll be brewing [essentially] outside during the winter months (year round) since I brew at my buddy's place on his porch (screened on two sides, the house is on the other two).

I don't think I'll need more than a 1/4" thick layer on the mash tun keggle. I'm basing this off of how things went with a single layer of Reflectix last time. I might even make a shroud to go over the keggle when no fire is being applied. BUT, I'd like to have something that I don't need to worry about during the months that it's not below freezing in my brew area.

What about a silicon rubber foam? Silicon potholders take some serious heat.

For one thing, cost of silicone sheeting large enough to cover the outside of the keggle mash tun will be in line with getting Line-X applied. For another, I'd either be pulling it off to clean the keggle, or have to figure something else out.

Plus, if I had them apply the Line-X to the section above the main body, where the handles are, it should be safe to touch with bare hands.

My other option is to get a welding mat/blanket (rated to 1800F), fold it over a few times, and secure it for use during the mash. It would be just shy of long enough to completely circle the mash tun. Plus, the fitting for the RIMS return would mess with things (with the silicone sheeting option too)...

IMO, straight Line-X or perhaps the previously posted foam and then Line-X on top of that, would be a better solution. Just looking to find out IF that configuration will be safe with a direct fire (propane) mash tun... I can get to the Line-X place on Saturday. IF I need the foam insulation too, then I'll need to place an order with McMaster-Carr with overnight shipping. I can only imagine how much that will hurt. Next weekend isn't an option for me, since I have truck maintenance scheduled for Saturday, and doubt that will be done in time to get to the Line-X place. Chances are, I'll be brewing either that day, or before the following weekend... So I'm under a bit of a time crunch here.

I don't direct fire so I went with the standard water heater blanket. A razor knife and some duct tape was all that was needed.

Ok, so that doesn't help me out at all... If I wasn't direct firing the mash tun (to both heat the strike water, and get it up to mash-out temps) I could just use the Reflectix I have left over (more than enough)...

I'm looking for a more final solution than a stop-gap measure here. Even if I need to augment it during the dead of winter to maintain temperatures better, then modify it once I'm able so that I don't need to do it again next season/winter. I am hopeful that I won't need to do that at all, with a thick enough layer of Line-X. I just don't want to spend a ton on that.

I need to get a couple more batches through the new mash tun to get a baseline established. Then I'll be ready to brew something bigger (10%+) with it.

Carbon fiber welding blanket on my direct fired RIMS MT. Works very well for me:

Where did you get the blanket from and do you have the details on its spec's? McMaster has a few different choices there.

How much temperature loss do you have during the mash? How often do you end up firing it to offset the loss? Is it one layer of blanket or a few thick?

Tranks Catt22

Here's a link to where I bought the blanket:

http://www.mytarp.com/4-x-6-velvet-shield-welding-blanket-hd.aspx

There really are no specs relative to our application. It's a welding blanket and if re-purposing it, as I have done, users are on their own. It was not designed to be used as insulation.

I bought the heavy duty 24 oz/sq yd blanket. It's approximately 1/2" thick. I cut the 4' x 6' blanket lengthwise into three segments of 16" x 6 ft, The 6 ft length wrapped around the 10 gallon Polarware MT provides a double layer about 2/3rds the way around the circumference. IOW, it's single thickness on the front 1/3rd and double thick for the other 2/3rds on the back side.

I circulate the wort continuously during the mash and the temp is maintained with the automated burner operated with a Johnson A419 digital controller. The burner only fires a few times for short durations during the mash. This is much less than when I ran it without insulation. The heat loss will vary with the ambient temperature, so I can't give you a straight up answer on the heat loss question. I have yet to test it in the dead of winter, but I think that is when it will be most advantageous as the temp delta will be much larger. I've also found that it really helps reduce the temp ramp up time when doing step mashes or raising the temp for the mash out.

The cost was initially high, but I was able to make three MT covers and sold the extras to a couple of my brewing buddies who are also using them. That cut the price down to a little more than $30 each which is very affordable IMO:

Check out this video for an interesting demonstration:

http://www.northerntool.com/shop/tools/product_200332391_200332391

Catt22 said:

Here's a link to where I bought the blanket:

http://www.mytarp.com/4-x-6-velvet-shield-welding-blanket-hd.aspx

There really are no specs relative to our application. It's a welding blanket and if re-purposing it, as I have done, users are on their own. It was not designed to be used as insulation.

Click to expand...

Any thoughts on whether the $25 one from HF would work? It looks like a fiberglass tarp and CHEAP: http://www.harborfreight.com/4-ft-x-6-ft-fiberglass-welding-blanket-67833.html

willie, not to be totally off topic, but have you given any thought to HERMS or RIMS to maintain temps?

I insulated mine similar to how it's shown in this thread https://www.homebrewtalk.com/f51/direct-fire-mlt-insulation-project-154652/
For the aluminum I used vinyl coated aluminum coil (what they use to wrap soffits ,windows etc..on houses). I just sanded off the vinyl.
It works great.

Found out, this afternoon, that Line-X is 'good up to 285 degrees as long as there is no direct contact with the flame'... So, I'm thinking that starting where the bottom skirt ends, or an inch above, should put it into the safe zone.

If anyone is brewing between now and Saturday morning, and can use an IR thermometer to get the temp of a keg mash tun starting at where the skirt ends, that would be a huge help. I might just order up the carbon fiber welding mat/blanket too, as a 'plan B'...

Plan B (or maybe C) could be to wrap the keg mash tun in the carbon fiber welding blanket and then have Line-X sprayed on to keep it there and protect it. With the carbon fiber blanket as a barrier, the temperatures hitting the Line-X coating should be well within it's tolerance range. Yes??

shroomzofdoom said:

Any thoughts on whether the $25 one from HF would work? It looks like a fiberglass tarp and CHEAP: http://www.harborfreight.com/4-ft-x-6-ft-fiberglass-welding-blanket-67833.html

Click to expand...

I looked at the HF fiberglass welding blankets. It was certainly cheap enough, but also very thin, much like a canvas tarp. I could not see that thin material providing much insulation value at all.

Ordering one from McMaster-Carr today. Think I'm going to give that a try first, before spraying on Line-X. I should be able to wrap it fully more than twice. Each wrap will actually overlap by a good amount. Also getting some adhesive that's rated for over 2000F.

I'll post up results from both applying the blanket and how it handles the first run next weekend.

Here's what my keg mash tun looks like with a single layer of the carbon fiber blanket glued to it...



I'm contemplating adding some to the area around the hole, to add a bit more insulation there. I'll have to see if I have enough glue left, that's usable, to do that. If not, then I would need to order another can, and I might not get enough benefit from that to make it worth the expense.

With the Velcro you see glued to the keg, as well, I can secure another layer of the blanket (goes around 1-1/2 times) for even more insulation.

if i use reflectix, does it go shiny side towards the keggle or shiny side out?

Both sides should be shiny... Just don't fire the mash tun with that around it, or you'll quickly find out why some of us have stopped using it. With how my mash tun is configured, it would have been too much of a PITA to try to get it to slip over the top. I do still use a circle of it on top of the lid for the mash tun, to help insulate the top. It's far enough away from the higher temps to be safe. But the lower 1/3-1/2 of what was around the keg got it's insides melted. Didn't smell all that nice.

I do BiaB in a 5 gal kettle so I was hoping to use this to maintain temps during the mash. Since no heat will be directly applied to the kettle while the reflectix is on, I am not too worried. This is just replacing the towels I use to surround the kettle during my mash. I don't think it will be an issue.

It's also BIAB on a indoor stovetop, not gas or propane.

Hi!
I also have to insulate my mash tun. I occasionnally fire the mash tun when doing multiple steps.
I am curious to know how the blanket worked for you?
Were you able to maintain your mash temp?

In order to know if the welding blanket is helping much, you should really do a heatloss comparison over some measured time.

I found the following used for keg insulation... has anyone used this??? They claim it's heat resistant to 350°F.

http://thekegkoozy.com/mash-tun-insulation

any reviews???

bajabrewer said:

I found the following used for keg insulation... has anyone used this??? They claim it's heat resistant to 350°F.

http://thekegkoozy.com/mash-tun-insulation

any reviews???

Click to expand...

Interesting... Be curious to see if any HBT members have used one for a keg mash tun yet. Might be worth picking up. Just not sure how it will handle the insulation I already have around my keg mash tun...

Just out of curiosity, why would you insulate your vessel? So you can walk away and do something else? You should do as I do, watch the temp fall at a steady rate, drink your beer as needed, then refire to maintain a somewhat steady temp. Just kidding, normally by the time the mashing in my un-insulated direct fire keggle is done, I have to take an average of temps and guess what to record in my brew book. my average rate is 4 beers for a 60 min mash or 6 beers for a 90 min. I've gottem pretty good and almost don't need a stop watch!

Golddiggie said:

Interesting... Be curious to see if any HBT members have used one for a keg mash tun yet. Might be worth picking up. Just not sure how it will handle the insulation I already have around my keg mash tun...

Click to expand...

I ordered one. Ill report back on how well it works.