Fiberglass insulation service temp limits?

[Marctrees]

Typical readily available pink or yellow fiberglass insul from my local lumber yard/ Bigbox store.

The regular old school stuff, nothing weird like "No scratch" or anything.

Regular fiberglass batts/ rolls insul sold for yearssssss.


Is it OK for a service temp of absolute max 400f ?

I want to insulate a meat smoker.

Wrap around exterior, and re sheath.

Will NEVER exceed 400, usually around 250f.

Will peel off the "Kraft face" or any laminate.

I'm pretty sure it should be fine, but would like experienced comments.

Maybe from Welders.

Thank you alll, Merry Christmas, Marc

 

[Fixed]

Be much better off using a mineral wool insulation like roxul

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[Marctrees]

Ok, thats what they say.

But , respectfully, I think we need to think about this.

We are not insulating the space shuttle glider belly.

"Roxul", even though a great product, is NOT readily available, m( at least NOwhere near me) more $, and seems to me to be totally overkill.

I did not say a firebox, I said absolute max of 400f, and rarely that high.

Marc

 

[Leaflessshadetree]

I used to wrap my smoker with it in the wintertime to get the temp up close to 200 deg. I got away with it quite a few times. The last time I did it resulted in tall flames.

 

[Marctrees]

Leafless - "Got away with it" ???

What?


"Tall flames" ????


What was flaming tall? Marc

 

[hangfirew8]

The problem is not the fiberglass, but the paper/foil backing.

-HF

 

[Marctrees]

Well, paper will be peeled of, insulation is the question.

Or, use un faced batts. Marc

 

[Orionrising]

Ok, thats what they say.

But , respectfully, I think we need to think about this.

We are not insulating the space shuttle glider belly.

"Roxul", even though a great product, is NOT readily available, m( at least NOwhere near me) more $, and seems to me to be totally overkill.

I did not say a firebox, I said absolute max of 400f, and rarely that high.

Marc

lowes carries it around here

 

[Marctrees]

lowes carries it around here

Please be more specific.

Lowes carries what and where ? "there" ???

OK, now I see Western Maine.

So the question still remains - ?What? are you saying the have? Marc

 

[Orionrising]

Lowe's carries roxul you should be able to order it for store delivery anywhere.

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[joe--h]

Seems there's only one answer you want, so go for it.
Joe H

 

[Orionrising]

According to http://www.engineeringtoolbox.com/insulation-temperatures-d_922.html fiberglass is good to 540. I would get the unfaced attic rolls.

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[ItsNemo]

**** it up and find roxul...I wouldn't feel comfortable with anything less.

 

[Marctrees]

I am looking for a scientific engineering answer, Not what your Mothers Cousin advises.

We can always use Titanium for a salad bowl, but I don't think it's necessary.

This is a Forum of intelligent people, hopefully not saying what their Mother would advise.

It looks to me , after all my Googling, that basic fiberglass batts are MORE than adequate for my specific application.

I'm just looking for confirmation, maybe from welders that do heat treatment procedures.

Let's stick to the facts Guys.

Abrasive? whatever. Trying to stay accurate.

Marc

 

[ItsNemo]

Seems you've already decided and don't need our help then. Buy whatever you want and burn your stuff to the ground.

 

[Marctrees]

Well, trying to get tech info before I finally "decide".

Have NEVER read/ known about glass degrading in any way, or even close to burning.

At least NOWHERE near 400f.

Maybe missed something, that's why I ask.

Guilty of looking for technically accurately founded info.

Still waiting for the scientific factual based answers.

After a few hours of Googling, it seems to be fine.

But still asking for experienced substantiation. Marc

 

[Marctrees]

Orion - Yes, Thank you, I have already been there among other places.

That's what I'm thinking.

Thank you for the link. Marc

 

[onewheat]

Not an answer to your question, but... Why would you want loose fiberglass fibers around your food? Regular insulation will drop fibers around and break down. If it is uncontained, those fibers will end up in your food. I don't care either way since I don't eat off your grill. but this conversation has gone round and round on several smoker forums and that is the general consensus about open fiberglass.

 

[Marctrees]

Onewheat - Thank you.

It will be totally separated from the food chamber by extremely well joint sealed 24 Ga steel.

From my OP - " Wrap around exterior, and re sheath."

I can not even begin to imagine thinking of installing exposed insul in the food chamber.

What a future mess, and more.

It would take a very uneducated and/ or unthinking person to that.

This application is on the EXTERIOR of a fully completed sealed chamber smoker. Marc

 

[ItsNemo]

Well, trying to get tech info before I finally "decide".

Have NEVER read/ known about glass degrading in any way, or even close to burning.

At least NOWHERE near 400f.

Maybe missed something, that's why I ask.

Guilty of looking for technically accurately founded info.

Still waiting for the scientific factual based answers.

After a few hours of Googling, it seems to be fine.

But still asking for experienced substantiation. Marc

Here's your technical info:

Non-combustible with a melting point of approximately 1177°C (2150°F)

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

Why would you want a hundred degree safety margin that may or may not be okay when you could have a 1500 degree safety margin?

 

[Orionrising]

what will the second layer on the outside of the insulation be a second steel shell? how much do pliability and compression matter?

 

[Marctrees]

Really don't understand how I'm asking a rude stupid question. Marc

 

[Marctrees]

Here's your technical info:



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

Nemo - Read that, thank you.

It talks about Roxul, I believe it's great stuff.

It does not address fiberglass that I see.

"Why would you want a hundred degree safety margin that may or may not be okay when you could have a 1500 degree safety margin?

"

Sorry, maybe I not smart so I missed it.

What is this "100 degree safety margin" you speak of?

Regarding what?

Trying to think like an engineer here, trying to stay to facts.

I have always overbuilt everything in my life, but I do know there is a difference in that vs going needlesly totally blindly overboard and throwing away $. Marc

 

[Marctrees]

Why do feel I am starting a fight here???

I thought my original post was factual, asking a technically correct factual question.

Marc

 

[Marctrees]

I have a few rolls of FB in my shop, want to use that, instead of spending 50$, ..... plus driving 40 miles in my case, when It seems there is NO advantage, in MY application. Marc

 

[Fixed]

You stated that temperature the material exposed to would be around 400F. Someone else provided the material specs showing the fiberglass to be good up to 540F. Nowhere that I have ever worked, with any material, would that be considered an acceptable safety margin when you're talking about combustible material.

Why people here could see you as being rude is the result of you being rude about advice that we took time out of our day to offer.

If you don't want to do it any way but how you want to, why bother asking and then arguing with people?

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[kaffine]

Well fiberglass is used for oven insulation and they get a bit hotter than 400ºF. Only concern would be if they use a glue in the residential fiberglass insulation that can't take the heat. They make fiberglass just for oven insulation but will be harder to find and a bit more expensive.

http://www.pacorinc.com/fiberglass-...blankets-range-glas-xg-lightweight-fiberglass


Take a piece of the fiberglass put it behind a piece of sheet metal and take a propane torch to the sheet metal to see what happens to the fiberglass.

 

[Marctrees]

Apologize that I was rude.

Again, just trying to be factually accurate. Marc

 

[Leaflessshadetree]

Leafless - "Got away with it" ???

What?

It worked with no negative affects the first several times I did it.

"Tall flames" ????

My guess, flames were 10 ft tall.

What was flaming tall? Marc

The smoker was pretty well engulfed on all sides.

I was using 2 layers of foil backed insulation (foil on both sides). I pulled the flaming material away from the smoker with a rake. There was
not much structure left to the fiberglass. It was no longer batts, just a bunch of small charred pieces.

 

[Abeo]

I'd say that fibreglass or rockwool would be up for the task...
BUT
The binders they use in the insulation might not be. A project at my work was trying to figure out what binders in insulation caused an expensive peice of equipment to crack and fail. Turns out the binders in the insulation were causing it. For you, it might not be a problem, just something to consider.
I'd also look into fireplace insulation, it's made for this task.

 

[bczygan]

If you want an "Engineering" answer, then call an Engineer. Preferably one at the manufacturer of the material in question.

 

[Crazyjake8493]

I'd get some Roxul. Fiberglass would hold up to high temperatures, but the resin that binds the fibers would break down with high heat.

 

[egdede]

Ok, thats what they say.

"Roxul", even though a great product, is NOT readily available, m( at least NOwhere near me) more $, and seems to me to be totally overkill.

Marc

I think lowes carries roxul, and I'd go for it if a roll didn't leave you with too much escess.

 

[Firebird 1]

I have had the unfortunate job of rebuilding several homes after fire. I have picked up many a remnant of fiberglass insul. The paper was gone as well as the colour being burnt out of it, but it was still there. I think you will be fine.

 

[bop_pa]

Things to consider. When it is successfully insulated the smoker may reach higher temps compared to before. So are you planning to manage the temps actively to ensure it does not exceed 400 degrees. I had my smoker running a month back and tried some new applewood brickettes and it hit almost 700 degrees. Too hot to smoke but you could grill with that. Regardless you would need to be mindful. Ever thought about some sort of fiber cement mix or fire brick

 

[PT Doc]

Go for it.

Take some photos. And video. Have fire extinguisher just in case.

 

[PT Doc]

This is what you need. 2400F
https://www.amazon.com/dp/B015GD0QCW/?tag=atomicindus08-20

 

[Handyfarmer]

I have used the pink stuff with the paper striped off to re-insulate an stove oven that had been stored and mice had messed it bad, been using it for over 10 years now, I guess they make special insulation for ovens, but if there is not any paper or it glue, glass melts at over 900F,

Glass is considered cold at room temperature. Its composition does not begin to change until it reaches a temperature of between 700 and 900 degrees. At these temperatures, glass begins to have the consistency of a pudding setting up. Those who work with glass know it gets to a workable temperature at around 1250 degrees where, it has the consistency of taffy. https://www.reference.com/science/temperature-glass-melt-64a34ca0402f0a30

 

[Angelfire]

Fiberglass melts at 540C, not 540F. So from a safety margin you are probably ok. That being said, I have no idea what else is in fiberglass insulation and what temperatures those materials are good for. Personally, I'd pony up for the mineral wool and be done...there's probably a very good reason it's used in so many applications like this.
Cheers.

 

[onewheat]

Onewheat - Thank you.

It will be totally separated from the food chamber by extremely well joint sealed 24 Ga steel.

From my OP - " Wrap around exterior, and re sheath."

I can not even begin to imagine thinking of installing exposed insul in the food chamber.

What a future mess, and more.

It would take a very uneducated and/ or unthinking person to that.

This application is on the EXTERIOR of a fully completed sealed chamber smoker. Marc

Cool - I guess I missed the re-sheath part. The topic came up on the other forum where guys wanted to save money over a grill-specific thermal blanket and use a Harbor Freight welding blanket (mainly fiberglass) or other homegrown fiberglass batt insulation blankets OVER the grill while smoking and then potentially disturbing the glass and creating the airborne fibers when opening the lid or having them on the surface of the grill or whatever. If you are enclosed - nevermind.