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kebwi 09-04-2009 02:58 PM

Refractory Mortar Poll
Simple question, what form of refractory mortar did you use, and why? Feel free to offer your experience after-the-fact, especially with regard to price, ease-of-use, and effectiveness.

[] Non-Calcium Aluminate Homebrew
[] Calcium Aluminate Homebrew
[] Heatstop 50
[] RefMix
[] Other

Brief reason: ?


kebwi 09-04-2009 03:13 PM

Re: Refractory Mortar Poll
Rats, in retrospect, I realize that a very useful distinction in the poll would have been between 'Other Homebrew' and 'Other Premixed'. Please specify in a comment.


dmun 09-04-2009 03:42 PM

Re: Refractory Mortar Poll
I used heatstop 50, because I'd used it before on a fireplace liner. It's really easy to use, and forms a strong bond. It mixes easily, and spreads like creamy peanut butter.

kebwi 09-04-2009 03:59 PM

Re: Refractory Mortar Poll
@dmun, I have access to HeatStop 50 here. It's $70-$80 a bag! I was planning on using it except that I started wondering about other options.

Let me ask you this, I'm making a 36" oven. Can I do it with one bag? (Let's see, the directions suggest 130-180 lbs. Is that dry weight, as in 3-4 bags of HeatStop?)

Are RefMix and HeatStop are volumetrically equivalent? Do two 22 lb RefMix bags mix about the same amount of mortar as one HeatStop 50 bag, and as followup, mortar the same amount of overall construction?

Les 09-04-2009 04:31 PM

Re: Refractory Mortar Poll
The poll may get a bit skewed. I used some Heatstop, Refmix, and home made. For the record, most was the home made.


kebwi 09-04-2009 04:37 PM

Re: Refractory Mortar Poll
Ah, I didn't realize there might be a lot of mixing. I'm just trying to figure out the best option. HeatStop is expensive (RefMix is virtually the same price). Maybe I'll just homebrew it...if I can fine the parts and be confident that I can mix it such that it actually works properly.

Coming into this project I can safely say I knew next to nothing about cement, concrete, mortar, etc. It's just completely unknown to me, but I'm looking for cost-cutters and the pre-mixed mortar seems very expensive.


Les 09-04-2009 04:43 PM

Re: Refractory Mortar Poll
It is expensive. I burned through the first bag of heatstop in a heartbeat. That is why I went to the home mix and it seems to work pretty well. I borrowed some refmix to attach my flue from Acoma. If you are going to buy the good stuff, buy Refmix - thats what James sells :)


kebwi 09-04-2009 04:51 PM

Re: Refractory Mortar Poll
The advantage of HeatStop over RefMix, in my case, is that I can get it without shipping and it's sold at the same place that I can get the firebricks for the lowest price around (so I'll be going there anyway). Since they're cost is nearly identical (I haven't even factored in shipping yet, which makes RefMix more expensive), I was leaning toward HeatStop...

...but *now* I'm leaning toward homebrew. ;-) Assuming it really does the job it needs to do.


captkingdom 09-04-2009 08:14 PM

Re: Refractory Mortar Poll
I used Sairbond. It spread easily and was very sticky. it is an air dry refractory mortar that was only $35/ 55lb bag.
I DO NOT RECOMMEND IT! Unless perhaps you are going to precisely cut everything and keep all your joints down to 1/8".
I suffer from myriad shrinkage cracks!:mad:
I wish I had tried the Refmix or the calcium aluminate home brew or the regular home brew, ANYTHING but Sairbond

RTflorida 09-04-2009 09:40 PM

Re: Refractory Mortar Poll
I used Heatstop 50. My 77 cent a piece firebrick supplier had it for $54 a bag, I bought 3 bags and used 2 on a 36" dome that was cut to fit (no gaps over 1/4"), but I did cover the entire dome with a 1/2" layer on the outside(that took up the entire second bag, otherwise I would have only needed 1 bag.
I really only had the heatstop and one of the wet mortars in a bucket to choose from at a local refractory supply. I had read many reports to stay away from the wet stuff in and oven build, I had also heard that the hombrew with lime can be a bit difficult to work if you don't get the amounts exactly right.....that sent me to the heatstop.
Heat stop is really easy to work, smooth and creamy like peanut butter and it has a great sticky ness when you get the water amount just right. My only complaint is the 4 time reoccuring arch crack. Even though it is a high heat area I am going to try type N this time...certainly won't make the crack any worse.


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