Refmix vs Heatstop Newbie Forum Discuss Refmix vs Heatstop in the Good Background Information forums; Are there any differences between refmix and heatstop for use as high temp heat mortars? Is one better than the ...

[rbigante]

Are there any differences between refmix and heatstop for use as high temp heat mortars? Is one better than the other? Any other products out there?

Also, can I use the high heat mortar to set the floor of my oven instead of the sand/fireclay mixture? Any other products recommended for setting the floor?

Just in the planning stages. hopefully i'll get a chance to complete the concrete pad, block stand and insulating hearth prior to winter setting in.

Thanks, Rino

[Les]

Rino,

I started using heatstop but the shipping was crazy expensive so I started rolling my own. It is really nice to work with. I just used refmix on my flue and didn't like it at all. The stuff fired on me really fast. I had to remove it and start over. I wouldn't set my floor in mortar - you just need it to be level.

Les...

[james]

As the guys who import Refmix (and someone who has used it a lot), I really like it. It's workable for about 20 minutes, then it sets hard as a rock very quickly. It's the #1 brand of refractory mortar in Italy (sold in over 4,000 locations) and is used for most fireplace and oven installations there.

My two cents. :-)
James

[mfiore]

Les, how did you find the home brew compared to the HeatStop? Heat Stop is very expensive here, and I am sure I will run out before end of the oven. Is there a concern about differential heat expansion, etc, using different types of mortar in different parts of the oven? It may be less of an issue for your oven, as you used less mortar than others in the joints.

[Les]

Mike,

It works pretty well. I used the heatstop on my entry and arch - thinking that is was the weak spot. I couldn't really tell you if there is an expansion issue, as I never had the two products touch each other.

Les...

[mfiore]

Originally Posted by Les

I couldn't really tell you if there is an expansion issue, as I never had the two products touch each other.

Les...

I was concerned more about even using two different products on the dome. Do you think there would be a problem with HeatStop on the bottom half of the dome, and another mortar on the top half?

[rbigante]

thanks for the replies. i guess it's a preference thing. I just wanted to make sure that either product can be used to construct the dome. There's a place near me that sells Heatstop. a 50# bag for about $72.

i was going to set them in a thin film of mortar similar as to how the instructions specify (similar to setting tile). Anyone see this being a big problem? or should I used sand/fire clay mixture?

great forum and hope to have some pics of my build posted someday

thanks,rino

[mfiore]

One benefit to the sand/fireclay mix is that the bricks may be lifted out and replaced in the future if needed. There may be other benefits, as far as allowing for expansion, but I'll let other, more technically minded builders pipe in!

[Les]

Rino,

I'm going with Mike on this - let them float, there is no harm.

Mike, in regard to using the two different products on the dome - I don't see how this could cause a problem - we're just talking about mortar. One may crack easier than the other - but that's all I can see happening.

Les...

[rbigante]

Mike & Les

what you guys are saying makes a lot of sense. I'll let them "float" thanks