Refrax vs Heatstop 50

[SCChris]

Re: Refrax vs Heatstop 50

Greg,
You're the man!!

Thank for all of the info. This will make my build easier / more economic.

Sincerly!!

Chris

[blacknoir]

Re: Refrax vs Heatstop 50

Very nice! I just found out my firebrick distributor is also a HWR Distributor so that works out nicely if I can get a decent price.

[SCChris]

Re: Refrax vs Heatstop 50

Harbison-Walker Refractory has 2 distributors in California, one in Richmond and one in Los Angeles.

Chris

[ttriche]

Re: Refrax vs Heatstop 50

Not sure whether Foundry Service & Supply is 'the' HWR distributor for Los Angeles but they get the products fast and at competitive prices. I actually had made some calls to HWR about mortar, but ended up playing phone tag with a rep and eventually lost interest. The HWR location in LA is down the street on Slauson a bit from where FS&S is located; I'll see if there's any difference in price (would not surprise me if HWR direct price were higher).

[Lars]

Re: Refrax vs Heatstop 50

I just did a simple tally.

I tried some expensive bucket mortar, (for high temp refractory situations) and it was NOT to be used outdoors. Dissolved in the slightest moisture.

After that I mixed my own recipe. (3:2:1:1/2) fine sand, fireclay powder, portland, lime) and it is the most friendly, fluffy -yet sticky, mortar you could ever ask for. Rough cost, 94# Portland, $10, 90# Fireclay, $20, 50# bags of fancy sand, $5 each.

Total cost for way over 200 lbs of mortar, maybe $50.

I have not fired my oven yet, but according to three potters, and a glass blower who have built kilns, it will work fine. I believe them, but I will be posting pictures of any cracks that develop this next week.

[ttriche]

Re: Refrax vs Heatstop 50

I believe it. I just called HWR and Mortar Mix 413 is a pallet order item (they won't do it for a few bags). Meanwhile I already have 1:3:1:0.5 lying around!

The HWR distributor's price for Kast-o-Lite is a bit cheaper than FS&S's, however. (That was the other thing I found out when I called)

[SCChris]

Re: Refrax vs Heatstop 50

I'm having to think hard about the (3:2:1:1/2) mix rather than the high end spread. The insulating board would be nice and clean compaired to vermiculite oatmeal. It seem like the board could save a week of build time. Am I right?

Chris

[Lars]

Re: Refrax vs Heatstop 50

Chris,

I think some guys/gals ( there are some women builders, too!) use vermiculite layer AND an insulating board.

I was kind of quick to pour my insulating layer, and , when I got started, I just didn't know how that vermiculite oatmeal was going to work...I really thought it was going to be a disaster. BUT... in fact, it turned out great! It's a VERY nice end product. Totally natural, masonry product, not too absorbent, but will retain it's shape even if it gets wet. I just saw some of the high test board today... and I am not sure I would use it even if I had the chance ( even if money were no object , but at least it would add another $50 to 100 to the project.)

I looked at two different plan sources, and the other guy ( aside from the FB plans) poured his structural layer on TOP of the insulating layer. Forno bravo does the opposite.

I put a SIMPLE form a 48" by 52" rectangle with 1/8" masonite bent around in the corners to make a 48" diameter circle in the middle ... all 2.5" thick ( it could have been thicker, but my oven was getting kind of 'too high off the ground' ) and laid in concrete in the corners, the next day I took out the masonite curves and filled it with the vermiculite mix. I used 4:1 vermiculite portland. At that rate, 8 coffee cans of vermiculite, 2 coffee cans of portland take about 2.5 gallons of water, and I used about 5 'hods' full ( your standard 2 lb. coffee can )

So, my insulating layer is not that thick ( only 2.5") directly below the oven floor bricks, but when I poured my structural layer, I used 2" of styrofoam. I may have to take it out, but if I dont see any evidence of it melting, it will make a great extra insulating layer, I am thinking.

As far as the 3:2:1:1/2 mix, I am certain it is the best mix for me. I was able to lay up 7 chains with no support except a 1/2" spacer block on the back side of each 1/2 block. ( I also used a tapering method I describe in 'tips and techniques ')

Anyway. I will be interested to know what you decide.
Lars.

[Les]

Re: Refrax vs Heatstop 50

I looked at two different plan sources, and the other guy ( aside from the FB plans) poured his structural layer on TOP of the insulating layer. Forno bravo does the opposite.
.

I think this is referred to as "Evolution". Will you let us know how the other guy's oven heats up? There is no problem with having the extra mass, but if you just want to fire it up for pizza, I think this would be the wrong approach.

JMO,

Les...

[ttriche]

Re: Refrax vs Heatstop 50

I'm having to think hard about the (3:2:1:1/2) mix rather than the high end spread. The insulating board would be nice and clean compaired to vermiculite oatmeal. It seem like the board could save a week of build time. Am I right?

Chris

Insulating board can be had from McGill's for about $100 per package of 3 sheets, 24x36x2". Probably direct from HWR as well (I didn't ask, I have extra left over). Those are mineral wool boards, I don't know if they're as good as calcium silicate vacuum-pressed boards, but they work and are structural (I have my floor, soldiers, and a couple of arches parked on mine -- the boards are strange stuff).

Vermicrete seems fine too, but I wanted my enclosure's overall height to be 59.5" (building code specifies that you don't need a variance for anything under 60" in my area) so I went with the maximum efficiency insulation every chance I had. I may pour vermicrete around the Kast-o-Lite buttress for extra support and insulation. Haven't decided yet -- if I have left over ceramic blanket, I'll probably use that instead.

If a distributor who stocked 413 (or, better, Refrax) were close by, I think the cement-bonding air-set refractory mortars would be preferable (don't want to build this twice). However, I have no intention of ordering a pallet load from HWR unless a bunch of other people in the LA area want to go in on it. I'll stick to 1:3:1:1 where I can get a tight fit or where the Kast-o-Lite is shouldering the bulk of the load, and Refrax where it's touchy (like where the dome meets the opening arch). I may buy more bags of Kast-o-Lite 22 for peace of mind and structural integrity, since HWR sells it for about $43 a sack (about 1 cubic foot worth of end product). Not too bad.

I wonder if the new FB Mortar is in fact HWR 413. Like someone said, there's an HWR distributor in Richmond, which isn't too awful far from Forno Bravo. Provided the mortar sets as well as Refrax, it is a huge cost savings if so.

[smuth10]

Re: Refrax vs Heatstop 50

I'm having to think hard about the (3:2:1:1/2) mix rather than the high end spread. Chris

After using two $77 bags of HS(and the assurance of Less and others) I decided to make my own (3:1:1:1) mix according to the FB plans. At first it was not as sticky as the HS and a bit rough for my liking. I bought the finest sand I could find, but I figured that was most of my problem. I ended up grabbing a kitchen strainer and running all of the sand through it. I was surprised how many small pebbles and garbage were in it. After I did this the texture and stickiness is pretty much identical to the HS. Regardless of which ratio you use I would recommend doing this. It helped out a great deal. Good luck!

[Lars]

Re: Refrax vs Heatstop 50

Les,
The 'other guy' was a real enthusiast in Australia who likes to build barrel vault ovens. His website is Wood pizza oven Building wood burning brick bread ovens I was kind of surprised at the difference in the approach ( one with insulating layer below, the other with it just below the oven floor bricks) and decided to go with the latter -- knowing that the heat might compromise the portland in the slab.

( In my case it really wouldn't be a problem because the dome transfers most of the weight directly to the base/stand and the 'structural slab' really only holds itself up and the floor bricks)

You know, I am sure he has success with his approach, and is a pretty competent builder, but it just made more sense to me to do it the way I did.

Lars.

ps... chris. the sand... just buy the really fine sand... you only will need a couple bags and it is really fine and sharp. Usually available at Lowes, Home Depot...about $5 a bag.

[SCChris]

Re: Refrax vs Heatstop 50

So many choices.. In the end that the structure is solid for many many years is critical. With all of the work that goes into these, can go into these, I just want it to last. It looks like no matter how high tech the materials and how carefully you craft the oven there are going to be cracks. Additionally, even a pile of the right rocks, or adobe soil with a hole in the middle can be used as an oven, and cost doesn't seem to be a factor in the overall success of the oven. Balancing the ovens functionality and asthectics with my finite resources, dollars and time is the tricky part. I like the idea of the Fiber board, but have heard that it's unknown how this product will hold up over time. Will it compress, how much, does it matter? The Fiber blanket on the other hand doesn't have to have any weight on it after installation, so even with the additional $ this costs I'm comfortable wrapping the oven in this and then using the vermiculite oatmeal to coat, and finish with stucco to cover.

BTW at this point I expect go igloo to blend with the Spanish colonial/Mediterranean of our home and lifestyle, although if she who must be obeyed decides that a tile roof is what must be done, then it will be done. A happy wife = a happy life.

;-)


Chris

[Lars]

Re: Refrax vs Heatstop 50

Chris,
So, let me get this straight, you are in Orange County AND you have a wife.

I know how you feel with the, seemingly many, choices. I didn't even look into the expensive other mortars much. I am using regular sand, portland, and less fire clay for my outer brick work, and there are fairly big stones in that 'all purpose sand'. I wish I could tell you that I have fired my oven many times and inspected the joints and found them to be hardened and waterproof, but I just have to rely on the advise of guys who have done this many times and used the same recipe with great success.

When I do have a few years on this oven, I will probably report back to this website. I know alot of the builders from the past 5 years have used the 'home brew' mortar with great success.

I want people to be making food and socializing in my little outdoor kitchen area in the country 100 years from now too, but who knows, a road could come thru wider and bull doze the right of way in 10 years for all I know. Nothing is forever.

L.

[SCChris]

Re: Refrax vs Heatstop 50

I hear you on the bulldozer part, I'm sure I won't care in a hundred years about the rest. Life is to important to worry about the little things and what can't be known. Hommer Simpson might be a bit "in the moment" but it's Friday and I keep hearing his voice say "Duff.... Mmmm"

:-)

C