castable refractory

[sonomacast]

Re: castable refractory

Really nice job on the sand dome. How are you going to cast the cement and keep the thickness constant? Will there be an outer mould? Will the ovens be segmented? Thanks

[mr g]

Re: castable refractory

Hi to fxpose and cuba. Wild Willy inspired me and a group of friends to make our domes out of castable. In all we have about 10 domes to build so we intend to reuse the sand dome. We are tossing up whether to make a fibreglass inner and outer mould from the sand one or whether the sand dome will hold up during multiple uses. I have attached some photos of the sand mould which is simply bricklayer's sand. The dome will have an inner diameter of 1000mm and an inner height of 450mm. The door opening is 450mm x 300mm. You'll notice that the mould has a narrower portion where the opening meets with the dome entrance - this is for the door jam. Since we intend to reuse the mould for multiple domes I have decided to paint the sand using ordinary houshold paint to bind the sand together. This has worked quite well and now the sand has quite a tough outer layer to help preserve all the edges. I also intend to wrap the dome in a plastic layer of some sort (possibly cling wrap) and then spray it with canola oil as a release agent. My only real concern is how thick to cast the dome. I don't think I want to go over 70mm thick but is this going to be strong enough and how long will it take to heat up? I'll post some more info when I have gone to the next stage. Hopefully next weekend.

[fxpose]

Re: castable refractory

If anyone wants plans or more photos, please ask. Easy to build, great to use.
Happy cooking to all.
Willy

If possible, can you please post some more photos here in this thread. I'm especially interested in how you set up the sand mold. I'm assuming the sand mold was demolished and excavated afterwards? Or was this a reusable mold?
Sorry about the newby question.

Thanks!!

[cuda]

Re: castable refractory

Willy, great work on the castable dome. Any plans or tip, techniques, suppliers would be most appreciated. I built my base and poured my slab with intentions to build a low ceiling dome from brick, but the idea of casting one won't leave my head. I think this is how I want to proceed, but am a neophyte with respect to the castables, especially the molding process. I will accept whatever info you have. Thanks a whole bunch in advance.

[jonkendall50]

Re: castable refractory

Yes, sorry about the typo there. The question was for Wild_Willy. We have a place locally that sells refractory castables, I just haven't pulled the trigger yet. I'm using a clay oven right now and it works great, but there is some cracking.
Would like to see more pics. Also, if you were going to start from scratch, anything you'd do differently?

Thanks

[wild_willy]

Re: castable refractory

Hi Johnkendall50
If you're enquiring about the castable cracks.
Been using the castable oven regularly since Xmas 2008 and absolutely no cracking. I can't believe how economical it is to fire up and maintain the fire. Been very cold here recently and the oven keeps quite good temperature overnight and well into the next day. Don't know why I didn't build one 20+ years ago.
If anyone wants plans or more photos, please ask. Easy to build, great to use.
Happy cooking to all.
Willy

[Wiley]

Re: castable refractory

Ha Ha :-)
I think it's a typo and he meant Wiley as I think I'm the only steel dome WFO here. As for cracks: none outside and of course, none in the inside... it's 5/16ths steel, and as for use, in a couple hours I'll be sliding three loaves of bread in the oven:-).

Last weekend, I baked 14 rolls and then slid in a pork shoulder replaced enough burning coals to smoke the shoulder for an hour, (placed soaked hickory chips in an aluminum foil "boat" on top the coals with door partially open). Then raked out the coals covered the shoulder and closed up the WFO. Next evening (27 hours later) opened and served wonderfully moist and still just over 200F degree pulled pork. One of these days I'm going to spend the time to make a proper insulated door. I'm still using a piece of 2x 12 stock cut to fit with an 8 inch Fire King pie plate set in it (for viewing). Just purchased 4 more pork shoulders at 79 cents a pound (at Safeway) for future pulled pork get togethers with friends.

bests,
Wiley

[jonkendall50]

Re: castable refractory

Willy, any cracking since you've been using your oven?

[berryst]

Re: castable refractory

hey riva
Many of us have done our own thing with our ovens, Mine is a one of kind. The closest oven to me is Willy's steel dome oven. I'ts pretty cool. It works.
I buried the whole works and landscaped around it.

I looked at castables when I first investigated wood fired ovens and the clerk told me it would not hold up. What an idiot I know better now.
None the less my oven is done and I use it. Made Pizza last night
Berryst

[Riva-t]

Re: castable refractory

Hi Berryst
Thanks for the reply. Will work on the tech. photo stuff over the weekend. Still tweeking the design side of the oven as everyones ideas are good and we pick a bit from each. I'm a great believer in "each to their own" and some times wonder why we don't just buy "the bit that works" and enjoy the landscaping around it!!!!! and put as much effort into developing our skills at using it. I guess never say can't.
Cheers

[berryst]

Re: castable refractory

Riva
This sound awesome I'll like to see your setup.....send PICS

[Riva-t]

Re: castable refractory

Hi
I'm new at this and tried a post the other day but it obviously dissapeared out there some where.

Am just casting my second oven dome for our own back yard. Last one was for a kitchen our son was involved with and it worked a treat. Have made a mould and cast the dome in three segments. (three seperate pours on the same mould.) Caste a floor in two pieces, and an entry/gather for the front. The suport frame was crisscrossed sleepers bolted with precaste concrete lintels layed across them(didn't have time to caste a slab). Then a 100mm vermiculite and cement layer with oven set up on top. Layer of blanket over dome and the remainder of the enclosure filled with loose vermiculite( about 9 bags)
The casting worked well and I put ss needles in the mix as recomended by the supplier. Being cast in a mould with good vibration made a good dence dome and meant it didn't need to be made on site. Oven worked well and held heat over night to slow cook the roasts. Just hope the mould lasts as son wants another one as well!!!!!!!!

[wild_willy]

Re: castable refractory

Hi to all
I guess it's time for an update on my oven!
Since I last posted the oven was completed in time for Xmas when we cooked pizzas and 2 turkeys. The oven gets up to temp within 3 hours with a steady fire going and attains a temperature of about 400C. Great for pizzas.
After cooking pizas at night the oven is still hot enough (250C+) in the morning just right for cooking a long roast or probably bread (haven't tried that yet).

The curing process was quite simple: just a matter of taking it easy and lighting a series of fires over about 6 or 7 days, starting with very small and getting progressively larger til it got to around 400C on the final firing. I did allow the conctete to sit and dry for 2 days, then placed a small electric radiator in the entrance and let it run for a day first. Since then its been full steam with at least 10 serious firings and there's been no issues with cracking.

I am currently working overseas and can't post any more photos but will do on my return mid March.

[david s]

Re: castable refractory

That reminds me of a time when my dog was running a high fever. When I took him to the vet he prescribed mustard. He said it was the best thing for hot dogs.

[david s]

Re: castable refractory

Hmmm, hot dogs !