Author Topic: So it begins..... (Read 12732 times)

BrickStoneOven · « **Reply #20 on:** June 05, 2011, 11:09:47 PM »

Are you going to be puting insulation around the deck bricks and build the first course on top of the insulation or are you going to build the dome around the deck? This is cool. I wanted to build an oven at first but ended up buying one. Very interested to see how things come along.

dellavecchia · « **Reply #21 on:** June 06, 2011, 06:44:55 AM »

Quote from: shuboyje on June 05, 2011, 10:30:18 PM

Insulating concrete is not like normal concrete. It's rough and crumbly. The surface would remind you of those old popcorn ceilings that were popular at some point before my lifetime. Needless to say it's not ideal for setting a nice level cooking floor. Most seem to mix the fire clay sand mixture into a thinset and install the floor like tile. That is actually the method in the Pompei book. I used it on my first oven, and attempted to use it on this one but am just not a fan. Problem is in the heat of summer the mix dry's out so fast it is a race against the clock to set the floor before it set's up. I decided to do it the way I described on the fly and found it to work much better IMHO. Now if you use ceramic board insulation this is all a moot point.

The hearth bricks are not mortared in place. If they ever have to be removed mortar would make it much harder, and there isn't really any need for it, when the oven is complete they aren't going anywhere.

Thank you for the explanation. From the picture it looked like there was mortar on the bottom of the firebrick, which is why I asked. I am learning alot from your posts.

John

shuboyje · « **Reply #22 on:** June 06, 2011, 06:54:01 AM »

The soldier course will be installed around the deck.

What you are seeing is some of the sand/fireclay mix I used to hold the bricks in place while I roll the oven around. I'll scrape it off before the soldier goes on.

shuboyje · « **Reply #23 on:** June 25, 2011, 09:17:08 PM »

Everybody cross their fingers for me. I just casted my entry. Everything went smooth and I did it all by the book. If all is well in 24 hours when I open the mold I will post pictures and a walkthrough of the whole project. This is by far the most complicated part of the entire oven, but the entry always is and this design will make the rest of the build go very easy.

shuboyje · « **Reply #24 on:** June 26, 2011, 10:01:52 PM »

I opened the form a little bit ago after 24 hours. I am on cloud 9 over the results. Once I grind and sand the edges a bit tomorrow it is gonna be perfect except for the small defect shown in the last picture. That was the one area I was concerned about with my form design, and it should be an easy fix. I have half a bag of refractory left that I will mix into a slurry and fill it with. Tomorrow I will follow up with the walkthrough of everything I've done to get to this point.

Ev · « **Reply #25 on:** June 26, 2011, 10:07:28 PM »

That's a beautiful thing.

What kind or brand of castable is this?

Jackie Tran · « **Reply #26 on:** June 26, 2011, 10:18:29 PM »

Very impressive sheboyje! Thanks for showing us how it is done.

shuboyje · « **Reply #27 on:** June 26, 2011, 10:23:50 PM »

It is KS-4V Plus Vibration cast with 430 grade stainless needles as reenforcement. I'll get into all the nitty gritty details tomorrow. I plan to document this whole process much better then I was able to find.

Ev · « **Reply #28 on:** June 27, 2011, 12:01:32 PM »

Thanks. I was wondering because I have to cast a manifold for the Duratech chimney I ordered. I found the same stuff(KS-4) in Baltimore, about a 2 hour drive from here. I'm driving there tomorrow for a couple bags. $32.00 per 50# bag.

Ev · « **Reply #29 on:** June 27, 2011, 05:33:20 PM »

Does the KS-4 contain aggregate, or is it just cement? I was thinking of using some for another project where aggregate would not work well.

shuboyje · « **Reply #30 on:** June 27, 2011, 08:35:51 PM »

Funny you ask, about an hour ago I patched the defect in the bottom center. I was advised by David S over at fornobravo (who has casted a lot been a great help) to sift out the aggregate and make a paste. There are a couple of different aggregates in there, but what really caught me off guard was a small amount of ceramic fiber of some sort.

Ev · « **Reply #31 on:** June 27, 2011, 08:55:11 PM »

That's interesting. Ceramic fiber. I wonder if that's what gives the refractory characteristic.

shuboyje · « **Reply #32 on:** June 27, 2011, 09:17:29 PM »

Ok, here is the castable walkthrough I promised minus any pictures. If anyone would like a picture of something specific ask and I will post it. Something came up and I ended up short on time tonight.

I started out by finding a suitable dense castable refractory that I could source locally. After a few phone calls it became clear in my area my only real choice for small quantity cash and carry was Harbison Walker. You can find your local brach here:

http://www.hwr.com/

To be honest I found their staff to be of little help, but luckily I did my research and seemed to know their products better then they did. What you are looking for is a Dense Castable, Dense being the key word because there are also insulating castables which are not as strong. All of their products have a duty rating of at least 2550F so my advice is to got for the cheapest one they have since it is vast overkill anyway. In my case they have KS-4V plus in stock for $28.50/55lbs. It is good to 2600F and has a yield of 125 lbs. per cubic foot. For my casting I needed about a bag and a half, so I bought two. I have the full data sheet on this product if anyone is interested.

Harbison Walker was unable to tell me if I needed reenforcement for my purpose, but they did tell me it can be used with this product. I decided that it would give me piece of mind to have it in there being this is a structural piece that will have the lateral load of the low dome on it. My local branch did not stock stainless needled, and instead needed to special order them from chicago. That sounded like a bit of a hassle to me so I went a different route.

High Temp Inc. sells Stainless needles for refractory reenforcement on ebay in 10# quantities here:

http://cgi.ebay.com/Refractory-Reinforcing-1-Stainless-Steel-Needles-10-/130337734449?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D2%26po%3DLVI%26ps%3D63%26clkid%3D953544977152901738#ht_500wt_1156

In their ad they mention they will sell any quantity, and to call 1-800-325-2492. I called on lunch last thursday and ordered 2 pounds. They are in Oregon, I am in Michigan. Saturday they showed up in my mail in a flat rate box all for about $10 shipped. I can not speak highly enough about these guys! They suggest 3%-5% by weight and I fell in the middle of that range.

At this point it is time for a form to cast into. MY casting was fairly complex and being a sheetmetal worker, I built it from annodized aluminum. Obviously use materials and methods here that suit your skills and tools. The key part is to make a form that can be opened wide for removal. My form have 8 parts that could all be seperated and worked out nicely.

The KS-4V plus I used can be rammed into place or vibration cast. There are different amounts of water mixed for each. Vibration was highly advised by everyone I talked to, and I decided to build a small vibration table to achieve that. I basically followed the design in this video:

<a href="http://www.youtube.com/watch?v=GWImU7CCU8g" target="_blank" class="aeva_link bbc_link new_win">http://www.youtube.com/watch?v=GWImU7CCU8g</a>

The only place I deviated was by not buying a pre-made vibrating motor and instead making my own from an old motor in my stock pile. To make the motor vibrate I simply installed an old pulley on it and used a metabo to cut away at one side of the pulley until I was happy with the vibration. I ended up cutting about half of it off.

Finally it was time to cast. I put the form on the vibration table and actually screwed it down to it for better results. I then lined the form with vegetable oil as a release agent. My form was pretty nonstick, if yours is not I was told motor oil and kerosene 50/50 is an great release agent. I then hand mixed the refractory and the needles dry with gloves on. Once I had a good mix I used a scale to measure out the water out to the amount the data sheet calls for and mixed it in. I then quickly shoveled the mix into the mold stopping every now and then to vibrate and ending it all with a fairly long vibration. The specs say to be careful not to overdo the vibration to the point of segregation so I was very cautious. I again followed the specs and waited 24 hours for a "hard set" to open the form, although I had a hard set after about 18 hours according to their test which was to strike it with a metal rod and listen for a distinct ring.

I think that about covers it for now.

shuboyje · « **Reply #33 on:** July 06, 2011, 09:19:11 PM »

Finally another update! After getting off schedule due to some events unrelated to the oven I put in a few long nights to get caught up. As you can see the first part of the soldier is completed. 44 Bricks in all. They were installed using home made mortar of 3 parts sand(finest I could find #53 silica), 1 part portland, 1 part lime, and 1 part fire clay.

wheelman · « **Reply #34 on:** July 06, 2011, 10:33:56 PM »

great work jeff. thanks for posting.
bill

ponzu · « **Reply #35 on:** July 06, 2011, 10:42:47 PM »

Quote from: shuboyje on July 06, 2011, 09:19:11 PM

Finally another update! After getting off schedule due to some events unrelated to the oven I put in a few long nights to get caught up. As you can see the first part of the soldier is completed. 44 Bricks in all. They were installed using home made mortar of 3 parts sand(finest I could find #53 silica), 1 part portland, 1 part lime, and 1 part fire clay.

You have mad skills. your oven is going to be beautiful. I'd love to hire you to build mine. Please keep on posting.

AZ

shuboyje · « **Reply #36 on:** August 12, 2011, 11:02:39 PM »

I finally have some updates. Sorry for the poor pics, the came of my iPhone.

Long story short I'm way behind schedule due to a bunch of issues again unrelated to the oven, but I've put a couple nights in this week and am getting back on track. The pictures show the oven with the soldier course completed and the sand form for the dome in place. Tonight I actually installed the first two chains of brick in the dome and hope to have the dome nearing completion by the end of the weekend.

I want to comment a bit on my choice to use a sand form, which seems to have fallen out of favor in the internet age, and I'm not really sure why, especially for a low dome oven. I went back and forth on using a sand form vs. using something I designed similar to the "indispensable tool" modified for a low dome oven. I even built my design and tried it out. It worked well but the final decision was based on structural integrity more then anything else. With a low dome oven you have all the weight of the dome pushing outward on the soldier course and this needs to be accounted for in the oven design with some sort of reenforcement. My last oven was reenforced with stainless cable. Upon demolition I found they did not hold up to the heat of the oven so it was back to the drawing board. This oven will be surrounded by perlcrete and the I plan to make a outer shell of water proofed laminated ferrocement. The force of the dome will be transfered to the ferrocement via the insulation. The problem with all of this is there is no reenforcement and hence no structural integrity until the oven is nearly complete and enclosed. This is a big heavy oven with a low aggressive dome. I just didn't feel comfortable with that. By using a sand form, the form will hold the weight of the dome until it is removed. I will simply leave the form in the oven until the ferrocement and insulation are installed eliminating the problem.

After using the sand form tonight to install the first two courses of brick I can't believe I built an oven without one. It's fast, absolutely precise, just a dream really. I laid over 50 bricks in 2 hours. For an novice mason building only his second dome I'd say that's pretty darn good.

BrickStoneOven · « **Reply #37 on:** August 12, 2011, 11:58:26 PM »

That looks awesome. I was wondering if you could go into detail on how you actually did the sand form. It looks like you have the sand suspended somehow but I can' really tell. Before I got my oven I really wanted to build an oven exactly the way you are doing it. After looking at other peoples builds(only 1 or 2 that are a "real" low dome) I know I couldn't have built one myself.

shuboyje · « **Reply #38 on:** August 13, 2011, 12:50:36 AM »

The sand form was pretty simple. My oven is 42" and the door is 18" so I cut some 14" wide strips of plywood(42/3). Everything has to come out the door at the end, so this is pretty important. I then nailed them together with some scrap drilled a center hole and used a router with a giant home made circle cutter to cut a 42" circle. The three piece circle was then propped up on some old bricks cut to height so it was just bellow the point where the dome intercepts the soldier course. I then covered the plywood in plastic sheeting to protect it from the moisture in the sand. I mixed the sand with water to a consistency where it would form a ball in my hand. I then cut a piece of sheet metal to the profile I determined for the dome in my cad drawing and mounted it to a piece of half inch rod. A couple of nuts and washers fastened the rod to center hole I had drilled. Now the fun part, shoveling the sand up to the plywood. Once that was done I simply used the profile to form the sand. Once I had it where I wanted it I removed the rod and profile, filled the hole in the center with sand and used a trowel to smooth it out. It may sound like a lot but it was really simple, just took a bit of patience with the profile to get a nice smooth sphere section.

Jet_deck · « **Reply #39 on:** August 13, 2011, 01:04:18 AM »

The Caputo dough will be begging for mercy in that low domed hellish inferno. More pictures as you get time.