K79 Oven Build

[UtahBeehiver]

Re: K79 Oven Build

I just went back to post 248 on your thread and the links works on this end. Go to GianniFocaccia's OctoForno thread post #73 if you can't get the link to work. It show a tapered arch off of vertical inner arch walls, just like yours.

[K79]

Re: K79 Oven Build

Ok I got it. So if I understand this correctly in post #215 of my thread it shows my IT. Its the Hendo Guage. Am I correct in saying that the angle of my hendo would be the correct upper and lower angle of my arch brick?

[K79]

Re: K79 Oven Build

I'm trying to figure this out on my PC. Below is a picture of my work. If I cut the purple brick as shown (that would be my keystone) you can see the yellowish/white brick (the ring brick that would intersect it) would fit nicely over the top (I'ld have to shave off about 1/4"). If I follow that angle around the arch with my Hendo that should work right? I'm worried that I'll have my ring bricks up in the air over the top of my march and have nothing to rest on? The top of my arch brick would only be 1" across... is that ok?

[UtahBeehiver]

Re: K79 Oven Build

K,

Here are couple pics. The first is the general shape of the tapered brick, they will vary slightly as the bricks move off the center of the arch. The second shows the pencil on the IT at the outer side of the dome and the inner side would be what ever thickness your dome wall is, assuming 1/2 brick or 4.5". The angle of between these two points is the same angle as the rod on the IT, I know mine show more but I move the pencil up to show clarity when I took the pic. The bottom angle of the brick on pic one is the internal arc of the dome set by the IT. Hope this makes sense.

[UtahBeehiver]

Re: K79 Oven Build

Are you basing these calcs of 1/2 bricks for your inner tapered arch? Your will need more depth then a 1/2 brick gives you, probably full bricks as a base line. I think mine ended up being about 7.5 inches deep but it also varies again based on where the brick sits in the arch. The worst case scenario will the the top dead center.

[K79]

Re: K79 Oven Build

K,

Here are couple pics. The first is the general shape of the tapered brick, they will vary slightly as the bricks move off the center of the arch. The second shows the pencil on the IT at the outer side of the dome and the inner side would be what ever thickness your dome wall is, assuming 1/2 brick or 4.5". The angle of between these two points is the same angle as the rod on the IT, I know mine show more but I move the pencil up to show clarity when I took the pic. The bottom angle of the brick on pic one is the internal arc of the dome set by the IT. Hope this makes sense.

I'm confused what you mean by the pencil on the IT at the outer side of the dome? My dome wall is 4.5". As I get lower on my arch the bricks get a bit longer right? Only the front 3" of the brick will be suppored by the arch wall on each side, extending the brick into the oven by about 4" or so is ok?

I didn't have my top "keystone" arch brick at the right height before. The picture below show's what the brick would look like in the right spot. It has a lot more mass to it now. Does this look ok. I think all these angles correspond to what you mentioned Utahbeehiver. My center brick would be about 6" long. The black line coming from the bottom right of the picture is in line with my IT.



same pic with my IT:

[UtahBeehiver]

Re: K79 Oven Build

K79,

My taper arch bricks were all approximately the same length only the amount of angle(s) change so the edge protruding at the front of the tapered arch changed but not to overall length. Look at Mr. Chipster pic again and notice that the inner and outer arch angles move in all three planes, x,y,z versa the section drawing off your pc is only x and y. I know it is confusing but you are getting close to visualizing it. The same thread has some other info that may be of help, check a few pages before.

[K79]

Re: K79 Oven Build

Ok I took today off to try and figure this out haha. I need to taper my arch bricks right so that they don't loosen over time and fall out? Also how do the back of my arch bricks look? Am I missing something? I'm just worried that I'll mortar my arch in and for some reasaon my ring bricks will have some sort of issue blending into my arch.

[kbartman]

Re: K79 Oven Build

79,
Looks great to me, I think tapering is a must. I decided to lay the arch bricks in pairs, as the dome bricks meet them. In my cut to fit approach aka: Geometry for dummies, it allows me to correct my mistakes as I go. I wish I had your understanding of CAD, access and your drafting abilities. Keep up the good work!

[UtahBeehiver]

Re: K79 Oven Build

K79,

Looks like you are headed right. I guess it is up to you whether you want to taper the sides, I did, but I have seen other who have not. You do not need to build the full arch right now, just stay ahead of your course with the arch bricks. You do have a complex initial tie-in but once that is done the course should marry to your tapered arch good. You are almost there. One tip, don't build your course right up to the last brick before the arch starts, a dry fit one or two bricks back. Alot easier to adjust those brick for final fitting than the complex tie-in brick.

[K79]

Re: K79 Oven Build

Thanks so much UtahBeehiver. I never would have had this type of arch in without your help. How does it look... good hopefully Thanks for the kind words Kbartman. Your's is looking excellent! Also I cut my next ring and that will go in tomorrow...my complex bricks on the end are cut and in place

[UtahBeehiver]

Re: K79 Oven Build

Tada,

Knew you could do it. It is hard to see this initially but when the light bulb comes on..........wow. This will help you a lot with avoiding a tear drop or the dreaded droop. Remember to trust your IT not your eyeballs. Good job.

Tip - It you have a diamond cup grinder for an angle grinder it will help fine tune some of the cuts and high spots as well.

[K79]

Re: K79 Oven Build

Can someone please tell me when it is safe to take my arch support down? Should I wait until my course closes over the top of it? I want to see what the bottom of my arch looks like and clean it up.

Course 3:


Course 4 (in progress):

[boerwarrior]

Re: K79 Oven Build

K79

I removed my arch support after 3 hours so that I could clean the underside. If your mortar mix is correct (high sand ratio) it should have plenty of compressive strength after a few hours. An arch is inherently "self-supporting." Heck, if it doesn't stay up after a few hours on it's own then there is something wrong and it's better to find out now! But yours looks great and I'm sure you will have no problems!

Neil

[K79]

Re: K79 Oven Build

My thrid ring I had to taper the inside face of the brick and move in by 1/2" to fix my "lack of use" of my IT. Have I created a weak point all around my dome now? You can tell where I'm talking about by the wide ring of mortar around my dome. (It's shown two rings down from the top in post #220.