Starting new 36" build

[Amac]

Re: Starting new 36" build

Looks brilliant Dennis - I looked in vain to see had you made any of the building mistakes I made.
- you have staggered the vertical joints
- it looks like you didn't allow the brick which joins to the arch to dip ever so slightly.
- no inverted Vs - only other dome builders will appreciate the work that goes in to minimise those. I saw even "Brickie from Oz" was hard to convince that they were a problem ( at that time he had built just vaulted ovens)

I found the homebrew sometimes really sticky and sometimes not so. I don't think it is so much the wetness but rather maybe use a little more than 1 of the fireclay - as Gianni suggested.
I also found that when I used some brick dust which I scraped up from my "workbench" and a "tray" which I put underneath - that it wasn't as sticky as the coarser clay which I bought. Not sure what advantage superfine sand would give - my sand is just labelled "builders sand".

Looks like the arch and dome are tying together nicely. I found that the IT was useful during the arch building as it gave reassurance that the dome would not drift off unexpectedly. It was worth giving it some attention in advance.
Well done
Aidan

[deejayoh]

Re: Starting new 36" build

Looks brilliant Dennis - I looked in vain to see had you made any of the building mistakes I made.
- you have staggered the vertical joints
- it looks like you didn't allow the brick which joins to the arch to dip ever so slightly.
- no inverted Vs - only other dome builders will appreciate the work that goes in to minimise those. I saw even "Brickie from Oz" was hard to convince that they were a problem ( at that time he had built just vaulted ovens)

Update - I'm about halfway through my 8th chain of bricks.

Aidan -

It seems that on the next chain after taking this pic, I endeavored to make as many of these mistakes as I could!

- On the joint spacing, I used a half brick in the middle of my 6th chain, and now that is screwing up the spacing in the 7th and 8th. I guess one learns quickly how any changes to the pattern are compounded in the next chain(s) as you move forward! I am trying to decide if I should just take the pain and allow some joints to line up in the 8th chain (and have even spacing) or keep trying to cut around the different sized bricks.

- I lost the curve on the brick that attached to the right side of the arch on the seventh chain. I had to go back and add a shim on top of it to get the level and radius where it should be.


- at least the "V"s are still working out. So that is good


The good thing that I have realized is that I don't need to angle the bottoms of the bricks any longer. On the 6th and 7th chains, I had cut 1/4 inch angle to the bottom of the brick to get the radius of the dome right. But I mocked up the dome to the top and realized from the 8th on, I can use full height bricks and get the correct radius by tilting each brick up about a quarter inch in the back. That should help me close this thing in faster. One less cut, and a quarter inch more brick in each chain. I think I have 5 more chains + the plug to go

[Amac]

Re: Starting new 36" build

I used a half brick in the middle of my 6th chain

You are bing much more precise than I was. It wasn't until the top 3 or 4 rows that I got the side angles and bevels figured more or less right. I ended up turning bricks inside out (wider on the inside than the outside) on a couple of occasions just to recover mistakes.

You should check out Laku's system for cutting 2 indentical bricks from one for the last few rows. The cuts are straight and include angles and bevels in 3 single cuts and just small ends wasted.
http://www.fornobravo.com/forum/28/m...tml#post102532
The same system can get you 3 bricks from 4 cuts.. Unless my memory is tricking me I think I did that for the last two full rows.
Maybe it works better (for a change) with the angle grinder since jcg31 had trouble with it on the HF saw.
Also on aligning the joints - now that I see the hairline cracks I can see one or two that have descended on those joints - but also on others, and on one almost complete circular horizontal joint. I have mixed feelings on them - on the one hand I prefer that the joints are not so strong that the brick splits. On the other I would prefer to see none - but is that possible at all?

Gulf had a good system for preventing the droop of the bricks joining the arch. He used a laser level set up at the back. It's hard to see with the naked eye because when you stand back and look at any row it seems to wave up and down even though it is perfectly level.

In the end it just meant I had a slightly egg shaped plug rather than circular.

Does that block on the form board slide up? If so good idea. One drawback of the IT is it doesn't keep the height consistent along the row - and a level is needed at least now and then. I tried to think of some attachment but gave up on it. Some hybrid IT and formboard would solve it.

Keep it up - nearly there - it looks brilliant.
I recommend Sharkeys vent (btw also used by Aceves) when you get there, although I spent a while after finishing the dome before I could work myself up to any more building. It seems to work very well even though I made the opening a bit narrow.. front to back

[deejayoh]

Re: Starting new 36" build

Does that block on the form board slide up? If so good idea. One drawback of the IT is it doesn't keep the height consistent along the row - and a level is needed at least now and then. I tried to think of some attachment but gave up on it. Some hybrid IT and formboard would solve it.

Thanks for the comments and reassurance

to your question, yes - the block slides up. Well, actually I slide it up and screw it to the board for each chain. But it does work to keep things level and at the same angle. I had to go this way because my dome doesn't have a constant radius - but now that I have it set up, I think it works pretty well. I don't know that I would have wanted to use an IT for each brick. Too much jiggling and scraping of mortar going on. I set each one, and then swing the form by to check the angle and position. Works pretty well.

I'll try to post a close up picture later.

[texman]

Re: Starting new 36" build

Great job Dennis!
I am starting row 4.

Tracy

[deejayoh]

Re: Starting new 36" build

Great job Dennis!
I am starting row 4.

Tracy

Thanks Tracy. I've been watching your build. Looking good. I love the covered location. Call me jealous! You may pass me if I don't get on this weekend (not that it's a race)

I got a Living Social deal on a two-hour intro to metalworking class in my email today. A little bit of welding knowledge should come in handy for building the door. Plus I've always wanted to know how to weld.

[deejayoh]

Re: Starting new 36" build

Hey all you smart builders. I need some advice here. I got about 60% of my 9th chain in last night, and when I finished - I realized that I had gotten off level a bit. If you look at the picture, you can see that the left side is lower than the right if you compare the outer edges. I think that the difference is about 3/8-1/2". I think I started dropping the angle of the bricks at the left edge of the arch, and continued around for about 5 or 6 bricks.

I'm thinking about knocking out those bricks and re-laying them tonight, getting it leveled up. Does it make sense to do that, or can I just make it up in the next level?

I am worried that the error is just going to compound as I get closer to closing up the dome.

Appreciate any advice.

Dennis

[Amac]

Re: Starting new 36" build

If you look at the picture, you can see that the left side is lower than the right if you compare the outer edges. I think that the difference is about 3/8-1/2". I think I started dropping the angle of the bricks at the left edge of the arch, and continued around for about 5 or 6 bricks.

If it is just that the left is 3/8" lower than the right I would do nothing - since you are still circling in to the dome top and it really doesn't matter if that is slightly offset. I would think it is eminently correctible. I only put a level on a few times during the build. I was just trusting that the IT would keep it level, and apart from a bit of droop at the arch in general it did.

What I think I see in your dome is that the last three courses look like they are taking a cone shape rather that a dome shape - i.e they look straight and heading for a point rather than rounded and flattening out.. Maybe it's the photo but if so it would mean that you re not tilting the bricks enough. When you use an IT the clamp takes care of that tilt. Are you using shims?

[texman]

Re: Starting new 36" build

Dennis

I was off right next to arch and removed one brick on the left to correct. You are well above the arch now and IMO, i would stay the course at this point and correct from here up. I you custom cut the next course and correct here, the rest will be straight again and i dont think will weaken the dome or be visibly noticeable where you correct that high in the dome.

But, hey, i am on course 5 and redoing some of my problems i decided i cant live with because i dont want to fight them the rest of the way up the dome either and i dont want to look at every time i look in the dome. I have about 3/8" to correct from one side of dome to next. Some of that off level can be from bricks being slighty longer/or shorter than 1/2. The upper edge will fluctuate where as the lower/inner edge is the true place to check level. Mine is from not mixing mortar consistent to hold and not using the IT correctly. You gotta believe the thing. But i am on the 5th course, so i decided to correct as i go(i hope) I am not intimidated about removing bricks anymore, i just want to do it sooner than later, and get better so i dont need to. Best of luck and your build looks great.

Tracy

[texman]

Re: Starting new 36" build

amac
Once again, you have the best eyes out there. I am sure the rest is ok too.

[deejayoh]

Re: Starting new 36" build

What I think I see in your dome is that the last three courses look like they are taking a cone shape rather that a dome shape - i.e they look straight and heading for a point rather than rounded and flattening out.. Maybe it's the photo but if so it would mean that you re not tilting the bricks enough. When you use an IT the clamp takes care of that tilt. Are you using shims?

Thanks Aidan. I see what you are saying about the "Cone shape" from looking at the picture.

I think I am ok but I will take a hard look at it when I get home.

Every time I finish a chain, I mock up the arc for the rest of the dome by laying up a cut brick for each chain on top of my arch form. I keep thinking "no way this thing is going to meet in the middle!", but based on that view, it looks like I am staying on the proper curve by tilting each brick about 3/8 inch per chain.

I've been managing the height of the tilt with just the mortar - no shims. That's probably how I got off level from side to side. I can see that the mortar gap on the bricks on the right side is much larger than on the left.

I will do another mockup tonight and maybe snap a picture to show what I am seeing. I have a sunny weekend in front of me with nothing else on my list of things to do - so I am hoping to make some good progress!

Dennis

[deejayoh]

Re: Starting new 36" build

Dennis

I was off right next to arch and removed one brick on the left to correct. You are well above the arch now and IMO, i would stay the course at this point and correct from here up. I you custom cut the next course and correct here, the rest will be straight again and i dont think will weaken the dome or be visibly noticeable where you correct that high in the dome.

But, hey, i am on course 5 and redoing some of my problems i decided i cant live with because i dont want to fight them the rest of the way up the dome either and i dont want to look at every time i look in the dome. I have about 3/8" to correct from one side of dome to next. Some of that off level can be from bricks being slighty longer/or shorter than 1/2. The upper edge will fluctuate where as the lower/inner edge is the true place to check level. Mine is from not mixing mortar consistent to hold and not using the IT correctly. You gotta believe the thing. But i am on the 5th course, so i decided to correct as i go(i hope) I am not intimidated about removing bricks anymore, i just want to do it sooner than later, and get better so i dont need to. Best of luck and your build looks great.

Tracy

Thanks Tracy. Good point about the inner edge being the key. I will check that tonight. Hard to get a level in there however...

Your comment about removing bricks resonates. Funny thing is, I knocked about 8 bricks off last night and re-layed them. So the picture I showed is actually the second try! In the last two chains I have put in, I have done a TON of rework. If I was getting paid by the hour, I'd fire myself.

[texman]

Re: Starting new 36" build

Thanks Tracy. Good point about the inner edge being the key. I will check that tonight. Hard to get a level in there however...

Your comment about removing bricks resonates. Funny thing is, I knocked about 8 bricks off last night and re-layed them. So the picture I showed is actually the second try! In the last two chains I have put in, I have done a TON of rework. If I was getting paid by the hour, I'd fire myself.

yea, i would be starving to death as a bricklayer, too.
Use a framing square and measure from floor to inner edge of the top course and check the consistency of round (distance from wall) and the height from floor(level). If you have a short level (like 24") you should be able to spot check the inner edge in various places and find the lowest point and get an estimate of the error, if any. You can also cut a piece of cardboard in the correct size circle of where your inner edge is and see the error that way too. The cardboard will probably have a tilt and the center of circle can be checked to see if the it aligns with the center of the oven floor.
Still fun though, right?
Tracy

[GianniFocaccia]

Re: Starting new 36" build

My thought is to continue on building by shaving 1/8" off the top of each brick that you place on the 'high' side of your dome. After a course or two your are back to level.

When starting each new course, I leaned the first brick flush against the curve of my dome template to ensure the proper angle and that I was keeping in 'round'.
John

[deejayoh]

Re: Starting new 36" build

Well, when I got home last night - I took a level and checked the angle of my top chain - and then I checked my sketchup drawing to see where I should be at that point. Answer? I was at a 50 degree angle and I should have been at 56 degrees. Thanks to you, Aidan, for pointing out my pointy-ness. You have a really good eye for this stuff!

Then I mocked up a few bricks to see what sort of tilt I'd need to put on each chain to correct the error - and it looked pretty shabby. So I knocked out the bricks on the top chain. Most came off pretty easily since I'd only laid them in the last day or two. One of them came off with a chunk of the brick under it - so I did have to remove three of the bricks that were one chain deeper. I thought that was a disaster, and then I saw Tracy's post this afternoon. I guess I got off easily!

Anyway - I did a variant of what John suggested when I put them back in. I cut about a quarter inch wedge from the bottom of each brick (works out to a 6 degree angle), and then checked the amount of tilt I needed with a level and protractor to get it exactly right. I needed 3/8" in the back. Using this measure, the chain went back in really nicely. It did help that my girlfriend came over and cut all the bricks for me. I was much more productive!

Now I am about 60% through the next chain and I am right on target for the angle I wanted - right at 63 degrees. I'm not really even using the form anymore to check the angle any longer. It's easier for me to check the height of the grout joint on the back of each brick. That seems to be working perfectly. Things are looking much "domier"!