To taper or not to taper?

[cholme]

Re: To taper or not to taper?

This is why I like this forum group, so much great input! I am hoping my bricks come in in the next coule days, so I can start the next step. In case anyone is interested I started a thread to share my progress. I figure I've been looking at everyone's for the last 4 years, perhaps my mistakes will help someone else.

Thanks for everything

Chris

http://www.fornobravo.com/forum/f8/3...aks-16176.html

[brickie in oz]

Re: To taper or not to taper?

I figure I've been looking at everyone's for the last 4 years, perhaps my mistakes will help someone else.

After 4 years of voyeurism you shouldnt have any mistakes.....

[boylanta]

Re: To taper or not to taper?

I tapered and beveled the 2 sides, virtually eliminating mortar between sides and eliminated that inverted v . It took me a full weekend about 3-4 hrs a day during the week to get my dome up. I'd guess about 35 hrs, plus another full day on the inner and outer arches.

RT

Newbie builder question.
My first post after pouring through the forum for a few weeks...

I'm sure I'm missing something, but does anyone see anything wrong with tapering just 1 side of the brick?
For example, instead of the first course requiring (2) ~5? cuts to make a trapezoid shape, what about taking ~10? off of one side only.
I'm thinking of only tapering the side(s), and shimming the vertical.

If you look at the sketchup thumbnails I attached:
the 1st pic shows 3 different ways to do the 2nd course, while shimming the vertical gap:
-4.5"x4.5X half brick, untapered
-making (1) ~10? cut on a half brick
-making (2) ~5? cuts on a half brick

the 2nd pic shows the backside of those 3 courses. You can easily see the larger mortar gaps on the bottom, un-tapered chain.
The top 2 (tapered ) have identical grout gaps.

the 3rd pic shows the 2 cuts necessary to make 2 bricks by making (1) ~10? cut and a 90? cut.

the 4th pic shows the face of the 3 different approaches.

the 5th pic is the half soldier chain and 1st chain without any taper

Does anyone see any issues with this approach of tapering 1 side only?
I realize the higher courses will require a steeper angle than ~10? to close off the dome.
I know I'm severely over-thinking this, but I'm waiting for my ceramic fiber materials to arrive, so I'm trying to plan out the most efficient approach moving forward, and this seems like it requires far fewer cuts.

Thanks in advance and thank you to all who have contributed to this forum.
It's a truly amazing resource.

Todd B.

[Ken524]

Re: To taper or not to taper?

Hi Todd,

I don't see any problem at all with your approach.

In your 3rd pic, why are you cutting the brick twice? Seems like it would be easier to center the 10? cut to have 2 identical bricks.

Looks like you are ready to start building!

[mrchipster]

Re: To taper or not to taper?

Look at my post on cutting 2 bricks with 3 cuts or 3 bricks with 4 cuts.

http://www.fornobravo.com/forum/f28/...tml#post121305

Chip

[Amac]

Re: To taper or not to taper?

instead of the first course requiring (2) ~5? cuts to make a trapezoid shape, what about taking ~10? off of one side only.

That is what a lot of people including myself have done for the lower courses. I think 10? is about right (depends on your dome radius) but don't do what I did and make that angle a fraction too big. Err on the small side if at all. You won't want thick joints at the inside. On the outside they are fine.

I agree with Ken - why not cut the brick in two equal halves at an appropriate angle. A sub goal for all of us who used an angle grinder was to minimise the number of cuts.

I realize the higher courses will require a steeper angle than ~10? to close off the dome.

The angle from inside to outside of the dome doesn't change even at the higher courses - you will still have 10? but you will have a trapezium shape at the exposed sides of the bricks, and then you will need something like Chips idea.

[mrchipster]

Re: To taper or not to taper?

A sub goal for all of us who used an angle grinder was to minimise the number of cuts.

A table jig like this would even work for the angle grinder as it would allow you to position the bricks at an angle that could then be cut through vertically allowing for a more consistent angle. You would of course need to clamp the brick to the jig table when using an angle grinder.

Chip

[boylanta]

Re: To taper or not to taper?

Hi Todd,

I don't see any problem at all with your approach.

In your 3rd pic, why are you cutting the brick twice? Seems like it would be easier to center the 10? cut to have 2 identical bricks.

Looks like you are ready to start building!

Ken,
Correct, that was a mistake. I meant to halve the brick w/ one cut as you mentioned. Thanks for the reply.
I've spent a lot of time studying your build. Looks great.
As you can see, my sketchup mock vent arch is modeled alost exactly after yours.
Tks.

Todd B.

[boylanta]

Re: To taper or not to taper?

Look at my post on cutting 2 bricks with 3 cuts or 3 bricks with 4 cuts.

http://www.fornobravo.com/forum/f28/...tml#post121305

Chip

Chip,
That looks great.
I'll think I'll end up giving that a try.
That will accomplish the taper & bevel to further minimize the interior mortar "V".

For the bottom board, that looks like a scrap of plywood, correct?
How did you afix the bottom board to the saw table, was just the clamp sufficient?
And what size saw do you have to allow that much clearance to allow for both boards?
I'm going to get HF 10" that I think most in the forum are using.
My 7" certainly won't be sufficient.
Once you were setup, did the setup remain consistent for each chain?
Thanks.

Todd B.

[boylanta]

Re: To taper or not to taper?

Look at my post on cutting 2 bricks with 3 cuts or 3 bricks with 4 cuts.

http://www.fornobravo.com/forum/f28/...tml#post121305

Chip

Chip,
How did you lift the outside of the brick to achieve your vertical, I assume just shims & mortar?
Tks again.

Todd B.

[mrchipster]

Re: To taper or not to taper?

Chip,
That looks great.
I'll think I'll end up giving that a try.
That will accomplish the taper & bevel to further minimize the interior mortar "V".

For the bottom board, that looks like a scrap of plywood, correct?
How did you afix the bottom board to the saw table, was just the clamp sufficient?
And what size saw do you have to allow that much clearance to allow for both boards?
I'm going to get HF 10" that I think most in the forum are using.
My 7" certainly won't be sufficient.
Once you were setup, did the setup remain consistent for each chain?
Thanks.

Todd B.

The bottom board was a piece of 2X10 but you could easily use a piece of plywood. I used the 2X10 because it gave me a better clamping surface, You can see from some of the photos that there is a clamp from the sled to the board. You could just as easily bolt or screw the bottom board to the sled.

I was lucky enough to pick up a 14 inch brick saw so I had plenty of clearance as you can see from the photos.
The angle of the small top guide board stayed consistent almost to the top but the last 2 - 3 chains get very nasty and you need to go to custom cuts on them.
The bevel Angle changes on each chain. and gets steeper as you go up.
The saw head cranks up so I was able to adjust the blade up no problem.
You can do this same of similar set-up with the 10" HF saw - because the saw head adjusts up. But be aware that the open side of the HF saw is opposite of my saw so everything will be reversed. Said another way the greater clearance is available on the right side of the blade on the HF saw, My saw has greater clearance on the left of the blade.

I did cut the tops off of my bricks (angled) also I created another jig for that but I do not have any photos of that. It may be difficult to cut al the way through the top but you can cut partially through the top and save a bunch of mortar. See attachment.

The top cut angle remains consistent almost to the top also. but be careful not to tip your bricks to vertical, Keep the top of the brick aligned with (pointed at) the center of the oven floor.

BTW those little pieces that are left over will make great filler for the outside as shims/filler should you decide not to cut off the tops.

....and one last thing I used home brew and am very happy with the result it is cheap and works great.

3-1-1-1

3 very fine sand - 1 fireclay - 1 hydrated lime - 1 portland cement

Chip

[boylanta]

Re: To taper or not to taper?

BTW those little pieces that are left over will make great filler for the outside as shims/filler should you decide not to cut off the tops.

....and one last thing I used home brew and am very happy with the result it is cheap and works great.

3-1-1-1

3 very fine sand - 1 fireclay - 1 hydrated lime - 1 portland cement

Chip

Chip,
Glad to hear that about the homebrew.
I just bought all the raw materials this week to make it.

On another subject, I see you placed your first chain on top of the FB board as the forno bravo .PDF plans show. Did you find any issues w/ this?
I'm cutting the floor as you did, instead of placing the first chain on top of the floor.
Seems to me like the downward force/weight of the dome on the FB board might cause an issue?
My FB board will be here tomorrow so I haven't seen it's compression strength yet.
Would you recommend doing it the same way again, or would you cut the FB board around the floor and place your firs chain on the structural concrete layer?
My concern w/ this was bleeding heat onto the structural layer...
Thoughts?

Todd B.

[SCChris]

Re: To taper or not to taper?

I came to the same thought as chip relative to a cutting jig. see..

http://www.fornobravo.com/forum/f28/...ool-12478.html

Chip, a 14" saw would have made things easier..

Chris

[wesslock]

Re: To taper or not to taper?

When I cut my bricks i did it similar to the third pic. But I wrote a formula that would tell me the angle for each row. Its been a few years so I cant seem to find it. It took the inside cirumference and outside , found the percentage - removed some distance for the kerf cut and then would make one cut that would leave two bricks with the same size. It worked pretty well. as you get higher the percentage changes quite a bit.

EDIT - found the formula - barely makes sense - but stll works.

[boylanta]

Re: To taper or not to taper?

EDIT - found the formula - barely makes sense - but stll works.

wesslock,
I don't see the formula in the post.
Is there an attachment or something I'm missing?
Tks.

Todd B.