30"/760mm Scotland Pompeii

[UtahBeehiver]

Re: 30"/760mm Scotland Pompeii

Both Mr. C and my jig used JCG31's data for our cuts. Remember it is not 100% but gets you in the ball park. I believe DJ made an adjustment to his fancy spread sheet to calculate using the JCG31 data and process.

[jms]

Re: 30"/760mm Scotland Pompeii

Spent a bit of time today playing with some pieces of wood and imagining jigs. Still considering which is the best to go with. Anchoring whichever to the table is going to be a pain, probably g-clamps everywhere.

I also thought a bit about the process of cutting things other than the dome half-brick. For the floor blocks do most people cut them without a guide? ie using a hand only to hold it. Lengthwise tapering the arch blocks also occurred to me, I'd probably have to use a long clamp to hold it tight against the front of the tray with a wedge to bump it up for the angle.

[texman]

Re: 30"/760mm Scotland Pompeii

look at post #133 on my build thread. That explains what I came up with.
I started out trying to clamp it all and make perfect cuts, but it just isn't worth the time and effort to me and I found I could get really close using the process described. If your blade is larger than 10", you will probably be able to make the dome taper cuts in one pass, which will be very nice. The HF saws are 10" and required two passes for those.

Also, look and Amacs, DJ, Beehiver and of course Octoforno and Les threads. They all did beautiful cuts with varying methods.

[jms]

Re: 30"/760mm Scotland Pompeii

This afternoon was reasonably productive. I bought a jigsaw and used it to cut the floor template. Then I decided on, and put together a chipster jig, when the digital protractor I've ordered comes tomorrow I'll be able to set it up with the soldier angle. Finished today by making up a template and cutting the CaSil for the floor.

The weather for the next two weeks looks to be dry, so all being well I'm going to start on the floor tomorrow. I've put up a cheapo DIY store gazebo for any surprises.

look at post #133 on my build thread. That explains what I came up with.
I started out trying to clamp it all and make perfect cuts, but it just isn't worth the time and effort to me and I found I could get really close using the process described. If your blade is larger than 10", you will probably be able to make the dome taper cuts in one pass, which will be very nice. The HF saws are 10" and required two passes for those.

Also, look and Amacs, DJ, Beehiver and of course Octoforno and Les threads. They all did beautiful cuts with varying methods.

The saw is 14", so I'm glad that it will be fairly simple. I think I'll clamp the first few cuts until I know how the saw behaves.

[jms]

Re: 30"/760mm Scotland Pompeii

I got the floor done today as planned. As a complete novice I'm pleased with the result. Took around an hour to cut the lot, and I was going very slowly.

The saw worked like a charm. It really didn't take much downward pressure to cut through the bricks. The cutting arm is misaligned by nearly 1 degree, but its nothing I can't compensate for with the jig. I'm going to try out my other blade tomorrow, its segmented and supposed to be for abrasive materials, I'll see if it has any benefit over the cheapo continuous-rim diamond wet cutting blade attached now.

I'm glad I wore old clothes to do the cutting, the water spray seemed to be aimed directly at my waist , and everything around got covered in a fine fireclay mist. My hair was fused together, so I'm definitely wearing a hat tomorrow.


The floor bricks are fairly uniform, but I'll still do the fireclay/sand mix layer on top of the CaSil. Is there any trick to getting an even layer? Then I assume I just tap down the blocks which are slightly too thick?

I also want to clarify; soldiers sit directly on the CaSil, no mortar?

[mrchipster]

Re: 30"/760mm Scotland Pompeii

Spent a bit of time today playing with some pieces of wood and imagining jigs. Still considering which is the best to go with. Anchoring whichever to the table is going to be a pain, probably g-clamps everywhere.

I also thought a bit about the process of cutting things other than the dome half-brick. For the floor blocks do most people cut them without a guide? ie using a hand only to hold it. Lengthwise tapering the arch blocks also occurred to me, I'd probably have to use a long clamp to hold it tight against the front of the tray with a wedge to bump it up for the angle.

I am sure you could use something like the bolt in the photo in the saw groove to hold your jig to the table

[texman]

Re: 30"/760mm Scotland Pompeii

Floor looks good! Glad you are cutting brick. And yes it is very messy. Even a wet saw is a mess but much better than dry cutting for the lungs.

I prefer the continuous rim to cut wet-much more control i thought.

Yes, you want the fireclay sand to set bricks on the calsil. Not much-just enough to level to the highest spot in the Calsil and give the bricks a flat bed. You can rip screed boards and set on each side of calsil to get it perfect, but i just spread the fireclay and used a 4' level to screed and kept screeding and adding fireclay until it was level and no insulating board was exposed. use a rubber mallet to level any offenders after setting. (gently)

Texman

[Bookemdanno]

Re: 30"/760mm Scotland Pompeii

You could get yourself a 10mm notched trowel and lay the floor bricks like tiles.
Get your mix all nice and fluffy, like cake mix, dampen everything off and spread out the mix. Drop all the bricks into place and the notched bed of mortar allows for plenty of movement to level everything off.

[boerwarrior]

Re: 30"/760mm Scotland Pompeii

What worked for me was NO sand or fireclay between the floor bricks and the CalSil. After reading that some people had trouble getting flat floors, I was planning on laying the bricks first and then trying to do some leveling afterwards. But I discovered after I laid my floor bricks on the CalSil that I was almost dead flat - so I decided not to mess with it! And several months and many pizza's later the floor is still flat and the ash has locked things together nicely

[jms]

Re: 30"/760mm Scotland Pompeii

Today I cut and dry stacked the soldiers, which fit together pretty well. Chipster's jig design worked great. In all it took around 2 hrs of cutting. I also placed the Casil on the plinth.

I was planning to set the floor and mortar the soldiers into place today too, but while I was taking a break the skies opened and the floor got soaked before I could cover it. I know it would probably have been fine, but I think I'll wait until they're not dripping wet to play around with levelling them on the casil.

I've also ordered some stainless steel tubing, ceramic rope, and thermal caulk to do the thermal break.

[UtahBeehiver]

Re: 30"/760mm Scotland Pompeii

JMS,

As you mortar your bricks, use any surplus mortar and render the side of the CaSi board, this will protect it from getting damaged as you build your dome.

[mrchipster]

Re: 30"/760mm Scotland Pompeii

Looks to be a fantastic start, glad the jig worked for you. I am surprised that it has gotten the name "Chipster's jig" aw shucks....

[jms]

Re: 30"/760mm Scotland Pompeii

Once again the weather was wet and miserable for most of the day, but it dried up enough to do some work after dinner.

I dry laid the floor onto the Casil and found it to be nearly perfect without any fireclay/sand mix levelling. Only two blocks are a tiny bit out above the rest, and I didn't think it would be worth the time levelling the whole floor to bring it into level with only two of them. I don't think a peel would have any problems with the seams as it is, but I might still take a quick pass with an angle grinder to the ones which stick out to make it perfect.

I did make a mistake though, in my haste to get the first soldier course mortared while there was still light I completely forgot that I had to rotate the floor by a couple of degrees to make it straight at the front It should be interesting to try to fix. Although I left a big enough gap between the floor and soldiers that I think it should be doable without ruining my mortaring.

The mortaring was interesting. I've never really mortared anything before so I watched a couple of youtube videos beforehand. I'm using a premix fire cement mortar at the moment, I have two 25kg buckets. Its quite wet and sticky.

I followed utahbeehiver's advice to use excess mortar to protect the Casil. I got about half of it covered with the stuff I had left over.

[mrchipster]

Re: 30"/760mm Scotland Pompeii

Looks like a great start now it's time to go vertical....

[UtahBeehiver]

Re: 30"/760mm Scotland Pompeii

I think most of us have experience mortar creep. What dry fits really well get adjusted by the mortar joints. Just make your adjustments towards the front half of the dome. You really on see the back half as you look in a completed dome. Do your best work and bond on the back half of the dome.