What cuts and how to make them?

[miles]

If I make a pompeli over I would like to make it with cut bricks rather than making up the angles with mortar. Obviously there's nothing wrong with that method and to all intents and purposes it does the same but I just like the "rightness" of the cut ones I've seen so far.

It does that the benefit of overcoming any issues with my mortar skills too

However I am a little confused as to what cuts I would need to make on each brick, how the cuts would be measured / determined (I imagine the central support /guide will play a part!) and how they would physically be made using the chop saw etc (i.e. how to hold them with safety and precision).

Any guidance gratefully received or I may have to go back to the idea of a barrel vault as the cutting is a lot simpler but it will not fit into the corner as well

Thanks

Miles

[turkey]

HI Miles,

for the general angle of bricks the indispensable tool will get you there, then you need to angle the sides, I am not sure but I think if you had a plum line or a spirit level you would just mark the side to make it vertical and then cut backwards to the corner of the brick, that is if you want a smooth internal face.

If you want to make the bricks fit as to almost eliminate the mortar then I am really not sure as you will need to make full trapezoids for each layer. I think most folks work out the angle of each layer with the indispensable tool and then make wedges that they use for each layer to support the bricks and also ensure they use the correct angle as the build progresses.

How to support the bricks I am not sure on but I suspect mostly depends on what you use to cut them, at a simple way use and angle grinder and a workbench and a simple wood plank mould if required.

I cut the bricks in half with a mitre saw and for the angled cuts used some insulation foam cut to the angle required with a knife to hold the brick, the weight of it pretty much held it in pace with just a hand on it, and it cut pretty easily with the diamond blade. This was the exception as most bricks where just simply cut in half and its only after a good few rings that you really need to angle the bricks to make it look good.

for a uk build with loads of cuts

ukwoodfiredovenforum.proboards.com/index.cgi?board=pompeiioven&action=display&thread=4

contains a link back to our old forum , you will need to register to see images but there is a picasa image host link if you just want images which include his cutting method.

[miles]

Yes that is one of the builds which inspired this desire for shaping the bricks I can't quite work out the cutting method though from the pics

Nor can I quite work out the actual shape of the bricks. I visualise that

• the front and rear faces of the bricks are the reference faces - they don't change
  
• the horizontal angle i.e. the angle which is cut on the top and bottom faces, is constant for all bricks - as if you were building an arch a single brick wide
  
• when presented at the final angle the sides must be vertical and at right angles to the face
  
• the side cuts "start" at the rear face - i.e. I would try to intersect with the rear corner of the brick to be able to preserve the max amount of inner face
  

But the problem comes when I try and visualise what is happening on the actual sides when trying to make the cut and how to measure this out whilst making the dome. I am not going to try to work out all the cuts in a computer program as I doubt that my laying / setting out skills are a match for the accuracy assumed in the CAD package! Even assuming I could use a CAD package as I have enough issues with sketchup!

[cannyfradock]

Miles

I can't add any more than Turkey has posted as I have never cut trapazoid bricks on any of my builds......sorry, but it's sheer lazyness on my part. The link that Turkey gave to Charley's build (not just his picture diary) is full of important tips on how he achieved such a brilliant result. This is the link again woodovenukforum.forumup.co.uk/viewtopic.php?t=315&mforum=woodovenukforum

The centralised "jig"...or indispensable tool comes into it's own when calculating the cuts....and if you follow Charley's thread it shows how he calculates the cuts to the rear of the internal arch using the jig. This is always the only time where quick drying....or Fondue cement is used as this gives a quick initial "grab" to bricks laid ....and left to set before the next one is laid.

Perhaps I'll get round to building a pompeii oven using trapazoid cuts one day, but until then, I am in total awe of the few members who have shared their builds with us using an angle grinder on the bricks of the dome.

Terry

[lemonsouffle]

Hi Miles,

there is a very detailed explanation with lots of photos of how to do trapezoid cuts on this thread on the Forno Bravo forum:

www.fornobravo.com/forum/f28/twist-tilt-2802.html

We have just finished a pompeii build and Mr LS started cutting the side surfaces of the bricks to create tapered bricks, then as he got more experience he did trapezoid cuts for the higher courses of bricks. It did require a huge amount of patience, each brick was marked for cutting and then cut with an angle grinder but once he got started there was a high level of satisfaction in cutting the bricks to fit more closely. Also since we were using Kiln Linings high heat mortar we needed to keep the layer of mortar as thin as possible.

You can see pictures of our build if you follow the link to my Flickr album in my signature.

Whatever you decide to do, remember the pleasure of a beautifully constructed dome is trivial compared to seeing your first pizza or first load of bread cook

LS

[miles]

Thanks for those links - that helps a lot. It seems that my expectation that the angle between courses does indeed remain the same but I was in the process of making a massive error of thought about the angle that the saw needs to be presented to the saw!!!
Regards
Miles

[marudge]

Hi Miles

I have been having the same problem - trying to visualise the cuts I will need to make.

The attached may help.

• A spreadsheet from the FB forum - which is amazingly helpful.

See what you think.

I have also put together a diagram just to test the spreadsheet figures - and it works great. I will attach it to the next post (as I can't seem to attach 2 items to one post.

I haven't built an oven yet, so bear that in mind, still planning it.

Attachments:

[marudge]

Other attachment

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