advice needed on time needed to build oven dome

[builder brad]

maybe I should spend less time thinking about it and get on with it!

[christo]

Don't rush it - it's all fun!!!

Christo

[builder brad]

Ok Guys,

I have placed the first 2 1/2 courses, with the first course of half bricks standing on their smallest face, before starting the dome proper.

I decided to use the Refractory mortar (Superplastic)that was supplied by Yorkshire Refractories to create the wedge shaped fillets and not bother to taper the bricks until I get onto the higher courses where the angle is more obvious. The mortar was so easy to work with I was planning to build the whole dome like this.

I have only done 2 1/2 courses as I have now used the 25kg of Superplastic Mortar, and in the process of trying to order some more hapened to talk to one of the techs at the manufacturer - Robert Lickley is the co. based in the Midlands. The advice I was given is that this product, like most of the other refractory mortars, is not designed to fill gaps and is less than ideal when used to create those fillets between the bricks. I did ask about this when I ordered it from the supplier and was told that this is the only product availible. The techs recomendation is to taper all of the bricks!

I am not concerned about the courses I have laid so far as the mortar is really only contributing to the dome at this low level. I will not go any higher without tapering at least the horizontal joints and possibly the verticals a la Les, although I do have another question.

I just tried to cut one of the bricks with my angle grinder which has a stone cutting disc and spent ages trying to finish the cut. No problems with the angles ect, and I can use the off-cut fillet in the next course. Is the diamond cutting blade with the water feed and bath considerably quicker? if its not I am going to spend the next month of Sundays finishing this project!

Brad

[dmun]

Whoa! Make a cut-every-brick oven with an angle grinder? No way!

To answer your question, yes, a ten inch diamond wet saw is much more powerful, and faster, but it's still a lot of work to cut every angle.

Your refractory mortar will be fine in the thicker sections. If you are worried about it, just use it for the inside of the joints, holding the outside gaps in place with temporary wedges, and when you are done, cover the whole oven with the cheap homebrew stuff (fireclay+sand+portland).

[builder brad]

"To answer your question, yes, a ten inch diamond wet saw is much more powerful, and faster, but it's still a lot of work to cut every angle."

thank- heavens for that! a lot of work does not bother me, its a lot of effort and slow progress that does my head in. on a really positive note I really like the fact that those bricks are consistent all the way through, and that the cut faces look the same as the finished surface. I think I am going to flare the entrance to my oven because of this.

I cannot get fireclay easily here in the UK, although Ball Clay seems a good alternative.

Brad

[builder brad]

dont know why I mentioned the ball clay thing, I typed what I was thinking I suppose.

Brad

[aureole]

Brad:

I've also ordered from Midlands refractories: they had (some) fireclay, but I think they've run out now - I think Travis Perkins can also supply it.

What I hope to be working with is a mix of the superplastic (on the fine angles of the joints) and then packing the larger parts of the joints with a refractory concrete from Midlands refractories. It's actually a very fine aggregate, so from my limited knowledge, I think it'll be very similar to mortar (or the sort of wide mortar you'd use to span gaps). With the semi-spherical dome, I think this (should) be fine.

[krosskraft]

Why don't you buy the type of saw you need, build your oven, post all your lovely pictures all over the UK, invite people to sample your goods to get them interested, and them rent them the saw as they build their's. Ba da bing ba da bang!

[aureole]

Brad: I'm currently setting my dome, on the first course, but it looks like I've got too many bags of fireclay anyway. If you still need some, I'm pretty sure I can be parted from one!

The superplastic was junk, useful for setting the base bricks but little else. Otherwise: I had some pencrete (from Penn refractory) that didn't adhere too good to the bricks- the guy recommended adding ball clay to the mix to improve adhesion (they actually sell a mix exactly like that for that reason). If you're on the south coast, it's ball clay city down there!