Making new firebricks

[Delta]

Hello, does anyone have any experience of making new firebricks?

I am aware of three options

Mouldable Firebrick - http://shop.vitcas.com/vitcas-mouldable-firebrick-5kg-20-p.asp
Heatproof screed, which it seems can be cast into bricks - http://shop.vitcas.com/vitcas-heatproof-screed-17-p.asp
Vermiculite boards - http://shop.vitcas.com/vermiculite-fire-board---fire-proof-insulation-72-p.asp

This is to replace the badly cracked sides, and the missing front brick of the of the fireplace pictured below.



For info, it is one of these -

The Preveril grate, made by R. Russell and Sons, Derby, and introduced in 1904, was one of a number of barless grates popular in the early twentieth century. Front bars obstructed the passage of radiant heat, so they were removed to expose more of the file to the room. The fire was also well forward of the chimney opening and is fitted with an adjustable canopy of brass.
 
Firegrates and Kitchen Ranges By David J. Eveleigh, Shire Publications, #99

Thanks

 

[CliffordPope]

Do you actually want to light fires in it regularly?

I mended our grate (and a rayburn once) using ordinary cement. Despite regular use it seems just as good as firebrick.

 

[Delta]

Yes, this is definitely a working fire.

 

[Zebra]

Why don't you buy normal firebricks and cut them down to size? You get two types now, the cement type, and the vermiculite type, which is softer, like cork. I guess you want the old fashioned cement type. If you buy some of the correct thickness (have a look on ebay, there are loads of people selling them) you could cut them down to the correct shape and size with an angle grinder, then the final touching up by hand with, I don't know what, sandpaper? I'm sure it could be done!

 

[davidbrac]

I used Vermiculite Fire Board in a working fire in our old place and the stuff cracked within five years of installing. It seems thin and not as robust as bricks.

When l lived in Wales there was an old lime kiln near to where we lived and l reclaimed some of these they worked fine for many years

 

[a twig]

I've used driveway bricks for kilns before - cheap too!

 

[eezageeza]

I used vermiculite board cut to size to replace knackered firebricks in our woodburner, and they seem to be standing up well. Much much cheaper than buying OEM replacements.

 

[Delta]

Thanks all.

My concerns with trying to get existing firebricks is firstly getting a brick large enough, but also how to shape them. The side pieces are quite tall, and ideally would be one piece, as they were originally. There is a nice sweeping curve to one side, as well as a rounded nose on the edge. Cutting a straight end would be easy, but curves are painful.

I thought "casting" may be easier, but to be honest I don't thing anything will be easy. I tried making a cardboard template and it isn't easy getting the right curve just cutting cardboard, so never mind making a mould, or trimming with a grinder.

Can you sand the vermiculite board to shape it, or would it tear out in small chunks?

 

[Zebra]

I don't think you could sand vermiculte as such, but I'm sure there'd be some way of shaping it effectively. Can't think what, but I'm sure it could be done.

 

[worms]

These guys might know the answer as there is plenty of stuff on shaping new-build ovens. Haven't built one myself but it is on the long-term wish list!

 

[Greg.Hobson]

I have used vermiculite boards in my stove and had to cut them to quite complex shapes in order for them to sit properly. This included cutting 2 boards to interlock snugly together on edge, one above the other.

I found that a dremel or similar machine with an etching or similar cutting end worked fine but took some practice - make sure you have plenty of spares. Use of a simple (but sharp) knife also worked at the larger scale.

I find that the boards become quite brittle over time and heated and cooled so I would expect them to fail quite quickly if they are subject to any load stress if not well supported. Even if supported, they will crack if subject to sudden physical shock, like a large lump of wood dropped against them. Having said that, my last efforts have been in place for the last 2 winters and are still serviceable, but I don't expect then to survive a 3rd!

 

[Penners]

I wonder whether you could carry out repairs to the existing structure with fire cement. It's very mouldable.

https://archive.org/details/101UsesForPyrumaPuttyFireCement

http://www.supremeplumb.com/cgi-bin/DMdatabase.cgi?action=/Shop/Purimachos_Products/EVERBUILD_Refractory_Cements_and_Mortars.txt&item=00007

 

[Delta]

Penners, it may be worth a try. Simples and obvious, probably why I didn't go for it, I do like to over engineer a solution. Having read that most interesting pamphlet, I can't but wonder how I've managed this long without Pyruma. My personal favourite uses are as wood filler and a nicotine filter for pipes. Still I have all he bits of the original bricks, I think!

Greg, thanks for the advice. Sounds promising that it can be shaped as you mention, albeit less of a endorsement for its durability. If anything I could go for a hybrid approach of firebrick for the flat simple rectangle which the fuel will sit on, but the vertical sides would obviously have less impact, and they are of course the difficult curved pieces.

Worms, thanks for the pointer. Whilst I didn't get too far into ovens, tempting though it sounds, one of their advertisers I noticed does very large sizes of firebricks, so Zebra's previous suggestion may now be possible. I'm not sure how easy it will be to shape, especially the curves. I have some junk pieces of firebrick, part of a previous fudge setup used to make a working fire, so I'll have a crack at shaping them first to asses feasibility.

Thanks