|Tony Martyr||06/11/2009 21:50:02|
209 forum posts
I am about to start making a boiler for a 3 1/2" loco. The last time I was involved in such work was as an apprentice 40 odd years ago when there was a full size coke and gas forge available.
Lacking these facilities I need to make a suitable hearth that can live in my garage. Is there a suitable design available on the web?
Where does one buy a few refractory bricks nowadays and what material is used to pack around the work now that the UK doesn't seem to make coke anymore.
|347 forum posts|
This thread elsewhere may assist:
Check ebay for vermiculite fire bricks
I got my fire bricks here: http://www.stove-glass.com/
They gave me good, cheap, quick service.
|371 forum posts||What about this:|
|87 forum posts|
Most decent builders merchants keep fire bricks which are often refered to as 'babies' for some obscure reason. Any wood burning stove shop will have a stock of 'fire cheeks' which are shaped fire bricks for putting inside stoves at the sides to reduce the fire area. Using a combination of the two you could easilly make the hearth Niloch has found for half the price. I don't know where you live but I have a stake of fire bricks from old storage heaters behind the shed, your for the taking.
|1017 forum posts|
Chris - no, I'm afraid not.
Most firebricks absorb heat, so the ones from stoves nightstores and so on are not usually a great idea.
One needs the expensive refractory ones. Vermiculite or whatever. Or that wool stuff. anyway, you need to be sure you don't have the absorbent ones (which I do I might add, and need changing)
Of course, to some extent it depends on how much heat you have available. If you have one of those big Sievert nozzles and propane at 4 bar, you can probably fry eggs at 50 feet in the arctic.
See Tubal Cain - ME handbook
Edited By meyrick griffith-jones on 07/11/2009 12:55:53
|Michael Cox 1||07/11/2009 16:14:44|
|544 forum posts|
I always use aerated concrete blocks (thermalite or celcon). These have great insulating properties and they are very cheap and they certainly easily withstand brazing temperatues. Any builders merchant stocks them as do Wickes. A few broken pieces of block are good to pack around the parts to be heated.
|1634 forum posts|
Not at all sure of the facts about this (never built a boiler), but have you looked into using Kiln Bricks as used to manufacture Pottery Kilns?
There may be other materials that could cross over as well.
Might be worth asking Bath Potters supplies www.bathpotters.co.uk
Or try googling pottery equipment suppliers to see if there is one near you, they all seem very helpful.
Edited By V8Eng on 07/11/2009 19:30:08
|Nigel Hyde||07/11/2009 21:06:01|
|45 forum posts|
I have just finished a 3.5" tich boiler
and for the hearth i used fire brick from wilkinsons they are about 11/4 thick and about 6" x 4" ish they are really good and dont retain much heat and best of all there about £2.50 ish each !
worth looking into
they also do a cast iron grate for full size fire places at about £19
all i used was an old workmate staked with wilkinsons fire bricks
i will use this method again
hope this helps Nigel
|371 forum posts||Enquire also from these people about a kilo or two of ceramic chips but I suspect that insulation blanket would do just as well. Pursuing V8Eng's post I've seen temporary pottery kilns made largely from blanket (& an angle iron frame) at ceramist fairs.|
|Les Jones 1||08/11/2009 09:31:03|
|2234 forum posts|
Here is another possibility
They have insulating fire bricks and high temperature insulating blanket. The problem buying this sort of thing mail order is the cost of postage. I plan to use them for materials to make a small furnace for melting brass and aluminium. I will be able to collect from them as they are only about 15 miles away from me. (They are in Liverpool)
|Tony Martyr||08/11/2009 10:01:50|
209 forum posts
Thank you all for these replies from which I can formulate my preferred solution.
Nigel Hyde's mail reminded me that I have an old workmate bench in the garden shed that would provide a more stable base than a fabricated frame of smaller footprint. For nearly 5 years I was the chief engineer of a cement and lime plant (in Fiji) and was dealing with kiln refractory brick constantly but that is designed to withstand high abrasion so is too heavy.
The 'kit' posted through Niloch is a ice idea but too small for my boiler.
I have no experience of the blanket materials but this sounds easy to organize than any coke replacement.
I am a great fan of this forum and hope I can be as much help to others as I have received
713 forum posts
Not suitable for tony's purpose, or any big job, but I find the flat red stones picked up on my local beach on the Moray Firth reflect heat well, and don't crack. I'm no geologist, but I believe the material is old red sandstone. I "rescued" a rusty barbecue my neighbour was throwing out, packed a few of the stones in the bottom, and had a primitive but effective brazing hearth for nothing.
|chris stephens||08/11/2009 13:02:59|
|1049 forum posts|
I hope you dried thoroughly them first! Steam in a stone can prove troublesome.
713 forum posts
Thanks, Chris. Forgot to mention that the stones are carefully dried in a domestic oven first. However, if this stuff is sandstone, it is virtually impervious to water.
|chris stephens||08/11/2009 18:17:56|
|1049 forum posts|
It may well be a very long time since my A level Geology lectures, and memory fades like Jaguar red in the sunlight, but Sandstone is known to be porous (very),
|1634 forum posts|
If you have any friends in the jewellery trade, ask them to show you page 555 of the Cookson catalogue. (probably most other jewellers suppliers too).
You may have to wade through several web pages to see it all this way.
Some of it might be of interest for this type of work.
Niloch. Yes seen some Raku firing done this way, and the name Ian Gregory springs to mind on temporary kilns.
Edited By V8Eng on 08/11/2009 19:53:16
Edited By Katy Purvis on 19/06/2015 09:51:41
|371 forum posts|
I don't doubt that this is not the right forum for responding to your last sentence V8Eng but, yes; Tim Andrews and Ashraf Hanna to name but two more.
I think in the early days of this forum there was a thread which asked members to state whether they had any other interests, at least you and I know what one of ours is!!
Edited By Niloch on 08/11/2009 22:29:56
|Stub Mandrel||10/05/2010 21:58:11|
4311 forum posts
I have two large slabs of vermiculite, about 18" square and 1 1/4" thick. They cost about £22 from a stove manufacturer - I was going to saw them into thin sheets to make a replacement insulating panel for a storage heater, but ended up salvaging a panel from a duff heater instead. They will become my new brazing hearth in time, but I'm worried about eroding the surface. I use smaller vermiculite blocks and tiles at the moment, but I find that easyflow contaminates the surface and causes it to erode badly.
I know in the past sheets of asbestos millboard could be used for this - is there a safe modern equivalent?
|Ian S C||11/05/2010 01:30:10|
7468 forum posts
|friend uses cat litter(not the kittens),I don't know much about this stuff but it appears heat proof,maybe he'll come up with something about it. Ian S C|
1936 forum posts
Hi Ian S C,
Most cat litter is made from fullers earth (basically bentonite) but some is made from recycled paper. I hope he's careful which one he chooses .
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.