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Ralph G
17-06-2015, 12:12 PM
Maybe you want to melt a bit more metal and your torch is not up to it? In this case a small kiln can help because it confines the heat better than melting in an open dish.

The easiest way to make one cheap i have found is just using a block of Ytong (aerated cement) . It has good insulation and is easy to work with rasps ,saws drills etc.
Take one block , saw it into 3 equal parts (Top, chamber, bottom). In the chamber part I cut a central larger hole for the crucible and from the side a smaller hole for your torch, this should be tangential to the crucible chamber. torch hole should be app. head size of your torch, if larger too much additional air is drawn into the chamber "diluting" the flame. What goes in must come out so drill a at least equally large hole (torch size) into the top. The bottom leave as it is. Thats all. Stack them and you are ready to melt.

A block of ytong costs about 1,80€/pc here so its not a big investment. Downside is that the so made kiln will not be a permanent affair. Its good for 5-10 melts then the ytong begins to crack. With a large enough burner (I use a homemade, blown propane burner ,3/4", from plumbing parts) I can also get it to glaze over and slowly beginning to melt if I go full throttle...It starts to melt at somewhere between 1100° and 1200°C. The one shown here is near the end of its lifespan and you can see there is some damage to it. If you melt silver in it it will last longer because of lower MP - I used this one mainly to alloy some shibuichi and varius bronzes and melting the copper first does take a bit more temp.

If you want a more permanent affair and melt on a regular basis use some soft insulating Friebricks. I have switched to firebricks (rated 1350°C) now and no damage, they take copper melting temps quite fine.

If you only have a teeny tiny refillable butane torch this will not do you any good - but regular sized ones like the kinds sold in the local"home depot" have worked fine with this. Failing to melt is most often not that your torch does not get hot enough but that the heat just dissipates to fast. Well, a certain amounts of BTUs must be present , same as you cannot cook on a flame of a single candle while 20 combined candles may do the trick.

Pros:
-cheap
-easy to make
-works well

cons:
-can only be used a limited number of times (but at the cost and effort involved not a biggie)

So if your Torch is just not strong enough, this lil contraption could give you the "Bump" in temperature without having to buy a stronger torch. Just wanted to share the idea, maybe its usefull for someone.

Regards
Ralph

trialuser
17-06-2015, 02:03 PM
I'm just off down the ytong shop now :-)
Actually, I'm hoping ytong is just lightweight celcon / thermalite type blocks.
A handy tip I hadn't thought of trying, thanks.

ps_bond
17-06-2015, 02:04 PM
Thermalite works well, but preferably not the stuff that's been left out in the rain...

theresa
19-06-2015, 03:49 PM
Very useful information, thanks. Will save for a future date.

vernon
03-09-2015, 09:52 AM
I posted a while ago, maybe two years, how to make a coffee can kiln. They call them that in USA! it will easily melt silver which I melted in two sided home made carbon moulds.