[modeleng] Re: Nameplate niggles

Sorry Tony! That should have said Thermit casting, as I haven't eaten 
yet, I tend to put extra eeee's in things...
Also 'waist wax' has nothing to do with your hips, (should be waste wax)
It is actually a welding process, in which you mix powdered Al +  oxide 
iron.
The mixture is put in a crucible (steel put with a clay liner and a hole 
in the bottom)
the hole in the bottom is a clay disk, with a stem sticking out of the 
bottom.
The mix is ignited by some permangante and a few drops of glycerin, a 
lid (clay) is put on the crucible.The Al reduces the iron oxide, and it 
is an exothermic reaction, that evolves 2500 °C !
After a couple of minutes, the crucible is held over the gate of the 
mold. The stem of the bottom valve is lifted, by touching the mold and 
floats to the bottom.
Very hot liquid iron runs in the mold and the casting is done.
This reaction can be done with as little or as much product that you 
want, and needs no external heat source


Tony Wells wrote:

>What is this "thermite" casting please Patrick? Whilst Tel is our foundry 
>man, and has made many name plates and such like, in his absence his 
>technique is to make a small wooden board, fit plastic letters to suit, and 
>bed this face down into a bed of damp sand. After the board (pattern) is 
>removed and the sand dried out then it is an easy matter to fill it with 
>molten lead, though he uses aluminium.
>
>I do a lot of lead casting, incidentally, as you are aware, hence my comment 
>on casting a name plate in it, but such as Chronos also sell various low 
>melting temperature (bismuth?) based alloys, for model figurines and such 
>like. Some of these alloys can be melted just with boiling water, and have 
>excellent low cooling shrinkage rates, so would seem to be ideal for any 
>personalised name plate, though as I say, they have a range and so some of 
>their other alloys have higher melting points, just in case the anme plate 
>ever gets hits with steam!
>
>Tony.
>
>
>----- Original Message ----- 
>From: "Patrick Coppens-Marian Lynch" <develop@xxxxxxxxx>
>To: <modeleng@xxxxxxxxxxxxx>
>Sent: Monday, August 20, 2007 6:25 PM
>Subject: [modeleng] Re: Nameplate niggles
>
>
>  
>
>>Did you ever consider thermite casting?
>>It is something that can be done on a very small scale, and is not so
>>difficult, nor do you need fancy equipment.
>>I have done it twice in the past, for small parts and it worked very well.
>>You can make your nameplate in wax, so you can use the 'Cire perdu'
>>method (that is posh for waist-wax)
>>and have very crisp castings, with high definition..
>>
>>Cheers
>>Patrick
>>
>>
>>R.L. Roebuck wrote:
>>
>>    
>>
>>>Hi there All,
>>>
>>>I'm after some nameplates for a Rob Roy I'm working on. I'm not after a
>>>personalised name for it, just want them to say "Rob Roy".
>>>
>>>      
>>>
>SNIP
>
>
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