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Posted to rec.crafts.metalworking
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Made some chips today.
On 2010-07-26, Ade wrote:
lid did gone and wrote:
On 2010-07-26, Ignoramus2966 wrote:
On 2010-07-26, Ade wrote:
lid did gone and wrote:
On 2010-07-25, Ade wrote:
lid did gone and wrote:
Abused some machinable wax,
Machinable wax is great stuff, isn't it? Did you buy it, or make it
yourself?
I bought it, but after that I read on how to make it. I bought a slab
of wax and stearine at a crafts store.
I didn't put any stearine in mine - just plain paraffin wax and freezer
bags from the local supermarket.
How much polyethylene you used per lb of wax?
The ratio is approximately 1:4 by weight, so 1lb of LDPE to 4lb wax, but
don't worry too much about it. If you find you cant' dissolve the full
amount, just reduce the LDPE quantity as required.
OK.
Got it.
And, I forgot to ask, what temperature?
Between about 150-180C (300-350F approx) is ideal, don't go above 200C
(400F) as you start getting towards the flashpoint of the wax. A jam
thermomemter works fine; or just use a deep fat fryer, which shouldn't
go above 200C anyway.
The Presto Kitchen Kettle has a dial that I can set to specify the
desired temperature. It is also VERY fast to heat wax to temp.
Great fun, in a watch-you-dont-burn-
yourself-or-set-the-shop-on-fire sort of way. I poured a 24x14.5x3.5
inch slab, out of which I carved a prototype dry sump for a BMW V8;
I learned a lot of machining thanks to the wax, & will definitely
use it again.
I bought a "Presto Kitchen Kettle" and an aluminum loaf pan at
KMart. This combo works pretty well. I will cast a few wax "loaves" to
be machined.
Looks ideal. The main thing is to pour an entire cast in one go. When I
made my slab I couldn't heat enough wax up in one shot, so I had to pour
it over 3 "sessions". The wax takes forever to re-melt, so the gap
between pours was quite significant; and I got quite a few fractures in
the wax between pours (where the new pour shrank away from the old).
Even so, it still hung together through a weeks worth of milling (& is
still in one piece now, several months later)...
Just buy that Presto kitchen kettle at your local KMart. It is awesome.
Actually the next project is to make molds for wax pieces that
we'll
cast for the kids railroad.
Sounds great - casting followed by machining? One thing I found about
the wax, it shrinks _a lot_, you'll need to make your casts about 10%
oversize.
We will experiment. I do want to write the scripts for making the
molds scalable. This is because we have N scale and HO scale
railroads. So adding extra size should not be difficult.
Sounds cool. I must get myself some CNC....
you will enjoy
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