What am I all about? What am I getting up to? How am I doing it?
by, 10-08-2016 at 11:58 PM (238 Views)
I think that I am going to like being a member of this forum for a number of reasons, the main one is that the members here seem to be "down to earth" types who do not simply roast you if you ask a question that they do not like.
The second reason is this "blog" feature.
However, unlike a "normal" blog, I will be using my blog as a place to document all sorts of things as they pop into my head with the hope that other members will take a look and tell me that I am being an idiot if that is indeed the case but also to tell me why I am being an idiot and give suggestions as to alternatives.
This means that sometimes an entry will be about me actually doing something (hopefully with photos and possibly video) and sometimes it will be about me trying to figure out something (maybe with some rough sketches).
Now for a little bit of "history" :
I am recently retired and instead of my current 9m by 9m workshop, I am having to move into a 3m by 3m workshop which is more than a little bit of a bummer - but I will survive.
The envisaged "retirement project" has for years been to build a robotic arm with a router attached which will be a rather nice 5 axis CNC router which could produce all sorts of art out of wood.
However to build the arm the way I would like I need to master a number of other skills, foundry work being one of the first so that I can cast all the bits and pieces that are required.
In my career I have dealt with burners for boilers, brick firing kilns, aluminium pressure casting environments and some other instances so the whole issue of foundry furnaces is not quite a "mysterious black magic" subject to me.
And in the process I learned a whole bunch of things, mostly because at the time South Africa had a major technology embargo in place (due to Apartheid) and we had to develop all sorts of stuff ourselves to get the job done - all of which helped to build up my knowledge and the ability to "make a plan" to work around or solve an issue.
Propane is the easy fuel to use but it is expensive so I will be using old engine oil as the fuel source. Its free.
But it is somewhat dirty - some people think it is too dirty but they have never had to deal with a boiler that uses "bunker crude" as the fuel - THAT stuff is dirty, smelly and the viscosity is inconsistent - so much so that by comparison, old engine oil is really nice and clean.
Now most of the old engine oil powered hobby foundry seem to go from the viewpoint of "throw the heat of hell into the foundry" which is fine when you are wanting to smelt steel but not necessary when dealing with aluminium or even brass (worked in a tap manufacturing plant at one time - excessive heat boils off the zink which is bad news).
The fact of the matter is that throwing such high temperatures at low melt point metals and alloys can and in most cases does bugger the metal / alloy up to such a degree that the cast end product has many inferior properties and issues.
3000 plus degrees tends to shorten the life of your foundry and your crucible quite a bit
I saw one guy proudly showing his aluminium BOILING (about 4500F) - do not want to know the damage he did to his foundry and crucible in the process...
So it makes sense to keep the temperatures down - just high enough to get the job done properly.
And 3000 degrees is far more dangerous than the 1221 (plus a little bit) degrees you need to melt aluminium.
Now most of the issues I will be able to identify, some I will be able to solve (and these I will document) but I am asking this community to help by adding their thoughts, point out other possible issues and their thoughts as to possible solutions.
This whole project will be "open source" and hopefully at the end of it, there will be a burner that is reliable, has pretty fine control of temperature and MUST be relatively easy to make without costing the price of a house.
So that is it - lets get started...