Lost wax casting.
- Thread starter GrahamMc
- Start date
Giles
Western Thunderer
This is extremely useful and interesting!
My very short experience of (microwave) lost wax casting does at least peartially address some of these concerns.
The mould is hot when we cast - it has just come out of the burn-out furnace, where it's been for two hours - and which has been glowing nicely internally. I'm afraid I don't know precisly what temperature it is when we pour, but there is certainly no evidence of chilling, and we've only had one item fail to come out with all its detail intact - and that was a rather optomistic piece by my wife! Conversly, she has tried casting a full bracelet it bronze (via the microwave) in Delft, which being cold, makes it noticably more difficult, and she took two stabs at that.
When it comes to the vacuum side, we were instructed to carve the 'skin' of the investment off the underside of the mould/flask to increase its porosity - certainly when we open the valve, it appears to take a gulp and the vacuum drops, before re-building after the pour (which it then maintains - as you say). At face value, it would appear to me that the investment 'surfaces' seal naturally, and when dry, one needs to carve through them. Indeed, the external dried surface is smooth and shiny - visibly different from the dressed body of the exposed investment.
However, it all appears to work reliably, and inparting a good level of detail.
If you were around the West London area, you'd be very welcome to come and have a play!
My very short experience of (microwave) lost wax casting does at least peartially address some of these concerns.
The mould is hot when we cast - it has just come out of the burn-out furnace, where it's been for two hours - and which has been glowing nicely internally. I'm afraid I don't know precisly what temperature it is when we pour, but there is certainly no evidence of chilling, and we've only had one item fail to come out with all its detail intact - and that was a rather optomistic piece by my wife! Conversly, she has tried casting a full bracelet it bronze (via the microwave) in Delft, which being cold, makes it noticably more difficult, and she took two stabs at that.
When it comes to the vacuum side, we were instructed to carve the 'skin' of the investment off the underside of the mould/flask to increase its porosity - certainly when we open the valve, it appears to take a gulp and the vacuum drops, before re-building after the pour (which it then maintains - as you say). At face value, it would appear to me that the investment 'surfaces' seal naturally, and when dry, one needs to carve through them. Indeed, the external dried surface is smooth and shiny - visibly different from the dressed body of the exposed investment.
However, it all appears to work reliably, and inparting a good level of detail.
If you were around the West London area, you'd be very welcome to come and have a play!
Last edited:
Giles
Western Thunderer
Hi Graham,
I hadn't fully appreciated the impact on quality of finish, which you so very usefully show! I think you are right, and as there is no way of precisly controlling temeperature of (particularly) the mould, this method will inevitably lack the extreme refinement of conventional techniques.
However the joy of it is that it does enable us to do lost wax casting at a demestic level, which we would otherwise not be able to do. I look forward to seeing how much quality we can sqeeze out of it!
The other point to make is that this is a time consuming process, and the flask is only 38mm diameter - so there is also no way it can compete on any commercial level. People are still probably best off getting their castings done professionally as before - unless they actually WANTED to do it themselves, or had a need to be able to produce odd items at random.
All the best
Giles
I hadn't fully appreciated the impact on quality of finish, which you so very usefully show! I think you are right, and as there is no way of precisly controlling temeperature of (particularly) the mould, this method will inevitably lack the extreme refinement of conventional techniques.
However the joy of it is that it does enable us to do lost wax casting at a demestic level, which we would otherwise not be able to do. I look forward to seeing how much quality we can sqeeze out of it!
The other point to make is that this is a time consuming process, and the flask is only 38mm diameter - so there is also no way it can compete on any commercial level. People are still probably best off getting their castings done professionally as before - unless they actually WANTED to do it themselves, or had a need to be able to produce odd items at random.
All the best
Giles