A new member from Brampton Ontario

[Oldarm]

I have no idea how I ended up on a Calgary metalworking site but it appears to be inhabited by some very enthusiastic members! If I can be of help to anyone with my admittedly fairly localized know-how then please feel free to drop me a line.

I am retired (ha, ha,) but actively engaged in developing a range of art deco aircraft. These models I cast from a master pattern either as a sand casting or as a gravity die casting. The materials I use are either aluminum or one of the zinc-aluminum alloys.

The sand castings are made in either a Petrobond or Mansfield sand. The die-castings are made in a die, also made of aluminum, which I build, oddly, without the aid of machine tools. I do like to keep things simple!

Anyway, as I say, if I can be of any help, please feel free to touch base. I'll try to attach a photo or two to show what I am up to if I am allowed as a "beginner".

John

 

[Johnwa]

Welcome to the group. Nice castings! You’ll have to tell us more about making casting dies.

John

 

[gerritv]

Those are fascinating models!
You are not alone, more and more of us from east of Calgary I'm in St Catharines.

Gerrit

 

[Tom O]

Very nice castings!

 

[Oldarm]

Welcome to the group. Nice castings! You’ll have to tell us more about making casting dies.

John

Thanks John! The easiest way to explain the die making is to imagine that you are making a plaster, rubber or resin mould from an existing model or pattern. Instead of pouring any of those mediums over the part to be reproduced I pour aluminum. One of the interesting side effects of this process is the elimination of the shrinkage/contraction factor. That is to say that the die cavity and resulting castings are, to all intents, exactly the same size as the original model. One primary rule of physics defeated!
Sounds easy but there are one or two tricks involved! However it is a rapid and ever interesting process of toolmaking without the need for any machine tools. Basically, all you need is aluminum and a sand box. When I say rapid I mean a die a day (or two). As you see, complex joint lines are not an issue. Because the dies are made from aluminum they do not need any external cooling, thermal conductivity and radiation take good care of that issue. Secondly, being inherently light in mass I do not need to mount the tools in fixtures, they are manipulated simply by hand and locked by the use of "C" clamps.

Great fun, keeps me out of trouble, young and an endless source of thinking stuff to put you to sleep at night (if you know what I mean.)
John

 

[Oldarm]

Those are fascinating models!
You are not alone, more and more of us from east of Calgary I'm in St Catharines.

Gerrit

Thanks Gerrit,
St. Catharines and Hamilton make me feel quite at home. Gritty and down to earth!
John

 

[Oldarm]

Very nice castings!

Thank you Tom,
When it's in your blood it's hard to stop messing about with metal!
John

 

[YYCHM]

I'm not following here.... You make an aluminium mold to make aluminium castings?

Love your models BTB. Canadiana for sure. Harvard, F86, Avro Arrow, F5, Canberra (not sure we had any of those?).

 

[Oldarm]

I'm not following here.... You make an aluminium mold to make aluminium castings?

Love your models BTB. Canadiana for sure. Harvard, F86, Avro Arrow, F5, Canberra (not sure we had any of those?).

Good evening,
Yes, the mould/die is made from aluminium. I replied to somebody else a short while ago so if you don't mind I will "cut and paste" (I've learned how to do that despite being a Silverback!) and attach it here. Sorry for the liberty but it makes life a bit easier! Good to see your "planespotting" eye too! Last I heard was that NASA still had two Canberra's on active duty believe it or not.
I'll try to attach a snap of the finished model to this mail.
John

The easiest way to explain the die making is to imagine that you are making a plaster, rubber or resin mould from an existing model or pattern. Instead of pouring any of those mediums over the part to be reproduced I pour aluminum. One of the interesting side effects of this process is the elimination of the shrinkage/contraction factor. That is to say that the die cavity and resulting castings are, to all intents, exactly the same size as the original model. One primary rule of physics defeated!
Sounds easy but there are one or two tricks involved! However it is a rapid and ever interesting process of toolmaking without the need for any machine tools. Basically, all you need is aluminum and a sand box. When I say rapid I mean a die a day (or two). As you see, complex joint lines are not an issue. Because the dies are made from aluminum they do not need any external cooling, thermal conductivity and radiation take good care of that issue. Secondly, being inherently light in mass I do not need to mount the tools in fixtures, they are manipulated simply by hand and locked by the use of "C" clamps.

Great fun, keeps me out of trouble, young and an endless source of thinking stuff to put you to sleep at night (if you know what I mean.)
John

 

[PeterT]

Really nice. Would like to see more pics of your molds/dies when you have time.
You have obviously mastered thin section detail judging by the prop & spinner -are those part of the main die or made separately?

 

[JohnnyTK]

Welcome great work! Collingwood here.

 

[Janger]

Really nice. Would like to see more pics of your molds/dies when you have time.
You have obviously mastered thin section detail judging by the prop & spinner -are those part of the main die or made separately?

I second this...

 

[Oldarm]

Really nice. Would like to see more pics of your molds/dies when you have time.
You have obviously mastered thin section detail judging by the prop & spinner -are those part of the main die or made separately?

Thanks Peter,
I will take a photo or two of a typical pattern, die and castings to give you a better and more tangible idea of the process tomorrow and forward them on to you.
The props? I make those in separate moulds.
John

 

[Oldarm]

Welcome great work! Collingwood here.

Hello Johnny,
And thank you for your welcome and assessment. Another Ontarian too!
John

 

[CalgaryPT]

I have no idea how I ended up on a Calgary metalworking site but it appears to be inhabited by some very enthusiastic members! If I can be of help to anyone with my admittedly fairly localized know-how then please feel free to drop me a line.

I am retired (ha, ha,) but actively engaged in developing a range of art deco aircraft. These models I cast from a master pattern either as a sand casting or as a gravity die casting. The materials I use are either aluminum or one of the zinc-aluminum alloys.

The sand castings are made in either a Petrobond or Mansfield sand. The die-castings are made in a die, also made of aluminum, which I build, oddly, without the aid of machine tools. I do like to keep things simple!

Anyway, as I say, if I can be of any help, please feel free to touch base. I'll try to attach a photo or two to show what I am up to if I am allowed as a "beginner".

John

I know little about aircraft, less about casting. What I do know is that those are beautiful, and I love anything art deco.

Super nice job...those as sales-worthy.

 

[Janger]

Thanks Peter,
I will take a photo or two of a typical pattern, die and castings to give you a better and more tangible idea of the process tomorrow and forward them on to you.
The props? I make those in separate moulds.
John

Please post the pictures in this thread John - many people will want to see what you are up to. I do.

 

[Janger]

Please post the pictures in this thread John - many people will want to see what you are up to. I do.

Process pictures are always fascinating. What kind of aluminium do you use - I mean scrap or chips or new stock or? and your furnace?

 

[Oldarm]

I know little about aircraft, less about casting. What I do know is that those are beautiful, and I love anything art deco.

Super nice job...those as sales-worthy.

Thanks so much for that. I understand too your eye for beauty. I am really only interpreting an eye that went before me when these creatures left the drawing board.
John

 

[Oldarm]

Please post the pictures in this thread John - many people will want to see what you are up to. I do.

Do you mean as opposed to replying to somebody?
John

 

[Oldarm]

Process pictures are always fascinating. What kind of aluminium do you use - I mean scrap or chips or new stock or? and your furnace?

When I was poorer than my current condition, yes, I used scrap metal, not turnings though. Pistons, gearbox housings, engine mounting brackets even a few airframe forgings went into the mix! When ones back is against the wall it is quite amazing what can be done with little or nowt. And that is what makes it all worthwhile at the end of the day.
At least, that is my opinion. And I'm not trying to sugar coat things one little bit.
Cheers, John