Casting the wheels for “Onward”.

[Maurice Cox 1Participant @mauricecox1]

I have just watched a video of the casting of the rear wheels for the replica traction engine "Onward". It is very interesting, but there was just music on the sound track. I could follow most of it except when it came to pouring the iron. First, a small crucible was used to pour a small quantity of iron into the mould, about the volume of two house bricks, then a much larger crucible was used to pour enough to completely fill the mould. Can anyone tell me what the reason for this was please, and is there a version of the video with a comentary?

[Maurice Cox 1Participant @mauricecox1]

Explanation of a video..

[Brian OldfordParticipant @brianoldford70365]

Did the second pour empty the crucible?

[Maurice Cox 1Participant @mauricecox1]

It appeared to, yes.

[Jeff DaymanParticipant @jeffdayman43397]

The first bit of iron may have been used to warm the runner system and burn off any water or flammable gases that may have been in the mould, while the runners and fill system were mostly open to atmosphere. If such gases or steam were present while the main pour was being done, filling the runners, an explosion of the mould might result. I've seen this "first pour" done on big steel pours (about 5 tons of steel) at a foundry I did a co-op term in many years ago. The shop men called it "wetting its' whistle". JD

[JasonBModerator @jasonb]

Could well be right Jeff as it looks like it was poured into the vent gate and did not look like it was done to make up for not enough capacity of the in the main tilting crucible.

I did have a look on Traction Talk at the thread when the video was first posted but could not see it mentioned.

J

[Maurice Cox 1Participant @mauricecox1]

Thanks for that gents. I did think that, as they were casting the iron round the cold ends of the spokes, it may be some sort of preheating from the radiant heat. It is a pity that there is no commentary.

[Ady1Participant @ady1]

Cheap pre-heating? Resulting in a better casting

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