The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Minto on 27.07. 2020 19:02
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Well, still can't find any badges for my 52 plunger tank, so I'm going to have a go at casting some in pewter this coming weekend. It would be way easier if I had a pair to take an imprint from but then, where's the challenge in that.
I've hunted around the internet for some dimensions but the only thing I've got so far is a measurement of the length of the badge being 4 7/8" long, with holes drilled 3 3/4" to centres.
I drew out the badge earlier but these measurements seem a little off. If someone could take a ruler to one and post up some vital statistics, that would help enormously. Length overall, diameter of the circle, hole centres, BSA font size etc.
Or if anyone has a pair they could loan me for an afternoon in exchange for a spare set of cast pewter ones (maybe to decorate a garage wall) that would be even more awesomer.
Any help appreciated.
Jase
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G'day Minto.
Is your tank an A10 or the smaller A7 tank?
Cheers
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Hi Musky, it's a new Indian made larger A10 tank. The part number for the badge is 67 8070/1.
Like bloody hen's teeth!
Cheers
Jase
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A quick search got this one.
Cheers
https://www.ebay.co.uk/itm/164303529044
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I will measure mine tomorrow.
How would you go about creating the moulds?
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Hi Greybeard, much appreciated.
If I could find a pair of original badges it's just a case of imprinting into green sand, and casting straight from that, or imprinting into modelling clay, pouring plaster of Paris into that to form a pattern for the sand cast. Otherwise I'll carve some patterns from some modeling clay, bake it then either use a high temp silicon mould compound or just sand cast. I'll probably do a fair bit of experimenting to see what gives best results.
I'll take pics of what works and what doesn't as I do it
I love playing around with this sort of thing.
Jase
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Cheers Musky, don't know how I managed to miss that, I'll keep an eye on it, though they do seem to fetch silly money.
Jase
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Hi Greybeard, much appreciated.
If I could find a pair of original badges it's just a case of imprinting into green sand, and casting straight from that, or imprinting into modelling clay, pouring plaster of Paris into that to form a pattern for the sand cast. Otherwise I'll carve some patterns from some modeling clay, bake it then either use a high temp silicon mould compound or just sand cast. I'll probably do a fair bit of experimenting to see what gives best results.
I'll take pics of what works and what doesn't as I do it
I love playing around with this sort of thing.
Jase
As you can imagine I'm loath to send off my badges in case they get lost or damaged in the post. How about I get some plasticine and make impressions to send to you?
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Greybeard, massive thanks that would be totally brilliant, and I'm sure I'll be able to work from that.
Do you still have my address?
Jase
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Greybeard, massive thanks that would be totally brilliant, and I'm sure I'll be able to work from that.
Do you still have my address?
Jase
Yes, I'm sure I have your address in messages.
I'm going to send you a PM now.
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G'day Minto.
You may have a market for them.
My grandfather was a pattern maker. I remember him telling me the pattern had to be a certain % bigger than the finished product depending on the material eg ?% for alloy, ?% for ci to allow for shrinkage when cooled.
I'm sure you already know this. Just for the info to others.
Best of luck with it.
Cheers
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See Lot 9:
https://www.a7a10.net/forum/index.php?topic=14889.0
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I will measure mine tomorrow.
How would you go about creating the moulds?
Easiest way is to use silicon moulding gel.
You can cast aluminium into most of them or get the cheaper stuff for white metals
Only trick is mixing the gel on a flat class surface so you do not entrap air
and if you have a brake bleeder, degassing the solution
Then place the original face up on some glass, put a baked beans can with neither top or bottom over it and pouring the moulding gel over the top very slowly to avoid trapping air.
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See Lot 9:
https://www.a7a10.net/forum/index.php?topic=14889.0
Clever idea to make a universal mould and remove the unwanted wings on either side.
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Hi Ted, if you still have this lot I'll definitely relieve you of lot 9, that's going to save me loads of time.
I'll try to pm you.
Cheers
Jase
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I will measure mine tomorrow.
How would you go about creating the moulds?
Easiest way is to use silicon moulding gel.
You can cast aluminium into most of them or get the cheaper stuff for white metals
Only trick is mixing the gel on a flat class surface so you do not entrap air
and if you have a brake bleeder, degassing the solution
Then place the original face up on some glass, put a baked beans can with neither top or bottom over it and pouring the moulding gel over the top very slowly to avoid trapping air.
There are quite a few different silicon products on the market nowadays, from gels to putties that you can imprint straight into. I have to admit I like the look of sand casts though. I'd leave the background grainy and polish up the raised parts.
Cheers
Jase