My Banksia Casting Mould

For those of you that have followed my journey into moulding would know I have been trying to refine my banksia casting and overcome the issues. I established that vertical moulding was best, but my electrical tubes presented a few issues (too slow to seal, leaking etc).

I had a 1.1kg pack of Barnes M4642 RTV2 Silicon Rubber and decided to make a mould of multiple 25mm casts. This allows the banksias to be sanded down to around 20mm dia but still leaving enough room for the resin to flow around the seed pod. I can also use it for vertical coffee bean casts, and other odds and ends.

I started with 65mm lengths of 25mm dowel glued to a piece of ply with around 10-15mm between them. I wanted a well above the tubes, to allow overflow or extra resin to be drawn in under vacuum etc. So I trimmed the ply and glued it down to another larger piece of ply. To this I glued some ply walls tall enough to enable plenty of room for the mould floor. I then used plenty of glue in between the walls to help hold it all together. All the time the glue I was using was cheap hot melt glue, the whole mould former took me less than an hour.

As a release I just filled the former with BLO, it also helped me check the volume of silicon I was going to use, which in this case was the entire pack :(. Drained out the oil, mixed the silicon and poured it in. Only 24 hours later the silicon seamed to be set, so I pulled the hot melt glue away and dismantled the walls and bottom away leaving a solid block of silicon with the dowels in it. Quick tap on the bottom and even the dowels came out easy, so BLO is an excellent release agent.

All done :2tsup:

I forgot to take photos as I built the former, so I just placed some of the timber parts back temporarily for the photos, but you get the idea :rolleyes:

Cheers

See what you can do when work doesn't get in the way lol, Probably have to be prepared for retail enquries hehe, lookin good though , cheers John :2tsup:

looks good mate

thats the hard work done, now for the fun bit:U

MIK

Called in to FGI Gold Coast (Fibre Glass International - http://www.fgi.com.au/) at Laborador yesterday to check out their supplies. I found clear casting resin at $24 for 1kg (ie 0.5 x Bunnings’ Diggers Resin price), 500mls of Catalyst for $20 (0.15 x Bunnings price), $58 for 1kg Silicon (cf $72 from Barnes, $89 delivered).

And hopefully best of all, I’m yet to try it, $34 for 2lts of clear 2 part epoxy based wood preserver – lasts for years if not mixed, 6 hrs after mixing. The only dissadvantage of this stabilizer is that you must use after casting if using poly, as poly doesn't stick to it, but it sticks to poly. Either that or use epoxy based casting resin (that costs more than poly). So I will try casting, then drill hole up middle, then stabilize under vacuum.

I have been trying a milky white wood hardener for $54 for 1ltr, oil based polyurethane at $25 for 1ltr, and a water proofing clear product for $20 per ltr, all from Bunnings. None of these provided a perfect product like the Ultraseal O/S pen turners use (not available in Australia. Apart from the transporting resins issues, it goes off in temps over 20C, so would go off on the way here :().

I'll let you know how the trial stabilization products go.

I couldn't resist trying the silicon out though straight away, so made a mould for the 19mm vertical casts. I used 19mm dowels this time with only 5mm between them to save resin. That way I have the larger 25mm mould with banksias min 19mm, and the 19mm mould for banksia min 16mm. I can also use the smaller moulds for the coffee bean blanks. The cheap silicon worked a treat.

I also went to collect some banksia from near the beach ready for the weekend, if I can wait that long :rolleyes:

That all looks far too "professional" hehe, All good info as well thanks for that ,I am sure those prices will appeal to a few around the place :) . Cheers ~ John

Aah .. he's a Silicone Demon now :D

Looks sharp!

Oh well,

Looks like that's Nick & I put out of business. Nice job. I haven't seen some of that stuff at my FGI. Will have to ask if they carry the same.

Russell.

you will be cruisin' now 16 in one batch and 7 in the other, how are you going to get time to make them all into pens

OOH OOH pick me pick me ,,,,, i can help:U:doh:

are you going to offer all these groovy casts for sale ?????

hopefully after next weeks visit to the dermatologist i will be back in the shed

well done mate

MIK

So Niel th Cast has been cast by the casted one :U

Well done Neil.:2tsup:

:oo: Couple of banksia nuts there.:D

Quote:

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Originally Posted by tea lady

:oo: Couple of banksia nuts there.:D

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that's no way to talk about Neil :p

Russell.

I will be selling these babies once I have the process down pat and I'm happy with the product.

It's fine when I turn them and the odd infill falls out as I can fix them easily myself, but not when I'm selling them, provided it is not turning technique.

A lot of people in US from the IAP site have requested some, as there is no supplier for the smaller Banksias over there (only the giant ones from WA), but quite a few of our members in Aus have also been in touch for some :wink: . I was going to put together a bulk order for USA to minimise postage, with someone over there coordinating it.

I was thinking of $5 for the 19mm dia, and $6 for the 25mm, cast and stabilized. They are big enough for Sierra/EB, but you would need 2 for other 2 part pens. May sound expensive, but there is a lot of work sanding them down to size, casting and stabilizing. There wont be much money it it, but I'm not doing it for that.

Looking good Neil. You are right it is a lot of work so the price is good to me.
David

price sounds good to me also