A didgeridoo? A DIDGERIDOO? Actually that's a good one! I could make a new slouch hat and a right hand holding a boomerang and I've got a whole new Aussi Digger figure!!
Anyhow, a quick update - I've done two castings of the final torso mould (biggest one I've done so far!) The first was a quickie to test the mould and revealed a few small blemishes which were easily fixed with my micro scissors as you'll see later. The second one was taken more slowly with some preliminary work before the mould halves went together and bar a single button it's come out perfect! (Just takes a long time swilling that resin around inside!)
So here's his right hand...
Photo 1 again shows the resin cast arm as it was last time, before the forearm was removed just above the elbow. With the Chindit holding the didg.. - er bamboo in his left hand, he’s using a machete in his right. Using reference photos off the web and estimating the size, I created a plasticard machete out of three pieces, the main sheet forming the blade and tang with two thinner sections forming the wooden grips as illustrated in Photo 2. The only details needed to be added were the three rivets in the handle formed by carefully tapping one of the smaller paper punches into the soft plastic and the hole through the handle (drilled into but not through from both sides). The hand itself was replicated in resin, the original in this case being a much firmer plastic than the left hand was. Unfortunately, whereas the left hand fitted tightly around the bamboo/hazel stick with no gaps, this one, as shown in Photos 3 and 4, has a sizable gap between the machete handle and the palm. Although this is perfectly natural, its going to give big problems when the hand/machete is moulded! Photos 5 and 6 show the gap being filled in with Superfine Milliput, this was the initial filling, once the Milliput began to harden off I did some further carving to remove just enough to block the hole without ‘filling in’ too much of the shape of the hand. Once that was done, the wrist was blended in to the forearm as shown in Photo 7. This entire arm and machete was then moulded as a single entity – however – I then found it was really difficult to cast the whole thing in one go! I could get a good machete blade or I could get a good arm but not both. After trying out various fixes I went back and removed the hand from the arm again and created a new mould for the forearm. So now the right arm is a two piece mould using a new mould to cast just the hand holding the machete and another one for the forearm. The join needs a little filler when assembled but that’s better than wasting so much resin! Again, I haven’t got a photo of the final cast arm so here’s another shot in Photo 8 using the originals instead. In actual fact the arm and machete are posed further to the left than shown here, it’s just that the original arm is a little loose on the torso peg, (with repeated fittings and removals) and it will only stay on if it swings to the right!
In the next installment – the Short Magazine Lee Enfield No.1 Mk III*

Until then, Happy Modelling to You All!

Robin.

Some lovely detail on that rifle Robin nicely done.

Al

Rifle looks the business Robin. You really have embraced the resin moulding process this year. Top job!

Regards,
Phil W.

Going to look amazing when complete Robin, top class work.....

Regards

Alan

Many thanks again to Alan, Ian, Kev and Mark! This whole project has been a huge learning curve for me, but at the same time so enjoyable! The build has progressed a great deal since the last post, in fact he's almost completed with just some extra painting to go once I've replaced my rock hard pot of Humbrol Brass acrylic (it was fine last time I used it!)
Before beginning the large final mould for casting the head-torso-upper arms piece, I first had to make up one last part for the figure. This is shown in Photo 1 and consists of a rectangular block from sheet plasticard. The previously sealed off base of the torso is glued onto the white end of the black and white box. The white part is a snug fit into the hollow top of the pedestal shown on the left. I then glued a collar of square styrene rod just below the black section – this will form a channel in the mould up to which the Roto casting resin will be allowed to coat the interior of the mould. With that glued in place I could then finally spray the entire figure with Poundland Grey Primer as seen in Photo 2, to seal in the PVA coated tissue paper shirt ( I’m not really sure how that would take to the liquid rubber!) At last, all the various media used in his construction look ‘as one’. Next job, illustrated in Photo 3 was to take my new large Lego brick base and build a surrounding box to encompass the figure. The torso was then removed and a base layer of about a cm of rubber was mixed and poured into the box and allow to cure. (Photo 4). The Lego brick wall was then built up higher ready for the first half of the mould and a quantity of silicone mixed up ready to pour. Before that however, I used an old paintbrush to liberally paint the rubber across the back of the torso as shown in Photo 5. This would, I hoped, prevent any air bubbles forming under the torso, as the rest of the rubber was poured in and around him. Fortunately it did just that as I later found out! Photo 6 shows the first half of the mould completed and cured. As you can see in this photo and the close up in Photo 7, I placed a series of single width bricks upside down around the edges of the mould whilst the rubber was still liquid and these have produced a good set of locating lugs for the second half of the mould. I now had to build up the Lego wall again for the second half of the mould and as you can see in Photo 8, I was getting a little short on bricks! I was also getting a little short of silicone rubber too! I managed to save a fair quantity however by designing my first ‘split level’ mould as seen in Photo 9. I poured in enough rubber to submerge the torso part up to the 1cm minimum but that left his left arm still protruding. Rather than simply filling the rest of the mould up, I made a little two sided wall, and once the rubber had cured, placed that up against the outer wall and poured another mix in to cover the arm. Placing my jeweller’s anvil on top of the wall gave enough pressure into the solid rubber below to seal the extra ‘box’ until it cured too. Finally, Photos 10 and 11 show the mould being carefully prised apart to remove the model and the two halves of the mould with the prototype. He’s sustained a little damage on the lead webbing, the buckles for the pouches were actually stuck into the front mould but were easily removed. The damage was in fact exactly where I expected it to occur (just less of it!)
That just leaves one more small mould to complete the main casting and that will be coming up next.
Until then, Happy Modelling to you All!

Robin.

Many thanks for that Kev! Its only the bamboo and machete to finish now and he's ready for the final gluing together!

After the huge torso mould was completed I tried a trial casting using the last of my original Roto casting resin. The result was pretty good overall but with some notable flaws. Photo 12 shows a close up of the inside of the mould with the arrow pointing at the cause of the main problems. Despite my trying to seal the edges of the webbing straps with Milliput, some of the liquid silicone rubber had in fact managed to seep in underneath giving rise to the ‘ragged edge’ seen here on the shoulder straps. What happens during the Roto casting is that as the liquid resin is slopping around the inside of the mould, air gets trapped between the thin overlap of rubber and the actual detail on the mould. This results in a depression in the surface detail (basically ‘sinkholes’). The solution is very easy however – I just had to go over the entire inside of the two moulds and snip away the excess rubber using the micro-scissors to leave a good clean edge to the impressed strap edges. After cleaning up the moulds I prepared for the second attempt using my new supply of resin. This time however I took some extra precautions! Once the resin was mixed I took a cotton bud and spread the resin along all the moulded straps as well as his ears, (air bubble in the first one), nose (removing the resin ‘bogies’) and the hollow tubes for the locating pegs. The second casting, shown in Photo 13 was almost perfect – in fact the only thing missing was the button on his right shoulder epaulette! I made a new one up and used that to make a plasticene mould to cast a dozen more – why I didn’t think of that on the prototype I can’t imagine! That just left the final small mould for the base of the torso. I cut off the portion of the plasticard box which formed the locating plug for the pedestal made previously, sealed the bottom with a new rectangle of styrene and glued it to the torso base. Then after making a solid rubber base the figure was placed on the rubber in his Lego box and liquid silicone poured in around the waist as seen in Photo 14. This did remove the last of his resin belt buckle on removal but the result was the small mould shown in Photo 15. To employ this one I make up a small amount of the standard resin and pour it into the hollow torso casting (keeping it on its side), and then quickly (I’ve only got about three minutes) fit the rubber mould around the waist ensuring the rubber peg fits in the waist hole and then sit the figure upright on the mould. The resin then flows down into the bottom creating the solid plug shown above the mould. So finally, in Photo 16, the first view of the entire figure! This one is built entirely out of reject and trial pieces, which is why there are air bubbles everywhere! Apart from the base and hat that is, the base is a good one and the hat still needs a grinding down under the brim. I needed to build a complete model though to design and fit the final part – the rifle sling shown here. Oh, and yes he hasn’t got any arms yet – I’ve only made the proper ones for the final figure so far!
In the next instalment, making that sling and then the hard part begins – PAINTING!
(Actually he’s almost completed now and I’m really pleased with the result!)
Until then, Happy Modelling to you All!

Robin.