Italeri RAAF Mirage IIIO. FINISHED

[tucohoward]

Incredible work as always, Eric. Can't be as easy as you make things look.

 

Jay

[MikeMaben]

Hey Eric, nice work. A tip I learned about pouring mold material is to

start the pour away from the part (obviously) then lift the container

up above the part such that the pour becomes a thin stream of material.

By the time it hits the mold cavity, any bubbles that were in the material

will have popped (keep an eye on it). With the extended pour time of the

Vario 15, this should work well as you could lift higher for a thinner stream

(which would take longer of course).

 

I haven't tried it with resin because I've been using Smooth Cast 300 which

is a hard plastic, but the same principle should/might work.

 

Have fun

[ericg]

Hi MMaben,

 

Thanks for the tip. I do that when pouring silicone already as well as degassing it.

 

Eric

[MikeMaben]

After posting the tip, I figured you probably already knew that one

I'm pretty new to casting but it's fun anyway.

 

Keep on truckin'

[ericg]

Some more work.

 

Practically every photo that I have seen of Mirage parked feature the shoulder harness wrapped over the top of the ejection seat, stowed out of the way by the ground crew. Pretty well every second ex-RAAF ground crew that I have met remembers strapping Sean in at one point in their military careers, and I know they would appreciate the extra mile that I have gone to depict this.

 

I cant remember ever seeing a resin ejection seat with the shoulder harnesses anywhere else but down over the front of the seat. I guess that it is much easier to mould as there are far less undercuts. I will be reproducing this seat in Resin, and am prepared to give it a go in the format as detailed below.

 

I made up all of the shoulder harnesses from lead foil and then draped them over the top of the seat. I followed this by making up the shoulder padding from Tamiya Epoxy Putty (Smooth surface) and then moulded this into its rough shape in the position that it is in in this pic.

 

 

 

I sanded and carved it into shape, as well as adding some stitching detail and then applied a rough coat of Mr Surfacer.

 

 

Some belt buckles where then made from plastic card. I drilled the hole first and cut the rest of the buckle out based on the hole.

 

 

These were then fitted over the lead foil belts.

 

 

I added a larger Lumbar cushion from the Tamiya Putty. This will be sanded and refined once cured. The seat is starting to look pretty cool and I cant wait to get this into resin and paint it.

 

Edited January 11, 2017 by ericg

[Scale32]

Very nice attention to detail mate. Must have been a pretty plain seat before the details!

 

Bevan.

[ericg]

Thanks Dan. I will pack some of the undercuts with modelling clay before it gets a bath in silicone.

 

Eric

[Rainer Hoffmann]

Those buckles are amazing. So tiny and stills so exactly shaped. Great work, Eric.

 

Cheers

Rainer

[blackbetty]

loving this, eric!

[amurray]

Ever since the length of the intakes was pointed out to me by Cheetah, I have been pondering a fix to shorten them. The kit for some reason has the intakes slightly too long and once stuff like this has been `seen', it cant be unseen! The front edge of the intakes should be behind the sill of the canopy like this:

 

 

The kit intakes look like this. Notice how far forward they come. Obviously there is some parallax error that needs to be taken into account. 

 

 

Excellent modification! All your mods are excellent!

 

You may have noticed also that the panel lines (looks like a paddle) on the fuselage directly below the ejection seat should likewise be moved to the rear a bit to correspond with your intake surgery.

Edited January 12, 2017 by amurray

[Guest Peterpools]

Eric

Bravo! Incredible work on the seat .. your attention to detail is nearly beyond amazing

Keep 'em coming

Peter

[DonH]

Eric, that has got to be the best bang seat I have ever seen and it isn't finished yet! It just looks "right".

[ericg]

Thanks guys. 

 

Some more work on the RPK-10's. This is part 2 of the RPK-10 Master mould. I thought I would show you what products I am using. I am using a Barnes product called Vario and have found this stuff to be excellent for tasks requiring a longer work time as it has an advertised pot life of around 120 minutes (pinkysil is 6 minutes), which is far less if you are working in warmer conditions. The good thing about it is that it gives you ample time to mix and pour it as well as move the mould around to allow trapped air bubbles to escape. This factor is particularly useful for those that don't have the equipment to degass the silicone before pouring. The small downside is that it takes around 6 hours to cure so nothing happens very quickly there. I am using a custom mix of Vario 40 and 15.

 

Once the modelling clay was peeled off, the first half of the silicone mould is exposed. I sprayed a decent coat of mould release over this and then carefully wiped the residue off the master part. I re-built the lego formwork around it.

 

 

One the silcone was degassed, I poured it onto the part. Remember this is the second half of the two part mould and I have had to build the second half of the pour spout from modellers clay. Notice that I have the container of fresh silicone up nice and high and am pouring it in one corner, allowing it to `creep' over the part. This greatly assists with the removal or prevention of air bubbles. Degassing the silicone means that I don`t have to be too concerned but am not taking any chances. The best part about this silicone is that it gives you heaps of working time and because it is fairly clear you can see any bubbles that haven't shaken themselves loose from the part, allowing you to get a toothpick or silimar and gently persuade it to move.

 

 

 

I am using a custom mix of 100:50:15 of the Vario 40/15 and catalyst. This gives me a hardness (Shore hardness 32) slightly more than Pinkysil. These products can be mixed in any quantity to achieve the required hardness for different tasks. This makes this product very versatile. There is $100 AUD  worth of product here, so its not for the faint hearted if you mess something up! the RPK 10 mould has cost roughly $20 in silicone alone.

 

Edited January 13, 2017 by ericg

[ericg]

Great to see more of your moulding operations Eric.

 

Great to see how the magic is done.

 

I like that the Vario is clearer than the Pinkysil and allows you to see any trapped air bubbles.  Whereas the two colours of the Pinkysil ( white and deep pink) allow you to better gauge that you have mixed the two parts completely.  Am I right that with the longer setting time you could work out any trapped bubbles before it's too solid to disturb?  Also how picky is it as far as the ration of catalyst to stock?  I remember my old pre-pinkysil days of getting the ratio oh, so wrong and never getting the darn mould to set.  Would it be safe to say that these materials are for the more advanced caster?  I am also assuming the increased hardness would improve the mould life but make it harder to get the part out of the mould.  Sorry for the barrage of questions. I just long moulding stuff and cracking new parts out of a new mould is so much fun

 

Thanks for sharing, your the tops!

 

Dan

I will have a go at answering your questions Dan.

 

The longer setting times allow you to work out any air bubbles. In fact, the far longer setting time allows you to spend more time doing whats important, that is, mixing the ingredients thoroughly and getting the pour right. You can pick the mould up if you have it on a tile or similiar and move it around whilst the silicone is still quite fluid to also help dislodge bubbles. Being able to see what is going on as it is is happening is a huge advantage.

 

I am not sure how picky it is as I haven't had an issue with the ratios yet. This product is mix by weight rather than by volume (like Pinkysil is), so I measure the silicone in one cup and the catalyst in another, only mixing them together in a separate cup when I have the weights exactly right  ready for mixing and pouring.

 

These materials probably suit the more advanced caster, but we all have to try different things one day and I am finding this stuff very easy to use. The only drawback is that you have to be a little bit more patient and allow the product to cure for alot longer than Pinkysil before pulling something out of the mould, like 6 hours rather than less than an hour with Pinkysil. I find the far less urgent requirement to get the silicone mixed, degassed, and into the mould before it sets allows for things to move at a more gentlemanly pace allowing more time to think about what is happening.  

 

It is a sliding scale as far as hardness and being able to pull the part out of the mould. Pinkysil has a hardness once cured of Shore 20, whereas Vario is sold in Shore 15 or Shore 40. The 15 is a little too soft and the 40 is a little too hard, so a combo of both is ideal. The manufacturer even give you a table on the Technical Data sheet that can be easily referred to to give the required Shore Hardness factor, ie: a 50:50 ratio of both silicones will give a hardness factor of 27.5. by referring to the table, any harness factor between 15 and 40 can be achieved to suit various applications.

 

Hope that helps!

 

 

Eric.

Edited January 13, 2017 by ericg

[Guest Peterpools]

Eric

Terrific tutorial and easily, food for thought

Keep 'em comoing

Peter