Scale Model Obsession: "Life after death" Diorama Part II

Ok, the scary bit....

Casting the mold

so after carefully preparing my mold from plexiglass gs (4mm) glued together with marine sealant. Also left overlaps on the mold for easy removal ( yeah right!). I mixed 300 ml NCS Resin (polylite 32032-20) with catalyst (Butanox M-50) at a ratio of 100/1 and added 2 drops of Tamiya clear blue x23 for a natural water colour. Went a bit greeny when catalyst added but not too panic that's normal.

Planned to pour in three batches....um

1st batch went in and looked really good, just a few air bubbles to take care of and the colour looked just right. Left it for about an hour. In hindsight, left it a bit long as the surface was almost set and I should have poured 2nd batch when it gets to a sloppy jelly consistency. Resulted in below slight separation line:

Ok, this is where it got fun.... quickly mixed up a second batch and this time decided to go for 500ml as I needed to take the kids out for the afternoon....bad move! I had originally planned to do this in 3 batches. I was in two minds because I didn't want to make the same separation level again but the obvious concern was heat generation. I decided To chance it. In hind sight, not the wisest choice.

So this is how it ended....

Just kidding, but it did get a bit nasty nothing like a bit of drama.....however, after rushing back with the kids in tow, hoping that it was not going to look like something out of the thing. . I had foolishly missed one very

important step, any guesses? Yip, I forgot to wax the mold for that apparently easy removal!

So in summary, steps not to take in future:

1. Set the mold using PlexiGlass GS 4mm and glueing together with Bath sealent with overlaps for easy removal(ummmm).
2. Forget to wax the inside of the mould with Ramwax before pours.
3. First Pour 100/1 ratio Polyute 32032-20 / Butanox M50,m 2 drops of Tamiya XF24 clear blue for water colour.
4. Chase any bubbles and eliminate (did this by dragging them to the sides of the mold and bringing to the surface.
4.Wait for approx. an Hour
5. Mix and pour 2nd batch 100/1 ratio but this time 500ml plus 2 1/2 drops of colour, as this time you will also have to fill the model too.
6. Quickly run out with the kids and wife and forget to chase the bubbles :( (and hope for the best)
7.Return after 2hrs to find one smallish crack (to be later injected with same resin) and one damaged (melted area). It was still fairly hot to the touch but completely set.
8. Try to remove said mold, snap!.....the end tab off without budging the mold sides that needed to be removed. Tried everything under the sun and ended up with only alternative.....good old brute force with Hammer and chisel, in the process ruining the beautiful glossy transparent sides and removing small chunks of resin that were close to the base "voila" (for the international viewers), my recipe for disaster!

Love the drama, hope it's not putting off any prospective modelers!
and this what I end up with.....plexiglass embedded in the resin.

In addition, there were some imperfections that I was was somehow going to have to overcome, first was some heat damage ( i can live with that as it sort of fitted), just a little addition weather and sorted.

And a couple of cracks, not so cool....anyway, onto that later.

See below, did not do any other damage to any of the other materials and suprisingly enough, nothing to the submerged parts of the sherman either.

Ok, so forward march.....stiff upper lip old chap, and "we'll will fight them on the beaches" type of approach if you know what I mean cockney gezzas.

So after paying a visit to my local R&D product specialist (cheers Eric). He advised the following:
1. Band saw away the damaged areas and then good old elbow grease to reinstate the beautiful glossy, smooth edges, and here is what I was left with.. slightly smaller version of what I wanted but still enough depth to get the desired effect.
See never give in, you can always pull these things back :) ....silver linings stuff.

So after reviewing not how to do it, here's the correct steps:

1. Set the mold using PlexiGlass GS 4mm and glueing together with Bath sealent with overlaps for easy removal.
2. Donot Forget to wax the inside of the mould with Ramwax before pours.
3. First Pour 300ml 100/1 ratio Polyute 32032-20 / Butanox M50,m 2 drops of Tamiya XF24 clear blue for water colour.
4. Chase any bubbles and eliminate (did this by dragging them to the sides of the mold and bringing to the surface.
4.Wait until surface is sloppy jelly like and still a bit of movement (approx. 1/2hr)
5. Mix and pour 2nd batch 100/0.75 ratio but this time 300ml plus 2 drops of colour. (less catalyst as we suspect the combination of the heat from first pour will help the second pour to set and give enough time so as to not melt or cause heat cracks, leave for 1 hr.
6. Final pour of 150ml to fill the tank same as second mix ratio.
6. Do not quickly run out with the kids and wife and forget to chase the bubbles :( (and hope for the best). Take your time.
7.Remove said mold, in the process leaving beautiful glossy transparent sides and top "voila", my recipe for success!

Disclaimer:
All generic disclaimers apply.
All opinions are my wife's; I have none. (In my opinion.)
All opinions expressed are 99.44% true.
All rights reserved - but some wrongs are still available.
Any disclaimer issued by me is subject to change without notice.

Back to reality....All ready for final 1200 grit wet sanding and then airbrush some Humbrol Gloss cote thinned down with enamel Thinners for the final clear finish.

Now it's time to kick back with a hot cup of java (it's all in the grind my friends)
Final bit of Sherman weathering and onto the surface water effects....