Tri-ang Big Big train MKII cut and shut and Easybuild Mk1's.

[jonhall]

I'm not quite sure about what your mould is made from, but Silicone rubber moulds don't need mould release at all - a light dusting of talc will help break the surface tension which will help reduce the bubbles.

 

I'm not sure I would use a polyester resin - polyurethane would be my recommendation.

 

If you can get the master out of the mould undamaged, then the parts shouldn't be a problem.

 

Jon

[jonhall]

Sean,

 

Ideally your talc bottle would have a lid that you could close down the apertures so that they are mostly closed, so that you get a tiny amount dispensed, before you use the mould, put a tiny amount of talc into the mould and then tap the mould to disperse it across the internal surfaces, I'm struggling to describe how little you need, a little goes a very long way - a pinch or less? Any excess is emptied out, and it shouldn't make any difference to the surface finish of the part. then pour the resin in.

 

I should add, if your resin or rubber specifically says use a release agent you should do, but if it isn't mentioned in the instructions, or isn't STRONGLY recommended I'd expect it to be OK without.

 

Your mould looks very good to me - I'd expect it to work well. With polyurethane resin you could try using a sheet of clear plasticard across the open face of the mould to get a flat back to the seats - it *should* peel away afterward. 

 

Jon

[mike knowles]

Sure Mrs P has some talc somewhere.

 

Cheers.

 

Sean.

 

Probably best to get some plain (unscented) talc. If Mrs P walks into your railway room and gets a whiff of her best Yves St Laurent talc the game'll be up!

[jonhall]

Pretty good for a first attempt.

 

Is your resin cloudy or clear when liquid? Having a clear when liquid resin makes chasing the bubbles a bit easier - you will find the bubbles are always in the same place, so it should be possible to go after them with a cocktail stick or some such, once dislodged they should float to the surface.

 

Jon

[BernardTPM]

I'd agree, quite good for a first go, though the infill between the pair of seats must be too thin as it should be almost the depth of the seats (check back to the prototype photo). That might make the resin flow easier too. You will need to prod the bubbles out before the resin starts to cloud.

[BernardTPM]

Sounds like a different resin to that I used to use which was transparent (sort of honey coloured) until it began to set when it went opaque cream. Another possible way of reducing bubbles is to wash a thin layer over the mould surface first, wetting it before pouring in the main bulk of liquid resin. Not 100% foolproof and you do need a supply of cheap expendable brushes, but it might help.

[Merfyn Jones]

Hi all.

 

So, it's been a while, but I have managed to mould my first seat.....

 

20131012_125749-1.jpg

 

20131012_125724-1.jpg

 

I think I can legitimately claim a partial success in that most of the finer detail has come out quite well. Unfortunately one seat is rather lumpy whearas the other is heavily dipped, this being due to the latex mould having some deficiencies which were not apparent to me, but would have been had I checked it better.

 

Also, both inner wings seem to have the fronts missing, so this will also need rectification.

 

This has all led me to have a ponder session. I think the best way to deal with it is to make another master, practice makes perfect as they say, but me being me, I like everything done yesterday, so I'm a bit miffed it didn't work first time! He heh.

 

Another thing I've been pondering was perhaps looking into 1/43 scale road coaches and seeing if any of the more recent types have similar seating? I've found that Corgi do one called a Plaxton Paramount which, if I can find a cheap one on ebay etc may be worth a look. I may also start a thread here as there appear to be a few bus fans on here too.

 

Anywho, I'm having my other knee done on Monday with another enforced period of sick leave so plenty of time on my hands to come to the right decisions.

 

Any bus advice would be greatly received.

 

Cheers.

 

Sean.

 

I think the Corgi Paramount was far too small, being about 1/64 scale. To my knowledge there are no 1/43 scale coaches made of British vehicles but there may be something in the foreign toy ranges, or possibly something in the Corgi 1/50 range which are mainly from the 1950s.

Merf.

[ozzyo]

Hello PoD,

 

looking at your master, it looks pretty good, if you could mount it on some plasticard about 1mm thick , that would would fit in a Lego brick wall that would give you the "rubber" mould.

 

Your casting looks like the "resin" has not flowed into some of the thin parts, if you mount the "Lego" wall on the base you should be able to tap the base on a surface to help release any bubbles in the mould (don't pour the seat in one go), but don't let the resin set between the pours. Another way that you could do it is to use an electric jigsaw with out the blade in it to vibrate the mould when you are pouring the resin in to it. 

 

Doing it this way the back of the seats should be nice and flat.

 

Hope this helps you, if you want to talk about it drop me your land line number,

 

OzzyO. 

[Talltim]

If you need any Lego PM me!

[uax6]

Using that cast figure as a guide I would say that you seat back is a little too short. Going from memory I recall that the 'wings' were about level with the top of Dads ears (he's 6'3" tall).

 

My limited experience with latex has been mixed, I'm not all that convienced with it tbh. I've bought some RTV to have a try with, not that I seem to get round to it! I'm interested to see the difference between to two.

 

Andy G

[uax6]

RTV is a 'proper' two part silcone for mould making. It's available in differing grades, so you can plaster cast, resin cast or metal cast. As i say i need to get round to trying it out, but it has to be better than the latex I've used!

 

Andy g

[Ian Fisher]

Hi Sean,

 

Have a look here:-

 

http://www.tiranti.co.uk/edgeimpactshop/search.php?Keyword=pot

 

One of the most comprehensive casting supply people maybe not the cheapest but definitely a good reference.

 

Thanks Andy.

Another option there for me if my current experiments fall short.

Cheers.

Sean.

[Ian Fisher]

Hi Sean,

 

I have found latex can create peelable moulds for cuboid shapes. A useful mould can be built up after a few dips.

 

Bath sealant as you say can be used also best for flat objects as it lacks firmness, the main draw back is it takes an age to go off fully.

 

With RTV silicone there are so many choices, maybe too many on first inspection, but the hig advantage is a mould can be created that supports itself, but with a much improved time cure time allowing the creation of a useable mould qiicker

[Colin parks]

Hi Sean,

 

I was looking through your recent posts on the seat moulding.  The seats do not look that short if the resin casting laid on the coach side is in the correct position in post #132.  The prototype photo in post#129 would suggest the tops of the wings are at a level of about half the height of the window.  Your pencil drawing looks a bit tall.  Certainly the seat backs would be angled rather than vertical. 

 

In my experience of working on upholstery, including seating and chairs I have designed, the backs of seating etc. have an angle of between 5 and ten degrees.  Hope that helps.

 

All the best,

 

Colin

[BernardTPM]

I don't have a side on window shot with the seats in view, so the height is guesswork. Comments are welcome.....

The interior shot in your post 129 gives a good indication as the headrest isn't that far from the wall, which would suggest the height is about right now, though I think your headrests should be a little more 'pointy'. Incidentally, I reckon that photo must be of a Mk.2 (or 2a) BSO as the space between the windows looks wide (BR used the BFK shell for the 2/2a BSOs).

[Colin parks]

Hi Sean,

 

I agree with Bernard re. the wing shape: make them more pointed. After all, these seats were designed in the swinging sixties and the coach interior very much reflects that period in terms of styling. The height of the backs in the photo from post #140 looks just about spot-on when comparing with the prototype photo.

 

All the best,

 

Colin

[lancer1027]

Hi Sean,

 

I have just started to scratch build the undergubbins on my mk2's and was wondering if you could take a close up pic of the fuse boxes and explanation of how you built them please. This would be most helpfull.

 

I have bought Peter Cowling resin battery boxes and am about to make the other bits, so any help/ tips would be appreciated.

 

 

 

[45125]

Hi Lancer.

 

You've exposed me for the thicko I am I'm afraid.....

 

Which ones are the fuse boxes?.....

 

Once I know which bit they are, I'll tell you exactly how I did them. Those castings you have pictures above look very crisp too, are the ones to the left the fuse boxes?

 

Cheers.

 

Sean.

Hi Sean,

 

they look like the Pressure Vent unit.

 

Regards

Al Taylor

[lancer1027]

Hi Sean,

 

I hope you dont mind, i copied your pic so i could paste it here to show exactly what i meant.

 

 

It is the on nearest the pressure vent unit but it would be handy to see close ups and know how all three of these bits were made.  right hand cluster ( three ).

 

Rob

[BernardTPM]

That looks handsome, Sean!

[lancer1027]

 

Hi Sean,

 

Thanks very much , that has helped me.

 

Rob

[lancer1027]

Hi Sean,

 

Did you use photographs for your detailling underneath.?

 

I cant find a decent close up pic of the fuse boxes and cables from it.

 

I did this on my BFK and have started to make some more for the TSO's

 

 

 

Rob

[lancer1027]

Hi Sean,

 

also do you have any pics of the roof detail on the toilet end?.

[BernardTPM]

Mine is one of the early vacum braked examples that ended their days in the highlands, (Mk2z?), and so have the earlier Mk1 pattern doors.

Just Mk.2 as Z is the TOPS style coding, used as the last part in the code. A Mk.2 TSO is AC2Z.

 

Probably the best place to check for 'errant' lettering (Inter-City, Scotrail, ScotRail) on these coaches is to browse through contemporary 1980s magazines: RAIL Enthusiast, Motive Power Monthly, Railway Magazine, etc. or perhaps the Platform 5 coaching stock books.

Edited October 26, 2013 by BernardTPM

[45125]

Thanks Bernard.

 

Your comment is very well received, I can assure you.

 

And to Lancer, I have taken you a couple of photo's of the parts you asked about, both front and back.....

 

20131025_102343.jpg

 

20131025_102308.jpg

 

The more chunky two of the three moulds are direct lifts from the Tri-ang chassis with various bits of plastic rod added to represent the bolts etc. The other one is from a Heljan Mk1 spares fret and from memory, was part of the Restaurant Car roof moulding, cut down and slightly adapted. The cylindrical "pipes' are just plastic rod and should, in reality be "ribbed". I may replace these with some air hoses if I can find some or if not, a bottom E string from a guitar.

 

Hope this is all of some use, please ask away if you need to know anything else.

 

Cheers.

 

Sean.

Sean, 

 

the piece of 'conduit' you have going from the bottom of the box to the other box in the photos dosn't need to be there, as the cables that link those two boxes go from the side of the small box(2 large cables and i small multi core cable) and enters the middle box about the position you have it. On Mk2abc these cables are in flexible conduit on a Mk2 the cables are usually wrapped in PVC tape until an elbow at the bottom of the middle box.

 

Al Taylor.

Edited October 26, 2013 by 45125