Casting windows and doors question

[FifteensAway]

So, can someone with experience walk me through using hobby casting resin (the cheap kind not the professional stuff - like I can buy in a local craft store, either Michael's or Hobby Lobby in these parts)?

Easy enough to knock up some masters (plastic best I'm guessing)?

I know it goes like this: create master, create 'box', apply release agent, mix resin, poor resin, pop model out.  But I'd like more careful and sage advise from someone with real experience.

Reason for question is I'm going to need dozens of doors and scores of windows for what I have in mind.

Thanks!   

[tomrommel1]

Up to building the box everything is alright but the mould for resin is made from silicone. So when made the master and build the box put in release agent and pour silicone for resin moulds in there box . Then dismantle the box, get the master out of the cured silicone mould and then apply release agent to the mould and pour resin into the silicone mould.

[Lovejoy]

These two old Kickstarter updates we did might help. They were for Burrows & Badgers terrain, so a bit bigger than widow size, but all the basic principles will be the same:

Moulding

Casting

cheers,
Michael

[snitcythedog]

Ditto on the above and nice toots Lovejoy.  Here is what I did as it is a similar project. 
http://snitchythedog.blogspot.com/2011/04/modern-windows.html
If you are casting just the frames like I did then you really need to ensure there are no bubbles.  A vacuum chamber will do the trick but if you are doing it without one then only cast one or two windows at a time and coax the bubbles out individually with a toothpick before the resin sets. 

[Codsticker]

Check out the Smooth On site; even if you don't use their products you could probably learn something.

[FifteensAway]

Thanks for the replies.  I will study on this and then get to work when time permits (seems to always be in too short supply).

[Klingsor]

Some random notes.

I glue the master to a bit of wood a bit larger than it is, the same dimensions as the mould box and attach the card, mounting board usually, to the wood, usually by stapling it. Then I make sure to seal all the gaps with masking tape and mark a point 5mm or so above the highest point of the master as a rough 'fill to here' guide.

The length, width and depth of this give me a rough guide of how much silicone to mix. Dont use a thin plastic or presumably polystyrene cup to mix the silicone  as it eats it but a waxed paper cup will work, you can reuse this container anyway as the cured silicone peels off.

I use a little set of scales for most of this, charmingly referred to as my crack dealers scales as there cannot be many innocent uses for them occasionally resorting to kitchen scales for bigger moulds. Do make a note of the empty weight of the mixing cup!

Resin needs to be warm to cure properly but will go off too quickly if it is too warm. Always wear gloves as resin and silicone are horrible and do put down plastic sheet or newspaper just in case.

Coffee stirrers are brilliant,  you cannot have too many of them but silicone usually needs something stronger to mix it like a tongue depressor.

If you did not mix enough silicone  don't panic, it sticks to itself quite happily so you can make another pour.

[Belisarius]

An easier alternative is to print out images of doors and windows in card or paper , resized to your requirements ie. 15 or 28mm .  Stick onto the model buildings and use cut matchsticks for the lintels or windowsills . Easy peasy lemon squesy. 😎

[Roo]

Genius idea and duly appropriated!

[FifteensAway]

I have given thought to Whitewash City.  They have a set or two of windows and doors.  Might work for much of what I will build - mostly 'background' buildings as opposed to 'foreground' buildings.  Will explain more when further along in the process since I'm still deciding what I'm doing to a degree.

[Andrew May]

Would a simple press mould work for this?
Also have you considered getting your masters cast by a professional? Once you factor in your time requirements it might actually be the cheaper option.

[FifteensAway]

Original thought was to be some sort of plaster mold that I poured something in to to create what I wanted since a dead flat back would be desirable.  So, I guess, yes, some sort of press mold might work.  Just thought resin might be it.  I am certainly open to other ideas.  I like cheap! 

[Brandlin]

If you really like cheap then look for "blue stuff" on the green stuff worlkd website. Its also called "Oyumaru" and cheaper elsewhere. Its a thermo plastic material that you heat in hot waterand then form over the item oyu want to cast. You can then press in green stuff, modelling putty or epoxy resin.

The Oyumaru is reusable simply by reheating it.

[Andrew May]

If you really like cheap then look for "blue stuff" on the green stuff worlkd website. Its also called "Oyumaru" and cheaper elsewhere. Its a thermo plastic material that you heat in hot waterand then form over the item oyu want to cast. You can then press in green stuff, modelling putty or epoxy resin.

The Oyumaru is reusable simply by reheating it.

I’d go that route myself but try using supersculpy or similar rather than greenstuff.