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Modelling => Buildings and Structures => Topic started by: berryr99 on March 25, 2015, 15:50

Title: Plasticard - Warping
Post by: berryr99 on March 25, 2015, 15:50
Hello all,

Now that Blaenau North is finished (although there is a whole debate about whether a layout is ever finished !) I am building a new layout which has china clay at its centre.

I have built a clay dry out of plasticard and this is the first building I have ever completely scratchbuilt.

However, some of the walls and most of the roof have warped. Therefore I must be doing something wrong.

Can anyone advise me on how many layers of plasticard should be used, whether I should use a balsa inner wall and what thicknesses of plasticard should be used.

I'm looking for a tried and tested technique that members know won't result in warping.

Thank you

Robert Berry
Title: Re: Plasticard - Warping
Post by: theelliotts on March 25, 2015, 16:30
If it is possible to brace internally then that should work. Otherwise an odd number of layers, as in most plywood, is best. This will hopefully balance the stresses and resist warping.

Good luck.

David
Title: Re: Plasticard - Warping
Post by: B.Meldon on March 26, 2015, 15:56
I have never found a way to stop palasticard from distorting with time so I do not use it for building or rolling stock sides. Although in small sections it is fine.

So I use tin (from biscuit tins) rather than plasticard.

It can be cut with scissors, bent (and bent back again several times if you get it wrong) soldered, glued and once in place it never warps and it is free as well!
Painting is easy and with the surface prepared and free from oil or grease I do not even use any primer.
It is very thin so can be used to represent metal sheet and if you need added detail like panelling strips you can just stick on some plasticard strips of the required size.
The only down side is that it has sharp edges that need to be careful with and may need to be filled down. It is also no good for thin (less than a couple of mm) strips as these tend bend when you cut it.

Brian Meldon
Title: Re: Plasticard - Warping
Post by: alan gee on March 27, 2015, 13:42
The best way to stop plasticard warping is to always use three layers. I use a outside layer of Wills sheet, which has holes cut in it to take the doors and windows. A second layer or clear sheet for the window glazing, And a third sheet of standard plain white plasticard with holes cut in it for the window openings. All three layers are held together with double sided sellotape not glued. You can not get glue to cover all the surfaces to make a perfect bond. Sellotape gives a 100% bond. Cut through two layers at one end to make a 3mm grove to give a good corner line up.
Kind regards
Alan Gee
Title: Re: Plasticard - Warping
Post by: berryr99 on March 27, 2015, 15:16
Many thanks to all for the various suggestions.

Robert