Polystyrene

Hi All     First time with Polystyrene , I have some scrap Polystyrene which I would like to use on my plank to round off the sharp corner between the baseboard and the end board. But obviously it needs stabilising , my objective is to glue it to the baseboard , but with which glue? I would like to add grass and weeds also a plastic kit , brick wall to the front edge as a “retaining wall”. Can it be done without melting or otherwise the Polystyrene or the retaining wall??Best wishes Kevin

Hi Kevin

Polystyrene will melt if it comes into contact with any spirit-based glues or paint but it can be successfully stuck down with ordinary PVA white glue.  It can be covered with filler/plaster, textured paint or plaster-bandage to create a hard top over which you can do whatever you like in terms of scenic treatment.  An initial coat of brown emulsion or acrylic paint will give you a base coat.  Brown emulsion will emerge if you mix together all those left-over emulsion colours that seem to lurk in the garage/shed.

Plastic kits of walls etc can be stuck to the polystyrene using PVA though you may need to use a piece of sandpaper to rough up the face of the plastic to give the PVA something to "key" into.

Once you get a hard top to the basic scenery shape, you can "plant" trees, fencing, lights etc into it with a dab of PVA.



The above photo was taken to highlight the J39 but in the foreground, the rising ground is a ploystyrene lump carved into shape with an old bread knife and then covered as described above before being treated with flock and static grass.  The fence is Ratio and the bushes are clumps of lichen.  The scenery to the rear of the baseboard is made the same way but has had Woodland Scenics tree kits made up and planted into into it.

A word of warning about cutting polystyrene - its the messiest stuff on the planet so cut it outside or indoor with a hoover standing by to pick up all the little polystyrene balls that will get everywhere and stick to everything!!  A hot-wire is better but if you haven't got one, the bread knife/hoover combination works just fine.

There are a number of very good books on basic layout construction that I would recommend - anything out of the Peco stable is probably worth reading.  A subscription to Hornby Magazine is also worth considering - the contributors tend to concentrate on basic construction of layouts as often as they deal with DCC sound.  I find that the Railway Modeller magazine articles show you the finished results but, IMHO, they are less keen to show you how its all done.  Model Railway Journal is for people who own lathes and cast their nown yard lamps.

Very broad summary of the UK magazine offerings I know!

Good luck with your project.

Barry

Hi Barry.  Thank you for your reply.  The filler that you mentioned, would Polyfiller work? Alas, I don’t have a Shed I will have to try something else. But I do have four plug in yard lights, a bit modern but I am not such a fussy Modeller .Best wishes. Kevin

I use pva or https://www.screwfix.com/p/no-nonsense-11665502-grab-adhesive-solvent-free-white-310ml/87451, note both are solvent free, you need to weight down the polystyrene for a few days to allow the glue to dry.



As for covering the poly, I use pollyfilla (or cheap equivalent) mixed with approximately 1/3 pva  to 2/3 water. This makes the polyfilla a hard shell rather than a crumbly filla..



The above mixture is soaked into J cloths, genuine ones, they have holes in them that allow the mixture to soak through, cheap ones don't have the holes. This is then laid over the poly which hides the Bubblyness of the edges of the polystyrene. More coats of just the polyfilla mixture is then painted over the top as required..

Hi The Q.  Thank you for your reply .  Genuine J cloths? The ones that I have been using lately are heavy duty and blue and one has to watch because the colour runs , alas No holes, I did notice that they are too thick for my “ Lanarkshire Model Service Track Cleaner “ , and that seems to be the choice, them or a plain white substitute. I realise now that I misspelt “ Polifilla “ . Overnight , I used PVA to stick some used “ glass paper “ on the foam to help stabilise it?? I only hope this works. that is weighted down until it sets, no rush, I am hoping that it will give the “ retaining wall “ something to adhere to. With the extra coats of pollfilla. Will that allow for grass and weeds etc?   Best wishes. Kevin

Hi Kevin,

Your local hardware store will have adhesive suitable for HD close cell styrene foam board. Check in the wall insulation department. PVA works, but poorly. Woodland also sell a styrene foam adhesive as part of their landscaping range.Small pieces can be put on with special CA glue.

I would also recommend getting a "hot-wire" cutting system for doing scenery with this foam. Bread knives, saws and the like will mean particles everywhere, and utility knife blades get blunt after 2-3 cuts..

Nigel

Yes I just searched around on amazon and got them fairly cheaply for a large amount (SWMBO had some as well). I'm not sure why but genuine ones have the word CHICOPEE formed in the blue and white stripes.

Hi Nigel.  Thank you got your reply. As for “ Local hardware store “ all of the one man band type of shops in Peckham have been replaced by “ cheap jack £1.00 shops “ where the staff don’t know or care. There are 
“Home Depot type stores “ B& Q for example. And with the small amount of scenery that I envisage on my plank a “ Hot Wire cutter would be superfluous , nice idea though. Meanwhile , it is back to Waiting for God and Glue to dry.
Best wishes. Kevin

Hi The Q.   Thank you . But I haven’t kept it a secret about having my I / D stolen, and since that day I have avoided  Amazon and eBay , the pair that had previously supplied a lot of suitable items. and I am still suffering the consequences, ie Apple seem to think that this very iPad is stolen property, and just because I was advised to change my bank account and email. I shall just have to “keep em peeled” .  Best wishes Kevin

Here is my method for working with polystyrene. To glue the blocks together or to the baseboard I use an adhesive called Weldbond. It is dearer than PVA but you don't need much.

I then cover the polystyrene with rolls of plaster impregnated cloth strips. I get mine from an art/craft store.

If an area needs smoothing say for a building to sit on or a road, I use polyfilla for large cracks.

I find both the cloths and polyfilla take acrylic craft paints quite well.

Good luck
Evan

Hi Evan.   Thank you for your reply. My Shunting Puzzle was never meant to have scenery or last so long. It was merely to get layout building and wiring practice after a break of 40 odd years doing other stuff. And I have been making it up as I go. I found a scrap piece of Polystyrene and it has gone from there, I needed to break up the sheer end board, the Polystyrene is 6”(150mm) long. And will sit at the bottom of a cliff? To represent rock fall or whatever covered in grass weeds etc?       Best wishes. Kevin

just A note, I've just updated my first post as I managed to mix 1/3 water with 2/3 rd water. It now says 1/3 pva with 2/3 water…

Hi The Q.  Thank you. Of course me being me, I misread it, and I managed to read it how it was meant to be.Best wishes. Kevin

[user=1938]The Q[/user] wrote:

just A note, I've just updated my first post as I managed to mix 1/3 water with 2/3 rd water. It now says 1/3 pva with 2/3 water…

Hi Kevin,

Dangerous waters here. PVA starts to behave rather funny when diluted too far. Loss of tensile strength for one. The recommended dilution for woodworking is 95:5 PVA:water v/v. Most applications of PVA in this hobby do not call for a lot of tensile strength, my own experience is that 75% PVA is around the limit for good adhesion. Gluing bits of styrene needs the neat stuff, and works best if the surface is roughed up a bit with some sand paper.

Big problem with styrene-based foams is that decent compression during the tack stage is normally not possible. Best approach is to glue the flat piece, weight it down, then cut/carve when attached.

For what you are doing a chunk of balsa would probably do just as well. If the styrene you have is the light, white material found in packing that compresses between thumb and finger I would bin it. You need the pink/blue/green one meant for insulation.

Nigel

Re cutting polystyrene, it is best cut with a very sharp carving type knife, little or no need for a hoover; any toothed blades will always require the hoover.

Hi Nigel.   Thank you.  My iPad is acting rather strangely at the moment? I was trying to reply and the battery was running on empty?  So I put it on charge. Anyway what I was saying, roughly, I only require a small piece of foam, six inches(150mm)  and the wrong type of foam, that I am using will do for now. Plus the fact that I never intended my Shunting Puzzle to have scenery,as it is supposed to be a test bed for a future layout that never materialised .Best wishes. Kevin

Hi Mike.  Thank you.  My bit of scrap foam didn’t need much cutting. I don’t know what is happening with my iPad today, but you message seems to have changed.  Best wishes. Kevin

Hi Mike       Thank you again . Your.    â€œ How many roads must  a man have to walk down???”  slogan of yours for some reason went walkabout,which is the reason for me having doubts about my iPad , I had best get my finger out and have my “Windows 10 Laptop “ working again.  Best wishes. Kevin

I'm having no problems with Win 7 on 2 PCs and a laptop. I have a little bit of software called "never ten"  to ensure it never invades here. :roll:

Hi Mike.  My HP laptop began life with Windows 8 . But the iPad problems began when I changed my usernameA right PITA    Best wishes. Kevin