Scratchbuilding pt. 4: Details

 

In the first two parts we looked at materials & tools, and in the last part we looked at some concepts & techniques for building scale objects out of styrene. If you followed along at home you will have seven part finished items from the last instalment - this time we'll look at adding a layer of two of detail to complete them.

Some of them (or even all of them) will come as no surprise :)

I don't want to be too prescriptive about this, all I can do is tell you what I used. I appreciate that you might not want to fork out for tools & materials under "optional", all I can really say is even if they don't get much use on the scale items in this article, they will come in handy in the future if you've got any ambition to continue building your own stuff :)

You will need:

  • Cutting Mat, Craft Knife, steel rulers;
  • Scriber (see section #6, below);
  • 0.5mm, 1mm, 2mm sheet styrene;
  • EMA Plastic Weld, bulk Dichloromethane, or other liquid/solvent type adhesive, small sacrificial brush(es);
  • M2 x 10mm screws (three), short M3 cap head screw (10mm suggested) (two);
  • 1.5mm, 2mm, 2.5mm and 5mm drill bits (& a drill to turn them);
  • Needle file;
  • wet & dry papers of rough, medium & fine grits (e.g. 120, 400, 1200), washing up liquid;
  • Long M3 Screws + garden wire or similar;
  • Isopropyl alcohol, lint free cloth;
  • Primer;
  • various shades of model paint (see later for suggestions).

Plan can be downloaded in the bottom of this article.

Optional:

  • Plain Paper Clips (c.33mm);
  • Small flat jaw pliers, small needle nose pliers, aviation snips;
  • Dremel & large sanding drum;
  • Regular Poly glue, Superglue (CA);
  • styrene forms:
    • .035" (0.88mm) round styrene rod (#220),
    • 1/16" (1.6mm) round styrene rod (#222).

 

#1: Box With Rough Edges -> Crate

With the addition of some 5mm wide strips cut from 1mm sheet this becomes a crate (and in the next instalment it'll get a passable wood effect).

Adding the strips has got to start somewhere, and it might as well be the sides: basic dimensions for the box were 50mm X 35mm X 35mm, so the strips along the top & bottom need to be 50mm long (total of four needed), and the strips up the sides 25mm (35 - 5 - 5), again four are needed. All the strips should be glued on level with the edges of the box (see image 01).

On the ends, the strips should be level with the box on the top and bottom, but also level with the strips previously added to the sides - i.e. the four top & bottom strips need to be 37mm (35+1+1), the four upright strips again are 25mm long (35-5-5) ( see image 02).

On the base and top faces of the box, all the strips overhang the box edges & match up with the strips already fitted, so the long parts need to be 52mm (50+1+1), and the short bits 27mm long (35-5-5+1+1) (four of each) (see image 03). A few gaps and inaccuracies will add to the realism - 1:1 crates are not made to exacting standards.

jr scratch 4 001 jr scratch 4 002 jr scratch 4 003

 

#2: Long, Low Box -> Ammo Box

The first step is to cut a 5mm wide strip of 1mm sheet, cut into two 80mm and two 27mm (25+1+1) lengths, and glue around the top (image 04). Fill (image 05) & sand back to get neat (or rather, near invisible) joints (image 06).

jr scratch 4 004 jr scratch 4 005 jr scratch 4 006

 

Note: in hindsight the rest of this section is probably too fiddly for a basic piece, I think it will pass with just the lid detailing done - so don't feel you have to do any more than that.

 

Cut a 4mm wide strip from 0.5mm sheet & cut off two 20mm lengths - these will be fake hinge straps. Mark each piece 5mm from each end & carefully fold one end outwards, one inwards (image 07).

Choose one long side of the box to be the back & mark 12mm and 16mm from each end, then glue the hinge straps between the marks. Be careful about how much glue you use as weakening the styrene at the already stressed folds can cause them to fail. Add two 4mm lengths of 0.88mm rod at the lower folds to simulate the actual hinges (image 08). This is particularly fiddly, I used regular Poly glue instead of DCM for these bits.

jr scratch 4 007 jr scratch 4 008

 

Cut two 8mm lengths off the 4mm strip, bend halfway & glue to the "front" of the box, opposite the hinges, then fix a 4mm length of 0.88mm round rod across the bottom of each (image 09).

Cut two 9mm lengths off the 4mm strip, and set two aside for now. Glue another 4mm length of 0.88mm rod across the top of the other two, and another about 2/3rds of the way down. Place (but DON'T glue) these assemblies beneath each of the upper "catches".

Form a small square (4-5mm across the inside of each side) out of paperclips: use a pair of flat jawed pliers to straighten a couple of ordinary, plain, regular sized (c.33mm) paperclips (image 10), then use a pair of small needle nose pliers to form the square with an overlap on one side (image 11). Cut through (aviation snips worked best for me) on the overlap, then bend the form square & straight again (image 12).

jr scratch 4 009 jr scratch 4 010 
 jr scratch 4 011  jr scratch 4 012

 

Place these parts so they pass over the two sides of the "catch" - then with the lower catch located properly the styrene parts can be glued down. Hold the metal parts on with delicate dabs of superglue (image 13). I found squeezing a bit of glue on to a cocktail stick & using that to apply it worked much better than using the glue direct from the bottle would have done.

Glue on 8mm lengths of the 4mm (x 0.25mm) strip so the rod part of the top "catch" is exposed (image 14).

jr scratch 4 013 jr scratch 4 014


Fake carrying handles at each end are 12mm x 8mm pieces of 0.5mm sheet, and 12mm lengths of 1mm wide strip cut from 1mm sheet along the top edge (not pictured).


#3: Box with rounded edges -> Cooler Box

This starts with yet another 5mm wide strip (at least 155mm long) cut from 1mm styrene sheet - glue on starting halfway along one end and wrap all the way round, clamping or taping as needed to keep it in place (image 015). That may take some time, but when you're done, fill along the top joint (image 16) then sand back until the top is even, then slightly radius all the top edges (image 17).

Cut a 102mm length from 5mm X 1mm strip, mark lines 3mm and 25mm from each end. On the 3mm lines, drill 2mm holes and round the ends of the strip. Bend around something at the 25mm lines (don't just fold, it'll snap) to form a broad U shaped handle. Also make two 5mm diameter spacers from 1mm sheet (image 18).

Glue the spacers on the ends, 2mm from the top edge detail. When set, drill a 1.5mm hole through the centres (image 19).

Test fit the handle to the box with M2 x 10mm screws (image 20).

jr scratch 4 015 jr scratch 4 016 
 jr scratch 4 017  jr scratch 4 018
 jr scratch 4 019  jr scratch 4 020

 

#4: Low, Wide Cylinder -> Spare Wheel Cover

The dimensions of 88mm outside diameter, 33mm depth are intentionally the same as the stock wheel & tyre found on most Tamiya CC-01 chassis, and there are a few things we can do to make it look a bit more like a spare wheel cover - and to make it easier to fit on to the back of a scale body (if that's what you want to do with it).

Use a small needle file to put grooves in (of random length and angle - don't go too deep) to simulate wrinkles (image 21).

Use lengths (around 280mm) of 0.8mm round rod for the seams (image 22).

The spacer/mounting on the back is two 20mm x 20mm bits of 2mm sheet. Drill a 2.5mm hole through the middle & fit a short M3 screw (image 23).

jr scratch 4 021 jr scratch 4 022 jr scratch 4 023

 

#5: Taller Cylinder -> 200 Litre Oil Drum

To turn this from a simple cylinder to an oil (or similar) drum it just needs a few half round details adding to it; you can buy suitable forms, but these are fairly easy to make. To make the top & bottom details (chines), take a bit of 1mm sheet at least 180mm (pi X D = 55mm X 3.142 = 173mm) along the long edge as the very ends tend to get a bit thin.

Sand back to a round shape - I used 180 and 400 grit papers with the bulk of the work done with a full sheet of wet & dry on the bench. Cut a 1mm thick strip off, and you should have a half round shape. Repeat for the second one.

Bend each strip (flat side down) around something small and round (like an AA battery) to help with the shape. Trim one end back a few mm to a square end & starting gluing on - the first part seems to take the longest to set so either hold it in place or use masking tape. Trim the other end to get a close join when you get to it.


The two middle details (rolling chines) can be made the same way, but with 2mm sheet as the starting point (see image 25) as they need to be more prominent. This will take a bit of extra work if you do it all by hand - I gave myself a head start with a Dremel & a large sanding drum. With these fitted (hold the drum up to the light & use the internal braces as a guide - see image 25), the diameter should now be a 1:10 scale 58mm to 59mm.

j

jr scratch 4 024 jr scratch 4 025

 

Drums like this typically have 2" (51mm) and 3/4" (19mm) bungholes - we could replicate them fairly effectively with styrene forms, but in the interests of keeping costs down by not buying another 3 varieties just yet, I'm going to suggest faking it with M2 and M3 cap head screws instead.

Start by making 5mm and 8mm diameter circles from 1mm sheet (image 26) & radius the edges on one face. Glue these 3mm from the edge (and 180 degrees apart) of the recessed end of the barrel (see image 27).
Once set, drill a 2.5mm through the centre of the larger disc, and a 1.5mm hole through the small one. Fit M2 & M3 screws as appropriate (image 28), these can be any length between 4mm and 25mm, if you have to buy some I think 10mm would probably be the most all round useful size to get.

jr scratch 4 026 jr scratch 4 027  jr scratch 4 028 

 

#6: Ellipse -> Surfboard

Most of what will make this look more like a wooden surfboard will be done later with paint effects, but there are a few details that can be added with more styrene.

Leash cup (point at which a leg rope attaches to the board): drill a shallow 5mm hole near the end of the board (mark the drill bit with tape 4mm from the end - see image 29) then fit a 5mm length of 1.6mm rod or similar in the hole.

Fins: cut a number of small fins from 2mm sheet, shape as you wish (but make the leading and trailing edges rounded while keeping the base flat) & glue on the underside near the tail (images 30 and 31).

Grip pad: cut a 25mm wide strip from scrap paper or card (image 32) & use that to make a template. Transfer that to 0.5mm styrene sheet, and sand the edges of the top face (image 33). Scribe in a pattern - I made a simple herringbone form (image 34). Don't glue the panel on yet.

Note on scribers: I'd recommend the Tamiya Plastic Scriber II; but anything small, metal and pointy will do in a pinch - a small flat bladed jewellers screwdriver can work quite well, but you can experiment with a pin, nail, even the point of a scissors blade.

jr scratch 4 029 jr scratch 4 030 
 jr scratch 4 031  jr scratch 4 032
 jr scratch 4 033  jr scratch 4 034

 

#7: Pallet

In my experience, real pallets usually come in one of two varieties - almost new, or dangerously dilapidated. I did briefly consider introducing a "break" in one of the upper planks & perhaps have one of the lower runners hanging off with fake bent nails sticking out - but I thought that would limit it's later use, so this remains unchanged from the previous instalment.

jr scratch 4 035

 

Preparation/Priming

Although it's technically possible to paint colour straight on to styrene, I think it's well worth using primer - for a start it can highlight any areas that need re-filling, and if not, another good reason to do it is that Plastic Weld (or Dichloromethane, depending on your preference) works by melting the surface of the plastic, and any areas where it ran along the outside of a joint rather than getting sucked in straight away can show up quite badly as a different texture to the rest.

Before we can think about spraying primer, it's worth thinking about how you'll get to all the angles of the part you're going to paint. Some people are happy to just let the object sit on a bench or a riser of some sort, then turn it over once it's dry to do the other side, but I'd rather arrange it so I can manipulate it while it's wet.

For most small items, my preference is to fix on a long M3 screw with a length of garden wire formed into a hook on one end. This means I have something solid to hold on to while painting - and can hang it up to dry.

Having removed the few screws from the seven objects, two of them (the barrel and the spare wheel cover) already have M3 threaded holes in that we can use. The cooler box handle can go on a bit of wire, and the surfboard grip pad can be blue tacked to a scrap bit of styrene sheet.

The surfboard itself can have a 2.5mm hole drilled part way through (put a bit of tape 4mm from the point of the drill bit to act as a guide & go slowly) the area where the grip pad will be glued on.

For the other objects (crate, ammo box, cooler, pallet), even though it'll leave a permanent visible hole, I think the best thing is to drill a hole through (or part way in the case of the pallet) an unobtrusive part - usually the base.

jr scratch 4 036

 

Our scale bits have a bit too many nooks & crannies (not to mention holes) for cleaning the parts in soapy water to be a good idea, however it's well worth giving them a wipe over with Isopropyl Alcohol (then another go over with a small section from a tack cloth when your cloth turns out not to be as lint free as you'd hoped).

Use whatever brand of primer you're happy with, the main thing is that it shouldn't damage the plastic, and it needs to be compatible with whatever colour paint you'll be using. If you're using an automotive brand primer, try to get the stuff intended for plastic. Halfords stuff is fine, lots of people say good things about Tamiya primer, and personally I like Hycote White Plastic Primer. Eurocarparts often have it on offer, at the time of writing (September 2015) it's 4.08 GBP for a 400ml can.

Spray on at least two coats (the second is to get the bits you inevitably missed the first time), and after allowing enough curing time, give the parts a very light rub down with wet & dry paper - 1200 grit or above.

This is best done wet - but in a very controlled way. Use a stamp sized bit (say 30 x 40mm) of the abrasive & dip in a bowl of water with a few drops of washing up detergent in it. Do a small area at a time & immediately dry off afterwards.

 

Base Colour

Just what you paint these with is up to you - I've got on quite well with Tamiya acrylics, both brush painting and through an airbrush so that's what I've listed here. Airbrushing gives a better finish, but you have to weigh that up against the faff: several coats of different base colours can feel a bit too much like work, so this time I used brushes while listening to the radio & found it quite therapeutic.

 

Crate: this will get a wood effect later & a beige colour is a good place to start that, so I used XF-57 Buff.

Ammo box: a military looking olive/green seems appropriate here - I used XF67 NATO Green.

Cooler: many scale coolboxes seem to have a white top & dark blue lower (I've made some like that myself), this time I went for X-15 Light Green, with X-2 White on the handle. Because those colours are gloss & I'd prefer a more satin finish, I added in a bit of X-21 Flat Base (3 parts paint to one part base).

Wheel cover: while satin black looks good on many modern vehicles, my plans for this involve something different - so it's the same shade of beige I used on the crate.

Barrel: these are often a light blue, Tamiya X-14 Sky Blue seems like a good choice, with a bit of flat base mixed in to tame the gloss (again a 3:1 paint to base ratio).

Surfboard: this will also have a wood effect applied to it (though quite different from the crate) - "Buff" again then, and more light green/flat base for the grip pad.

Pallet: because of all the hard to reach places on this I think brush painting is the only option here - at least on the inside. Once again the colour was "Buff".

The number of coats needed depended on the colour - white only needed one, buff took two, sky blue and NATO green needed three, and the light green needed five to get an even finish.

jr scratch 4 037

 

Downloads:

Plan 1 (right-click and choose "Save link as..")

 

Next Time ...

If you've been building along at home you'll now have seven fairly detailed 1:10 scale objects, but I'll be the first to admit that some of them look a bit flat and not that realistic in a single colour.

In the next instalment we'll cover some paint techniques to make scale objects look a bit more real.

 ________________________
Written by TB member Jonny Retro

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