Tips: Scratch Building

Scratch Building

CORRUGATED IRON

Imitation corrugated iron can be quickly made by using aluminium foil and a pair of pliers. Take a strip of foil four times the length of the jaws of the pliers, fold this in half and glue a piece of paper in between. This latter strengthens the foil and enables a better impression to be made. The jaws of the pliers are now pressed firmly on to the foil and slowly worked along the strip, which, of course, leaves the impression of the ridges.

RIVETS IN PLASTIKARD

People who scratch-build items such as locomotives and water tanks leave out such super detailing as riveting for fear of ruining the appearance of the model if not done well. For places where rivet detail is essential, such as smokeboxes, use Plastikard. The rivets are produced by placing the Plastikard on a piece of semi-soft wood (Balsa is too soft), and pressing with a pointed instrument such as a needle file. The type of rivet depends on the point and the pressure applied. When you have mastered the knack of doing this, and produced rivets that are equidistant, the card can be stuck to the metal of the item with an impact adhesive.

CUTTING CARD

When a lot of card has to be cut, such as when making up a card kit, a simple gadget can easily be made which will give greater accuracy. Obtain a steel engineer’s 12in rule and drill a hole at one end (it may already have one). Now screw the rule down to a piece of flat plywood or other similar wood that does not have a soft grain. The card to be cut is now slipped under the rule, and slight pressure put on the other end, with the palm of the hand resting on the card not to be cut. More concentration can now be given to the actual cutting operation.

LOW-TACK PARTS HOLDER

Positioning small parts can be tough when model building, but here is a good trick that makes it easy. Dip the end of a toothpick in a glue stick (paper paste in a retractable tube). Grab the front of the part with the sticky toothpick, add a drop of super glue or plastic cement to the back of the part and place the part exactly where you want it. Wipe off sticky residue with a cloth.

TELEPHONE POLES

For realistic plastic telephone poles, drag an old razor saw blade down some plastic rod (like whetting a knife blade). Repeated scraping creates a pattern of groves that make the pole look more like wood. Paint the pole brown then dry brush to highlight the details. Be sure to dry brush around the bottom to replicate creosote.

SIMULATING BOLTS

Cut off the heads of ordinary pins and push them into wooden structures such as bridges to simulate bolts. They also make convincing rivets on simulated metal structures. Save the unused part of the pin for inserting into the feet of people and animals to fix them on your layout.

BENDING PLASTIC TUBING

This can be a problem in that at the curve point the tubing may collapse. To prevent, or lessen, this problem insert a length of flexible wire of as near as possible to the diameter of the inside of the tube. Now place the plastic tube in boiling water for a moment or two and carefully bend it to the required shape. Hold the tubing at this new shape and run it under the cold tap until set, then carefully remove the wire.

PAPER BACKING

A piece of paper or light card stock cemented to the back of scribed or milled wood siding eliminates many problems encountered while cutting window and door openings. Cutting openings too close together, or near the edge of the sheet, often cracks off a strip of wood that wasn’t intended to be removed. The paper backing holds the sheet together, allowing intricate cutting.

FIND THE EXACT CENTRE

How often have you wanted to find the exact centre of a circle? You can if you follow these simple directions using a compass and a little maths. The radius of a circle is equal to half its diameter, or: R = ½D. For example, trace a one inch diameter circle on paper, set the compass at half an inch, place the point of the compass on the pencil line and draw an intersecting circle. Place the point of the compass on one of the intersecting points and draw another circle. Repeat this step at the other intersection to draw another circle. The second and third circles will intersect at the centre of the original circle.Using a ruler, draw a diameter line through the centre of the circle. Now all you have to do is to apply this example to the size of the circle you want to find the centre of and the rest is easy.

FOIL PREP

Here’s a handy hint for finishing with foil. Wrap a cotton bud, or your finger, in soft cloth to flatten and smooth the thin foil from chocolate or candy bars. Brush a 50/50 mix of rubber cement and mineral spirits on the foil and let it dry overnight, then apply the foil as desired.

TIGHTENING STRETCHED SPRUE

To tighten stretched sprue antennas or similar items where the fine sprue sags, use the hot match-head trick. Stretch the sprue to the thickness you want, attach one end to the model with a tiny drop of gap-filling superglue and allow it to set. Attach the other end in the same way but don’t worry if it isn’t tight and straight. Strike a match, let the head flare up, then blow out the flame. Quickly pass the hot, smoking match-head about 10 mm under the sprue as in the illustration. The heat rises with the smoke and at first the sprue sags a bit, but then it becomes taught. Remove the match so you don’t melt the sprue. Practice makes perfect. Try this a few times on test models so you can get the hang of the separation distances and timing of the process. The type and thickness of plastic sprue and the location on the model will all affect the application of this trick so don’t be put off by early flops.

BOLT HEADS

Pins with different sized heads make great bolt heads, door knobs, and similar raised rounded objects. Cut off the shank to the desired length and press the pin into the model.

MAKING STAIRS

Take a length of stripwood 1/8” square and about 2 inches long and tape the ends to a flat working surface. Now cut two properly distanced crosswise slots halfway through for the stringers. Clean out these slots. The width of the slots should be only wide enough to provide a snug fit for the backs of the stringers. It is not necessary to glue the strips in place. Once this is done, you have a firm set of stringers that will allow you to work without their moving. This method will also work for wider stair units having three stringers, as well as for similar projects such as wooden ladders.

EASY CABLES

Coat a segment of string or thread evenly with superglue. When the glue dries, you will have an easily shaped cable. Cut it to length and glue it to a plastic cable end or tie it off with the wire from a twist tie.

PHOTOETCHED PARTS

Before you use your hobby knife to remove photo-etched parts from their frame, apply a piece of masking tape to the back of the frame. The tape will keep the parts from flying across the room or falling onto the carpet. Paint thinner will remove any tape residue from the parts.

CHROME REMOVER

If you need to remove chrome plating from model parts but don’t want to buy expensive commercial strippers, try soaking the parts in vinegar for a few days. Vinegar is mildly acidic and will gradually soften the plating without harming the plastic underneath.

SHEET METAL SOURCE

Before you throw out damaged 3½ inch computer disks, remove the metal protecting device that covers the surface of the disk. The metal is thin and cuts easily. It is ideal for scratch building and other modelling purposes.

CLEAR PLASTIC

Always be on the lookout for supplies of clear plastic acetate sheet. Limited amounts are commercially available including overhead projection acetates, however, several free sources are worth investigating. Some shirts still come with such material as reinforcement packaging for the collar which tends to be of good quality. Of lesser quality, but more plentiful, is food packaging as well as packaging around other household and clothing items. Depending on what you want it for, lower grade sheet can be used for broken windows on buildings or shattered windscreens on vehicles. Dusted with pastel chalk, they look very realistic. Naturally, better quality sheet should be used for windows in buildings and the use of fine permanent pens, used for overhead projector transparencies, are good for drawing directly onto the sheet to simulate stained glass windows.

SILVER FOIL WRAPPING

Thin metal foil such as that found wrapped around chocolate bars can be ironed flat and burnished with a blunt wide tool such as the back of a spoon. When glued to a piece of flat plastic with PVA glue, the foil can now be used to simulate a mirror in a building, or a vehicle mirror. Use the glue sparingly and avoid a dusty environment as any uneven surface will be emphasised by the reflective material. The effect is much more realistic than silver paint which is not quite convincing when applied with a brush. Aviation modellers use this technique to simulate an aircraft left in bare metal finish. As you will have realised by now, most hobby techniques have applications across more than one modelling discipline.

ETCHED BRASS FRETS

If you use photo-etched accessories in your modelling, the left over empty frets can be of use as well. The fret, which is the parts carrier like the sprue on an injection molded plastic kit, is a very useful supply of small strips of brass. Being relatively thin brass, it is easy to cut and can be bent using a metal ruler and a wide flat blade or strong pair of tweezers. If you don’t use the photo-etched parts yourself, try asking other modellers at a local club who do. These left-over frets are worth having in your spares box and you will find many uses for the brass strips.

COPPER WIRE FOR LIFE

Ever wanted some fine copper wire for a modelling project? Discarded electrical equipment such as lamps, irons, toasters and the like are your answer. Cut off the cord before you throw the appliance away, strip off the insulation and you have all the wire you need.

COTTON BUDS

As well as the normal uses for cotton buds such as for cleaning and polishing, especially in inaccessible areas, do not aimlessly throw them away. They have further uses. Soak the cotton off of each end by immersing in water overnight and the hollow tubes remaining can be used in various scales for a host of purposes. For example:- scaffolding, lorry loads, pipe lines for water or oil, fence posts, and many more which your active brain will be able to think of.

STAPLE SUPPORTS

Ordinary office staples are very useful for many things helpful to the railway modeller. They make good braces under roof walks or under brake platforms on cars and they also make realistic grab irons on freight wagons.

STIFFENERS

Plastic boxcars, walls of buildings and other plastic models tend to cave inwards after frequent handling. One method to strengthen these is to use material which normally would be thrown away such as match sticks, ice cream sticks and other scraps of stripwood. Glue these stiffeners to the inside walls of buildings, wagons and similar structures in need of strengthening.

TILING ROOFS

Reproducing tiles for roofs from cardboard is easy if you have a not too sharp knife, a pocket knife is probably best, some cardboard about 2 mm thick and a little patience. Score lines with your pocket knife across the cardboard to represent the lay of the tiles. This is done freehand to give an uneven finish and the lines should be fairly deep but not right through. After scoring, insert the point of the knife underneath the loose card at intervals along the lines. These need not be mathematically even as the more irregular the downward scores, the better the finished tiles will appear. The edges of the card can be peeled to obtain scale thickness at the sides of the roof. Dabs of Indian ink should be applied to the roof and allowed to dry before painting. These will show through as dark patches and give a weathered appearance. Use poster paints — a mixture of red, cobalt blue and chrome yellow will give various shades to suit your taste.

STRENGTHENING CORRUGATIONS

Modellers who use corrugated cardboard, the kind found in cellular phone boxes and the like, will often find that it needs stiffening when used to represent corrugated iron for roofs, fences and so on. A simple trick is to insert thin copper wire into the rounded parts of the cardboard before painting.

MAKING CORRUGATED IRON

Here is another way of making corrugated iron for fences, roofs, farm sheds, or whatever structure needs this material. All you have to do to make this gadget is to look out your old Meccano set from the attic, or raid your son’s Meccano box. The Meccano parts needed are: 1 only 5½ inch x 2½ inch angle plate. 3 only 2½ inch x 1½ inch angle plates. 4 only ¾ inch gear pinions. 3 only bushes. 1 only 3½ inch rod. 1 only handle. Now assemble as shown. Some aluminium foil from the kitchen cut to 1¼ inches wide, doubled and fed through makes good sheets of corrugated iron in no time.

TINTING WINDOWS

Here is a trick the model aeroplane builders use to tint windshields and aircraft canopies. Colour Johnson’s Klear floor polish with a few drops of brown water-based writing ink. Brush-paint the windscreen or window with several coats to build up the colour depth, and as the Klear is so thin, the brush marks self level. It is important to use a water-based ink as some other substances can turn to gel when mixed with the Klear. Note: In America, Johnson’s Future floor polish is the same product.

KEEP THAT OLD UMBRELLA

Don’t throw out that old wind-ravaged umbrella. The fabric is ideal for many modelling applications such as car convertible tops, tarpaulins on railway wagons and lorry loads, and many other uses.

SIGNAL BOX LEVERS

After spending a lot of time building an HO kit of a signal box, you study it and decide it looks a bit bare inside. Because you can see clearly through the large windows, lever frames are the obvious equipment to start with. Take a discarded comb and cut away the teeth. File the base flat and paint the levers as follows: One lever at each end is yellow for distant signals; the home, starting and siding signal levers next to the distant are red; the remaining levers for points are black. The tops of all levers for 3 mm down are painted silver. These dummy levers are now stuck to the floor about 5 mm from the window and when seen from the outside, give a vastly improved appearance to your signal box.

USEFUL CRAFT STORE SUPPLIES

Take a wander through your local craft store and you will be surprised just how many items they have in stock that are useful to modellers, especially those who scratch build.

EXPERIMENT

Don’t be afraid to experiment with new techniques. The modeller who never made a mistake never made anything.

RAID THE SEWING BOX

If you are modelling pipes, cables, handrails and similar items, instead of using wire to represent these, raid the sewing box for black elastic. If you carefully cut it lengthways, you will find you have lengths of black rubber of varying diameters which make ideal pipes, cables, and so on. They are flexible, so less likely to be snapped off by clumsy fingers , and also self coloured , which means the paint will never chip off to leave an unrealistic shiny patch.

KEEPING PUTTY MOIST

Take a tube of Tamiya putty and squeeze the contents into a bottle of Testor’s liquid cement. Allow the mixture to soften and then shake it to get a uniform consistency. In just a few minutes you will have a great filler that won’t go dry on you, is very easy to apply, and will ensure a better bond between parts. As the jar already has an applicator brush, you will not ruin any more of your good paint brushes either.

SOLENOID SOURCE

If you know of anyone throwing out an old electric typewriter, ask them for it. The typewriters contain a number of low voltage solenoids which are ideal for use in working signals.

SPENT LIGHT BULBS

The coiled tungsten elements in burnt-out light bulbs can be used to simulate microphone and electronic cords for models. Take care when breaking the bulbs to remove the element and wear eye protection.

STRETCHING SPRUE TECHNIQUE

Sprue is the plastic “tree” that holds the kit parts together in the box. Cut a length of about 120 to 130 mm and roll it with your fingers over a candle flame at about 10 mm above the point of the flame. Keep rolling it while it heats and soon it will swell slightly, look wet, then become loose in your fingers. Remove the sprue from the flame and pull the ends apart. The temperature of the plastic and the speed that you pull will determine how fine you can stretch the sprue. It needs a little practice to get the hang of it. Always use super glue to attach stretched sprue as plastic cement will melt it.

GRAIN IN PLASTIC

If you want to give plastic poles, strips or sheeting a wood grain texture, you can use very course grain sandpaper rubbed in the direction of the grain. Another method is to use a fine saw blade and stroke it along the grain direction. Follow this treatment by rubbing along the direction of the grain with a hard toothbrush to remove any loose plastic while still retaining the grain effect.

STEEL WIRE STEPS

The flat steel wire often included in model kits to be used for making steps on rolling stock, is generally too brittle to bend without it breaking. This material can be made quite bendable by heating it over a candle flame. Be sure to hold the material with a pair of tweezers or other suitable tool so you don’t burn your fingers. Pass the steel very slowly through the candle flame. The metal will heat up and glow with a dull red/orange colour. Allow the heated material to air-cool on a non-combustible surface, and, after it has cooled, the steel can be readily bent to any required shape with no fear of breakage. Any surface contamination can easily be wiped off, and the discolouration does not have any subsequent impact on glueing or painting.

A SOURCE OF BARRELS

The metal tops which hold the erasers onto lead pencils can be used as large barrels on an HO layout. After carefully pulling them off the pencil, the eraser may be removed for an open topped barrel, or it may be cut, sanded smooth and painted for a closed barrel.

SCRAP ELECTRONIC EQUIPMENT

If you get the chance of getting your hands on electronic equipment that is destined for the tip, grab it. Such things as computer printers, typewriters and the like are crammed with gears, wheels, springs, fasteners and similar gadgets which are great for repairing or kitbashing model railroad items and some even make interesting loads for wagons.