Metal parts

Lexan is a polycarbonate with applications in various fields. In industry it is used for its resistance to impacts and shocks without shattering or forming splinters. For this reason, it finds various applications with bullet-proof, shatter-proof, vandal-proof or anti-intrusion functions. Its transparency index is comparable to that of glass with a much lower specific weight of 1.2 g/cm3.
Thermoforming is the most widely used technique for processing lexan. Tamiya has built the success of some of its models on the precision and accuracy with which lexan bodies were constructed.
The technique for building a lexan body is called thermoforming: a mould and a lexan sheet are required, the mould and lexan sheet are heated and the hot mould is used to shape the lexan sheet.
Lexan bodies are prized for their impact resistance, but it is well known that a lexan body when damaged is not easily repairable.
Today, UV adhesives make it possible to repair damage to lexan bodies. There are two operations that can be performed: gluing a part that has come off and closing a crack or hole.
The UV glues are in liquid form and the repair kit consists of two parts:

1 – Liquid dispenser in the shape of a felt-tip pen with a metal spout to distribute the fluid correctly on the surface and
2 – UV LED lamp, the liquid only solidifies when illuminated for at least 10 seconds.

Lexan bodies have an aesthetic and functional function; they protect the chassis from minor impacts due to lexan’s property of being elastic and resuming its shape after an impact.
These glues are transparent and can be painted in exactly the same way as a lexan body.
Another advantage of these glues is that when they solidify they have the same elasticity as a lexan part, a body repaired with UV glue becomes rigid again and has as much shape stability as it did before the breakage while maintaining the same elasticity in impacts.
UV glue does not chemically attack lexan, it forms a thin layer that joins two different flaps of material.
It is a common opinion that a lexan body that has a breakage should be replaced with a new one, there are cases that this is not possible: the body is either no longer in production or has ‘historical’ value as it is complete with accessories and stickers that are no longer in production.

Glueing parts
In the event of very strong impacts, it is possible for stressed parts to tear away from the body. Due to lexan’s characteristic of not falling apart, the break is usually linear and clean enough to be suitable for repair. The break must be linear: not necessarily straight, it can take the shape of a wave, but not look like the teeth of a wood saw. There is no point in trying to file or sandpaper the break lines, the two parts to be glued together must have overlapping edges like a jigsaw puzzle. Parts that break off must always be kept, they cannot be replicated.
The following sequence of pictures shows the procedure for joining the front bumper of a Porsche 959 model 58059 that has detached from the rest of the body:

– when the body is free of paint, clean the affected parts with denatured alcohol,
– fix the bumper from the outside of the body using masking tape,
– Use the dispenser with the metal nozzle to place a layer of fluid along the break line. Distribute the fluid in a slow, linear movement in one direction only; avoid going over the same spot twice so as not to accumulate too much fluid. If you are not convinced by the quantity placed, pass another film of material after the first layer has dried,
– light the liquid with special LED lamp for as long as it takes to count from 1001 to 1015,
– when possible, leave the protected part exposed to sunlight for an hour, the liquid solidified with the LED remains sticky. Sunlight treatment solidifies it completely,
– if the repair is not solid, apply several coats, repeating the procedure from step 3 to step 5,
-remove masking tape and
– paint the part

In this restoration it was decided to keep the stickers, the body was very badly damaged: the aim of the restoration is to restore integrity to the body. Stickers of this model are very rare. Before the repair, the paint was removed and after the repair the body was completely repainted.

Closing a hole
In the event of rollovers, some corners of the body may become perforated, in which case the body must be rebuilt using as much original material as possible. Never work the breakage points with glass paper or blades.
The following sequence of pictures shows the procedure for closing four holes in the rear of a Porsche 959 model 58059:

– When the body is painted, clean the affected parts with warm water and dish soap. Rinse with plenty of hot water,
– close the holes from the outside using masking tape,
– use the dispenser with the metal spout to place a layer of liquid to completely cover the hole,
– illuminate the liquid with a special LED lamp for the time needed to count from 1001 to 1015,
– when possible, leave the sheltered part exposed to sunlight for an hour, the liquid solidified with the LED remains sticky. Sunlight treatment solidifies it completely,
– if the repair is not solid, apply several coats repeating the procedure from step 3 to step 5,
– remove masking tape and
– varnish the part

In this restoration, it was decided to keep the stickers, even if the body was in a bad way: the aim of the restoration was to restore integrity to the body. The stickers in the Rothmans version are typical of the Mk1 version and are even rarer than the Racing version present in the previous restoration.
The paint has not been removed, only paint has been put on in the parts where the paint has come off and in the places where repairs are carried out.

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