January 2011

Detailing resin body, creating and casting bumpers & seats


Jan. 16th 2011: After a short winter break today day number 5 in the Giardinetta Furgone project will commence. An interesting fact is that I won't be the only one today making a favourite scale model at the YowModellini studio. A gentleman from the city of Nagano will continue his work on a Subaru prototype car from the seventies and I will see how much progress I can make on my own project. According to my teacher Ito-san the plan is to make the stiffener grooves in the roof, create and attach trim to the roof, start work on the front & rear bumpers and start the correction of the seats. Let's see how far we get. The stiffener grooves in the roof are the fist thing to work on. These stiffener grooves are a very important feature which clearly distinguish the Alfasud Giardinetta roof from the Alfasud Berlina and/or TI roof. The work starts with sticking a 10mm wide masking tape in the centre of the roof as a clear indicator where the middle is, then sticking thin masking tape to the roof as guidance for drawing a pencil line where the stiffener grooves are supposed to come. After a few iterations the thin tape is in the desired position. Now the target lines can be drawn with a pencil. After drawing the target line on the left hand and right hand side all tape can be removed from the roof. Carving the grooves will be irreversible so I will practice on a piece of resin first. I will use the whole area of the resin block in order to get a feeling of how much force is required to carve the desired depth with the carving knife. The groove will be made by using 3 different tools. The first tool is a carving knife which will create a V-shaped groove, the second tool is a very narrow U-shaped carving knife, the third and final tool is a wider U-shaped carving knife. After applying the tools the finishing touch will be made with 300 grade sanding paper. The end result looks very nice and fills me with joy. This will be the first Alfasud Giardinetta scale model with attention to this important feature.

Wide masking tape in the middle and thin tape as guidance on lh & rh side.


Carving knife and piece of resin for practicing purpose.


Required tools for carving the grooves in the roof.


Masking tape to determine starting point of grooves.


After using the 3 different tools the final touch with sanding paper.


Removed resin material from roof.


Giardinetta with grooves in roof &  Minichamps base model without grooves.


The second item to do today is the application of the roof trim. First a decision has to be made on how to make the trim. Metal wire with a diameter of 0.6mm or square plastic material of 0.5mm. During a trial fit the plastic material appears the best so the choice is made for that option. How to make this material fit nicely to the side wall of the roof is the next tough hurdle. The idea is to start from the rear of the vehicle, apply masking tape to keep the material in the correct position and then apply superglue. This meticulous work is nerve wrecking. I start with practicing on the piece of resin also used for practicing making grooves. The application of the thin pieces of masking tape is done with a pair of tweezers. Basically the practice session is going quite smooth, I'm wondering how well this represents reality. Starting from the rear going towards the A-pillar seems fairly easy once the correct position is determined. The car looks quite funny with the trim in place on the lh & rh side due to the material which is sticking out towards the front of the vehicle. After bending and gluing the trim on the A-pillar I realize that the roof section is no completely straight. Ito-san and I believe that this caused by the stress introduced by the bending at the A-pillar. The glued trim on the LH & RH side is removed and the remaining glue sanded down to give it another try. This time I will start from the A-pillar and hope the trim becomes straight this time. Now I realise how much patience is required for making a scale model. A lot of respect for an artist like Ito-san who creates 1:43 scale models from scratch with ample detail. I need a lot of practice to achieve half of his skills. The method of starting from the A-pillar seems to work better and now the trim is straight to a point where it's acceptable for me and also for my teacher.

Practicing application of thin pieces of masking tape on piece of resin.


Sketch of intended working method and lh side trim applied.


Lh & rh trim applied. Strange appearance with the front sides sticking out.


A-pillar trim bent and glued in position on rh side. End result in rear section not straight.


Second try starting from A-pillar.


End result of second try better than first try.


Lh & rh roof trim in position.

Body end result for today with trial fit of wheels.

The third activity will be the making of a silicon mould for the front & rear bumpers. The Minichamps base model has overriders on the bumper and those are not correct for a Giardinetta. With sharp pliers these overriders are removed as far as possible to minimise the sanding work once the bumpers are casted. In order to create the first silicon mould for the bumpers firstly a box has to be made. I start very enthusiastically and the box is finished within a whisker. Unfortunately I misunderstood the explanation of Ito-san and I didn't pay enough attention to the sketch of the box made so the height has become the width and vice versa. By cutting the tape and making 1 side of the box this rather stupid mistake is corrected relative quickly. As always foam like material is applied to the upper edge of the box and tape is applied to avoid overflowing of the silicon material during vacuum operation. Ito-san tells me some ingenious tips which basically sound very logical but are very normal beginners mistakes. Luckily for me he points these items out and the first bumper mould is progressing quickly. pieces of plastic tube are glued to the bumpers under an angle. These plastic tubes will function as runners for the mould. The bumpers will be under and angle in the mould to minimise negative effects of air included during casting. Also the front side and rear side of the bumpers is decided based upon air inclusion. The rear of the bumper will not be visible once assembled to the car, so small air inclusions on the rear side are not fatal. All in all very informative tips given by Ito-san. The tape to avoid overflowing is very high, but previous casting during this project showed that that is absolutely necessary. The bumpers themselves are pushed into green clay with the runners pointed downward into the clay, also logical if you see it, but the person who thought of this first is quite a smart person ;-) The mixing of the silicon mould and the hardener is an easy task. Now the silicon material is ready for filling the box. Again the amount of air popping up during vacuum operation is amazing. It keeps surprising me. Now the bumper mould needs to harden in a temperature controlled box. That's it for the bumper mould today.

Bumper silicon mould box with width and height mixed up, how stupid.


Bumper silicon mould box with height and width corrected.


Bumper overriders of base model cut away as far as possible.


Bumpers with mould runners (white material) pushed down in clay.


Bumpers in mould box with taper wrapped around to avoid overflowing.


Silicon and hardener material mixed ready for casting.


Silicon material on tape after vacuum operation.

Temperature controlled box for hardening of silicon mould.

The 4th item for today's activities is the creation of a box for a silicon mould of the front seat which needs quite some adjustment to suit the Giardinetta. The headrest will be deleted and the side supports will also need to be deleted as these are applicable to the Alfasud TI and not to the Giardinetta. This time I made no mistake in the box dimensions. The front seat is cut out of the Minichamps base model and put on a cardboard plate which will be put the mould box. This will come at a later stage. The last operation for today is a small adjustment to the chassis at the rear LH wheel. During the application of the roof trim I realised that this section was not done properly. Some small corrections with a Stanley knife did the trick and now the chassis is ready. That was it for today. A very enjoyable and educational day. A great thanks to Ito-san for spending his free time to teach me something.

Silicon mould box for front seat with front seat cut out out from base model and attached to cardboard plate.

Jan. 23rd 2011: Another day in the project. Today the casting of the bumpers and seat for which we made the silicon moulds will be done and then these parts have to be adjusted to suit the Giardinetta Furgone. The first thing to do is to cut the silicon mould vertically to be able to get the parts out. After this operation tape needs to be wrapped around these 2 moulds for casting purpose. Ito-san is finished within 10 seconds for the bumper mould, I'm having a little more trouble with the seat mould. After 6 trials and wasting a lot of tape I get a result that is "acceptable". Ito-san tells me whilst laughing that this silicon is rather soft and therefore the application of the tape for casting is more tricky, but I guess what he really wants to say is ........ why does it take 6 times to get it right. The resin which will be used is of a harder kind then the one used for the body. This is necessary because the small parts need to adjusted in shape and the same hardness resin as used for the body would lead to too much material taken away during sanding. The vacuum operation is as usual interesting to see. Soon the bumpers and 2 seats are casted. The bumpers are taken of the resin base block with the aid of a knife. The seats are sawed off. This sawing operation is done in a circular motion to avoid getting a crooked base. Each side of the chair gets 3 strokes with the saw and is then turned 90 degrees. Basically very logical when Ito-san tells me, but I guess I wouldn't do so if I wasn't told.

Bumper & seat silicon mould filled with base model plastic parts.


Silicon bumper mould cut almost in half to remove plastic base model parts.


Tape wrapped around silicon seat & bumper mould to avoid resin overflowing.


Vacuum operation to remove enclosed air.


Bumpers and 1 seat hardened


Casted front & rear bumpers and seats on resin base blocks.


Saw to remove seats from resin base block & bumpers removed from base block.


The remaining parts of the overriders on the bumpers are sanded away with fine sanding paper (P600) and also the protruding portions in the centre. The base model bumpers of Minichamps basically reflect the facelifted chrome bumpers and the Giardinetta Furgone should have the initial geometry chrome bumpers therefore the centre section needs to be made flush with the rest of the bumper. Some sanding further the geometry is looking the way it should.

Then the seats will be the next item to take care of. The headrests are taken off with a chisel and then the rough surface left by this operation needs to be sanded down to get a smooth surface. The side supports which are present on the seats of the base model are valid for a Sud TI car, but not for the Giardinetta so these supports are trimmed down with a chisel and sanding paper. The end geometry looks much more like the proper geometry then the base model seats, regarding the geometry I'm happy now. Now the height has to be adjusted to suit the Furgone with the own made chassis. The adjustment of the height is done by turning circles on quite rough sanding paper (P80). After several trial fits and adjustments the correct height is achieved, the rough surface surface caused by the sanding paper is smoothened by using a Stanley knife and scratch the surface. It's nice to see these detailed interior parts come to life.

Fine sanding paper with which the remains of the overriders were removed.


Rough sanding paper to adjust the seat height.


Base model seat (left) and adjusted seats (headrest removed, side supports trimmed).

Trial fit of the seats, added the wheels just for fun.

In the mean time the rest of the interior is taking shape. The gear lever and handbrake lever are taken from the base model because they have the correct geometry. The dashboard of the base model which is the accurate shape (just not accurate colour) needs to be trimmed in the width to fit into the resin body. The resin body is more thick than the zamac (zinc en aluminium alloy) material of the base model. During a trail fit of the dashboard it appears to fit. The next part for today is to make a tunnel for the interior to fit the gear lever and handbrake lever on. This tunnel is made by casting a resin cylinder and sanding it down with rough sandpaper until it reaches a height and width which suits the vehicle. The sanding lines created by the rough paper are taken away by scratching with a Stanley knife. The final parts to be done today are the door cards. The door cars of the base model are really good, a big compliment for Minichamps to make such representative parts. The only thing for me to do is to make sure the height is correct by sanding away material at the bottom. Also the length has to be adjusted because the rear inner wheel arches also need place. Some cutting with pliers and sanding later the parts are the correct height and fit in the car. I had a lot of fun again today and again learned some stuff. Who knows one day I'm able to make a scale model on my own ;-) Once again thanks a lot to Ito-san for an enjoyable day.

Resin casted cylinder which needs a lot of sanding.


Trial fit of tunnel on chassis, still some sanding to be done.


End result of today.


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