Dyeing the material

As i had a little time spare, i decided to make the teeth and tape.
With the help of Faye Young i managed to dyed the material 'calico' , and string. the correct color, and create the tape of the zip, to scale.

I used denim as the material, and used wadding to bulk out the edges, to create the illusion that the material has been folded, as the material was not thick enough on its own

whilst doing this i learn alto of basic sewing and dying techniques, which i can transfer in to next projects.

Testers of finish effects

On this piece i have tested out the plain and simple wire wool, brass polish, with grate polish added on afterwards to darken sections. I think this was the best and closest brass finish effect. and i used this method on my final.





Here i was testing to see what the result would be if i mixed the metal powder with the fast cast, came out well, but wasn't as dark as the polyester resin.







First attempts to get a perfect cast, from these i learn that i needed to add more pour holes. the second attempt was perfect apart from a few minor air pockets





Here i tested how well i could drill through the resin. and how much pressure to use, successfully drilled all the way through, then vibrations shattered the end. When drilling final, attached to MDF to add support. Worked fine.






Molds- tryed to use as little silicone as possible.

Development

To make the inside spring mechanism i needed to have strips of resin. instead of making silicone
molds i made styrene molds and sprayed the release agent mac wax in to them. this worked fine and meant i did not have to wait the 16 hours curing time for the silicone, and waste materials. Once the resin strips were out of the styrene mold i cut the down and in to shape using the band saw. I chose this alternative as i want to experiment and find a wide range of alternative methods
to a problem, and ways at achieve the same out come faster and cheaper,








Below are the parts being glued, and to add strength i have drilled through metal rod.

I also added a thread to acrylic pipe so enable me to actually bolt down the work.







.

moulding and casting continued

This it the vacume form of my master. I used 2mm styrene to ensure that it picked up all the detail in the master and could with
stand the heat produced by the resin



This was the box ready for the silicone to be poured

To add the detail on the inside of the zip, i added styrene as it was quick and allowed me to demonstrate my hand skills. I could have CNC them out as another possible method.

Moulding and casting the Master

This will show the development of me molding and casting the master zip


One problem i had with the silicone mold was that it did not bleed under the master, to solve this i referred to previous research i found on you tube. How to make a two part mold video, and added more silicone on top, and cut open via the sides with a scaple to make a two part mold.



Research ensured that i fully supported the mold, to avoid unnecessary leaks. and to apply the pressure evenly, to not distort the mold, i achieved this by clamping the mold.















When casting the zip puller, i had a few air bubbles in the cast, this was because i poured from two separate pour holes which in consequence traped the air, and because i needed more air holes, which i was advised to insert when re looking at research i had gathered.

I again made this as a two part mold, and used acetate located in the middle to give a seam line and to as as a separator to enable me to open the mold easier. this worked quite well.



As an alternative to making a mold out of silicone for this specific piece i decided to vacuum form the master piece to create the 'mold' and paint the gel coat in to it and to add strength lay weave in to the vacuum form. This method worked really well, and saved me wasting time and resources.

Development and testers

As a method of adding texture and antiquing the zip, i experimented by melting wax and pouring it over silicone, quickly dabbing with an dry paint brush, I would do this on the insides of the silicone moulds, and once cast, could easily melt the wax out of the final casts using a lighter giving me an varied texture through out,
This small experiment allowed me to also become familiar with the moulding process.

This is the effects that were created using this method. I think they will be suitable for this purpose. Another method to achieve this desired effect was to dremal in the master, to create the surface wear. I chose not to do this as I wanted to create a variety of finish effects, and wanted each cast to vary in texture.

To create a brass effect on chemi wood, i experimented by coating in thick black paint, and sprinkling brass metal powder, between the layers of paint. Once dry sanded.







Here is the result when sanded ( bottom half) i used copper powder for this tester. this method worked well, and if i have enough time, i would like to apply this finish to my master model.







This image shows the resin tests i did to match the color of the original zip. The best result i found was

20g brass
50g poly
1g catalyst

I will use this ratio for my final.

Development of zip

I have made the zip body,and today CNC all parts necessary. i have made this piece as a whole and then sawed off the desired measurements, this was to save time matching up the curves later, as it was quicker to create the curve first, sand down and then cut to ensure they will all match perfectly

Routring and development

To ensure and even and accurate curve I decided to router the edges of the zip puller. I made a jig for the base of the router to sit upon to ensure a consistent depth was obtained while routing

Thi is how the model stands at this current stage.

CNC Contiuned

Once all the technical drawings were completed, and had set all the right settings in the program Excalibur. I was ready to CNC

Zip puller

To make the zip puller i laser cut acrylic and stacked them up, as
this was far faster than to CNC out as an whole object

To add the texture on the zip puller i looked at dry spraying, speckling and sandpaper. i found the sand paper worked the best as it gave the right grip and texture that i was looking for. I used grade 180.