Friday, March 25, 2011

Talking about a Bangle, a Ring, a Chain, and Vacuum stuff.

Curve-Bangle

I have posted this bangle twice before. Each time my customer comes to St Maarten, she  has me add some more to it.

Firstly, ( or secondly ) the top outer ‘waves’ and the thirdly the bottom waves.

This is quite tricky but it came out nicely, I think.Birthstone-Ring 

Gold carved ring set with very sentimental stones.

Birthstone-Ring-1  

All the stone are symbolic with her children's birth stones. Very cool.

Carved with a 1mm ball bur out of a half round wedding band directly into the metal.

It requires strong hand control with a hanging motor.

Half-Moon-Carved-Amethyst

This is an amethyst I carved in anticipation for setting into a hybrid titanium and gold ring---- coming to a computer near you.

Titanium-gold-chain

I FINALLY finished this wedge link chain. This is the last one ( I swear) I am going to make. A bucket load of work……

It is 650mm long and it took about 60 hours to finish.Titanium-gold-chain-2

Since there is no handy local Titanium Shoppe on the island I use 5mm titanium off cuts from titanium plate and saw out rough square shapes.

Titanium-gold-chain-1

This picture shows the titanium plate at the top, the rolled out sectioning in the middle of the picture, the links cut off to size at the bottom right and a pre rolled wedge link prior to filling on the left.

Then , after all the links are rolled out, I file them into the final shape and sand them down and polish them. This is the bulk of the work to make a chain like this.

It is the polishing and blueing that takes the most time.

Also, when the connecting gold jump rings are soldered, one has to watch out that no flux gets onto the blued titanium.

Reason is that the flux contains fluorine, and that reacts at heat with the titanium oxide coating on the links and causes  white spots on the final finish.

This fucks the link up and it is back to sanding and polishing and starting again.

Many evil words are thus then spoken in the workshop.

Casting-Machine-2

This is a vacuum casting machine that I use as a vacuum pump to remove bubbles from my investment.

I spin cast exclusively and I have actually never used this machine for any other purpose ever other than to vacuum my flasks. ( reason is that a single vacuum pump cost the same as this machine, so why not buy it…at least it does more that a single vacuum pump.)

Andrea from Cape Town in South Africa asked me if I knew how to access the filter bottle at the bottom right of the machine.

As it was, I just happened to be servicing the vacuum pump so I took these pictures to show her how to  access the bottle.

Maybe the pictures are handy for others, because it is a  somewhat cumbersome design.

The front panel has to be removed, unscrewing ten self tapping screws.

Casting-Machine-1Then the bolt of the clamp at the bottom of the glass bottle is loosened  and slid to the bottom of the bottle. 

Casting-Machine

The red plug then can then be removed from the bottle. This requires the copper tubing to be slightly bent upwards but that is no problem, because it is soft copper and also allows itself to be bent back easily.

Reassembly is in the reverse order.

This is the picture that Andrea sent me, which was worrying her about her machine.

And while there is some oxidation on the copper, I don’t think there is anything terminal here.

Remember, when the machine is busy vacuum casting, it is drawing in ‘air’ at some 500C via the flask and then through the copper tubing.

I suspect the iron swarf around the copper tubing ends in the bottle act both as a heat sink and a filter for any investment flakes that are sucked into the vacuum machine. ( the cooler the air, the better.)

Also, as her machine has cast some 50 flasks, the green ‘growth’ on the copper tubing in a sulphur/heat/oxy reaction of sorts.

Nothing to worry about really.

Super-Moon

We had a great “Super Moon” the other day.

Lekker clouds and all.

Super-Moon-1

Here is another one.

Cool or what?

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