today's work

[He Who Shall Not Be Named]

A true geometric naughtylass prop?

You betcha!

I'll post pictures today of the assembled propeller master and will include some documentation that will better connect the work to Harper Goff's NAUILUS.

[Subculture]

A true geometric naughtylass prop?

[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

[Subculture]

The propeller on the SS Great Britain is based on the first version. However later in its service a four bladed screw was made and fitted. You can see a model of that prop in the foreground of the photo.

[Subculture]

That prop is definitely the one on the SS Great Britain. They had to reconstruct the prop, along with much of the upper works as the remains of the ship were just a hulk brought back from the Falkland islands in the early 1970's. Amazing it survived at all really.

[He Who Shall Not Be Named]

The picture of the prop for the Nautilus is of the S.S. Great Britain, isn't it?

The photo said, Britannica.

[DrSchmidt]

The picture of the prop for the Nautilus is of the S.S. Great Britain, isn't it?

[He Who Shall Not Be Named]

hi, question on the mold technique above (obviously I don't have much expertise on casting), I assume you are referring to the soft inner liner as the "glove" and the outer frame as the "case".

Do I assume correctly that as you make hulls the glove will wear out and that you can make replacement gloves and keep the same case?

It seems that it would be difficult to make replacement gloves that would fit tightly against the case.

This is a most interesting series. Thx for response, Khim

Correct. The rubber glove gives form to the eventual GRP laid up parts.

The outer case (strongback/case/shell/mother-mold) keeps the floppy glove in proper shape during the lay-up process.

The initial glove is either poured into a pre-formed mother-mold (BJB's TC-5050) containing the master, or the glove is formed over the master directly, and the case formed over the cured rubber later (BJB's TC-5040).







Once production work has fried the glove you simply mount the mother-mold over the master(s), punch sprue holes into it, providing tall sprue and vent channels (gravity is your friend) and pour in a batch of TC-5050. Done. The annular space between master and case is filled with rubber.

[He Who Shall Not Be Named]

[Marylandradiosailor]

hi, question on the mold technique above (obviously I don't have much expertise on casting), I assume you are referring to the soft inner liner as the "glove" and the outer frame as the "case".

Do I assume correctly that as you make hulls the glove will wear out and that you can make replacement gloves and keep the same case?

It seems that it would be difficult to make replacement gloves that would fit tightly against the case.

This is a most interesting series. Thx for response, Khim

[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

Why do you cut the master in two and then make two separate molds? When I learned mold making, I was taught that you loose precision by cutting masters. Instead I was taught the method using parting planes.

It's easier to handle half of a master than an entire master. Also, when it comes to making the tools, I prefer to do the glove and case in one sitting, not two.



























And I suppose it's how you're taught; both methods have their advantages and problems.

David

[DrSchmidt]

Why do you cut the master in two and then make two separate molds? When I learned mold making, I was taught that you loose precision by cutting masters. Instead I was taught the method using parting planes.