Mold Locators

[Eaglewood]

I am in the middle of doing a 2 part mold for a sculpture that I have to get laser scanned and reduced, Which I am having done by my new partner and the original is invaluable so I cant be shipping it around the country.

I am doing a poured blanket mold for this item. I wanted some locators for the 2 mold halves and didnt want to use clay due to the irregular shape, so I did the following:
I took a round 1 teaspoon measuring spoon and hit it with a little mold release, then I filled it with hot glue and let it set. I made a few of these and there ya go. Also when I did the fasteners to put the 2 halves together, instead of drilling thru the flanges and just throwing some bolts in there, I wanted a more precise fit, so I glued some of the screw inserts used for woodworking onto the molding flange and then laid up the mother mold compound, in this case resin,chopped strand for strength and Forton MG.

After it all set up overnight I flipped it over and removed the flange material support, which in this case was roof flashing tin, (easy to cut and remove) I then popped out the half round hot glue locators, took the screws out of the other side and there ya go.

I will glue washers to the screws and then install them about 1/2 inch from the surface of the first half, lay up the mother mold compound on this side, let it set, remove the screws, pop the halves apart, remove the clay blanket and then put the halves back together, pour my rubber in and let it cure.
Then I will remove the mother mold and slice the rubber along a flange that I have put on the mold for a cut line. After that , I remove the original, put the rubber back into the mother mold and pour my resin or whatever I want for the reproduction.

I have some PDF files from a sculptor friend of mine who started using this process and walks you thru it from start to finish, I have just modified it a bit. I will see if I can post them here--if not PM me and I will email them to you if you are interested.

Good luck!!!

 

[Eaglewood]

Well, I have been asked to post pictures as I proceed, so I will back up a bit here and post starting pics.

You will see the original trophy
Then I wrapped it with plastic and covered it with a layer of clay about 3/8-1/2 thick. The raised clay sections are my cut line areas where I will cut the rubber to remove the original. I will be using a clear-translucent rubber with some flexibility to it so I dont cut the original and can see exactly where I am cutting.
after that I did the sheet metal flange and then the locators and screw inserts and applied the mother mold .

I will post more as I do the other side.

 

[Eaglewood]

Here are some more progress pictures. Basically these are showing the second side ready to have the mother mold compound laid on.
The mold has been treated with mold release, the locators in place and the washers hot glued to the bolts as they will stay in the mother mold.
The threads of the bolts have vaseline on them so they will release easily.

Then you will see the first layer of resin applied and then the second layer applied on top of that with chopped strand for strength and for the Forton MG layers to adhere to more securely.
I will lay up a few layers of the Forton to the desired thickness, let it all set up and then remove the bolts and if I have done everything correctly--it will pop apart easily.

More pics to follow as I progress.

 

[tango'd fett]

Very interesting process , will look forward to seeing more of this and the pdf if you can post it.

 

[Eaglewood]

Ok--Here is more of the process as it is going along

Here is the sequence in the pictures

Bottom support/locator platform removed
Screws removed from mold halves
First half removed to reveal clay blanket
Mold is ready for rubber pour, all clay cleaned out, remounted to locating board and ready to go. Estimating rubber volume .

I will be pouring the rubber today and possibly one plain resin casting. I will be doing a cold cast bronze also. Will get pics and post them as I go.


Here are the PDF files from the friend of mine Dave Parvin who showed me this process. I have made a couple of modifications, but in essence used this as a tutorial.

 

[Eaglewood]

Ok--we poured today.
It took more that my supplier or I expected, but it went well. Took about 18lbs of rubber to fill the mold.
Demold time 24 hours. maybe tomorrow. Then we cast a resin copy and then a cold cast bronze.