Clay, Application to Refinement


home   content  my profile   tools  technique  contact  links

 Corvette Scale Model (pt 2)

Armature build (pt 3, page2) (pt 1) (pt 2) (pt 3)

In the previous section Armature Build (pt 3, page 1) I had cut the Styrofoam? blocks to the shape dictated by the tape drawing allowing a minimum of 1" or 25.0mm of clay to the outside surface. The foam blocks had been pre-fitted together over the wooden baseboard and are now ready to be glued together.

Styrofoam blocks pre-fitted on baseboard before gluing.

The image to the left is a recap of the progress from the previous page viewing the foam blocks sprigged together before bonding with Gorilla Glue.

The indicator marks made with the wax pencil will allow me to disassemble the foams and guarantee the placement being exactly the same once glued.

Complete side view of the foam Corvette buck before wheel envelope cutout.

The side view image gives a good indication of the Styrofoam? sitting on the baseboard with the support towers showing. The wheel envelope is yet to be marked out.

There are many methods of gluing Styrofoam? together, from epoxy resin to contact cement but with these type of bonding agents there is always the risk of excessive heat (exothermic reaction) melting the foam. Care has to be taken not to over apply the contact cement as the solvents in the glue will dissolve the foam leaving a less than satisfactory bonded surface.

With Gorilla Glue the only risk is to ensure that the foam being glued together is clamped securely. Applying the glue on one surface and spread thinly with a homemade spreader from a cardboard box is more than adequate, water becomes the catalyst to set the reaction in motion. 

As you can see from the image to the right, the three elements required to ensure a good bonded surface.

Gorilla Glue, spray bottle and spreader are all that's required to glue up the foam.

All foams sprigged together in front of the Corvette tape drawing.

Foams dismantled prior to being glued with Gorilla Glue.

With the pre-fit of the Styrofoam? to the base proved out the next step entails dismantling and stacking them in an orderly manner ready to start gluing. As you can see from the image above my Workmate and half a sheet of 3/4" plywood provided the bench space that I needed. To keep the plywood free of glue it is covered with a heavy duty builders paper. The wooden sprigs are at the ready together with the Gorilla Glue, water spray bottle and home made spreader.

Gorilla glue applied to the foam for assembly.

The inside of the outside foam block has been marked with the wax pencil to indicate areas that should not have any glue spread on. This will eliminate any chance of the finished foam block from fouling on the baseboard when placed into  position.

The number two block has been coated with glue ready to accept the next foam block inline. Very little glue is needed to give an even spread and with the expansion of the glue when curing it will fill any voids that have been left uncoated. It is at this stage that the foams need to be secured in place with wooden sprigs to reduce sliding of the foams on the wet Gorilla Glue.

The amount of working time after spreading on the Gorilla Glue and priming with water to catalyze the glue is approximately twenty minutes. After that you will notice the chemical reaction taking place with the glue frothing as such. By that time the layers of foam should have been securely clamped to prevent them from being spread apart from the expansion taking place.

To keep the page loading time to a minimum this will continue on Armature Build (pt 3, page 3) towards the completion of the foam armature build process.

Copyright © 2007 - 20 Steven Austin