Clay, Application to Refinement

 

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Rakes

The main purpose of a rake is to remove material in an efficient manner, therefore giving you a clay form that is representative of the design required. Even if it is a very rough representation.

 

By achieving the basic form very early in the modeling process, the designer has time to consider changes that will enhance the overall look thus leading to an appealing design.

Selection of clay rakes as use in automotive sculpting.

 

Rakes come in various forms; from large flat rakes which are used primarily on convex surfaces to curved rakes which are used on concaved surfaces. They usually range in size from 2"or 50mm to 6" or 150mm in width but can be of any size if custom made. The blade is normally double sided which gives you the opportunity to file teeth into the opposite edge. The reason for this is to reduce the amount of resistance when shaping the clay surface.

 

To construct your own rake the following materials are required:

 

If you are going to produce a curved rake, a set of press tools will need to be made so as to set the curve into the blade. These blocks can be made from 2"x 4" lumber, with the curve being 20% tighter than the curve being set into the blade. This allows for spring back.

Exploded view of how to bend the blade of a clay rake.

 

Cutting list

 

6"x 3/4"x 1/8" cold rolled steel

8"x 3/4"x 1/8" cold rolled steel

or 2 off 8"x 1/4"x 1/8"

1/2" Dia. x5/8" brass or copper

2 part 5 minute Epoxy Resin

6"x 1 1/4"x 1 1/4" oak, pine etc.

To fabricate your own rake you will need the materials set forth in the cutting list. These materials are for making a straight 6" rake or a 6" curved rake with the aid of a set of press blocks.

 

Start off by splitting the 8"x 3/4"x 1/8" down the middle with a hacksaw. This will give you two legs of        8"x 5/16"x 1/8" that will support the blade.

 

Mark out on a sheet of paper the angles required to bend the steel. This helps in keeping the legs symmetrical when you braze or silver solder the legs together. Bend the legs so as the distance from the blade to the point of entry to the handle is approximately 3 1/2". This will give you a nice overall balance.

 

Diamensions of the legs used to support the blade of a clay rake.

 

Silver solder the legs together so as to create the letter Y, then space the legs so as to meet the mid point of the blade and remain equal about the ends of the blade. Silver solder into place and allow to cool.

 

At this point you are now ready to shape the handle from the wood stock. This can be done on a lathe or simply by tapering the wood so as to accept the ferrule. The ferrule being the 1/2"Dia. x 5/8" brass or copper.

After shaping the handle to the style that you want, fit the ferrule so that it is a snug fit. Drill a 3/8" hole in the ferrule end of the handle to accept the blade assembly and mix equal parts of 5 minute epoxy resin, apply to the hole in the handle and the tang of the blade assembly. Insert into the handle and support in a vertical position until the resin has cured.

 

Scribe on the face of the blade two lines which will be the indicators for grinding the cutting angle for the blade. Set up the bench grinder and gradually remove material until you have a knife edge from the line to edge of blade, repeat this procedure for the opposite edge.

 

Angle of clay rake blade to the grind stone for producing the bevel.

Filed in teeth on the clay rake blade for quick clay removal.

The sketch shows angle of blade to bench grinder wheel.

 

End view showing ground blade. Plan view showing teeth filed into blade.

 

You may find during the grinding process that a burr forms on the back face of the blade, this can be removed with a file. The blade should now be sharp and able to remove clay with ease.

There is also the option to file teeth on one edge of the blade, ( approximately 1/8"-1/4" spacing ) this should be done with a triangular file.

With the serrated blade the material is removed far quicker because there is less resistance. It also gives a raked finish which indicates that the surface is still being developed.

 

Finally coat the handle with a sealant, allow to dry and smooth with some fine wet and dry paper. Apply some paste wax and buff smooth.

                                   

              You now have a rake that is ready for action!!!!!

 

Copyright © 2003 - 16 Steven Austin

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