The Traditional Sign Maker

Introduction

This guide is designed to provide a step by step method for carving house signs in HDU. Comprehensive notes accompany a set of photos detailing the process used at Clover Signs. Photographs follow a recent sign, 'Pry House Farm' through the production processes.

Preparing a Blank

The structural qualities of HDU do not allow for long unsupported spans. Therefore, each sign is first laminated onto a PVC backing for added rigidity and to allow it to mount firmly when in place. The process of lamination involves sandwiching a layer of high strength glue, such as 3m 9088 double sided tape, between the sheets of HDU and PVC. The HDU side of the blank is then given a surface coat of Acrylic paint. This coat consists of three layers of paint. Each layer must be allowed to dry for at least two hours before the subsequent coat is applied. The final coat must then be left for a full 24 hours before any stencil is applied. We have found the best paint to be MSP - made by Bedec.

Applying the Stencil

A paint stencil can now be cut out with the design you want, weeded and applied to the blank. The blank should be cut slightly larger than the stencil; the edges will be machined later on in the process. Application of the stencil should be done carefully using transfer tape. The sign is now ready to be carved.

Carving

Carving is a skilled process requiring patience and expertise. First, a small groove is carved down the centre of each letter using a Right-Angled V-tool. This removes enough material to allow further carving, and gives a point of reference for the bottom of the finished carving. An ordinary chisel is then used, its size corresponding to the size of the letters being carved. With the chisel held at an angle of 30 degrees to the sign face, the sides of the centre groove are carved out until only a narrow shoulder of un-carved HDU remains within the stencil. The most important thing is not to cut the stencil with the chisel, as this will make the edge of the letter look ragged. The angle of the carving greatly affects the reflective quality of the gilding.

Profiling the Edge

When the carving is finished, the sign can be cut accurately to size, and the edge given an appropriate profile. First a scroll saw is used to cut out the shape, staying 1-2 mm from the stencil edge. A disc sander can then be used to bring the edge precisely in line with the stencil. It is then necessary to use a finer grade of sandpaper to remove the marks left by the disc sander. This is most simply done by hand, but must be done with a rigid sanding block since it is otherwise difficult to keep the two materials abrading evenly. Finally, the corners can be chamfered. A decorative edging can be used on the front edge to compliment the design. The back edge should be bevelled to prevent the build-up of a rim of paint later on in the process. The sign is now machined to its actual shape and size, and is ready to be painted.

Painting

The first coat of paint that is applied to the letters and edge must be the same colour as the surface coat. This 'chokes' or seals up any voids that exist between the mask and the surface of the sign in order to prevent the next layer of paint from bleeding under the mask. The choke coat should be brushed evenly onto the letters using an appropriately sized brush. The edges can be painted using a paint roller. After 1-hour drying time the choke coat should be given a light sanding. Next, two coats of cream coloured paint applied to the letters, leaving two hours of drying time between coats, provide a smooth surface for gilding. The light colour also enhances the final appearance of the gilded letters. The edge of the sign can also be given another coat of paint in the appropriate colour. However, the final edge coat should not be applied until after the gilding process is complete so that stray particles which may adhere to the edge during the gilding process can be covered by the final layer. The paint must be allowed to dry for at least 24 hours, allowing most of its moisture to dry out before a sealing coat of oil-based size is applied.

Gilding

Gold size, or simply 'size', is an oil-based medium similar to varnish. It provides adhesion for the metal leaf. Various sizes are distinguished by their drying time. The first coat of size on sign letters to be gilded is 3-hour. This simply acts as an undercoat, filling in any pores or surface imperfections that may be present. A coat of 12-hour size is then applied since this longer-drying size has superior weather-resistant properties, and will increase the lifetime of the gilding. The drying of the size must be monitored closely. There is a narrow window of up to an hour during which the size will be ready for gilding. Before this time, the size will be too soft, giving the finished product inferior shine. Too late, and the leaf will no longer adhere. When the size has reached its optimum dry-time, letters can be gilded. The sign must then sit 24 hours to allow the size to cure before the excess metal leaf can be sponged off using moist cotton wool.

Artwork

The final coat of paint can now be applied to the edges of the sign. The PVC back can also be painted. This will normally require two coats of paint before sufficient coverage is achieved. The artist uses high quality acrylic paints to copy the design directly onto the surface of the sign, removing parts of the mask where necessary. Finally, the rest of the mask is peeled off the sign using a sharp tool and the finished sign is revealed!

Conclusion

This is just an outline of the method we use for our signs. Working in HDU has some complexities, however, once these are overcome, you will find yourself able to make beautiful signs with little effort. What more, HDU signs will far outlast signs made of other materials.