Renovating Corbels - Canadian Woodworking Magazine

Home Improvement: Sometimes it’s the smaller details that are the most important. Corbels on a house are the perfect example. If yours are in need of some TLC you can follow these steps to breathe some life back into the look of your home’s exterior.

Giving Our Past a Future: Renovating Corbels

Giving Our Past a Future: Renovating Corbels



Photos by Josh Silver

Corbels often reside at the eave of a house or on the top of columns. The location of these brackets makes them often hard to access. This often means that they may not receive the proper paint and care to allow them to last the life of the house. When replacing a bracket on your home, it is important to ensure safety when accessing the brackets. Remember the 1/4 rule for ladder safety: for every four units up, a ladder must be out one unit, which places the ladder on a 75º angle. This is the safe angle required by industry and occupational health and safety.
 
Often houses have a large number of duplicate brackets and, more often than not, if one bracket needs replacing, many, if not all, need replacing. Keep in mind, a large volume of the work in bracket reproduction is the set-up, so there is little effort in making dozens of exactly the same bracket. The first one is the hardest.
 
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Trace the Shape – With a dark crayon and some masking tape, transfer the shape of the corbel to a large sheet of paper.
 
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Lots of Information – It’s a good idea to obtain as much information as possible from the work area while you’re there. Here, Silver measures a few critical dimensions before heading back to the shop.
 
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Good Examples – Here are two corbels, one a single layer and one a double layer. Having the mostly intact corbels in the shop while you produce the new ones is helpful.
 
Make a paper rubbing
Assuming the brackets are still in place, we will start by making a paper rubbing of the outermost face of the bracket. Before making the rubbing, the paper must be prepared with a perfect 90º angle. Using a framing square, mark and cut the paper. Then colour-code the paper; blue for the ceiling and red for the wall. Try to choose the bracket in the best condition for your rubbing. Avoid brackets with excess paint, protruding nails, bird droppings, or missing pieces, as these will produce inaccurate rubbings. In a few cases, you may need to use the rubbings from a few brackets to obtain an accurate outline. Place the paper over the bracket and use the colour coding to help keep track of the bracket’s orientation. Use a black crayon with its paper removed, or a charcoal lead, to make the rubbing. Painter’s tape can be used to keep the paper in place while you complete the rubbing, and allows for two free hands. If the paper moves even slightly during the rubbing process, the rubbing is rendered useless. Bring along a ruler and a camera. Tape the ruler to the house as an accurate scale and take numerous reference photos.
 
If you are working with a three-dimensional bracket, which is made up of several layers, it is often easiest to remove the bracket, as sympathetically as possible, from the home. If you’re not removing the bracket, ensure you take note of the overall width and length of the bracket, and measure the thickness of each layer. You are now ready to head to your workshop with the information you have gathered.
 
Make a Jig
If you have removed the bracket from your home, once you are in the shop, dismantle the bracket as carefully as possible. Separate and clean all of the layers to ensure they are free of paint and debris. Use these layers as templates for tracing onto plywood to make a jig for each layer. If you have not removed the bracket from the house, then cut out your paper rubbing and tape or hold the paper firmly on top of a piece of 1/4" plywood. Trace the shape onto the plywood. Cut out the tracing using the scroll saw, bandsaw or jigsaw. We usually use a combination of these three tools to give us the cleanest, most accurate edge. The plywood bracket will become your jig. Make a jig for each layer of your bracket, labelling each jig as you go with its location within the bracket.
 
It is critical that you carefully sand the edges of your jig(s) to ensure they are as accurate as possible, as the shape of the jig(s) determines the shape of all future brackets.
 
Select wood for your bracket
Examine the original material to try to identify the type of wood used. It is recommended that you choose wood for your replacement bracket that is as close as possible to the original material. Also, choose a piece of wood that is as clear as possible. Try to avoid all knots, splits, checks and other defects. The brackets are fairly delicate, thin and ornate and defects in the wood will result in future weather-related rot and deterioration and decrease the life of your bracket.
 
Cut out the bracket layers
Trace your plywood jig onto the wood. Take your time to cut out the bracket layers as accurately as possible. It may be possible to ‘gang cut’ pieces in order to save time.
 
Once all the layers are cut out, the sanding begins. This is an important and often missed step, as it is the only time that each layer can be sanded effectively to remove all cut marks. Once the layers are glued together, it is too late to sand in the intricate corners that are produced. Most often we use sandpaper rolled up to the required diameter of the curve being sanded. If several pieces are being sanded it pays to use a 6" length of dowel to wrap the sandpaper around. This step could take hours, depending on how many layers you are making and how smooth your cuts are.
 
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Master Template – Once Silver has the tracing back in the shop, he cuts it out and transfers the shape to a piece of 1/4" plywood to make the master template.
 
At this point we advise stacking all the same layers on top of each other in order to find and eliminate all variations. The main goal is to have all brackets identical. Identify the layer that is closest to perfect and trace this on all the other layers to eliminate deformities. Use a permanent marker and label each piece. As with the jig, label the roof side, the wall side and which layer it is. We put these marks on the end grain so they are clearly visible to the carpenter but hidden from the public once mounted. Dry fit a complete set of layers to see how they fit. Compare this to your original data and alter if necessary.
 
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Cut Out the Templates – Silver carefully cuts the template to shape with whichever method is most appropriate (above). He then ensures the templates are smooth, as all the corbels will follow the same shape and size (below).
 
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Paint or stain the bracket
This bracket will be outdoors and not easily reached for the remainder of its life. You should put the highest quality finish on it that you can find. Brackets may require an artist’s brush for the detailed corners so it may be easier to paint or stain before the bracket is assembled.
 
Assembly
Once dry, the piece can be laminated. Use a high-quality exterior wood glue. Be very careful not to over-apply the glue. If you get squeeze-out, it will be very difficult at best to clean. As with all wood projects, it is necessary to clamp the bracket while the glue dries.
 
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Laminated Layers – After the different layers of corbels have been glued up, Silver traces the shapes onto each piece and cuts them out.
 
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Glue Squeeze-Out – Once the layers have been assembled, be sure to remove any excess glue with a chisel or knife. Clean, crisp corners are important to ensuring the final product looks great.
 
Mount the bracket
Wait for a good weather day. Prepare the area on the house where the bracket will be mounted by cleaning all excess paint, dirt, etc. from the area. Use the same exterior glue to glue the bracket to the wall and ceiling. Use a 16-gauge nailer to fasten the bracket to the house until the glue dries. At this point you can add any necessary paint to complete the corbels.
 
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MEAGHAN LISTER AND JOSH SILVER
MCLister@hollandcollege.com
JLSilver@hollandcollege.com

Meaghan and Josh are two of the instructors in the Heritage Retrofit Carpentry Program at Holland College, Prince Edward Island. They would like to thank Hal Forbes of Forbes Restoration (halforbes.com) for his expertise on this topic.