Butting two cornices together in a corner

  When we are making a corner cornice where two boards come together and wrap around the corner with no returns the most effective joint will not allow any light to peep through.  If the measurements from the corner to as far out as you want the cornice to go are 125″ on the left side and 72″ on the right side we will make the top board (dust cover) 124 1/4″ because it fits inside the left return which is 1/2″ wide plywood and we want a little wiggle room (1/4″) on the right end.  The dust cover on the right side board is the same size as the face board minus 1/2″ because it fits inside the right return.  How do we figure the size of the face boards?  If you look at the photos you will see that the right side board butts up against the dust cover  of the left side board.  Let’s say we have 6″ returns so our dust cover board is 5 1/2″ wide.  If the customer wants the right side cornice to extend 72″ from the corner we would make the face board 72″-5 1/2″ = 66 1/2″.  The face board on the left  side will but up against the finished face of the right side which is 6″ deep.  With the left side measure 125″ from corner to outside left return we will make the face board 125″-6″= 119″.  Notice from the photos there is about 1/4″ between the inside end of the left side dust cover and the wall at the corner.  This is the ‘wiggle room’ we need so the joint is nice and tight.

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Edge joining plywood to make a long cornice board strong

   When interior designers ask us to build upholstered cornice boards that are over 110″ long we need a way to make them strong so they won’t break while being transported to the customer’s home.  Plywood comes in 96″ long sheets so if we have an order for a cornice board 185″ long and 12″ high we could just edge join two boards-one 96″x12″ board to another board 89″x12″  with a joint roughly in the center.  But that would be the weakest point of the board if two people each lifted an end.  A much stronger solution is to cut five boards 2@96″x6″, 2@ 44.5″x6″ and one at 89″x6″.  The two 44.5″ pieces would be attached at each end of a 96″ piece producing a board 185″x6″ and this would be used for the bottom half of the face.  The other 96″ piece would be joined to the 89″ piece producing another 185″x6″ piece which would be used for the top half of the face.  Then the two 6″ sections would be joined together to make a 185″x12″ board.   Most cornice boards have a dust cap or top board that lays on L-brackets for when the cornice is installed.  The joint(s) in the dust cap boards would be located at least a foot away from the joints in the top face board.   By alternating our joints this way we can build cornice boards up to 20 feet long with very little loss of strength. 

   The five boards are laid out on a table to make sure we have made the bottom three  6″ boards the same length as the top two 6″ boards.  Next we measure to make sure they add up to 185″.  There is a good old saying “measure twice and cut once”.  When we are sure the five boards will make one board 185″x12″ we lay a long straightedge on top of the boards at the long edge to make sure the joined boards will be nice and straight (we can’t just assume we made  perfect 90 degree cuts so the straightedge shows us where we have to adjust the lineup).  We will first staple all the boards together on one side, then flip the whole thing over and staple them together on the other side.  Then we hammer in aluminum edge joiners (dog ears) every two to three feet along the horizontal middle joint and spaced every two to three inches along the vertical joints since these joints will have the most stress.

Ceramic Medallions on the face of a cornice board

   Today we are building an upholstered cornice board that would be placed in the Elaborate Treatments of the Quality Cornices Website because we will be bolting ceramic medallions on the face of the board to support swags.  After our board is built and the location of the medallions is marked we drill holes through the plywood and insert bolts through the back side of the board that will screw into the back side of the medallions.  The bolts have nuts and washers on the front side of the cornice board to hold them securely in place. Batting is stapled to the board and finally the batting is covered with muslin because the finish fabric is a shiny polyester that would show the irregularities of the batting if we didn’t first cover in muslin.  Now we apply the finish fabric and cut slits for the bolts to poke through.  Since I don’t know how much swag fabric must be placed behind the medallions I’m going to use what I call ‘bolt extenders’.  They are female/female threaded couplers that will have one end screwed onto the protruding bolt.  Another bolt will have its head cut off so it can be screwed into both the medallion and the other end of the bolt extender.  This fabric is ideal for using Millennium Tape to make the welt and to fasten the welt to the bottom edge of the cornice board because the tape sticks tightly and won’t show any goofs that might show  if we used hot glue or fringe adhesive. If you put your cursor over a photo you will see an explanation pop up.

Finishing the upholstered headboard

   Now that we have built the frame, glued on the 2″ foam, covered the foam with batting and upholstered the headboard with muslin we can apply the finish fabric.  The fabric is first pinned in place and stretched tight so we can take a look to see if it is positioned properly before we begin stapling to the back side.  After the fabric is stapled in place we cover the legs with pieces that match the pattern.  Then with the face completely finished we flip the headboard over and apply lining fabric to the back.  I like to use an ultrasuede lining because you can’t see any of the knots in the plywood through it.  We start at the bottom of the back side and use a cardboard tack strip to hold the lining in place.  Then we pull the lining toward the top of the headboard, use pins to stretch it tight and then fasten it in place with staples every two inches or so.  The shape of the top is marked on the lining fabric by running a finger along the edge while holding a pen or pencil to make a mark about 3/4″ in from the shaped edge.  After the excess has been cut off we staple the top shaped edge of the lining fabric in place and then glue a piece of scroll gimp over the raw edge.  I like to use ‘Fringe Adhesive’ from R.W. Rowley because it has a nice, thick consistency and holds the gimp in place very well.  So that’s it.  Our headboard is done and someone can enjoy a good night’s sleep in a beautiful bed.

Building the frame for an upholstered headboard

  We have a work order to build an upholstered headboard that is 70″ high and 62″ wide.  Normally we will ask the customer to give us the height of the top of the box spring off the floor (the bottom of the headboard will be an inch higher than the top of the box spring) and the height of the top of the mattress off the floor ( so we can center the pattern between the top of the headboard and the top of the box spring).  First we go to the lumber yard and find a nice, straight sheet of 5/8″ cdx plywood for the face and cut it to a dimension of 48″x62″.  Then we make four pieces of 15/32″ cdx plywood that are  8″x70″ for the legs.  We will fasten two of these pieces together for each leg which will be stronger than using a piece of 1″x8″ pine board.  The legs are now screwed to back of the 5/8″ face board.  Between the two legs at the top of the board we will attach another two pieces of 15/32″ plywood that are fastened together like the legs.  If the top of the headboard was straight we would make this top board about 4″ high but since we will be cutting an arch that is 12″ high this top board needs to be about 16″ high.  In an attempt to keep the weight of the finished frame as low as possible we will cut off all but 4″ of the upper part of the arch.  Since the top of the box spring is 14″ off the floor the bottom of the face board needs to be 15″ off the floor which requires a face board 55″ high and 62″ wide.  The 5/8″ sheet we used for the face is only 48″ wide so we have to edge join another piece 7″ wide to the bottom of the face board.  When we made the original 62″ cut in the 5/8″ plywood it left us with a piece 48″x34″.  From this we now cut a piece 48″x7″ and two pieces 8″ wide to be used as filler (not for strength) on the face of the legs.  After the 48″x7″ piece is edge joined to the bottom of the face board we fit another doubled piece of 15/32″ about 4″ wide between the legs at the bottom back side of the face board.  Now we have a face board 62″ wide and 55″ high with legs 15″ long.  At this point we draw the shape of the top and cut through all three pieces of plywood at once (the 5/8″ face board and the doubled 15/32″ boards.  We do the cutting with a long blade in a jig saw.  After the shape is cut we use 3M Super 77 spray adhesive to attach a 2″ thick piece of foam to the face of the frame.  Then using an electric carving knife we can cut the foam to the shape of the top of the frame and trim off any excess foam on the sides.   A piece of lightweight batting is laid over the foam then the headboard is covered with muslin before we apply the finish fabric.  The muslin is an extra step but produces a better surface for the final covering.

Bendable materials for an arched top cornice board

When a shaped dust cover is required for a cornice board there are several alternatives.  We could use bendable plywood (wiggle board) which is about 1/4″ thick and not suitable for today’s application.  Another choice might be FirmaFlex, a bendable fibre board which can be ordered in six foot lengths and edge joined for longer pieces.  If you are building your own cornice and cost of materials is not a big issue this could be a good choice but for the average workroom it would be a little too pricy.  Next you could buy dimensional lumber such as a 1″ x 4″ board and cut hundreds of slots (kerfs) across the width of the board until it can be bent to the shape you want.  Once again for the average workroom time is money so the time involved would rule this out.  My choice of material for today is Homasote, a recycled newspaper material.   They put the old newspapers in a huge vat, add water or other liquids and stir until the mixture becomes a mess of sludge.   Then the sludge has most of the liquid removed, it is poured onto a flat surface and highly compressed to get the remaining liquids out.  The finished product is cut into 4′ x 8′ sheets that are 1/2″ thick and similar to plywood although the cost is about twice as much.  Homasote is easy to cut with a circular saw but very, very dusty so it is best to use a dust mask while cutting.  For our arched top cornice we need 3 1/2″ returns so we cut strips of homasote 3″ wide.  Since the cornice board will have a finished width of 111″ and the homasote comes in 96″ long sheets we will need to cut two strips and join them end to end with aluminum or steel edge joiners (sometimes called ‘dog ears’ because of their shape).  Once the ends are joined we cut the strip about six inches longer than needed, stand it up on one edge, and lay the cutout plywood on top of the other edge.  Then we start the process of stapling and bending, stapling and bending with the staples about three inches apart all along the top edge of the cornice.  With a little extra beyond each end we can now cut down through the homasote at an angle to match where the curved top meets the straight top of the returns.  You can either staple through the top board (homasote) into the top of the return board or staple through the top of the return board into the edge of the top board.  The first way seems to be the most simple.