Hi all,
Due to some nasty weather in Syracuse and Buffalo, our trip to the north country has been postponed for a couple of days. Not being one to waste any time, I decided to get started on the soundboard. The soundboard will be made of quarter-sawn Sitka Spruce and will be 1/8” thick (or less, in some areas). I’ve ordered 13 linear feet of 2x6 stock (I received 2x8 stock, but that’s a story for another day). Once resawn, this should be enough for 3, maybe 4, soundboards. The first step is to transform this 2” thick stock into 3/16” thick pieces. Here’s a photo of the raw spruce. The middle board is the one we will use for this soundboard. It has been jointed, planed, and cut to 5 ¼” in width. The final width of each plank will be about 5” so I have a little extra width for final jointing.
The next step is to resaw the plank into 3/16” slices. Since I work alone and the spruce slab is 66” long I use a roller stand to support the trailing end as it goes through the bandsaw. I have a shop-made resaw fence, made out of ¾” MDF. Nothing fancy – just a 90 degree fence and apron that I clamp to the bandsaw table. I use a feather board to keep the bottom of the stock firmly against the fence. Before starting, I go over the bandsaw pretty carefully – adjusting blade tension, guides, etc. I’m using a 3 tpi Woodslicer blade. I used to have a lot of trouble re-sawing – all my own fault. I’ve found (the hard way) several tips that make re-sawing easy.
1.Use a good quality, SHARP, blade.
2.Make certain that one face (the one riding the fence) and one edge (the one sliding on the bandsaw table) are perfectly square to each other.
3.If you’re using a roller stand like I do, make certain the roller is level with, and parallel to, the bandsaw table. lf it isn’t, you’ll never get the stock to sit at 90 degrees to the fence. My roller stand (a HF special) is out of parallel by ¾” so I block one leg up ¾” with a piece of scrap.
4.Listen to the bandsaw and DON’T RUSH! Feed the wood at a pace that is comfortable for the saw.
With this blade, my bandsaw doesn’t drift and getting consistently thick and even results is not a problem. Here’s a couple of pictures of the setup.
My bandsaw was in a good mood today and I got eight 3/16” thick planks out of the original plank. Here they are.
Next, we run the planks thru the planer to get down to a thickness of 1/8” plus a bit to allow for sanding. My planer (Delta 12 ½” model 22-560) can plain down to slightly less than 1/8” without using a sled. We have to remove about 1/16” from each 3/16” plank and I do this in 4 passes of 1/64” each. No sense in taking chances with this thin stock by trying to save a few minutes by taking off more with each pass.
After the planing, the planks are placed loosely into position in the case to get the best grain match. This particular plank has a few more blemishes than usual. While this won’t effect the sound of the harpsichord, we’ll try to arrange the planks to cut away as many blemishes as possible. Sandy will hide the remaining blemishes by covering them with a bug, butterfly, flower etc. Once the decision is made as to which planks to use, they are cut roughly to length – leaving them a couple of inches too long to allow for trimming when we install the soundboard into the instrument.
Next, we’ll take each plank and joint one edge perfectly straight and square on the jointer.
Now we’ll take each plank to the table saw and, placing the jointed edge against the fence, cut the plank to width. This assures that both edges are parallel to each other. This cannot be done on the jointer alone. Once you joint one edge, if you flip the plank over and try to joint the other edge, the original, jointed edge will be facing upward and not making any contact with the fence or jointer bed. Therefore, the jointer has no way to register edge #2 to edge #1. The second edge will end up square to the face of the plank but will not (usually) be parallel to the first edge. After edge #2 has been cut parallel on the table saw, we’ll take a very light cut on the jointer to clean it up.
After all the plank edges have been properly jointed, it’s time for the glue-up. I use the same wedging system we used when gluing the registers. It doesn’t take a lot of pressure to edge glue these panels – in fact, too much pressure can starve the joint, especially on stock this thin. I start with the longest two panels and use wooden cauls to keep the panels flat under clamping pressure. Here’s a photo of the first two panels being edge glued together.
The remaining five panels are similarly glued to the first two. The wedges are removed and moved to accommodate the next panel. Weights are used instead of cauls (which won’t reach as the soundboard gets wider) to keep the panels flat while drying. The shorter panels are glued two at a time to save time. When all of the panels have been edge glued, we remove the soundboard from the clamps – scrape the glue lines – and give the new soundboard a good sanding. Here’s the result.
Next step is to cut the soundboard to rough shape and fit it in position inside the instrument case. The soundboard blank is clamped onto the top of the case and, using the top of the case sides as a guide, the shape of the perimeter of the case is drawn onto the bottom surface of the soundboard blank. Here’s a photo of the blank clamped to the case.
And here’s the outline of the case drawn onto the bottom of the soundboard blank.
Then the soundboard blank is cut rough to shape on the bandsaw. The next photo shows the rough-cut blank sitting on top of the case.
That was the easy part. Since the rough shape of the blank is roughly equal to the outside perimeter of the case, the board is too big to fit inside the case and must be trimmed to size. This trimming is done mainly with a sanding band mounted on a Dreml rotary tool, a sandpaper stick, and some patience. A mere 3 ½ hours later the soundboard shaping is done. Here’s the soundboard in its position in the case sitting on top of the soundboard liners we installed into the case in Part 7.
Here’s a close-up of the fit of the soundboard along the bentside and cheek.
All that remains is to trim the front edge of the board. The front edge ultimately will be glued to the top surface of the Upper Belly rail flush with the front of that rail. To trim the front of the board a vertical line is drawn onto the spine and cheek showing the front edge of the Upper Belly rail. The soundboard is placed in position and is marked by extending these lines onto it.
The two marks are connected with a pencil line and the waste is trimmed off on the bandsaw. The last photo shows the fully fitted soundboard in the case.
There’s still much to be done to the soundboard before we glue it in for good. Bridges must be made and glued to the top side. Braces and rails must be added to the underside. A rose must be made and installed. Next time, we’ll do none of these. Instead, we’ll add some spruce to the top of the pinblock to match the soundboard and equalize the height of these two components. Then we’ll add some pinblock bridges and drill 102 tuning pin holes. There’s still plenty left to do. Patience, patience, patience.
Leaving tomorrow morning for snow country ..... maybe.
Till next time,
Ernie
Due to some nasty weather in Syracuse and Buffalo, our trip to the north country has been postponed for a couple of days. Not being one to waste any time, I decided to get started on the soundboard. The soundboard will be made of quarter-sawn Sitka Spruce and will be 1/8” thick (or less, in some areas). I’ve ordered 13 linear feet of 2x6 stock (I received 2x8 stock, but that’s a story for another day). Once resawn, this should be enough for 3, maybe 4, soundboards. The first step is to transform this 2” thick stock into 3/16” thick pieces. Here’s a photo of the raw spruce. The middle board is the one we will use for this soundboard. It has been jointed, planed, and cut to 5 ¼” in width. The final width of each plank will be about 5” so I have a little extra width for final jointing.
The next step is to resaw the plank into 3/16” slices. Since I work alone and the spruce slab is 66” long I use a roller stand to support the trailing end as it goes through the bandsaw. I have a shop-made resaw fence, made out of ¾” MDF. Nothing fancy – just a 90 degree fence and apron that I clamp to the bandsaw table. I use a feather board to keep the bottom of the stock firmly against the fence. Before starting, I go over the bandsaw pretty carefully – adjusting blade tension, guides, etc. I’m using a 3 tpi Woodslicer blade. I used to have a lot of trouble re-sawing – all my own fault. I’ve found (the hard way) several tips that make re-sawing easy.
1.Use a good quality, SHARP, blade.
2.Make certain that one face (the one riding the fence) and one edge (the one sliding on the bandsaw table) are perfectly square to each other.
3.If you’re using a roller stand like I do, make certain the roller is level with, and parallel to, the bandsaw table. lf it isn’t, you’ll never get the stock to sit at 90 degrees to the fence. My roller stand (a HF special) is out of parallel by ¾” so I block one leg up ¾” with a piece of scrap.
4.Listen to the bandsaw and DON’T RUSH! Feed the wood at a pace that is comfortable for the saw.
With this blade, my bandsaw doesn’t drift and getting consistently thick and even results is not a problem. Here’s a couple of pictures of the setup.
My bandsaw was in a good mood today and I got eight 3/16” thick planks out of the original plank. Here they are.
Next, we run the planks thru the planer to get down to a thickness of 1/8” plus a bit to allow for sanding. My planer (Delta 12 ½” model 22-560) can plain down to slightly less than 1/8” without using a sled. We have to remove about 1/16” from each 3/16” plank and I do this in 4 passes of 1/64” each. No sense in taking chances with this thin stock by trying to save a few minutes by taking off more with each pass.
After the planing, the planks are placed loosely into position in the case to get the best grain match. This particular plank has a few more blemishes than usual. While this won’t effect the sound of the harpsichord, we’ll try to arrange the planks to cut away as many blemishes as possible. Sandy will hide the remaining blemishes by covering them with a bug, butterfly, flower etc. Once the decision is made as to which planks to use, they are cut roughly to length – leaving them a couple of inches too long to allow for trimming when we install the soundboard into the instrument.
Next, we’ll take each plank and joint one edge perfectly straight and square on the jointer.
Now we’ll take each plank to the table saw and, placing the jointed edge against the fence, cut the plank to width. This assures that both edges are parallel to each other. This cannot be done on the jointer alone. Once you joint one edge, if you flip the plank over and try to joint the other edge, the original, jointed edge will be facing upward and not making any contact with the fence or jointer bed. Therefore, the jointer has no way to register edge #2 to edge #1. The second edge will end up square to the face of the plank but will not (usually) be parallel to the first edge. After edge #2 has been cut parallel on the table saw, we’ll take a very light cut on the jointer to clean it up.
After all the plank edges have been properly jointed, it’s time for the glue-up. I use the same wedging system we used when gluing the registers. It doesn’t take a lot of pressure to edge glue these panels – in fact, too much pressure can starve the joint, especially on stock this thin. I start with the longest two panels and use wooden cauls to keep the panels flat under clamping pressure. Here’s a photo of the first two panels being edge glued together.
The remaining five panels are similarly glued to the first two. The wedges are removed and moved to accommodate the next panel. Weights are used instead of cauls (which won’t reach as the soundboard gets wider) to keep the panels flat while drying. The shorter panels are glued two at a time to save time. When all of the panels have been edge glued, we remove the soundboard from the clamps – scrape the glue lines – and give the new soundboard a good sanding. Here’s the result.
Next step is to cut the soundboard to rough shape and fit it in position inside the instrument case. The soundboard blank is clamped onto the top of the case and, using the top of the case sides as a guide, the shape of the perimeter of the case is drawn onto the bottom surface of the soundboard blank. Here’s a photo of the blank clamped to the case.
And here’s the outline of the case drawn onto the bottom of the soundboard blank.
Then the soundboard blank is cut rough to shape on the bandsaw. The next photo shows the rough-cut blank sitting on top of the case.
That was the easy part. Since the rough shape of the blank is roughly equal to the outside perimeter of the case, the board is too big to fit inside the case and must be trimmed to size. This trimming is done mainly with a sanding band mounted on a Dreml rotary tool, a sandpaper stick, and some patience. A mere 3 ½ hours later the soundboard shaping is done. Here’s the soundboard in its position in the case sitting on top of the soundboard liners we installed into the case in Part 7.
Here’s a close-up of the fit of the soundboard along the bentside and cheek.
All that remains is to trim the front edge of the board. The front edge ultimately will be glued to the top surface of the Upper Belly rail flush with the front of that rail. To trim the front of the board a vertical line is drawn onto the spine and cheek showing the front edge of the Upper Belly rail. The soundboard is placed in position and is marked by extending these lines onto it.
The two marks are connected with a pencil line and the waste is trimmed off on the bandsaw. The last photo shows the fully fitted soundboard in the case.
There’s still much to be done to the soundboard before we glue it in for good. Bridges must be made and glued to the top side. Braces and rails must be added to the underside. A rose must be made and installed. Next time, we’ll do none of these. Instead, we’ll add some spruce to the top of the pinblock to match the soundboard and equalize the height of these two components. Then we’ll add some pinblock bridges and drill 102 tuning pin holes. There’s still plenty left to do. Patience, patience, patience.
Leaving tomorrow morning for snow country ..... maybe.
Till next time,
Ernie
