Acornhouseworkshop

With the kerfing glued and levelled, the final step before attaching the soundboard, is to cut socket for the braces to fit into. These need to be cut as precisely as possible; too short, and the top won’t make a solid bond, too deep, and the brace won’t transmit the energy as well. Using a saw to cut the sides, careful chisel work removes the waste.

With the top fitted to the sides, we can glue and clamp. The clamping method I used this time, was to screw short pieces of MDF to the mold, pushing the top down tight. Make sure the mold is held tight to the work surface, however, or it will just lift the mold.

With the top attached, check for any gaps and do any spot glueing and clamping. any holes will create a weakness, in both the structure of the box, and the sound. Before repeating the kerfing process for the back, the sides must be angled down towards the headstock, so that the back will have an arch to it from top to bottom, as well as from side to side (from the arched bracing). Once the taper has been marked and sawed, I use a sanding board to even the sides and the cut, as well as to ease the transition from flat to angled.

Then, the kerfing is glued and clamped as before, and sockets are cut to fit the back’s braces. One final step is to add side braces for additional support — especially on an instrument that is this deep. On my parlor guitars, I didn’t need to since the sides weren’t that deep. (In future guitars, I will be using a different side brace technique that puts the braces under the kerfing, extending the whole side.) Also, now is the time to sign the inside of the soundboard, and add any other notes for posterity.

The back gets glued on out of the mold using a variety of clamps and binding cords (in this case, old bicycle inner tubes tied together.)

After the glued has cured, and everything is tight, the overhang on the top and bottom is trimmed away using a laminate trimmer. The soundbox is complete, ready for its traditional resonance test of holding a lit match at the soundhole, and thumping the belly. If the match goes out, its a good’n. This one passed!

With the bracing on the top and bottom completed, its now time to move to the bending iron and shape the sides. After soaking them for an hour or so, I let the iron (which is a electric BBQ starter connected to a switch inside a 2″ galvanized pipe) heat up. When bending, the key is to always keep the wood moving to avoid scorching. Don’t try to force it too quickly, that will result in a sickening *CRACK*. Gentle, but firm, is the key. As the heat dries out the wood, frequent spritzes will keep the steam coming, and it is steam, even more so than heat, that is the key. I am using an oven safe glove on one hand, but that is almost not needed. You just have to be aware of the hot pipe.

The bent side are checked against the mold, and then clamped with an iside mold and left to dry for a few days.

After they are dry, the ends are trimmed to fit, and the mahogany heelblock is shaped to conform to the mold’s curve and glued to the sides. The headblock is taken to the tablesaw to form the tenon and then curved and glued.

Once the glue has cured, the kerfing can be glued to the top side, with the inner molds keep the sides to shape. Clothspins and the occasional spring clamp do a good job of clamping the kerfing.

A couple of hours later, after the glue has dried, we can see the kerfing.

Once the glue has cure, the next day, we can take the sides out of the mold. The kerfing, even with only one side completed, gives it a lot of rigidity.

Next up, the sound board will be fitted and glued. No more topless bass!

The bracing for the soundboard is a little more complex, but essentially the same techniques. But before any ribs can be glued to the top, the rosette must be inlaid and cut out. I am going with a simple, fancy design using purfling material and a ring of MOP. The channels are routed out using a laminate trimmer on a pivot to a depth of about 1/16″, maybe half of the top’s thickness. Then the rosette material is glued in and then flushed smooth to the top, and the soundhole cut out with a flywheel cutter on the drill press. (Any gaps are kept at the top where they will be covered by the fingerboard.)

Once that is done, the braces can be added to the underside. For this plan, only the x-bracing is arced, every other piece has a flat bottom. First the upper transverse braceing and the maple bridge plate. (You can see how important it is to have the soundhole cut out first. It is a handy clamp location!)

Next, the lap jointed x-braces go in one at a time. An extra piece is added to reinforce the lapped braces afterwards.

Then the lower tonebars, followed by the finger braces. Notice that the soundhole is also reinforced with spare soundboard cutoffs.

The result:

Once again, like the back braces, all of these braces are carved and shaped for weight reduction and optimum sound production.

The finished top provides enough support to counteract the pull of the strings without deforming, while being light enough for maximum sound volume and tone. (At least that’s the goal!)

Next its time to torture some wood on a hot pipe!

With the backboards glued together, it was now time to give them some support. Even though the seam is well glued, with only 1/8″ of wood contact at the joint (which will be even less after all the scraping and sanding is done), it is necessary to reinforce it. I use pieces of quartersawn spruce left over from one of the parlor guitar’s soundboard. These pieces are glued cross grain along the seam for the best support. Gaps are left where the braces will go. The Spruce is rounded over at the edges and sanded.

Notice that I have two backs here. I plan on completing another “Beast” this summer to have available for sale.

The bracing, of different thicknesses and heights according to the plan, then needs to be glued in the gaps, again, spaced according to the plan. To get as tight a fit as possible, the gaps were left too small, and the exact width is marked from the braces themselves.

Then the excess is carefully chiseled out.

Once all of the braces have been fitted, they can be glued onto the back. They have had their back arced so that the back will end up concave, not flat. This is done for strength, as well as for additional sound projection.

Once all of the braces are glued, they can be shaped; both to minimize the height of brace that will need to be let in to the kerfings, but also to remove excess weight, while retaining strength.

There are many ways to carve the braces. I used my favorite chisels, finishing with a card scraper and some discreet sanding.

Comparing the finished, carved, braces with the the uncarved ones, you can see the difference.

“The Beast” has a backbone!

I’ve had to take a brief hiatus from blogging, since I was in the midst of a commission that was going to be a birthday gift, and the giftee was someone I knew and might read about what was going on. But, it has been delivered, so I can now catch everyone up on what I’ve been doing.

The project was an acoustic bass guitar, based upon the plans of Mark Stanley. This was quite a contrast from the acoustic parlor guitars that I had built; not only was it an acoustic bass guitar, but it is probably one of the biggest bass guitars around. Stanley’s design calls for a much deeper body, and slightly wider too, than the acoustic bass guitars that are available commercially, for good reason. Most, if not all, of the mass produced ABGs, quite simply, are useless acoustically. They are unable to be heard without amplification, especially the low strings. And that makes sense, low strings produce large vibrations; large vibrations need more room; a smaller body cuts off the vibrations, effectively muting them. So, while this ABG does have a pickup installed, the design of the body, and the bracing pattern, and the woods used all combine to produce an instrument that is usable both plugged in AND au natural, shall we say!

For the top, I used western red cedar; a softer (although more stable) wood than the spruces that are typical for steel string guitars, but common on classical guitars, and preferred for this design of ABG. For the back, sides and neck, I chose walnut. Not only is it eco-friendly, being a domestic wood, it is very nice to work with on the bending iron, and, most important of all, it sounds good. I found a nicely figured board from my local supplier that was just big enough for the back.

Of course its size was too big for my band saw, but a visit to the Fine WW building here at school resulted in two sets of bookmatched backs. After thicknessing them to about 1/8′ at the drum sander, I was ready to glue the backs together. Joining boards this thin requires a different technique than normal, regular clamps would just break or bow the pieces. A simple method, which works well, is to butt one board up to a series of nails in a workboard, and then put nails against the other side of the other board so that they meet in the middle about an inch up from the workboard.

Then, after applying glue to the seam, pressing them flat produces just enough pressure result in a nice tight joint. Any type of weights can be used to keep the seam flat.

After drying and scraping the seams of excess glue (plus a little mineral spirits to see the true color), the backs are now one, revealing their wonderful bookmatched patterns.

The cedar tops get the same treatment.

Tapping on the glued up tops and backs reveals the resonance to come.

Next up (very soon this time, I promise), bracing.

The workbench for inside the house is finished. No more freezing my %(#&^@! off when I feel the need to do some WWing in the dead of winter.

The six inch jigsaw blades were just the ticket to trim off some wonky bits on one end of the slab. (Apparently, the slab came from a tree that had been downed by a lightning strike.) It cut through the maple with no problems, leaving a fairly smooth surface, to boot. Aside from getting rid of the bad, unstable wood, I also wanted to create a projection tailor made for working on guitar necks from both sides. There is still a bit of nastiness on the underside, but it should not be a problem.

I started surfacing the slab by tackling the underside with my No. 6 and No. 608 Stanley planes (Sweetheart vintage, of course). That got the underside flat and level enough for the base. It also left my arms a tangled mass of limp spaghetti! So I took the expedient route for the top and brought it up to the Fine Woodworking program‘s wide drum sander at school, and Eric Matson and I fed it through until the top was parallel and flat. Before bringing the top to its final surface, I marked out and bored the dog holes. I decided on three in the back, for holdfasts, and four in the front, to work with bench dogs and Veritas’ wonder dog (in lieu of a bench vise). The holes line up at both ends for planing wide boards like guitar tops and backs. I used a 3/4″ spade bit to get through the maple, and then the laminate trimmer to put a light chamfer on the tops of the holes. Then sanding to 240 grit and two coats of Danish oil to really bring out the curls and figure of the maple, without putting a film finish on top of the wood.

There was one crack (over the punky area) that demanded some long term medicine, so I made, and inlayed, a butterfly out of cocobolo.

In keeping with the live edge of the slab, and the rustic nature of the curly oak legs, I decided to leave the back and sides as they came from the saw(s). The slab is attached to the base with two lag screws. That will allow for any wood movement, and combined with the weight of the slab, is more than enough for a solid unit. It will also make for easy separating for moving, if the need should arrive.

The final piece of the puzzle was to attach two ledger strips for a shelf. I used an orphan board of ash (with some checking) that had just enough board feet, and milled some tongues and grooves. They are laid between the legs with no glue or fasteners.

Under the bench proves to be the perfect spot to park a giant dustpan, a MUST for any in house woodworking.

Now, a funny thing happened when I went to insert the bench dogs into the holes: they didn’t fit! These are commercial made ones that I have used for years, so I know they are sized for 3/4″ holes. So I checked, and, lo and behold, the holes are too small. Checking the spade bit, I found that it was almost 1/16″ shy of the 3/4″ that it claimed to be! Handy and speedy, yes; accurate, No! Thanks to the chamfer, I was able to widen the hole with a (true) 3/4″ forstner bit.

The bench is solid and massive for its small size, with a rustic, yet elegant quality appropriate for fine, modern furniture. Call it Arts & Crafts meets Nakashima.

The only thing that remains is to get some no slip pads for under the legs. While it doesn’t rack on its own, it does tend to move on the bamboo floor when pushed, not good for planing. Now, I just hope the cats approve.

With the base of the workbench done, it is time to tackle the slab top. I quickly realized that I needed a little more ammunition in my arsenal to handle the cuts that I want to make, so I had to order extra long jigsaw blades. While waiting for them, and with slightly warmer weather predicted, I decided to tackle a commission for 3 saltboxes. These make a good weekend project. I will make two with a cherry base and birdseye maple lid and one with a curly maple base and a figured cherry lid.

The first step is to mark the area to be hollowed and drill out as much waste as possible with a forstner bit before routing. This eases the stress on both the router bit and me. (As useful as the router is, it also has the potential to do a lot of damage in a blink of an eye, so anytime I can minimize that potential, even if its a little extra work, I take it!)

After the forstner bit has done its job, I attach a circle template with screws in a waste area of the wood and rout to the template with a pattern makers bit. While I am using a circle, you could be a creative as you want with the bowl part. I rout in multiple passes, until I am past any forstner bit marks on the bottom.

After routing I draw the outside shape, leaving an area for the pivot pin. While I could make a template for this, I just draw the outline by hand. Its not that complex, is good training for my eye, and adds a little hand made uniqueness to each piece. Then its over to the bandsaw to cut the rough shape just outside the line.

Next step is to remove the saw marks and refine the shape. Now, if you don’t have an oscillating belt or spindle sander, I would advise against this project. While I’m sure you could figure out other ways to shape it, the oscillating sander makes the process so easy. I start out with an 80 grit belt for the initial shaping and finish with a 180 grit belt for final smoothing. A word of warning. Be careful when you are working with the 80 grit belt; its aggressive bite can grab the piece and propel it across the room. (Don’t ask me how I know.) So make sure you have a good grip on the piece!

With the box complete, its time to address the lid. After milling the stock to thickness, I trace the box shape onto the lid and cut it out at the band saw. Next, I tape the rough lid to the box and drill for the pivot pin. I am using 3/16″ brass rod. With the pin in place, I can go to the sander and, by removing the tape one area at a time — and then retapeing after sanding — I flush the lid to the contour of the box.

Then, with all of the tape removed, I do a final sanding with the 180 grit belt; being VERY careful to keep the lid and the box lined up. Since the 180 is far less aggressive than the 80 grit belt, this is not too hard.

After hand sanding to 220 grit, its off to the finishing room. Since this is intended for extended food contact, I only finish the outside with a couple of coats of Danish Oil. This brings out the character of the wood while leaving it with a natural feel. With salt inside, any moisture will soon get absorbed. After finishing, I peen over one end of the brass pins, put a drop of thick CA glue in the pin hole in the box and attach the lid. This will keep the lid tight while still being able to pivot open.

All ready to dole out pinches!

Even with the new semester beginning at school, I’ve managed to make some significant progress on the workbench. With all of the mortice and through tenons done and fitted, next up was getting the holes drilled for the pegs. For the solidest bench, I am using the ancient timber framing technique of drawboring the pegs. After drilling the holes for the pegs in the legs, I put the tenons through (dry) as tight as I could get them. Then using the same size drill bit (3/8″) I marked the hole location on the tenons. Then, after removing the tenons, I marked another hole 1/16″ in from that mark. THAT is the place to drill the hole in the tenon. By offsetting the holes, when driving the peg through, it will lock the joint together tighter then any clamp could ever do.

You can buy (or make) drawbore pins which help prepare the holes for pegging (see Chris Schwarz’s article in Woodworking magazine), but I was able to drive the oak pegs through with no real problems. The end of the pegs have to be tapered a little to work through the offset, but with a stout mallet, the pegs drove home.

Notice that I prefinished the ends of the through tenons with shellac to avoid any problems with glue wicking into the end grain. I started assembly with the short sides. One of the advantages of drawbored tenons, is that they do need any clamps. The pegs combined with the glue mean these joints aren’t going to move any time soon. (At least for a century or two!)

For final assembly of the base, and for finishing, I moved everything up to school and the shop area of the Theatre, a nice perk from the day job. (I really try to avoid doing any oil/varnish fishing in the house, and my finshing room (garage) is too cold for the finish to ever cure.) More glue and mallet whacks and the base is assembled. After the glue dried, I sawed the pegs flush, scraped and sanded and put the first coat of finish on. You can really see the curly oak pop!

For the stretchers, I used a stopped double chamfer on the top edge with a light chamfer on the bottom edge. That way, if, in the future, I choose, I can easily add a sliding deadman to the front. I will be adding a shelf after installation. The through tenons also got a light chamfer.

Even with out the top, the base is solid with no hint of wracking under pressure. Next step is to trim the wonky bits from the maple slab top and flatten it with my No. 608 jointer. Hopefully that will be my Ace in the hole.

One of the drawbacks to the Acorn House Workshop, as it is at the moment, is that it is an uninsulated, woefully under heated, former one car garage. Which means in winter, woodworking becomes a chilly proposition. Even bundled up, with an overhead radiant heater, trying to do extended work out there — especially quality work — becomes a race against hypothermia. Very frustrating when the creative juices are flowing but are apt to freeze if I try to do anything!

So my first project of the new year will be a workbench for the house. After reading about, and seeing in person, Chris Schwarz’s small Roubo bench with the cherry slab top that he intended for a similar, in house, part-furniture, usage, I searched for a suitable slab for the top. As I wrote in an earlier post (the second slab pictured), I found the ideal candidate in a 3 1/2″ thick curly maple slab, approximately 20″ wide and 3′-4′ long. I am going to go a little outside of the box and will keep the gentle curves of the live edges rather than squaring everything up. That limits the type of structure and vises that I can use, but I think for the intended purpose (luthiery and small hand work), it will be more than sufficient. So, as impressive as they are, I won’t be using the through dovetails of Schwarz’s bench, and will go with a through tenoned, Arts & Crafts inspired structure for the base and attach the slab to it with a couple of lag screws.

I was lucky enough to get the legs from a friends timber frame project. Quarter sawn white oak (QSWO) cut offs 3 1/2″ x 2 1/2″ thick that match the rustic nature of the maple slab. More cutoffs and left over 5/4 and 6/4 QSWO from the dining table build will provide the material for the stretchers. The first task was jointing and squaring the rough leg stock. (Even though I am keeping the curves in the slab, the base joinery is SO much easier on squared stock.) The legs proved to be not just quarter sawn white oak, but CURLY QSWO; really pronounced in two of the legs (I’ll use those for the front legs).  I dialed in my “new” mortise gauge to scribe a 5/8″ mortise, and marked the first set of mortises. (The two front legs are on the right.)

In order to save wear and tear on my router, and provide a safer, less stressful rout, I drilled out the waste from both sides with a 9/16″ forstner bit first.

Then, using a 1/2″ spiral upcut bit and the router fencer, I finished the sides of the mortises,. Not having to hog out ALL of the waste with the router was so much easier on both me and the bit. All I had to worry about was the grain direction of each side, doing a shallow climb cut first on any problem sides to avoid massive tear out.

After routing, the rounded ends needed to be squared up with a chisel and mallet. I much prefer a square end mortise to rounding the ends of the tenons to match the curve of the router bit. Especially as my mortise is wider than the router bit and isn’t perfectly round.

Making the tenons to fit was a piece of cake using the tenoning jig and the table saw. I will be pegging the tenons, so a snug fit was necessary. I will do a small chamfer on the protruding tenon ends prior to glue up. The top stretcher of these side assemblies will be dovetailed into the top (you can see them on the left). This bench won’t be racking any time soon!

(You might notice, I’ve set up a worktable inside the house for assembly and fitting. Can’t wait to get the real thing finished!)

One of the benefits of being a woodworker, whether amateur or professional, is that when gift giving occasions come up, we have the means to create something more than yet another meaningless Mall purchase. Sometimes the element of surprise is lost, when the gift is a request, or the recipient needs to provide dimensions; but, an unexpected creation is still possible now and then.

I’ve been in full blown gift mode for the last few months, what with birthdays, weddings, thank yous, and, of course, Christmas. For my Mother’s birthday, I made a (requested) countertop screen to hide an unattractive  back of a counter shelf unit. I upped the ante by trying something new for me. Using Craig Vandall Stevens excellent beginning book on artistic chip carving (which focusses on a more Asian, literati approach rather than the more traditional multi-facet patterns on Northern European chip carving) I did a pair of chip carvings on a wide poplar board in a frame of cherry. Using a greener board made it a little harder, because of the hardness of the heartwood, but I progressed through it, and each slice was better than the last.

The next project was another jewelry box as a thank you for help in wiring the Butternut Deuce. The only real difference was the configuration of the inner dividers.

Next was a bowl for a former student’s wedding, turned the morning of the wedding. The wood is an Australian Karri burl. Not a tremendous amount of burl, but enough to set off the warm grain of the bowl.

For family X-mas gifts, I had a couple of requests for frames, one for a watercolor, and one for a mirror. For the watercolor, I used walnut; my sister had requested a dark frame, at least 2″ wide. The wide expanse of walnut seemed to need to be broken up somehow, so, instead of routing various moldings, I decided to inlay a strip of birdseye maple, which provided the necessary contrast. When making a mitered frame, no matter how carefully you set up your saw, the miters are going to need tweaking. The easiest (and cheapest) tool for that is a shooting board with a well sharpened plane. After cutting the pieces to length and test fitting them, I made up a 45° angle jig for my shooting board, sharpened up my low angle block plane and made the adjustments. In no time at all, I had tight fitting miters and some beautiful shavings.

The result, after glue up and a couple of coats of Danish oil (minus the artwork):

For the frame for the mirror, I took my inspiration from Greene and Greene. Using a cloudlift template that I already had and some cherry, I used mortise and tenon construction for the larger piece. Danish oil and wax was, again, the finish of the day.

Now all it needs is the mirror.

I used some more cherry (as well as one piece of butternut) for a bedside table lamp. This was turned from 3 different block, with the main block being a two piece glue up (that way, I could cut the channel for the lamp cord ahead of time, and not have to drill though 8 inches of solid wood!). One miscalculation I made was not letting the top piece acclimate indoors before final assembly. Due to the difference in relative humidity between the shop and the heated house (oh yes, did I forget to mention, that I was making these gifts in a workshop whose average temperature was, with heater, around 35° !) after the lamp hardware had been fitted and everything glued together, the top piece must have shrunk just enough so that the nut on the threaded rod is no longer tight. As a result, the lamp socket now freely turns. Heavy sigh!

The last gift (save one!), was a saltbox made from curly and birdseye maple. The center was drilled and routed out, and the outer shape was done freehand at the spindle sander. The lid pivots on a brass rod for easy access.

One of the perils of making one’s own gifts is the time factor. Unlike a store-bought gift, some things take more time than is available; so instead of a present, somebody will have to get an IOU. So, I will be building a liquor cabinet in the near future, probably out of hackberry. Sorry, Brad.

But at least I don’t have to brave the Malls for my gift giving needs. I have the tools, I have the technology. I just need a little more time.