Jim McConkey's Flood Mandolin Twins

[Jim McConkey]

So where are all the other entries?!?

In an homage to 20 years of MIMF contests, I have decided to combine the current theme with (most) of the past contests into my own MIMF-themed, $100, acoustic, scrap materials, try something new contest entry. And since I am supposed to be one of the judges, I hereby recuse myself. This project is 7 years overdue, but read on and you will see why. Like everyone else, I hadn’t even realized the contest had begun, so I am, of course, way behind, and am just hoping I finish on time, but it is a good story regardless.

I have been a member of this Forum almost from the beginning. Within a year Deb invited me to be a staff member. I have been ever since, now 19 years and counting. I have made many friends, seen many fade away, learned a lot, and shared what I know. I have experienced some of the great courses we used to offer, and watched with awe the creativity and workmanship in the many contests we have hosted, and on occasion even participated in a few. But nothing has touched me more than the generosity of this Forum when it comes to sharing knowledge, not to mention time and sweat when disasters happen.

I am good friends with former MIMF staffer and MIMF Poet Laureate, Amy Hopkins, who only lives a couple miles away. When she announced plans to go to New Orleans after Hurricane Katrina [LINK], I rounded up a whole bunch of spare tools from friends and myself and delivered them to Amy to use in her efforts. Then, in 2010, when fellow staff member Clint Searcy’s house got flooded out near Nashville, I quickly hollered “who's up for a road trip?.” Amy was the first to volunteer, others followed, and a bunch of us headed out to Nashville for a week. If you haven’t read the story, please take the time to read it here.

[Jim McConkey]

This was the situation at Clint’s house a week or two before we arrived:



Deb started a fundraiser almost immediately, and generous MIMFers from all around the world contributed and bought things in our benefit auctions to raise an unbelievable amount of money for repairs. Staffers Amy Hopkins, Ellie Ericksen, myself, and our spouses and friends drove out to Nashville to spend a week. MIMFers Ryan Faust and Brent Bivins showed up to work and loan a pop-up camper for the volunteers. Clint and Alicia had no idea what or who was coming. They didn’t know any of us, except on-line at the MIMF, and weren’t quite sure if they could trust this motley crew that just invited themselves to move in. But after a week of 14-16 hour, stinky, grimy, sweaty days, they quickly changed their minds. One of our few respites was a little late night noodling on whatever instruments were still playable. Clint was particularly taken by Ellie’s mandolin playing, and remarked that he would like to get one to play with some day.

[Jim McConkey]

One of my last acts before leaving was to steal a couple pieces of reddish 2”x6” that had been demolished out of the house, mostly because of their unusual color. I had some vague notion of making something, but after we got back time slipped away as we started hunting for a new house of our own, then went through the seemingly endless moving process. Of the big advantages to the new house was that I was finally going to get a dedicated room for my shop. Yeah! The shop, of course, was the last thing I got together, almost two years after we moved in.

[Jim McConkey]

Fast forward two years and we are finally almost moved in. Then the Polar Vortex of 2014 hit. We quickly discovered that whoever had remodeled the upstairs bathroom for the previous owner was stupid enough to run the PVC toilet water supply pipe in the outside wall of a north-facing dormer. I shouldn’t say quickly. We weren’t home at the time, and by the time we returned, there were several inches of water in the basement, and the drywall, now little more than mud, had completely sloughed off the joists in the hallway beneath the bathroom. All our beautiful distressed hardwood floors were now even more distressed and buckled and warped like crazy. It took us over a year just to find a contractor who would tackle this mess, and well over another year to finish everything, even though I ended up doing half of the reconstruction myself in the mean time. My new shop, of course, was the last thing to get repaired since it was the only place we had to store boxes. While the hardwood floors had to be completely replaced, and the vast majority of it had warped and twisted and gotten moldy beyond repair, I was able to save a few straight pieces for future projects.

The water also got into the laminate floor in my new shop, so they had to rip part of that out. Now missing a big chunk, I had to remove the rest of the floor and all its underlayment, then the former new shop was quickly converted into box storage for everything else moved hastily out of other wet areas. Of course, that meant the shop was the last place to be unpacked after all the other renovations were completed two years later. I had bought extra boxes of the now-unobtainable flooring anticipating repairs. I thought I had enough, but with what had been removed, I ended up two rows short. So I had to rip it all out and start over a third time. Third time was a charm, with proper moisture barrier and underlayment, and new baseboard all the way around. Now almost 5 years after we moved in, I finally have a shop again. Well, it is still full of boxes, but I have enough room to work. I built a new workbench and now it is time to inaugurate it with my first build in years!

[Jim McConkey]

With two major floods behind me, you might now be able to guess where this is going. With several pieces of top-quality flotsam now in my stash, I am setting out to build a matching pair of archtop A-style flood mandolins (which can double as emergency canoe paddles). These will be my very first mandolins, and first completed archtop instruments (well, my fiddle from Bill Moll’s MIMF violin class years is carved, but I still haven’t finished it, so I have at least a little carving experience). Due to the somewhat constrained wood selection, these will be more like fraternal twins than identical twins.

One will be a surprise gift to Clint (he doesn’t know yet, so if you know him, PLEASE keep your mouth shut until he gets it!) and I will keep the other as a perpetual reminder of our shared miseries and adventures.

Here is what I had to choose from:

and after a little sorting:

The two pieces of 2”x6” framing lumber from Clint’s house will become the tops.
Several pieces of my oak flooring from my house will become the backs, sides, blocks, binding, and necks.

Please don’t complain about my poor choice of tonewoods. The woods and their histories define this project and we will get what we get from them.

I have an old A-style mandolin (that will be the subject of a forthcoming discussion), Siminoff’s “Constructing a Bluegrass Mandolin,” and Don Macrostie’s plans from Stew-Mac to use as guides, but due to the time constraints and my own nature, I am just winging most of this.

[Jim McConkey]

So off to the bandsaw I went, with a shiny new Woodslicer blade I got for Christmas. I have very little resawing experience, and none of it good, but this was a breeze with the correct blade. I just sliced each 2”x6” in half lengthwise. I was able to get 4 side slices out of each 3/4” floor board, but not all were usable.

I have a 14” bandsaw, but no riser blocks, with a Kreg fence, and a 7” resaw guide for it. But as you can see in the last picture, the guide is just slightly too tall and hits the blade guide wheels, even when fully raised. It has sit in front of the blade, not beside it which is much prefered. Not wanting to wait for the delivery of a 4 1/2” resaw guide (I have since gotten one), I took a chunk of 2”x4”, copied the curve of the resaw guide, and cut the 2”x4” to match, then simply taped it onto the fence. Stupidly simple, but it worked like a champ!

[Jim McConkey]

The flooring was tongue and groove, so I had to slice off the tongue and cut the groove side deep enough to get to the bottom of the groove. This left me with 2 remnants of the groove edges which are just about right size for binding, if I sand them a little. What I was left with was not quite wide enough for a two piece mandolin back, so I opted for 3-piece backs with a tapered wedge up the center. The wedges were cut on the table saw with an angle jig.

[Jim McConkey]

Using my new shooting board and newly trued plane. I planed all the edges clean until they fit with no visible gaps when held up to a bright light.

[Jim McConkey]

A few minutes under a small blow dryer to warm up the edges, and quickly painted with fresh hot hide glue, the plates were ready to be joined. Having fours sets to do at the same time, I opted to simply rub the joints well and leave them. This worked better than any time I have clamped the plates! I don’t think I would use it on thin plates, however.

[Jim McConkey]

Trying to maximize use of the fresh hide glue, I also glued up the angled part of the necks at the same time. I used the old trick of putting two staples in each and cutting off the heads. This, in theory, should keep the parts aligned while gluing. It worked great on one of the necks, but failed on the other. It was a PITA to get the misaligned one apart to glue it again. I chose this particular style of joint because I got to thinking about a headstock overlay, and then decided, “Hey! The wood is already finished, so why don’t I just leave it. So the headstocks will have the original floor finish on them since it really suits the recycled flotsam theme. Some extra blocks will be glued on later for the neck tenon.

[Jim McConkey]

The sides weren’t all as uniform as I hoped, but I was able to get at least 2 good pieces out of each. While the newly joined tops and backs were drying, I ran the sides through my half-finished homemade luthier’s assistant to thin them to about 0.080” (2 mm) for easier bending.

[Jim McConkey]

So now the tops and backs are all glued up. I finally found my old Safe-T-Planer in some obscure box, sharpened it, and put it to good use flattening the tops and backs. The flooring had grooves on the bottom, which I took off, and the tops were not quite flat due to my inaccurate resawing. I bandsawed the rough outline of the body on all of them, with a little excess.

[Jim McConkey]

Then it was back to the Safe-T-Planer to very roughly terrace out the plates to save on the planing required. OK, so this is really a little too rough, but it did get the job done. It probably took an hour a place to rough out the terracing. Although it looks rough, less than 10 minutes with my trusty Ibex finger plane and smooth curves started to appear. Of course, it takes a lot more time to finesse it into a “nice” curve.

On the left the terracing has not been touched yet, and on the right how smooth you can get it after only a few minutes. It is not quite as fast on the harder oak!

The only problem is that I have to do this a little at a time, over many days. My fingers don’t do this enough to have the right calluses to use those little Ibex planes for very long without getting blisters. If anyone has any hints for using these little planes without killing your fingers, I am all ears. The soft tops were easy enough, but I quickly took to using my block plane to starting the beveling on the oak. I had to revert to the Ibex curved plane to finish the planing, but it did save some wear and tear on the fingers.

[Jim McConkey]

I won a cheap e-bay special luthier’s bender right before we moved, and it has been in the box ever since. I finally got a chance to break it out and use it. I got the small mandolin extension from StewMac, and their great customer support was happy to tell me what size hole I needed to drill and tap to secure it (5/16”-18 thread, 9/16” deep). It turned out to be a lot easier to use than my old plumbers soldering iron in a copper pipe! I have built with oak before, and it has always seemed particularly susceptible to scorching, but I had very little problem, and only on the highest setting, since I am still getting used to the 0-10 temperature control. I was worried about how thin I made the sides (0.080”), afraid it would only make them more susceptible to cracking, but now I’m glad I made them that thin. I wet only the bending side, waited patiently until the wood went pliable, and I had no difficulty even at the tightest bend where the neck attaches, with not even a hint of cracking.

[Jim McConkey]

Bend a little, check to the form, and repeat until done. Probably 5-10 minutes per side, if that.

Only now that the sides are bent, I realized I had foolishly cut the sides for a flat-top mandolin. The sides of an archtop need to be an inch or so lower, so the overall thickness with two arches ends up about the same. Oops! Back to the bandsaw.

But my mistake was also my gain! A quick reset of the fence, and a couple quick passes, and I had pre-bent binding for the top.

[Bryan Bear]

I love everything about this thread! I can't wait to see the finished product. You are a good man Jim. Thanks for all the good deeds you have done. These mandos will have so much mojo that they may be too dangerous to play <G>

I'm glad you finally have your shop back; it is well deserved.

[Jim McConkey]

Thanks, Brian!

I am not completely ready to say I have a shop back yet. It is usable again, though just barely. Like you'll notice I am using my drill press on the floor (and kind of prefer it, actually). I still haven't found half my special tools (I hope I can find my binding attachment in time!), and the room is still stacked with boxes that have not been unpacked yet. I am still working on flow and seeing what tools go best where. Let's just say it is a work-in-progress, but I am glad I have any workspace at all at this point!

[Bryan Bear]

Let's be honest. Your shop, my shop, all of our shops will always be a work in progress. I keep rearranging or rethinking my layout to improve flow. I do that more than I actually make anything <G> By the time I am finished putting it back together, I have already had a new idea to change things.

[Jim McConkey]

Now that the tops and back plates are all arched on the outside, it is time to start thinking about arching the inside. This can be done entirely by hand with gouges, but why work so hard when we have machines to mess up faster?

This little guy is the star of the show, a 10 mm 2-flute end mill.

It should go without saying, but I will anyway, that drill presses are only designed to drill (go in straight), NOT to mill (move laterally). The chuck is only held on the spindle by a tapered fitting, and it can easily pop off if lateral pressure is applied to the bit. This milling bit will ONLY be used for vertical (up/down) drilling. The only difference from a normal drill is that this one has a flat cutting surface.

For some odd reason, my inlay sawing jig doubles as a thickness jig. It is nothing more than the rounded top of a broomstick stuck in a hole, then placed directly underneath the milling bit in the drill press. The semi-spherical top is small enough that almost any curved plate will ride over top freely, even small violin plates.

[Jim McConkey]

I have a run-of-the-mill drill press with no fine table height adjustment, so how will I somewhat accurately set the milling depth? My digital caliper will not fit, and rulers are hard to see. I need one of those stepped blocks you use for table saws, etc., but I don’t own one.

But just having installed my third shop floor, I remembered these guys:

You use them to space laminate flooring from the walls while you assemble the floor, and I have a whole box of them. They are 5 mm thick on one end and 2 mm on the other. They are even marked. How convenient! I need to mill to 4 and 5 mm for the contours. Simply place the spacer on the bottom support, lower the milling bit until it is touching, and set the depth stop on the drill. The one end does for the 5 mm setting, and I just stack two of the 2 mm to get 4 mm.