Body binding question

[John Soper]

Thanks to members of this forum and the numerous posts on this discussion board, I've managed to generate much sawdust & shavings (and fun), without making major goofs during my first mandolin build. After successfully topping, backing & necking the A-5 mando box, I screwed up my courage, paracticed on scraps with the Dremel Stew Mac routerbase with binding guide to route out the ledge for binding... decided (fortunately) to go with the back first, rather than the front...

I felt slightly light-headed as the sound of the Dremel was amplified by the box & imagined all sorts of horrible consequences. I quickly discovered on my first shallow passes where the tearout was going to occur & took it slow & easy, repeating the mantra of "you can always take off more wood later"... I must not have noticed the little lurch when the guide slid out, or maybe the screw loosened slowly because of vibrations, increasing the lateral depth of the cut... I felt a slight wave of nausea when I measured the ledge against my strip of I/B/I binding & found it fit with enough room for another thin lamination in all the areas where I had a clean ledge. Fortunately, the ledge was the correct height... It was close to midnight & I decided to sleep on this one...

So now what should I do? The options I thought of last night: 1) I could laminate an available strip of ivoroid binding to make the binding "fatter" than the channel & sand it down to fit the sides. 2) I could fill the channel with wood putty & reroute shallower (hide with a dark-edged sunburst finish). 3) I could use the I/B/I binding and sand the wood down flush to the binding.

I guess I'll measure much more frequently in cutting subsequent binding channels...

Any words of conselation or advice would be appreciated. Thanks in advance. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Luthier]

I know this isn't much help but I never liked those .."Stew Mac routerbase with binding guide to route out the ledge for binding.

".... I felt a slight wave of nausea when I measured the ledge against my strip of I/B/I binding & found it fit with enough room for another thin lamination in all the areas where I had a clean ledge."

Sounds like a good plan to me.

Don

[Jim Hilburn]

If your going to sunburst, (and if its your first, that's a good idea)I would use a thin strip of wood. Use your wood glue and then use the binding as a way to clamp it in place. Glue in the wood strip, then tape the binding in place without gluing, just to hold the wood in place. I don't know how much too deep the rout is ,but you may be able to use some maple veneer.

[Jim Rowland]

Hi John:

I can certainly sympathize with you on this one. Actually,you are not in too much trouble here,as the small error will not affect the sound qualities unless you decide to remove more wood from the sides. Depending on how much room you have,an additional .040 strip of ivoroid or b/w or the maple veneer will do the job nicely. I would avoid the wood putty idea. If you plan to build again,consider a simple routing jig a la MacRostie or Dudenbostel and avoid a world of dread and agony.

Jim

[Magnus Geijer]

I had some serious tear-out when routing the binding channel on my #1, and had to use some filler there. After that I was too afraid to put the router to the mando again to finish the job, so I ended up just beveling the edges instead, and I'm rather happy with how it looks, although it's not for everyone. Anyway, just an alternative.

/Magnus

[Chris Burt]

From your description, I see you're a thoughtful person--an excellent attribute for a luthier. Use your problem solving skills to fix your problem.

If you can't fix it, feature it. Consider adding a decorative purfling strip. You've not yet cut the binding ledge on the top, so anything you do to the back you can repeat on the front. Purfling strips won't have the depth you need, so make a maple filler strip that goes under the purfling strip. For that matter, check out Stew Mac and LMI for existing bindings that may solve your problem. Perhaps someone else in this forum can suggest another source for bindings and purflings?

I make all of my own binding from wood, Brazilian Rosewood in my last instrument. Wood purflings are easily purchased.

Don't let the mistake rush you. Take some time to think out the process. If you do it well, nobody will ever know the added decoration was engendered by a mistake--and don't you tell them. Luthiery is yet another place in life where mistakes are really opportunities in disquise.

Chris Burt

PS. I also vote that you loose the dremel setup and upgrade to a router setup or learn to cut the channel by hand, which is what I do. The hand method is what I was taught so it's what I'm comfortable with. I've been thinking of trying out the router method to see if I like it.

[Hans]

I always put a .020" black strip on the inside next to the wood. Makes a great line to scrape to...and you don't dig into the wood and mess up the stain.

[Chris Baird]

I've routed too wide a channel myself a couple times. I just added an extra layer of black like Hans does and it fixed the problem. And also, as has already been stated, those dremel setups are junk. I would far prefer using a purfling cutter to those dremel attachements. A purfling cutter is also vital in avoiding tear out using a router. Set the cutter up to score the width of the binding cut and score it into the wood about 1mm. I then make 3-4 passes using a router setup(used router from pawn shop $30, homemade router table and jig $20) to creep up on the scored line. All tearout is stoped by the purfling score.

[mikeyes]

Does anyone have a picture or a URL showing the router jig for binding?

Mike Keyes

[Darryl Wolfe]

Here's one I use..it's simple and works well. #Socket head cap screws under the top piece secure it to the router table. #The top #piece has a slot for final depth adjustment

[John Soper]

As always, I appreciate the feedback- rather than go with an added lamination of ivoroid on the outside, the inner black lamination sounds like the visually most attractive option & for 1-2 spots where my inner hand cut is "less" than perfect, I can fill & mask with the dark part of the sunburst... Also might make for easier/less precision needed when scraping off the stain during finishing.

Thanks everyone! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[Luthier]

Very nice jig Darryl.

Don

[bobz]

Hi John,
Every one keeps putting down the Dremel tool and all it`s attachments. I`ve never had any problems with this tool, if used with regard to it`s power limitations, it gets the job done. It also has some benefits when routing the binding channel on an F5, especially at the points where a router table setup can rip a chunk of soundboard material at these points. Using my homemade flexible shaft attachment in the photo, you can take a climb or chop cut at these vunerable areas and as can be seen in the photo you can rout as far as the tool can go round the scroll. I rout my mandos with the body held vertically in the vice and keeping the fence on the tool flat to the sides.

[Jim Rowland]

That looks like a neat tool Bobz. I believe that most of the complains come from the Stew-Mac attachment which is based on one invented by Roger Siminoff. I own both and have had success with both,but difficulties with both. I may try to knock off a copy of your little gem though. It appears thoroughly workable.

Jim