Binding Side Ports

[Eric Knapp]

Hello, I'm trying out making a side port on my next guitar. I have an elliptical hole cut on a test piece that is quite good. Since the sides are laminated I want to bind the edges of the port. How do you all do this? It doesn't seem trivial.

Thanks,

-Eric

[Alan Carruth]

I've bound F-holes on archtops by super gluing on strips of veneer. It's about the only way I can think of for binding an irregular hole.

For round holes I've made tapered plugs that can be used themselves if you drill a hole through them, or as forms to laminate veneers. The taper allows you to sand the edges of the hole to fit, and then glue in a binding piece. You might be able to make an elliptic plug.

[Bryan Bear]

I made one elliptical port but switched to round as soon as I decided to start binding them. I couldn't see an easy way to do it. Now that I have a little more experience doing round holes, I think my technique MIGHT apply to ovals as well but with more difficulty.

I have a chunk of wood with a hole the same diameter as my (round) sound port. I build up my purfling and binding layers inside this hole. Then, I glue the whole thing in the side and trim it flush by hand. I bend my layers to be a little tighter than the actual hole and put a scarf joint along the width (not the thickness) of the layers. As I force that scraf past itself, it forces the layers into the perimeter of the hole. Once glued, it is a perfect match to the hole in the side. I suppose this would work the same on an oval if you put the scarves in the long areas of the curve. The challenge would be figuring out how to make a blank with exactly the same oval as the side. You could just build it in the side itself but then you only get one shot. Anyway, food for thought. . .

[Carl Dickinson]

I haven't done this before but have thought about adding several more laminations to the area where I want the port, alternating light and dark wood layers. Cut the hole and bevel the edge to show the alternating layers. No binding but an interesting feature.

[Randy Roberts]

Carl's idea works well, and is easy if you have the top or back still off.

just bend a short piece of a couple contrasting woods at the same spot on the bender as your sound hole location, glue them in, and then cut the sound hole.

Hard part is getting yourself to ram a forstner bit into a perfectly ok body.

[Bryan Bear]

That looks really nice!

I've been using a sharp hole saw on the drill press; I agree, it is always difficult to bring myself to start.

[Eric Knapp]

These are all great suggestions. My current guitars might need some binding though. The sides are laminated and I'm not sure how good it would look to show them. They are very stiff and strong already and don't need more reinforcement for side ports. Here's a photo of the edges of the sides. One is very thick and the is less so. The middle layers are basswood.

I consider these two guitars to still be learning instruments so it might not matter much. I am trying to look forward and I've seen some ports with beautiful binding.

-Eric

[Pat Foster]

I've done ports two ways. First was binding like what we put around the back and top, bent on a hot pipe. At the junction, instead of having the two ends meet at a line perpendicular to the binding, I made it so that the line is at a diagonal, like a scarf joint. Another way, which works better with darker woods is to laminate it, using thin layers and wrap it several times around a form.

[Bryan Bear]

I hope these pictures post okay.

This first picture shows how I glue up the scarf joint in the dummy hole. Squeezing the scarf across itself, forces it tight into the hole along the perimiter.

The next shot just shows the binding plug squared up after gluing the layers. The outside layer is a cherry veneer to match the side purfling. This fits perfectly into the hole in the side then after it is glued in, I trim the height flush with the curvature of the side.

In this last pic you can see that the scarf is visible (at about 8 o'clock in the picture) but doesn't look too bad. It is easier to hide in some woods than others. Also, after it was flushed up to the side, I glued in a layer of katalox to match the side wood on the inside of the binding.

[Bob Gleason]

I use the "brass inlay router bit templates" that are in all the router bit catalogs, combined with my cordless Makita compact router.Wonderful tools.I do the soundport ring glue-up before I bend, using Titebond 3 which takes heat O.K. I have also used CA. Doing something like a simple koa ring in a contrasting wood side is easy. Adding purfling takes a bit of handwork, but still is not difficult. I think adding wide contrasting binding rings works just great without the purfling.The actual inner port size I do by hand with a carbide bit in the Dremel and finishing off with Dremel sanding drums. It's not CNC, but it works!The inlay template gives you a perfect fit of the wide ring to the side hole, using a 1/8" bit. If you play around with the inlay template, you'll figure it out. Nice thing about this is that you can make surround rings wider than it would ever be possible to bend. Just another way.-Bob