Bending Binding/Purfling

[Darryl Young]

Do you guys chamfer the inside corner of the binding before you bend it? Seems the easiest way but you have to be very careful how the binding is placed in the bender so the shamfer stays on the inside.

Do you bend the purfling at the same time as your binding? Thinking of alternating purfling/binding in my stack and then bend, sound doable? For the record, it's cocobolo binding and narrow herringbone purfling. Is there a possibility of bleeding color from the coco to the purfling if I try this?

[Kevin Sjostrand]

I chamfer the edge of the binding that will lay into the channel AFTER I bend it. Just use a razor blade and scrape, it works great.
I haven't bent purfling so I can't respond to that part Darryl.

Kevin

[Darryl Young]

Thanks Kevin!

Where are John and RD? Maybe one of them could give advice on this.

[tippie53]

moment of gyration I think it is called. but I also break the inside corner with sandpaper or a scraper.

[Darryl Young]

Thanks for the tips! Much appreciated.

[Tom West]

Darryl: I glue my side purfling to the binding, then tape the combination with the binding back to back,especially taping the tigh bend areas. Bend dry or very light spritz in the bender.Scrape the inner lower edge after bending. The herringbone I run under hot water for about 10 seconds,then form around a guitar shaped form. The form is nailed to a larger peice of plywood. I use a light caul outside the herringbone and tack it tight with small brads gradually working from one end to the other.Then leave till fully dry. I use LMI bone and have been doing it this way for over 25 years and have not had one peice come apart because of the soaking in hot water. Maybe I'm just lucky.
Tom

[Darryl Young]

That's an interesting way to bend the herringbone Tom. Thanks for posting that. Any chance you have a picture of herringbone in the form? I don't have a pipe bender so this is appealing. I'm using the smaller herringbone pattern. Can't recal for certain but I think I bought it from StewMac.

Also, I have my normal hot water which is probably under 140F. I also have 190F hot water in my sink for making hot drinks. Which do you think would work the best?

[Tom West]

Darryl: Sorry but I'm pretty lame about posting pictures. The form is simple,cut a guitar half shape from 1/4" mdf and nail it to a thicker piece of mdf about 22" by 10". Make a caul about 3/16" by .060" by as long as the bone from a soft wood like pine.Wet the bone and starting at one end of the guitar shape place the bone leaving about 1" overhang,place the caul against the bone and than drive a small brad into the thicker mdf to hold all in place. Start forming the caul and bone around the shape placing a brad every inch or so. Be careful not to let the bone flip 90 degrees in the tight bends.Hold tight and place the brads close together. I never use water hotter than my hands can stand. Also have used a hair dryer to help while bending if the bone gets stuborn. You may get a crack or two on the outer layer but not to worry if all holds together. It's helpful to make sure the bone at the ends measures the same width and the bone patterns are similar on both peices before you bend so all works out OK when you install. You don't want any misalignment or mismatched patterns at installation. Tom

[Blake Dixon]

Hi Darryl,

I just bent the binding and purfling together, I glued the purfling on the lower edge of the binding with Polyurethane glue in a jig I built to hold everything in place. I am putting rosewood on my maple cutaway with a thin purfling along the bottom edge of the binding. Since I bent for a cutaway as well I used poly urethane glue to put the two together. I placed about four sets of binding in my bender and used John Hall’s advice on bending in the Blues creek bender. The binding turned out perfect the first time. I also through a set of binding in using titebond to see if it would work. On the non cut away side it did but let go on the cutaway side hence always use the polyurethane glue from now on. It is a little harder to use but the results are much better. It works.
Blake.

[watergunn]

I am about to glue my first set of wood purflings. What is polyurethane glue?

It is the same as Weld-On?