Glueing Purfling to Bindings

Got a new way of doing something? Or maybe an old method that needs some clarification.

Moderators: kiwigeo, Jeremy D

Post Reply
User avatar
Allen
Blackwood
Posts: 5038
Joined: Thu Oct 11, 2007 5:39 pm
Location: Cairns, Australia
Contact:

Glueing Purfling to Bindings

Post by Allen » Sat Mar 15, 2014 8:01 am

This could be old hat to some of you, and others will always purchase bindings with purflings installed, but what do you do when you want something custom like most of my stuff is?

I was running a couple of batches of bindings today and thought that some might like to see the process I use to glue the purflings to the edge of a binding strip. It use to always give me fits doing this until I worked out a simple trick that works 100% every time.

Binding strips are cut and sized. I use a table saw and drum sander. These ones are some Cocobolo that turns a very rich ox blood red color in a day or so. The purfling strips are black / maple / black. The reason to glue them to the edge of the binding is that they are far easier to install on an instrument that way, than trying to do so on their own.

I use hot hide glue because it's by far the easiest glue to use in this situation. And yes, I've tried several.

I use two slabs of granite. Off cuts from counter tops that were found at the local tip. The reason I use them is that even here in the tropics, they stay rather cool, so the initial grab and setting of the hide glue through drop in temperature is improved. As well, when glueing these small bits together there is bound to be glue spread all over the place, and clean up off the granite slabs is very quick and easy.

First up, I brush a fat bead of hide glue onto the edge of a binding strip and lay it down on the granite slab up agains the other piece that acts as a fence. Then position a purfling strip next to it.

I then use a piece of perspex to push the purfling up agains the binding strip and clamp it in place. It doesn't take much pressure, and hide glue actually pulls parts tighter together as it dries.

I also use a another piece of perspex to make sure that the purfling and binding strip are sitting flat and aligned to the granite slab.

In about 5 minutes the clamps can be removed and the parts carefully removed. You need to do this before the glue fully sets, as you will not be able to do so without destroying them should you wait too long.

Let dry fully overnight and then they are ready to use.
Gluing purlfings to bindings.jpg
Gluing purlfings to bindings-2.jpg
Gluing purlfings to bindings-3.jpg
Gluing purlfings to bindings-4.jpg
Allen R. McFarlen
https://www.brguitars.com
Facebook
Cairns, Australia

Kamusur
Blackwood
Posts: 756
Joined: Thu Dec 30, 2010 10:08 pm

Re: Glueing Purfling to Bindings

Post by Kamusur » Sat Mar 15, 2014 9:11 am

Thanks Allen those granite slabs are always a great score, then comes the tricky bit. Do you have any separation problems due to heat (or to much of it) with bending on the iron or blanket and form?

Steve

User avatar
Allen
Blackwood
Posts: 5038
Joined: Thu Oct 11, 2007 5:39 pm
Location: Cairns, Australia
Contact:

Re: Glueing Purfling to Bindings

Post by Allen » Sat Mar 15, 2014 10:46 am

I bend all mine on an iron dry. No worries at all.
Allen R. McFarlen
https://www.brguitars.com
Facebook
Cairns, Australia

Bruce McC
Blackwood
Posts: 332
Joined: Thu Apr 07, 2011 1:29 pm
Location: Canberra ACT Australia

Re: Glueing Purfling to Bindings

Post by Bruce McC » Sat Mar 15, 2014 2:38 pm

Thanks for this post Allen I found it useful and thanks Steve for your question,
the issue of bending also crossed my mind.
Bruce Mc.

User avatar
Allen
Blackwood
Posts: 5038
Joined: Thu Oct 11, 2007 5:39 pm
Location: Cairns, Australia
Contact:

Re: Glueing Purfling to Bindings

Post by Allen » Sat Mar 15, 2014 5:42 pm

HHG actually takes more heat before releasing than PVC does. As well, if there is a spot that does release, with HHG all it takes is some more to glue them back in place. Whereas with a PVC you're just hoping that whatever you end up using keeps them in place.

As many of you may know, I build almost exclusively with HHG. I use epoxy where required and CA for things like some inlay, or a quick tack of a component. When I glue the binding / purflings in I use a liberal brush of HHG on both surfaces and then tape and then pull into place with twill tape (Herringbone tape). The HHG hydrates all the components, so making swell slightly and then as they dry they pull parts tighter together. If for any reason there was a loose spot of purfling then the HHG will wick in and reglue the parts together.

While the same thing so far as hydrating goes with PVC, it doesn't pull parts together like HHG does.

I've had plenty of commercially made binding / purling combo's when I first started building that came apart on me. Have no idea what glue they would have used, but I'd bet next weeks pay that it wasn't HHG.
Allen R. McFarlen
https://www.brguitars.com
Facebook
Cairns, Australia

Kamusur
Blackwood
Posts: 756
Joined: Thu Dec 30, 2010 10:08 pm

Re: Glueing Purfling to Bindings

Post by Kamusur » Sat Mar 15, 2014 9:55 pm

Thanks for the tips Allen

Steve

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest