Herringbone Purfling how deep?

[ozziebluesman]

Hi there to you all,

I have a small acoustic on the bench and would like to install some herringbone purfling on the top inside some 2 mm x 7mm curly maple binding.

How deep do you cut the channel for the herringbone purfling?

Cheers

Alan

[Mark McLean]

I have used the Stew-Mac herringbone which is 1.65mm deep. It scrapes and sands down well so if you cut the channel around 1.5mm or a little less you will have it a little bit proud, and then you can bring it down to be flush with the top. Adjust the measurements if the stuff you are using has different dimensions, but the idea would be the same. You need to pre-bend the herringbone on a moderately hot iron with a light spray of water - bends easily.

[nnickusa]

I left mine slightly proud and took it down to the top as well. I bent mine dry onto the template I used for that guitar without a pipe, and clamped it with clothes pins for a couple days. Worked great.

Mine was a dread, so tighter radii may need more help?

[Allen]

I've always left the purling a little bit proud Alan. So there is still top wood left in contact with the linings.

To prebend it I've laid out some finishing nails on a piece of plywood to the shape I want and then coax the herringbone into the shape required. I used a hair drier to warm it up which helped get it to lay flat.

I used HHG to attach to the body and the heat also helped a lot getting it to lay flat.

[Jeremy D]

I did mine similar to Nick and Allen.

It has a fairly tight waist radius. The way I did mine was to soak the purf in a hot bath for about 5 mins. Then I bent it around a 5 mm ply wood template. I used plastic thumb tacks to hold it in place around the template and let it dry. It actually worked really well. When it came time to route I did some test channels in mdf and used a small offcut of the purf to get it set just proud and went for it. Once it was all installed it was an easy job with a scraper to get it flush with the sound board.

Being my first build I was really worried about the herringbone because it was so stiff and I was afraid of it de-laminating on a hot pipe. Using this method the whole process was trouble free.

The curly maple I used for the binding was a difference story. I hadn't had experience with curly wood before. I think bending it and then scraping it flush after installation was one of the hardest parts so far (I haven't yet attached the neck and made the bridge). I think I broke the stuff about 4 times while trying to bend it. Just just kept gluing it back together with CA. It was a mistake to soak this wood also because all the curly bits swelled more than the rest making it very challenging to bend and install.

EDIT: forgot to mention I used titebond and 3m green tape (the medium tak stuff) to install which also worked better than expected

EDIT EDIT: I realise most of this is probably not really relevant to you. I just thought I would share

Cheers.