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View Full Version : Purfling Around End Graft: How does that Work?



sequoia
04-30-2015, 07:12 PM
I am a great admirer of how some of the pros here can run their purfling around the end graft in an all most seamless run. Beau comes to mind as well as others who post here. Incredible stuff.

I really enjoy the inlay/marquetry part of the build process almost more than anything else and I'm scratching my head a little bit on how it is pulled off. I'm puzzled. Below is a picture of my fairly crude end grafts:

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Note how I did a poor join of my binding and enlarged it and stuck in a piece of black plastic which only made the joint more visible. Doh! Anyway, I'm trying to get my mind around to running the purfling around the end graft. This is how I think it is done:

After I cut my end graft rabbit(?) channel whatever, I don't glue in the end graft piece, but glue on the top and back, then route out the binding and purfling.

Then I glue in my binding but not the purfling. I lay in the purfling and cut it at a 45 degree angle at the edge of the end graft rabbit. This has to be tricky as you only get one shot to make it perfect.

I then lay in my end graft measured perfectly to butt to the binding and cut my purfling to a 45 degree angle to line up perfectly with the the binding purfling. I've already glued the purfling to my end graft going down and around so that is pre-made. Does that make sense?

My question: How on God's Earth do you make a perfect purfling splice at the the binding junction and won't there be a joint that shows between the perpendicular end grain joint of the end splice and the binding?

Sorry, I know this is a bit off an the wall question, but I'm getting ready to start cutting some wood and any help would be nice. Thanks for any help.

Michael Smith
04-30-2015, 08:38 PM
The way I do it.

After the body is topped and backed and rough sanded and or scraped.

Route out the end graft with a template using a router bit that is .030 cut.
Use the same template and bit to cut an end graft.
I use BWB purfling strip that are .030 (notice, the same width as router bit cut)
Glue in the end graft with the .030 BWB purfling on each side leaving the end graft and purfling long to be trimmed later. (as long as you have enough that it will be covered by your routed binding channel obviously you are good)
When end graft glue is dry trim and sand flush with the top and back if long.
Sand end graft to final shape with the sides
Then tape a piece of cut up credit card the same width as the end graft to the top and do the same to the back. You want to cut the credit card strip in such a way that you have plenty on the top or back so it won't be knocked loose when your route your binding channel. So if the end graft is 1/4 inch at the back I make the credit card strip 1/4 by about 1 inch so I can stick it down good with binding tape. A credit card is pretty close to .030 (then when you route the binding channel the router will rise the thickness of the credit cart strip taped to the back and top @ the end graft. That is if you are using a binding channel routing set up that uses bearings and rides on a plastic disk. But it won't rise up at a 90 degree angle.
Now you need to go back and very carefully par out the binding channel so it is square at the end graft (skill and a very sharp chisel or scalpel or like tool is required for that operation.
Now you can cut a 45 degree angle on the purfling now exposed at the end graft which will be exposed the thickness of credit card strip and tape. (you can make your binding is such a way that it already has a .030 BWB purfling attached and just nick the BWB at a 45 degree angle.)
If your purfling is loose do the following.
Chop a 45 degree on your BWB purfling strip that will go under the binding and butt it up to the 45 degree you cut on the end graft purling strip
I find it easiest hold the purling strips that are going under the binding in place with push pins for the first half inch or so and wick in some thin CA and use some accelerator.

Please note I have used a BWB .030 purfling strip for this example obviously you could use any type of purfling as long as you kept the measurements like.

Allen
04-30-2015, 08:55 PM
Lot's of ways to go about this. Here is one method I've used few times when the sides I had as off cuts from some other project where just that little bit too short.

You can glue your sides along with the end graft and purflings to the tail block all at once. That way there is no need for a template to route that piece, or any calculations to get the parts to fit.

Then when it comes time to route for bindings and purflings on the body, you set the router to cut the depth of the bindings only and go over the end graft.

After that is cut, then you reset the depth to add the purfling depth for the side. Now you route the rest of the body, but take care to stop before you hit the purflings that are framing the end graft.

The rest is done with a very sharp chisel. Polish the back so you can see a reflection in it. This makes it easy to gauge a 45 degree cut that you will want on both those pieces and the ones wrapping the side of the body.

Now when the bindings go on they will sit flush with the end graft, because you cut them to the correct depth, and the purflings will frame the side / end graft.

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jcalkin
05-01-2015, 04:27 AM
Sequoia---Make your back binding look like you top binding and everyone will think its a feature and not a mistake.

Hluth
05-01-2015, 05:06 AM
I build it from the outside in. 1) Route your channels and end graft. 2) Install the side purfling using miter joints where it meets the graft channel (I use plastic spacers and binding tape to hold the purfling in place when gluing). Install the binding in the usual manner and inlay the graft.

Hluth
05-01-2015, 08:22 AM
One more thing. I used to use binding with the edge purfling already glued to it. Problem with that is the purfling tends to buckle when making tight bends like you would for a cutaway. It also buckles and is nearly impossible to bend on edge by itself, so I use clamps on my bender to prevent this. The picture shows these clamps and some bent 3-line purfling. These are similar to what Stewmac offers, but a lower profile. It's important to maintain a lower bender temperature (you're heating 3 sides) and allow only about .010" play between the clamps and purfling to get good results.

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sequoia
05-01-2015, 08:51 AM
Thank you all for your replies. It isn't easy writing out those complex descriptions. Some good ideas...