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I need some advice as I’m hoping to cut binding channels tomorrow and need to nail down measurements. Of course, it wasn’t until tonight I noticed that the two top/back purflings I hope to combine are different heights. Not the width or thickness, but rather the distance from top plate to back one, or perhaps better called the depth.

Anyway, my scheme is binding piece, then red purfling in the middle and a B/w/B one on the inside. The height of the BwB one is .080”. I have different options for the red ones, but none of the same height. One option is .060” high. Another is .125”. I also have sheets of the red veneer.

For now, once I get the two purflings sized better, I’m leaning toward taping both in place and using CA, but could consider fish glue.

Some ideas, after cutting both binding then purfling channels:

1. Cut the purfling channel to only the depth of the small red one at .060”, leaving the BWB proud, and then scrape down. I’m on the fence about whether it would be easier to do the two purflings separately, and do the binding later, or install all three at the same time (with the binding channel cut to near final depth, leaving the binding minimally proud). This is my preference so far.

2. Cut the purfling channel the depth of the BWB at .080”, and combine with the taller red one of.125”. The colored purfling piece will be on the outside of the BWB so it seems this might be tough to get things to stay flush in bottom of the channel, with the taller piece of red flopping over.

3. Try to cut or sand the .125” red purfling down to .080”. Not sure how I’d do this. Could maybe try running it flat through an oscillating sander with a fence, or a luthiers friend on the drill press. Seems like that would be trickier than the more typical thicknessing manuever. Maybe stack some purflings together b/w two edge guides and hand plane down to size.

4. Cut the veneer to correct dimension on band saw or Byrnes model saw. I’ve seen a post here for using a full sized table saw but not set up for that. From lots of band saw experience I’m thinking consistency would not be good enough for something so narrow.

Thanks. Jon

Option three seems pretty good. Plane your red purflings to the .080 height of the b/w/b. Would be pretty easy to make a jig to accomplish that…

Thanks for the quick reply! Wasn’t certain any of this would make sense. It barely did to me

It does. Been there, lol. Just make sure you don’t use a purfling shallower than the depth of cut. It sucks big time to find out the purfling is below the surface of the wood. Not that that’s ever happened to me…

Can you show photos of the purflings you have to work with? That will make it easier for folks (OK, for me) to fully understand what the red purfling looks like. I hesitate to offer an opinion until I see the red purfling.

Should have done this from start

OK. The red will be standing up, right? In other words, the faces we see in the photo will be vertical, right? If that is true, just use a straight edge and a utility knife and cut slices off the wider one that roughly match the height of the bwb.

If you intend to try to have the face of the veneer face up, I don’t think that’s going to work. The veneer doesn’t bend in that direction.

If the problem is that the red veneer is too thick, there are ways you can sand it down, but that depends on what equipment you have for sanding things to a specific thickness.

Maybe I don’t understand your question, and if that is the case, I apologize. I work with veneers a lot to make purfling lines. The veneers always stand up for that. In other words, the thinnest dimension is the left/right dimension. The face of the veneer is always vertical, and what will show in the completed purfling pattern is the edge of the veneer, not the face.

I hope that helps.

I'd go with option 1, and glue everything at once.

If you use fish glue, don't try to steam any gaps closed after it dries. It can wick into the spruce end grain and leave permanent stains. I've never had any issues steaming gaps with hide glue, but it's more messy and nerve wracking during the glue-up. You have to go fast adding glue to a few inches at a time so you can get it mostly squeezed out before it gels, and then reheat when the whole strip is done and tighten down the tapes. I shellac all the surfaces before cutting the binding channel, which makes it easier to clean up the squeeze-out, and helps prevent tearout when removing the tape. I also wick a drop of alcohol under the tape as I peel, to release the adhesive.

Yes , the red purfling veneer will be standing up, vertically. Thx for advice.

If I understand the problem…

Another option would be a stepped channel. The binding ledge is whatever height you are planning, the next step up is .125” deep and width of red purfling, the last step up is .080” deep and width of the BWB.

A little fiddly and dependent on having the right bearings. I actually had to do this recently to use up the last of my Gurian BWB which was .040” tall for three sections (I only had three pieces left) and then cut one section at .060”. Just a bit of a hassle.


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Don’t forget that you can install purfling proud and just scrape it down after the glue cures.

A few things that may help with the cutting here:

1. As I stated above, you can just cut the veneer with a straight edge and a sharp blade. It can be useful to tape the veneer down on each end, and also tape the straightedge down on each end, once you have it positioned. Without the tape or some clamps, your "stabilizing" hand becomes a pivot point around which the two ends of the straightedge can revolve when you apply pressure. This messes up the cut. It can drive you batty.

2. Take many light passes with the blade, instead of one deep pass. When you take one deep pass, the grain lines in either the veneer you are cutting or the sacrificial board underneath can lead the blade to wander. That can drive you batty, too.

3. Cut it a bit wider than the height of the bwb. It is good (as Bob says) to just scrape it flush after gluing. Having it stay too tall can cause some problems, but having it be just a little taller than the bwb is fine, and better than it being too short.

Good luck! I make purfling lines from dyed wood veneer pretty regularly. Be mindful of how the veneer is more fragile than the fiber used for bwb. It has grain lines that can cause breaks. And when you apply glue to the dyed veneer, it gets pretty squishy, way more than fiber does. But I love the look, so I put up with it.

Absolutely cut the channel to the shallower depth and plane it down once dry IMO. That’s how I’d approach it, personally. That way you’re not worrying about starting the cut for each channel in just the right place or trying to square them up together before gluing the purfling in.

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Don,

I tried to reply and thank you, and all of the other posters who offered advice yesterday, but it seems my post went to cyber purgatory. Each time I use the quote button to your reply, I’m getting some error message which I don’t understand.

Anyway, thanks. I pretty much did what you suggested. I did clamp the straight edge on the veneer sheet and you’re right, that Xacto knife did want to wander a little. But purflings are cut just a shade oversize and now I’m doing things like cleaning the garage as the next step is the one most concerning since I started, cutting channels.

Glad it worked out! As you do this more and more, you will find ways that make it easier. For instance, a marking knife or utility knife will flex less than an Xacto blade. There is also a thing known as a veneer saw, which is just a little handsaw with a curved blade. And if you have a table saw, you can get a thin blade that makes cutting veneers very easy. But for now, you have the lines you need. Good luck!

At one time, I needed to narrow some plastic binding.

I made a scraping tool by routing a channel in one corner of a 1x2, then installed three T-nuts so I could use screws with another 1x2 to clamp the binding into the channel.



Here's a close-up.



These days, I just use my MacRostie Binding Trimmer from Stewmac.

One thing to think about with a wide purfling channel is how thick the top is. If you have a .060 binding cut and .080 more purfling that’s pretty wide. If the top is say .118 at the edge you don’t want to go to deep so as to leave a reasonable amount of top glued to the lining.

I usually use purfling .060 or less deep. In your case I probably would have just gotten some 0.060 bwb but your plan sounds good.

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