Ring - Concave / Convex Pliers for Bending Binding

[bpatrick]

I have seen mention on the forum of using "ring pliers" to make the tight curves while bending binding. It makes sense to me so I ordered a ring plier off Ebay. I tried to match the plier (pliers?) with a photo posted by Sunburst.

My question - How do you bend the binding without getting "chatter" marks on the side of the binding. My new ring pliers have an edge on the concave half that leaves nasty marks on the side of the binding. I've posted a photo of the pliers and some bent scrap binding.

I've considered regrinding the concave half of the plier to try and remove the offending edge, but I'm not sure that will fix the problem.

[fscotte]

Heat it up a bit more, or less.

There seems to be an ideal temperature where binding bends easily. I did binding in very hot water and let gravity make the initial curve as I pull it out of the water.

[Richard500]

Non-builder here. The marks exist because each bend you made is shallower than the curve of the pliers, so contact is always going to be at the two edges, even if you ease them somewhat. That is, IMHO, the pliers are designed for bending one specific radius. You could flatten the radius by adding something (tape?) in the bottom of the concave part, but I think you’d be better overall using a wood puck of a little less than the desired radius, and bending outboard of it by hand. An ordinary tubing bender might also work. For concave bends, maybe needed on an F, the outside is going to ‘bunch up’, the opposite problem, unless you somehow either soften the material and use a mandrel or swage of the appropriate shape. Making tools is as much fun as using them. Want to hear how you luthiers do it!

[crooksj]

I too bought those pliers after Sunburst’s post. I found that for tight outside bends I had to pre-bend with a heat gun wrapping binding around a dowel larger than final radius before using the ring pliers. Then moving they pliers a very small distance after each squeeze helps. I had no luck heating binding then going to the pliers while still soft...just made Plier marks deeper. With 0.060 bindings I still gets small marks that will sand out. Your photo looks like 0.090 binding, which I think would make ring plier marks harder to avoid...

[sunburst]

Those marks will go away with a little heat. Hold the binding in it's bent shape and heat it until the dents swell back out to smooth then let it cool held in shape. Even if they don't go away completely, after sanding, staining and scraping the binding they're long gone.

[bpatrick]

Thanks for the advice Sunburst. I'm still finding limited use for the pliers. Maybe the radius is too small? The best use I've found is making the little tight bends at the very end of the scroll button miters. Wrapping the hot binding around a proper sized socket is working better for me.

[bpatrick]

Has anyone used a ring plier like this for binding bending?