Purlfling TWISTING ... ghaaaaaa!

[SnowManSnow]

ITs quite frustrating.. my plastic purlfing that came with a martin kit is twisting and doesn't want to cooperate.

any advise to keep it from twisting like this
i'm new to the process so theres a great chance i'm just doing something WRONG!

the width is ~.065

[Rodger Knox]

Are you talking about side purfling, below the binding? That's usually glued to the binding before installing.

[SnowManSnow]

NO sir.
I believe it is between the binding and the top wood. on the sound board.

[Rodger Knox]

That sounds weird to me, it shouldn't want to twist unless it's wider than it's height. I've never used plastic binding, so no direct experience. I'd try warming it a little with a heat gun.

[SnowManSnow]

Originally Posted by Rodger Knox

That sounds weird to me, it shouldn't want to twist unless it's wider than it's height. I've never used plastic binding, so no direct experience. I'd try warming it a little with a heat gun.

the stuff that is with the kit is just cheap i think. I'm going to put on something I like a bit more. when I undid it from the tape it was already bent. I think somewhere along the line it either got really hot or maybe dented or something.

[jeff crisp]

Binding & purfling aren't just following the contour of the sides, they're also following the contour of the dome. It is normal for them to want to twist. Thankfully being plastic you can usually force it to conform to your satisfaction. Tape selection, taping technique, bevelling back/bottom edge of binding or thick purfling, pins (with purfling, if not gluing up at same time as bindings) and even clamps are employed by some. I suggest doing a dry run before applying glue. YouTube can be helpful.

[SnowManSnow]

Well to put this one to bed:
I took the strips to a trained eye and he said "what tha..."
The bindings were really short and the purlfing was very inconsistent (almost like it was heated).
So, we took some measurements and better stuff is on the way


Sent from my iPhone using Tapatalk

[srick]

Originally Posted by SnowManSnow

The bindings were really short and the purlfing was very inconsistent (almost like it was heated).

I wouldn't doubt that this was from poor storage conditions in the warehouse or staying too long in a UPS truck. Temps in the UPS truck can go upwards of 160F. Smart move to order some new material.

best,

Rick

[jeff crisp]

Ok, twisted as opposed to twisting. I've never purchased plastic (or timber) that didn't need cleaning up in some way.
When you do go to bind the body you'll notice what I was pointing to. Even true flat tops with no radius added to braces, mated to non radius rims usually have slight radius on upper brace. This will cause what ever you're using to cut channel to rise & fall. Combined this with the contour of sides & you'll aways have binding or purfling wanting to twist to some extent.