Ni-chrom wire

Re: Ni-chrom wire

Jim Barbour

I too have found Nichrome to be superior to copper, stainless, fence wire, etc. I've used it for both burning tips and burning wire since I learned it is the wire used in electric heating coils. If it can stand that type of heating and cooling it can certainly stand anything I am going to throw at it. A roll should last a lifetime.

friction burn

John K Jordan

Do you mean for friction burning?

I don't like copper for friction burn lines. My favorite is a thin wire (iron, soft galvanized steel?) made for lock-out/tag-out tags which I use for everything. I got a lifetime supply from somewhere. I never thought of nichrome - I'll have to try some and compare. I have some different sizes.

With any wire, I find that a friction burn works better if I scuff up the wire with some sandpaper when new and then occasionally. Gives the wire a "bite".

JKJ

Re: friction burn

John C Lucas

I use both copper wire and guitar strings. They all work well if you wrap them fairly far around the piece. It increases the friction which is what its all about.

Re: friction burn

Clifton C

As John says, more wire on the piece = more friction, so, less pressure is needed to make the burn. I use stainless steel fishing leader. (single strand without vinyl cover) Comes in different weights so you can very thickness of burn. I've watched a guy who frequents this forum use the sharpened edge of a piece of Formica (plastic laminate) to burn some fine lines. If you happen to be in one of the big box stores and have been thinking of a kitchen remodel, pick up a few Formica samples in the kitchen section, but only if you are thinking of a remodel...

cc

OK John, I've got to ask, how......

JamieDonaldson

.......in the world did you friction burn an angled surface like these tops with a piece of wire?

Re: friction burn

Roger Chandler

I also prefer to use guitar strings, especially the wrapped ones. They produce a good burn and last a long time. Getting the smoke out of the shop is the challenge!

Re: OK John, I've got to ask, how......

Clifton C

Formica works good for plates, platters or even a spinning top...

A little grove first...

If you can find "vertical grade" P-Lam, it's even better, as it's 1/32" and a bit more bendable then regular P-Lam.

My method, Re: OK John, I've got to ask...

John K Jordan

Jamie,

A while back I wrote here about this technique. The thread was diluted a tiny bit with some "better" ideas which turned out not to be as controllable or to not produce as fine a line or make a relatively sloppy line. (Believe me, I have tried many things.) I have friction-burned lines like this hundreds of times, mostly on finger tops.

I developed this technique maybe a dozen years ago. I've never seen it done by anyone else nor have any of the many people I've shown. But since very little in woodturning is new I wouldn't be surprised if someone had! Maybe even a couple of hundred years ago...

So as briefly as possible:

Basically, I shape the slope the way I want it but leave a little extra wood on the slope, maybe an extra 1/16". Then I begin my finishing cut.

I interrupt the finishing cut partway down the slope, stopping to form a valley. I friction burn the line in the valley, then continue the finishing cut, stopping again if I want to make another groove.

Two things are important for a good line. One, to burn deeply enough. Two, to not cut the burn mark away completely when continuing! I try to cut the line in half to leave a sharp and smooth-bottomed line.

For example, suppose we want to burn two lines on a slope like in this photo:

We want to create the lines on the left slope as shown in the profile at the top of this sketch. The black dots shown at the top represent the desired burn marks.

Step A: As represented by the green line, leave the surface a little bit higher than the desired profile. I never measured the amount of wood I take off but it doesn't need much.

Step B: Cut the final profile down to where we want the first burn line. Hold the wire in the little valley and burn the line.

Step C: Continue at the 1st valley and cut the final profile down to where you want the second line and repeat the burn.

Finish: Continue cutting the to the end of the profile.

There, simple, once you know how!

- Sanding too much will remove the groove! Sharp tools and a careful hand on good wood should require little no sanding. (I usually hit it with a touch of 600 grit.)

- Most of the wires I see used to friction burn lines are way too thick for my taste, especially on smaller things. I have a big stash of thin galvanized wires about 12" long. After all these years I finally measured one just for you: they are about 0.016" (1/64").

I showed this technique to a long-time amazing woodturner recently and after he gasped his comment was "Before today I would have thought no one could possibly show me something new but you just did!" Made me smile. :-)

JKJ

New to me as well, and very well.....

JamieDonaldson

.....illustrated in your post. Thanks for the response, and now I've learned something today!

Re: Ni-chrom wire

Dennis in Southern Oregon

One of the problems with copper wire in addition to being weak is that it has very high thermal conductivity. Therefore, much of the heat generated by friction is conducted away from the area of contact (and to your hands). Steel has a much lower conductivity and nlchrome much lower still.

Re: friction burn

Jim Barbour

If you ask the folk in the big box stores they will gladly give you samples from discontinued patterns.

Re: My method, Re: OK John, I've got to ask...

Jim Barbour

Nice hint John. You may have been the only one doing it this way, but I bet that is changing soon!

Regarding grooves in general: I saw a demonstrator making groves in a plate and he asked if anyone had ever had their groove change width as they sanded the plate - some areas wider than others. Of course several had had the problem - it comes from V-shaped grooves. He was using a very thin (1/16" or so) parting tool to make his groves so they have straight walls and flat bottoms. Then if they are sanded a bit more aggressively in one area than another, the width will stay constant.

Absolutely obvious, but I had not thought of it so perhaps others have not as well.

Grooves

John K Jordan

>>> I saw a demonstrator making groves in a plate and he asked if anyone had ever had their groove

>>>change width as they sanded the plate - some areas wider than others. Of course several had had the

>>>problem - it comes from V-shaped grooves.

Another thing that helps is to make the groove as narrow as possible. A sharp skew is sometimes good for this. If using a point tool, some are not pointed enough! I grind my point tool this way - the point is a little narrower and I think it cuts cleaner than the normal pyramid. I call it my Wicked Point Tool. :-) Sometimes I grind it with an even sharper point.

I've run into the line width issue with the burned "grooves" too. When continuing the cut it is easy to cut away too much and make the second groove a different size than the others near it. I might use a light shear scraping with the spindle gouge in that case, or to just get a thinner, finer groove.

JKJ

Re: friction burn

Bob Lalonde

Roger, I recently switched to a steel guitar string. Works like a champ. Mine's a G string; how about you?