North Branch Reels

This post documents another attempt to mark my reels. Here I have used an electrochemical etch kit from Lectroetch. They promote its use to knifemakers, where the blades are typically steel.

The kit consists of a low voltage AC transformer with pad and alligator clip electrodes, bottles of etching electrolyte and neutralizer, and some stencil material.

The stencil material is a laminate of permeable and impermeable layers. The impermeable layer can be rubbed away with a stylus. It can also be removed using a mechanical typewriter (remember those?). Below are stencils that Lectroetch made for me.

This is my fixture. I am etching the oversize head of a nickel silver screw, which threads into the center hole. A small groove at one corner is a grip point for the alligator clip.

Here I am ready to etch. The stencil is secured in position over the screw head.

After etching with the wetted electrode pad, I had a black image. But when I wiped it with the neutralizer, most of the black oxide came away.

I sent a nickel silver sample to Lectroetch, and they confirmed that the oxide does not adhere on this material. So it looks as if I can get an untinted etch, if I can figure out a way to remove the rest of the oxide without defacing the image.

I later tried etching some 303 stainless, and the black oxide adhered.

One problem with the etch on both nickel silver and on stainless is that it is quite shallow. The logo is quickly obscured by a little sanding at 1200 grit. I think that the engraving done by a jeweler, even by diamond point drag, is more durable.

In the previous post I showed the artwork for a logo in the form of a circular monogram. This is meant for use in electrochemical etching. After making this artwork, it occurred to me that it might be simplified to the point where it could be engraved using just my vertical mill and its rotary table.

So here is my attempt at engraving with the mill. This is a 5/8 inch diameter brass slug that represents the head of the rear spindle screw of my reel. It has been engraved with a 1/16 inch diameter square end mill. The depth of the engraving is 0.005 inch. When I have taken parts to jewelers to be engraved, the depth is about 0.001 inch.

The final appearance would be enhanced if the bottom of the groove were burnished with an appropriate tool.

I am still working on electrochemical etch and will save this as a fall-back process if that proves unsatisfactory.

Update 3 Dec 2012: Here I have filled the milled grooves with paint

This is another post on the problem of marking my reels. In the spirit of “divide and conquer”, I have decided to put just the initials “NB” on the external screw head, and the sequence number somewhere inside the reel, perhaps with stamps.

Having the same “NB” on every reel lets me consider electrochemical etching, which I expect will make a dark impression. Also, I can make a real logo rather than just a couple of standard text characters. So here is my artwork, for which I am seeking a stencil.

My tool for making this was Microsoft Paint. Had to do careful arithmetic on pixel numbers, and delicate positioning of the mouse.

This post is about another attempt to make identification marks on my reels. Number punches are often used to mark a serial number on equipment nameplates. The resulting characters are usually readable but not very neat; the punch is not accurately placed, it is hit too hard, etc. Is it possible to make neat letting with punches if the are accurately placed and guided to be normal to the surface punched? My conclusion is that it still does not produce neat lettering.

Here are the parts that I made to serve as a punch guide: a base to hold the target screw, a spacer, and a guide for the punch.

By rotating and/or flipping the guide, four character positions are realized.

This is the punch assembled for the first character position.

Here I have made all four characters, using a hammer. The “N” and “2” are deeper than the other characters.

My fixture positions the punch well enough that I can go back and hit a second time, but I was unable to improve the result.

Here I used an arbor press to make the impressions.

The right side of the “N” is not deep enough, and alignment is not very good.

So I will resort again to an engraving service.

Update 18 Jan 2013: Here, I believe, is the proper use of the punches: add serial number to an inside, hidden surface. I may settle on this and forego external marking that must be done at high quality.

Note that the “1” here is a deeper impression than the other characters. It has a smaller total line length, and should therefore receive a lighter tap from the hammer.

I like to put some identifying marks on my reels, typically the letters “NB” (for North Branch) and a two digit sequence number. In the past, I have taken a group of rear bearing caps to a jeweler’s shop and had them engraved. The local jewelers have machines that push a stylus across the surface of the metal, making a rather light scratch. A rotary engraver would make a better impression. I made a bracket to hold my Dremel tool on my mill (this blog, 14 Aug 2011). This lets me carve straight lines and circular arcs, but is not sufficient to do lettering. Making a pantograph that is large enough to hold the Dremel is too big a project for the value realized. One can buy rotary engravers, but they are expensive.

So I have been thinking about etching to create the letters and numbers. On my new reel model, these go onto the head of a large screw that secures the spindle to the reel backplate. The area to be engraved is a circle of about one half inch diameter, so the four characters need to be about 1/8 inch tall. As best I can determine, the preferred etchant is Edinburgh Etch, a mixture of ferric chloride and citric acid. To make a mask, I bought some fine point “opaque paint markers” meant for calligraphy, but could not form characters small enough. So my experiments here are with Press-n-Peel, a medium used for DIY circuit boards. Below is my artwork, and the copy made on Press-n-Peel.

For a heat source, I borrowed a craft iron and made a bronze disk to hold the screw while it warmed up. The disk has a hole on its outer diameter where I can insert an oven temperature probe.

The iron had enough power to get the screw above 300 deg F. But I had trouble getting complete transfer of the mask. Here you can see a poorly transferred mask and the piece of Teflon that I used to apply pressure on the hot screw head.

It was difficult to hold the Press-n-Peel in the exact position while pressing. If I make additional trials with this method, I will make some type of mechanical clamp that I can assemble cold, then put the whole thing into an oven.

After getting a somewhat satisfactory transfer, I covered the edges of the screw head with paint.

Here is the etching process, using electrical tape to make a dam to contain the etchant.

The instructions that I had said to etch for 20 to 60 minutes, depending on the newness of the acid. I etched for 30 minutes.

But the result was an insufficient impression, plus gouges where I did not adequately cover with paint.

It looks as if the etchant is strong enough; the “gouges” at the paint gaps show good etching. I think that the problem is the Press-n-Peel mask. It looks as if the characters are unmasked, but something has partly blocked the etching there.
The effort so far is unsuccessful. I post this as information for anyone who may work on a similar approach.

Update 6 Nov 2012:
In the replies to this post, Rich has suggested hand engraving. This has caused me to buy a book, The Jewelry Engravers Manual. I recommend this book to anyone who has interest in this dying craft. It explains gravers and sharpening, and how to cut several type of letters. Last week a jeweler told me that hand engraving is the only way to get a deep impression, but that he knew no one still offering it as a service. This book will sit on my shelf as another technical reference on a subject that I will never pursue.

I did go to an engraver and have several parts done.

He did a good job, but as with previous machine engravings, the impression is not very bold. He told me that the engraving would not look very neat if done more deeply. I have dealt with four different jewelers on this matter, and the result is consistent: machine engraving can produce only a faint impression.

For a while I watched the Ebay auctions for pantograph machines. These go for $400 to $750 (with motorized spindle) and a font set is more than $100. To me, this is too much for a machine that only does one thing.

Leroy’s suggestion about electrochemical engraving has since become my interest. From what I see, this process causes a darkening of the etched area (why?) which gives contrast even though the etch may not be deep. A $60 machine is certainly in my ballpark. So I am going to pursue this option. My stencil will just be the letters “NB”, and I will stamp or otherwise mark the sequence number on an inside, hidden area of the reel.