Metal shank bands have been around almost as long as pipes have. Used both decoratively and as reinforcement for weak or cracked shanks, bands are an indispensable part of the pipe repair inventory.
Banding round shanks is fairly straightforward – find a band that fits snugly on the shank and press it home. This basic practice is also true for diamond and square shanked pipes but comes with the added complication of sizing and shaping a round band into a square or diamond shape that fits tightly onto the shank. A loose fitting band is not going to keep a cracked shank together, after all.
The pipe on the bench this week is a good case study for this issue. The pipe, a vintage Frontenac Bent Bulldog from, I’d guess, the 1970s or early 1980s, arrived at the shop with a long crack running down the right upper quadrant of the diamond shank, from mortise to the rear edge of the bowl.
Other condition issues included a ragged inner rim, a buildup of old carbon cake in the chamber and the general need for a good cleaning. The pipe’s Acrylic stem was in worn but otherwise good condition.
The pipe is stamped “Frontenac” on the upper left flank of the diamond shank, and “Made in France” over “Fabrique [en France?]” on the right flank. Brackets are mine here as the “Fabrique” is legible but the following words are not due to the crack running right through everything.
Here’s a close shot of the shank damage. A long, thin crack winds its way down the entire length of the shank, terminating inside a patch of rustication where the shank meets the rear edge of the bowl.
I decided to take care of the structural work before dealing with the routine cleaning. I didn’t want my handling of the pipe to exacerbate the problem any more than necessary. To get the ball rolling, I used a tiny 0.8mm drill bit to bore a hole at the far end of the crack. This doesn’t go all the way through into either the airway or the chamber, which would be a bad idea. Rather, the tiny pit acts as a firestop or pressure relief at the end of the crack, effectively stopping the crack from progressing any farther up the bowl.
After drilling the firestop hole, I flowed thin CA glue along the entire length of the crack, making sure the glue filled the damage everywhere, including the firestop hole. Some of you may protest here that I’m effectively sealing the surface dirt under the glue, and that would be true if I didn’t come back and remove the excess glue after it had cured.
Here you can see the shank after sanding away the excess CA glue. Care must be taken not to erase the stamps while sanding the shank to 2000 grit.
I was pleased with the progress so far, but glue alone would not hold this shank together under the stress of use. Expansion and contraction of the briar would simply pop the glue joint open again. The solution, as you may have guessed, is to install a shank band over the end of the shank to stop the briar from expanding too much.
All shank bands arrive as round bands. It’s not possible to order square/diamond shaped bands, so the task of shaping a band falls to the restorer. Thankfully, a little high school geometry makes this task a bit easier.
Using my digital calipers, I first measured the width of all four sides of the stummel’s diamond shank. In most cases, these measurements are similar but not exactly the same, so measuring all four sides is important to getting an accurate band size. Adding up the width of all four sides gives us the total circumference of the area to be banded. In this case, I calculcated a circumference of 54mm.
Then, using the formula for the circumference of a circle, C=2πr, I could drop in my known variables and solve for the radius:
C=2πr
54 = 2(3.14)r
54/6.28 = r
r = 8.59
Since the radius of a circle is half the diameter, multiplying the radius above by two gives us the diameter of the shank band we need to fit to this diamond shank:
8.59 x 2 = 17.2mm
Shank bands are sold in half millimeter sizes = 10mm, 10.5mm, 11mm etc. It’s important to note that these sizes are NOMINAL. There can be a fair amount of variation in the ACTUAL diameter of the bands, so careful and accurate measuring is important.
The pics below show my first attempt at shaping a band for this shank. I formed the corners of the diamond shape by placing a file inside the band and pressing the band flat against my topping board. Spacing of the corners is done mostly by eye with a bit of judicious fudging to line up the creases with the points of the briar shank.
This pic shows the nickel band slipped over the end of the shank. It was a touch loose.
As you can see in this shot, the band lost contact with the briar in several spots, even though the corners were in the correct location. This told me that the band was slightly too large. It also told me that I’d have to try again, as a band that fit this loose would not clamp the crack shut properly.
I went back to my supply of bands and selected a band roughly 1/4 of a millimeter smaller than the first band. This time the fit was spot on perfect with no glue required. Instead, this band fit snugly enough that heating it up allowed me to press it home onto the shank. When the band cooled, it contracted, clamping the shank firmly.
Now that the pipe’s structural stability was not in question, I moved on to the cleanup. I reamed the old carbon cake from the chamber and gently sanded the inner rim and the rim surface to smooth out the jagged spots left by the careless scraping of the bowl with a knife blade.
I was happily surprised to find that the pipe’s shank and airway were already fairly clean. It took only a few pipe cleaners and cotton swabs dipped in 99% isopropyl alcohol to remove the remaining tars and dirt. Not shown is the single pipe cleaner required to clear a tiny bit of tar from the stem’s airway and slot.
While I had the alcohol out, I dampened a cotton pad and wiped the exterior of the stummel. Clearly whoever cleaned the pipe’s internals hadn’t bothered to clean the outside! Ick.
My work on the rim had removed the original stain there, and since the finish on the rest of the bowl was quite faded, I decided to refresh the entire stummel by wiping on a coat of Dark Brown Fiebing’s Leather Dye. This both helped unify the finish and push the repaired crack into the background visually.
After the dye, I followed up with a wipe of mineral oil. This helps to set the new stain and add depth and pop to the briar. I let the oil sit on the surface of the stummel for a moment, then hand buffed the excess away with a clean towel.
The briar got a chance to rest a moment while I adjusted the fit of the stem tenon in the shank mortise. Adding a shank band often reduces the effective size of the mortise, so a judicious sanding of the stem tenon is usually required afterwards.
When I was happy with the stem fit, I took the entire pipe to the buffer for a run on both the Red Tripoli and White Diamond wheels. This removed the excess stain, allowing the briar grain to shine through, while simultaneously removing any stray sanding marks. A few light coats of Carnauba wax completed this restoration.
This French-made Frontenac Bulldog is now looking nearly as good as it did when it left the factory. The briar is fresh and clean, the nickel shank band adds a touch of bling, and the original Acrylic stem shines like glass. With a bit of care and feeding, this old pipe should serve faithfully for many more years.
I hope you enjoyed watching this restoration. This was a somewhat more technical post than others, but sometimes a bit of math is exactly what’s needed. The formula illustrated in this post is simple enough but vital to achieving optimal results.
Until next time, Happy Piping! Here’s the finished pipe.
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