Blog by Steve Laug
Over the years I have owned and sold several Duncan Hill Aerosphere pipes. The system on the pipes and the thinness of the bit always made the airway too tight for me and the draught sluggish at best. I have repaired several of them over the years as well and never found one that really worked well for me. Then in one of the lots I picked up on Ebay that needed new stems there was a Duncan Hill Aerosphere bowl without a stem. It had a wide open airway and was in decent shape. The bowl had a light cake and the rim was tarred but not damage. The bowl was still round and obviously the pipe had not been smoked very much. I figured it was an opportunity to restem it with a standard stem and see what I could get from it.
I tried two different stems on the pipe. The first was a flat blade saddle stem blank. I turned the tenon with a PIMO tenon turning tool and fit it to the pipe. I decided to put a nickel band on the shank for cosmetic purposes as I thought it would look good with the saddle stem. There were two problems with this fitting. The rustication pattern on the Duncan Hill made a smooth fit of the band virtually impossible and the gap around the shank did not work for me. The second issue was that the stem itself was just a few millimeters’ smaller in diameter than the shank. It was not noticeable except with the band it was accentuated. I removed the band and tried the stem without the band and it did not work well. I abandoned that option and went back to my can of stems to see what else I could find that might work in terms of both diameter and length.
For the second stem I found an older “pre-used” stem that worked in terms of length and diameter. I cleaned up the tenon and shortened it slightly and the fit was quite good. I left the band in place and tried to rusticate the band to match the bowl rustication. I heated it and used a scribing tool to carve it up to get the bowl finish look. I stopped that rustication process and worked on the stem fit. For some reason the stem taper on top and bottom did not match. With the fitting on the Duncan Hill bowl the angles at the top did not match the bottom. Reversing the stem made the stem fit even worse. The diameter needed slight adjustments to repair the taper and fit it well against the band.
I used a Dremel to take off material on the stem to adjust the taper to match on both the top and the bottom. I also used the Dremel to clean up the fit at the shank/band. I tried to mark the band with the Dremel in the process as well. I used a scribing tip and still did not get much more of finish than I had with the hand scribing tip. I did not like the look so I took the stem back to the worktable and sanded it to remove the scratches left behind by the sanding drum.
I sanded the stem with 220 grit sandpaper, a medium grit sanding sponge and a fine grit sanding block to clean up the fit and also remove the scratches. The more I looked at it the less I liked the band. The area around the stem shank union looked terrible and the scribing merely looked like scratches. It was awful looking. I decided at this point to remove the band from the shank. I heated the band and slipped it off the shank. I cleaned up the light marks left by the band on the shank with micromesh sanding pads.
With the band off the pipe the tenon was too long for the stem to seat properly. This was not visible to me with the band in place. It felt tight but without the band there was a gap at the junction. I measured the tenon and found that I needed to remove some of the length on the tenon and also needed to countersink the mortise slightly. The countersink on the mortise is a slight bevel inward. I used a knife to bevel the inner edge of the mortise. Once the mortise was prepared and the tenon shortened to measure the stem fit tightly against the shank. I used 220 grit sandpaper and a medium grit sanding sponge to remove a little more of the diameter of the stem to clean up the junction. The two bands on the stem appear to be briar but are actually Cumberland/brindle inserts. I sanded the top of the bowl/rim and the colour matched the twin bands on the stem.
I sanded the stem with micromesh sanding pads from 1500-12,000 grit to remove the scratches on the vulcanite and polish the stem. I wet sanded with 1500-2400 grit micromesh pads and dry sanded with the remaining grits. Between 3600 and 4000 grit pads I polished the stem with Maguiars Scratch X2.0. It polished the stem considerably. I then finished sanding with the micromesh pads. While I sanded the stem with the micromesh I also sanded the rim to polish it. With each successive change of grit the rim and the twin bands on the stem began to truly match. The combination looked like it was factory designed to be a combination. I wiped the stem down with Obsidian Oil and set it aside for the evening. In the morning I rubbed the stem down and then waxed it with carnauba.
I gave the bowl a several coats of Halcyon II wax and buffed it with a shoe brush to raise the shine. I buffed the stem with carnauba several time to raise the shine as well. I then buffed the pipe with a soft flannel buffing pad. The finished pipe is pictured below. The look of the Duncan Hill with the banded stem that matches the rim is a great combination. The improved draught of the pipe is exactly what I was aiming for. The Duncan Hill Aerosphere pipe re-enters life with a new level of service to the pipeman who ends up with it in their collection.