An Amazing transformation of a 1946/47 Design by Curtis Pat. Pend. Metal

Over the years, I have been both amazed and humbled by folks wanting to help the Daughters of Bulgaria through donating pipes to The Pipe Steward.  In January of 2019, my wife and I were still living in Bulgaria and the mother of Bonnie, one of our interns helping us in Sofia, brought pipes with her on a visit to be added to the ‘For “Pipe Dreamers” ONLY!’ collection benefiting the Daughters, one of our efforts in Bulgaria helping trafficked and sexually exploited women and girls.  Bonnie’s mother found 4 pipes in an antique shop in Peachtree City, Georgia, near to their home.  Bonnie is a remarkable young lady who is not only a pilot but also an accomplished website guru.  Her skills have helped with the creation of the official Daughters of Bulgaria website and another website I manage in response to the war in Ukraine (  Bonnie is now working in Washington DC using her skills to great benefit. Pipe man Robert saw the ‘Design by Curtis’ in the ‘For “Pipe Dreamers” ONLY!’ collection and he heard it whispering his name.  Robert is a from Scottsdale, Arizona, and works as respiratory therapist.  Robert also commissioned a Dr. Grabow Regal Ajustomatic Dublin that was in rough shape, but no longer (Rescuing a Dr. Grabow Regal Ajustomatic Pat. 2461905 Dublin).When Robert commissioned the Design by Curtis, he wrote, “Metal pipes are my passion. I have Kirstens, Falcons, Vikings and Greenwich House. The Curtis is my absolute favorite and the epitome of Mid-Century design.”  Here are pictures of the Curtis that also got Robert’s attention:The nomenclature is stamped on the undercarriage of the barrel.  Stamped in fancy cursive is ‘Design by Curtis’ [over] PAT. PEND.I’m fascinated with the metal pipe genre’ mainly because I’ve never had a metal pipe in my own collection, but whenever I talk with metal pipe enthusiasts, they say essentially the same thing: ‘There’s nothing like it.’  I’ve never used a metal pipe, but I’m always interested in learning more.  To learn more about Curtis I looked at both Pipedia and Pipephil and was surprised to find no reference.  I next turned to and found that Steve had indeed worked on a Curtis which looked very similar to the Curtis on the worktable (  I liked Steve’s description of the Curtis he was working on which closely mirrors the pipe on the worktable:

This smoking metal pipe is really Art Deco looking. It has a metal finned bowl with a pressure fit top cap holding in a briar bowl. There is a threaded connector between the bowl and the metal shank base. The connector threads into both the bowl and the shank. The shank has a pointed end cap that is frozen in place. The bowl was caked and worn. The stem had bite marks on both the top and the bottom sides near the button. The stem is a military mount that sits in a stepped down interior of the metal shank. There is a tube at the end of the airway in the shank that seems to have holes in it as the air flows through when blown into the end. The exterior of the pipe is oxidized and dull. The bottom of the shank is stamped Design by Curtis over Pat. Pend. It is a brand about which I know nothing.

Steve’s lack of knowledge of the Curtis name matched mine, but thankfully, Steve’s research found a site called Smoking Metal Pipes which had some helpful information.  The site has a picture of a Curtis which appears to be the same model as the metal pipe on the worktable. Another picture shows the Curtis dismantled, or partially dismantled.   I can say, ‘partially’ because after diving into the dismantling process myself, I discovered the picture below misses a few points after reading the comments in Steve’s post and reaching out to Doug Brisbee of dk Metal Pipes who I connected with on the first metal pipe I worked on – a Kirsten.  More of these “missing points” to follow.  The internal tube can house a filter which is capped off with the narrow airway nipple. Steve’s post continued with information from the Smoking Metal site that the Curtis patent was applied for December 25, 1945, with a patent number of #D143257.  The inventor of the Curtis design was Howard Abrams from University Heights, Ohio. The Smoking Metal site also showed a cross-section photo with the innards of the shank and the bowl revealing the briar cup inside.  I found the commentary on the Design by Curtis on the Smoking Metal Site to be both interesting and prophetic as my own difficulties emerged attempting to disassemble the pipe:

The Curtis Custom-Built Pipe Model 100 – Manufactured by Curtis Industries of 1120 East 222nd Street, Cleveland 17, Ohio. First seen around 1946.  The actually markings are Design by Curtis PAT .PEND. The bowl insert appears to be briar, despite having only had many examples am still unable to get the bowl apart, I am loathe to risk damage. The top plate does revolve but whether it is a screw attachment or a push fit cannot yet be ascertained.  The interior of the stem is more complicated, taking an inline filter inside the tube. The shape of the end plug makes it more than interesting to undo. On many examples this part is the piece most damaged by pliers. With so many threads in the ‘gunk’ part of the pipe it can be a problem to clean.   25 Dec 1945 US patent # D143257 Inventor Howard Abrams, University Heights, Ohio.Also at the Smoking Metal site was a Curtis brochure which was included with the pipe.  I enjoy looking at these historical snapshots and the descriptions given. The brochure reads, ‘The Curtis Custom-Built Pipe’ on the front panel.  Following this is a description of the quality assurances: ‘Streamlined, Precision Built, Guaranteed’. The guarantee of 6 months, manufacturing number and company address are on the back panel. The manufacturer, Curtis Industries, was located at 1120 East 222nd St. Cleveland, Ohio.  The model number ‘100’ is described as ‘Patent Pending’.The inside panels lists, ‘A few simple ways to care for your CURTIS PIPE.’I’m thankful to Steve for taking the time to type out what the brochure describes:

  1. Break your pipe in slowly. For the first few smokes fill the pipe loosely and only halfway then smoke the new Curtis Pipe slowly and all the way down. Don’t puff hard or fast or you may burn your tongue and may burn out the bowl as well.
  2. Don’t collect too much cake, a cracked, burnt and useless bowl will result.
  3. Never knock your pipe on hard surfaces since you may split the shank or break the bit. Don’t bite on the bit too hard.
  4. Keep your pipe clean. Use your cleaner every few smokes and occasionally use a good fluid to cleanse it.
  5. By removing the knurled cap on the pipe stem, a standard pipe filter can be used.

The Curtis Pipe, new in design is produced with a high degree of precision, designed for a cool, clean smoke. Enjoy the full smoking benefits of the pipe by following above suggestions.

One more question remains in my mind regarding the Pat. Pend. designation in the nomenclature.  If this patent was pending, is there a way to determine when the ‘pending’ expired and the pipes became simply, ‘Patent’?  To explore this further a simple search at came up with copies of the original patent application by Howard Abrams.  Looking at these documents are fascinating to me, especially the diagrams.  Mr. Abrams calls his design as an ‘ornamental design for a smoking pipe’. I’m especially interested to know if it can be determined when the pending statis changed to patented?  The only thing that seems to indicate a time frame is that the Pat. Pend. status is described as: “Term of Patent 14 years”.  With some searching on the internet regarding the meaning of ‘Patent Pending’ I found this interesting information from the site called Investopedia:

The patent-pending notice has no legal force in itself. The product or process is not legally protected at that point.

However, it warns potential competitors that a patent application has been filed and that they can be sued for patent infringement after the patent is granted if they lift the idea. Moreover, the patent protection will be backdated to the date that the provisional patent application was filed.

A patent-pending notice indicates that an application date has been established.

The patent-approval process is lengthy. It typically takes nearly two years but can take as long as five years or more. The “patent pending” designation gives the inventor some level of protection in the meantime. patent-pending status granted through a provisional patent is meant to last for one year. Its use can be extended, however, if a patent application is rejected and then revised and resubmitted.

From my understanding of what I’ve read, the patent ‘pending’ period is usually from months to a year – or longer if there are revisions to the original design.  With this information understood, if Mr. Abrams made application on December 25, 1945, the pending status would change to ‘Patented’ usually by the end of 1946 or into 1947.  If this timeline is generally true of the Curtis patent, then the Design by Curtis ‘Pat. Pend.’ on the table was produced most likely later during this pending period as commercial production ramped up.  This would have Curtis at the rich vintage age of 76 or 77 years under his metal belt.  The ’14’ years reference in the document specifies how long the patent remains in force after the application is approved if the patent is not renewed. That is sweet 😊.

With a greater appreciation for the Curtis name and the Model 100 on the worktable, the process of carefully taking the pipe apart begins so that a proper cleaning can follow.  The aluminum shank unscrewed easily from the stem showing the inner tube with the screw on nipple.  In my communications with Doug Brisbee, caution was given regarding the threading beneath the nipple – that it was thin and easily broken off.After carefully unscrewing the nipple, I discover that the thread had already broken off a bit.  On the male threads, the thread end is somewhat hanging out there by itself.  Looking into the nipple threading, I believe I can see the broken threading still lodged.  The good news is that the nipple still screws on.  The word of caution for a new steward is to be careful.  The tube is for a filter if one chooses to use one.The next step is to remove the bowl by unscrewing it from the shank.  This is done with no problem.Taking a look at the top of the bowl, the rim needs cleaning.  The briar cup inside the bowl has thick carbon cake build up. The briar cup has a draught hole at the bottom of the bowl that fits within the threads that pull the bowl tight to the shank or barrel.In Steve’s Curtis post referenced above, I discovered some helpful information in the comments that pipe men posted in response.  One important piece of information was that the rim cap comes off enabling the briar cup to be removed and cleaned or replaced. This was alluded to from the commentary from Smoking Metal Pipes site above. I figured out that it was Doug Brisbee of dk Metal Pipes that had sent these pictures of the rim cap being removed in the comments of Steve’s post.After seeing these pictures, I tried in vain to remove the rim cap of the Curtis in front of me. I was concerned about gouging the aluminum by using anything metal to pry the cap off by wedging between the ribs circling the bowl.  Fingernails would not help.  I finally reached out to Doug to find out how to pop the cap off which was pressure fit – not threaded.  His response was music to my ears.  He had stopped the practice of removing the rim cap in his restorations because it was a bear to do, and it was too easy to damage the briar cup inside.  With this information, the decision is made to clean the cup chamber intact in the bowl.The next challenge was to remove the vulcanite stem from the metal fitting.  in our communications Doug said it would come off, but after twisting, heating, and twisting again, the stem would not budge. I’m thankful for folks like Steve and Doug who have been doing restorations longer than I and have a wealth of knowledge to share.  Doug’s specialty in working with metal pipes comes after years as a professional metal polisher.  Doug’s advice to remove the stem was to pop it out by placing a metal dowel through the metal fittings and tapping it with a hammer.  As my metal dowel, I utilized a 3/16 inches stainless tubing.  After securing the metal fittings in the bench vise protected by a piece of leather, a hammer gently tapped on the end of the tubing.After a few taps the stem begins to separate.Another mini project done just trying to dismantle this Curtis pipe!The next mini project has to do with the nose cone.  The nose cone is threaded and is supposed to unscrew in order easily to clear accumulated moisture.  This feature can be helpful to keep the shank clean, but the cone shape reminds me of the old Apollo capsules used to take the US to the moon.The scratching on the cone gives evidence to others’ attempts to remove it.  The cone would not budge by me twisting it.  I also bunched up some painters’ tape to wrap the cone to give grip to turn – unsuccessful.  After reaching out to Doug, his advice was to fill the end, up to the bowl threads with a penetrating oil, like WD-40 and let it soak for 2 or 3 days.So, WD-40 is lightly sprayed down the shaft filling the end of the barrel with oil and then propped up to allow the oil to do it’s work on the nose cone.  While the cone is soaking, I act on one more piece of advice from Doug to help remove the difficultly shaped cone without scratching it.  I’m always happy to add one more tool to my arsenal – soft jaws pliers.  They have been ordered from Amazon and are supposed to arrive in time for putting them to work after 3 days soaking.After the soaking with WD-40 for a few days the soft jaw pliers arrived.  Unfortunately, even the pliers were not able to grip the cone well enough to create any movement.  With a degree of disappointment, the decision is made to move on.  A new steward will have to unscrew the barrel from the stem to remove moisture build-up.With the pipe disassembled as much as I am able, after some days of struggle (!), the actual clean up begins.The first order of business is to clean the stem’s airway with a pipe cleaners moistened with isopropyl 99% alcohol.  To address any oxidation on the stem, the stem is placed in Briarville’s ‘Stem Oxidation Remover’ for several hours to soak.Focusing now on the metal pieces, the chamber has moderately thick carbon build up in the briar cup in the bowl.The Savinelli Fitsall Tool is used to ream the cup.The briar rim of the cup is also scraped with the Savinelli Fitsall tool and then sanded with a piece of 220 sanding paper.  The paper does a good job of removing the darker ring where the cup and metal rim meet.Next, the chamber is sanded using 220 paper wrapped around a Sharpie Pen.After wiping the chamber with a cotton pad, the briar cup looks to be in good shape.Next, the briar draught hole is cleaned.  There is crusting on and around the small briar extension that transitions down into the shank.A pipe cleaner and cotton bud moistened with isopropyl 99% are used to clean.The Savinelli Fitsall Tool scrapes built up gunk around the extension.Next, a small piece of 220 sanding paper is rolled into a narrow tube and inserted into the draught hole and is used to sand around the briar nipple.The results are good.  During the cleaning and reaming process, the briar cup loosened and can freely rotate in the metal bowl. The 0000-grade steel wool goes to work next on the metal rim followed by applying the wool to the ribs circling the bowl.  Steel wool is also worked into the troughs between the ribs using my thumbnail.Next, the cleaning process is focused on the barrel that traps all the moisture.  It becomes a bit more difficult to clean since the nose cone would not budge.  I first use cotton buds moistened with isopropyl 99% to reach into the barrel.  To add some muscle to the cleaning, 0000 grade steel wool is also used by twisting it tight enough to fit and force down the barrel to the end with the help of a stiff wire.  Alcohol is then placed in the bowl junction hole and absorbed into the steel wool.  Next, the steel wool is rotated to create the abrasion to clean the inner barrel.After the steel wool is retracted, the cleaning continues with cotton buds to confirm that the barrel is clean.Next, the internal filter holder tube and narrowed end piece nipple are cleaned.The airway restrictor internals are cleaned with a pipe cleaner and isopropyl 99%.  The external surface is cleaned and polished with 0000 steel wool. Steel wool is also used as before – twisting it and inserting it in the filter cavity and rotating to clean.The external surface is also cleaned and polished using 0000 steel wool.The next picture shows the thinness of the threaded part of the filter tube.  Part of the threading has already been broken off and is lodged in the female threads of the airway restrictor.  Earlier, I used a dental probe to see if this broken off portion could be dislodged.  It was firmly embedded, and I decided to leave as is.  The airway restrictor/nipple still screws on snug enough, but when the threads are exposed as in the picture, care must be given not to hook the hanging metal thread.With the internals reassembled, I take a look and it looks good.Next, the external surface of the barrel is cleaned and shined with 0000 steel wool – before and after pictures follow.Turning now to the stem, it has been soaking in Briarville Stem Oxidation Remover for several hours.  After it is fished out, the stem is vigorously rubbed with a cotton cloth to remove raised oxidation.  The oxidation was minimal from the start, and it looks good now.The teeth chatter on the bit is significant.  To address this initially, the heating method is used by painting each side of the button with the flame of a Bic lighter.  As the vulcanite heats the physics of the rubber go into action and the rubber expands to some degree recovering its original condition.  The before and after pictures show not much improvement after the heating.  First is the upper bit:Next, the lower bit:Sanding commences using 220 grade paper.   It is interesting working on different rubber stems, coming from different countries and times, the rubber of this Curtis stem is very ‘thick’ – almost charcoal-like.  The sandpaper shows the black residue. After some sanding, it becomes apparent that one tooth bite compression will not be removed with sanding.To address the compression, after the area is wiped with alcohol, Medium-Thick Black CA glue is applied to the compression and to quicken the curing process, it is sprayed with an accelerator.Utilizing a flat needle file, the patch mound is filed flush with the rubber surface.Next, sanding continues to smooth out the patched area and to remove the remaining chatter from the upper and lower bit.The entire stem is a scratched landscape so sanding expands with 220 paper to the entire stem.  A shouldering guard is used to keep the sanding from rounding the stem facing edges.Sanding of the stem continues with 470 paper using the guard.Next, wet sanding is employed with 600 grade paper followed by applying 0000 grade steel wool.Next, sanding/polishing with the regimen of micromesh pads starts by wet sanding with pads 1500 to 2400.  This is followed by dry sanding with pads 3200 to 4000 and 6000 to 12000.  Between each set of 3 pads Obsidian Oil is applied to condition the rubber stem and to guard against future oxidation.  The pop of the rubber resulting from the process is fun to see emerge.Next, comes what I’ve been looking forward to, where the magic happens – polishing the aluminum pieces of the Curtis by applying compounds with the rotary tool.  After talking with Doug Brisbee, I discovered that the finest compound he uses in his restorations is the application of the ‘Green’ compound, which is not as fine as Blue Diamond, which is what I normally use.  Experimenting, I will use the less fine Tripoli compound and then Blue Diamond if needed – we’ll see how it goes.  After mounting a cotton cloth buffing wheel dedicated to metals, with the rotary tool set at about 50% full power, the compound is applied to each of the Curtis pieces.After applying Tripoli compound to all the pieces, the pieces are buffed with a micromesh cloth to remove the compound dust and residue.After seeing the results of applying Red Tripoli compound, I’m very satisfied with the polished sheen of the aluminum – very nice.  After deciding not to apply Blue Diamond to the metal, a new cotton cloth buffing wheel is mounted on the rotary tool, and the pieces are buffed to continue clearing residue compound and to raise the shine.After reassembling the barrel and the filter tube by screwing it on, the stem is easily remounted and set to a proper orientation.Next, another cotton cloth wheel is mounted and the rotary tool is set to about 40% full power.  Blue Diamond compound is then applied to the stem.After application of the compound, a felt cloth is used to wipe and remove compound dust from the stem in preparation for the application of wax.Finally, with another cotton cloth wheel mounted, carnauba wax is applied to the stem and this is followed by hand buffing the stem and the entire pipe with a microfiber cloth to raise the shine.The restoration of this 1946/47 Design by Curtis Pat. Pending metal took some twists and turns with the proper disassembly of all the parts.  Now cleaned, polished and reassembled, I’m very pleased with the outcome.  The sheen of the aluminum surface is mezmerizing and I am tempted to only wear gloves when handling it!  The briar cup is in good shape and is ample for much time and fellowship with one’s favor blend packed in the bowl. The size of the Curtis is:  Length: 6 1/2 inches, Height: 2 inches, Rim width: 1 1/2 inches, Chamber width: 7/8 inches, Chamber depth: 1 1/8 inches.  Robert commissioned this Curtis and will have the first opportunity to claim him from the Pipe Steward Store.  I’m thankful also to Bonnie’s mother who allowed her daughter to serve with us in Bulgaria and gave this pipe to benefit the Daughters of Bulgaria – helping women and girls who have been trafficked and sexually exploited.  Thanks for joining me!

Please pray for the people of Ukraine





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