Blog by Steve Laug
Using the stem on the little Barling I repaired earlier as an example I thought I would post the process of repairing bite marks with Black Super Glue. The glue is available online at a variety of sources, though I purchased mine from http://www.stewmac.com/shop/Glues,_adhesives.html a company that is a supplier for stringed instrument repairmen. They offer super glue in several colours and viscosities. I order the black super glue from them that comes with whip tip nozzles as I find that it is easy to control the size of the drops used. I also have used the clear super glue and it works very well in several other applications including repairing and replacing fills on older pipes. They also carry a wide variety of micromesh sanding pads and papers. It is a great resource for hard to find items (at least in Canada) that I use regularly in my repairs.
I always seek to repair a stem in the least intrusive manner possible. In the case of the stem below I heated the tooth dents to try and lift them as much as possible before any other method was used. This can be done carefully with a heat gun – I stand the gun on its stand, turn it on its lowest setting and move the damaged part of the stem in the heat about 4-6 inches above the tip of the gun. If it gets too close the vulcanite is damaged through burning. The other method that I have used avoids this problem – it involves putting a cup of water in a microwave and boiling it. Once it is hot place the stem button end down in the boiling water and leave it. Repeat as often as necessary or until there is no more lift on the dents of marks in the stem. Note if the dents have sharp edges, or are cuts, the heat will not lift the dents at all. It also will not work on holes or bite throughs on the stem.
In Photos 1 and 2 the stem is pictured as I received it on the pipe. The first photo shows the top of the stem and shows the damage to the button and the surface – mostly dents. The second photo shows the underside of the stem. It was significantly worse that the top. The dents were very deep and the button was virtually destroyed. At this point it is probably pertinent to ask whether the stem should have been replaced or not. Several things went against doing that in my opinion. The first was that this is an original Transition Era Barling stem. It is hard to find replacements that have the slab look and slight taper on the saddle that are hallmarks of the Barling stem. The second was that the tenon on this one is very tiny. I did not have a tool that allowed me to turn that small of a tenon. Thus I decided to give it a repair. Then of course, if you have followed this blog for long you will understand, there was the challenge. Could I possible restore the stem to at least a semblance of its original “glory” and functionality?
So with the decision made I turned to work on this stem. I used my heat gun to lift the marks as much as I could on the top and the bottom of the stem. The two pictures below show the effect of the heat on the stems. The first photo shows the top of the stem – the heat actually lifted those bit marks quite a bit. It took out the rounded edges of the dents. What is left was actually sharp edges or cuts from the teeth on the button and on the surface. You will also notice that some of the oxidation burned off in the process. I also sanded the surface with 240 grit sand paper to better see what I was dealing with on this stem. The second photo shows the underside of the stem – the heat lifted the dents significantly but not totally. The sharp edges on the dents still remain, as does the destroyed button and the hole is very visible. I repeated the heating process several times (to be honest I lost count) until there was no more visible improvement in the dents. It was time to prepare for the patching process.
Before I use super glue to patch a hole or fill dents in the stem I prepare the surface to be clean and debris free in order to get a good bond on the glue. I sand the surface with 240 grit to remove the oxidation as much as possible. I want the area under the patch to be black so that the glue matches. Oxidation on the edges of the patch makes that match impossible. Once I have the surface sanded I buff it with Tripoli to take a bit of the roughness out. I don’t want a glossy finish as a little roughness gives surface for the glue to bite into. But I do want it clean. I wash the stem with isopropyl alcohol to remove any debris that still remains, including any of the Tripoli. I use a dental pick to make sure that the edges of the hole are not cracked or broken. Doing this often opens the hole a bit larger but it also removes chips or cracking that will not provide a good base for the patch. I finish the cleanup with yet another wash with alcohol and a cotton swab. The surface should have solid edges to bind to and no extraneous sanding dust or debris that will be in the way of the patch.
On this stem the easiest part to patch was the top of the stem so I started with that part. I used the whip nozzle on the super glue and dripped it on the stem. I smoothed the drop out with the end of the whip. I want the dent and cut to be totally filled so I moved the glue back and forth until it was all covered and then set it aside to dry with the end of the stem propped up to keep the patch level. The first picture below shows the patch after the glue had dried. It formed a solid patch on the stem. I always layer the patch doing multiple layers until I have built up the hole and dent. In this case I also used the glue to build up the button. While the picture does not show it clearly, the glue is actually level with the top of the button and small spots of glue are moved into the dent marks in the button surface itself. In the second photo the stem shows the patch after sanding with 240 grit sandpaper. The object was to get a smooth surface on the stem. The dent marks in front of the button are gone. The brown spot on the stem is some oxidation that has not been sanded out yet. The button is also repaired and you can see a bit of the bulk that is now there. The button will need to be shaped and recut with needle files once the underside of the stem is also patched.
Once I had the top surface of the stem to the point it is pictured above I turned the stem over to work on the underside. This part of the stem was really the challenge on this one. It had deep tooth cuts and a bite through that needed to be repaired. The first step for me was to repair the bite through. I fold a pipe cleaned to fit the flared slot on the button. I greased it with olive oil and inserted it in the slot. I wanted it to be smooth and not pucker through the bite hole, so I tucked it down with my dental pick. Once it was set I put in the first drops of black super glue. Remember at this point I am not work on the surface detail of the holes only the bite through. Once it was patched I went on to fill the other deep dents and marks on the surface and build up the button. I set aside the stem on a level surface and raise the tenon end to keep the bubble of glue level so it would dry.
Once the glue dried I removed the pipe cleaner from the slot. This is always the moment of truth for me – did I grease it well enough that the pipe cleaner did not permanently bond to the slot. In this case it worked perfectly and it came out easily! Whew! Once it was removed I filled the rest of the dent marks with the super glue and also built up the non-existent button. I forgot to take pictures of that step. So the verbal description and the picture of the topside fill will have to suffice. I set the stem aside again and leveled the glue so that it would dry and not run up the stem. Super glue dries very hard and is a lot of work to sand off the surface. Once it was dry I sanded the surface with 240 grit sandpaper once again to level out the surface. The picture below shows the stem at that stage in the process. The fills appear to be white but that is the sanding dust on the surface. You can clearly see the three large patches on the underside of the stem in this picture as well as the rebuilt portion of the button. Again I over filled the patch to the level of the top of the button to provide a solid new surface for me to work with when I recut the button with the needle files.
The next two photos show the result of the sanding process with the 240 grit sandpaper on the top and the bottom of the stem. I wanted to make sure that the patches blended into the surface of the stem. You will note that in the first photo of the top of the stem, that the patch is virtually invisible. Though it is not very clear, I had also recut the button with the needle files to give it a good sharp edge against the surface of the stem. I use wedge shaped file and a rectangular file to cut that edge cleanly and the result is a button that looks original. In the second photo you can clearly see that the patches are fairly well hidden. The one against the button and the large one at the top of the photo were the deepest ones. After this sanding and recleaning the surface I refilled those two spots, let them dry and sanded them again. Once that was completed the underside of the stem looked exactly like the topside of the stem at this point.
I failed to take pictures of recutting the button on the underside of the stem but you can see the new button in the pictures below. I cut and shaped it with the same needle files that I used on the top of the stem. I like the clean angles of a new button so I was aiming for that with just a little wear or rounding to match the age of the pipe. I finished the sanding and polishing of the stem using 400 and 600 grit wet dry sandpaper and then used the normal list of micromesh sanding pads from 1500-6000 grit. I keep a bowl of water close by to dip both the paper and the pads in as I sand as I find it more effective in removing the scratches and remaining oxidation. Once the stem was finished I put it on the pipe bowl and gave it a buff with Tripoli and White Diamond to get a good sheen to the surface. I never buff a stem apart from a pipe as I do not want to damage the stem shank junction by rounding the clean edge of the stem. The top two photos below show the top and bottom of the stem respectively. You can see the repair is complete and the button is very clean and present. The second two photos below show the stem from the right and left profile so you can see the flow of the stem surface – uninterrupted from either side with the tooth dents as before and also the profile of the button. It is distinctive and present. The stem was finished with several coats of Obsidian Oil and then carnauba wax to protect the surface.