Titanium comb suitable for Hohner 270
by Andrés Vicente
We started the construction process of titanium bodies to adapt them to the Hohner 270 chromatic harmonicas. First of all we acquired Titanium plate, it is best to choose the Titanium as pure as possible, the most common and that in this case was used is grade 2 with a composition of 0.07 O2-0.10 Fe, which has a good mechanization. Titanium and its alloys are already firmly established as materials for the construction of aircraft and the aeronautical industry, also in the chemical and petrochemical industry, currently in constructions for tanks, dryers, reactors in the chemical and bleaching industries, large exchangers of tubular and plate heat, pumps, valves, heating coils, gas cleaning equipment and equipment specialized in the production of nuclear fuel elements. On the other hand Titanium is resistant to the corrosion of most electrolyte solutions in metal finishing processes. Titanium coils, Titanium coated immersion heaters and Titanium tubular heat exchangers are used to heat chromium and nickel plating solutions. Titanium is also used in anodizing frames for its electrochemical properties. The adaptation and lack of rejection of Titanium to the human body are so good that it is being used for a wide variety of surgical implants. Its use in oral implants is also very booming.
For this construction we have not opted for a sheet of 12 millimeters high and milling the upper and lower channels as usual and previously we have done, this time, we made three separate pieces that will later be joined in the body of the harmonica. We start with a sheet of 6 millimeters and another one of 1 millimeters that will be the one that performs the function of dividing partition between the two superior and inferior.
The 6 mm sheet is cut with our own designs through a current process of cutting with water and directed by numerical control by http://www.precisiondecorte.com which guarantees a perfect cut, free of burrs and without subjection to high temperatures.
After obtaining the pieces we continue with our work of union between them and we rectify to stone the two faces that will support in front of the separating sheet of 1 mm. With the perfectly rectified and flat surfaces, we make the holes that will form part of the holes through which the air will pass to the channels. Observe that the partitions will have a top post joining the partitions, notably increasing its robustness as a part.
Once this work is done, we proceed to weld the three pieces with TIG welding, which is done without input of material, advanced machinery and highly specialized hands. The photographs detail more clearly the disposition of the parties.
Now we start the work of finishing the body of this harmonica. In the first place, we rectify the front face, just where the elements of the slide and the mouthpiece is screwed. Once this face is mechanized, we can place the threaded holes that hold these parts and the hole that houses the spring is made.
Once the front elements are screwed and fastened, we mark the rest of both threaded and past holes that the bodies must have. In these bodies have been threaded directly into this metal to be able to directly screw each tab plate independently the upper one of the lower, so we can remove one of them without the need to remove the opposite.
Also the screws that hold the plates that cover the tongue plates were threaded, so they also have the possibility of disassembly independently.
Now the rest of the faces are ground to stone, which increases the quality of the finished piece, since grinding is a process of more accuracy and superficial quality than in other processes of machining or cutting by tool. The channels and some surfaces have also been polished with diamond paste for an improvement of their surface appearance.
After this phase, all the burrs are eliminated, all the edges are cut off and rounded corners, along with some more polished, finishing the construction work on these parts completely. The approximate final weight is about 132 grams.
Although this material has great and positive characteristics as its reduced oxidation, these bodies have received a surface treatment in the form of a coating of Titanium Nitride, with its peculiar yellow-gold color, a procedure by which additional characteristics are offered to the surfaces that are applied. This coating is widely known and used in the industrial sector for the improvement of the parts that are treated with this treatment. Chip cutting tools are well known with these types of coatings, molds for die-cutting, medical implants, etc …
This modern procedure and material is accepted for the alimentary use, option for which it was chosen, next the document with the certificate of authorization of use of this coating for the food industry is attached.
Documento PDF: Certificado TiN 308K
This guarantees that the external aspect will have a duration theoretically superior to the use that will be used in these bodies of harmonics and possibly survive the generation of which here writes this document. This process provides material as we know before with all the wide range of coatings, 3 microns form the standard measure, on which any doubt of sealing between the union of the pieces is resolved with the seal of the interior joints with the contribution of this material by coating. All this information can be expanded by visiting the website of the company that offers these coating services:
Titanium can also receive a surface treatment in the form of anodized, a method also used in decorative pieces, medical, jewelry, etc …
All this laborious work, in this expensive material such as titanium, machinery and special tools that have been used throughout the construction process make the resulting parts have a high price, approximately more than 700 euros. This will result in pieces made by high technology, modern materials and high physical performance that improve the standards in the quality of our harmonicas and even undoubtedly beyond other musical instruments.