Tonbak Drum Skin Replacement
A Note on the Tonbak Skin Replacement
Introduction. Drum skins (drumheads) have an impact on the sound of your tonbak and the music you play. There are several factors to consider when choosing drum skins and changing them. The main purpose of this note is to explain which skin to use and how to "replace the tonbak's skin" (in Persian " ta'viz-e poust-e tonbak تعویض پوست تنبک").
A brief on the tonbak. The tonbak (also known as tombak, donbak, dombak, zarb) is a Persian goblet-shaped drum and the chief percussion instrument of Persia. The tonbak has five parts and their names are skin, body, throat, small opening, and finally large opening. The skin of the tonbak covers the large opening and it is fixed on the edge of the tonbak with the help of a traditional and natural glue called "serishom سِریشُم" in Persian.
A brief on the serishom. Serishom is a sticky substance obtained by boiling the bones, cartilage and skin of some animals such as cows and fish. It turns yellow or dark after drying and is used in carpentry to glue wood and boards. The antiguity of the use of the "serishom سریشم" as a traditional Persian glue dates back to centuries ago. For example, the Persian poet Nizami Ganjavi (c. 1141 - 1209) mentions the term serishom in his poems. I bring one of his verses including the term "serishom" in the following:
سبویی که سوراخ باشد نخست به موم و سریشم نگردد درست
How to replace the tonbak's skin
If for any reason the skin of the tonbak is damaged which cannot be repaired, it is necessary to replace it with high quality skin. To replace the skin, one will need to carefully remove the damaged skin. Now I explain how to replace the skin carefully. It is necessary to wet the part of the skin stuck to the body of the tonbak, using a suitable amount of water based on the skin type. For instance, if the skin of the tonbak is camelskin, one should pour some water (say half a centimeter) in a big pan and put the tonbak in the water upside down and let the skin become completely wet. After some time, say one hour, the skin and the "serishom" glue which is between the skin and the wood of the tonbak are moist enough. This is so that one can easily and smoothly separate the skin from the tonbak, say with the help of a screw driver.
It is not necessary to put the tonbak in water upside down if the tonbak's skin is softer than camelskin, say for example, it is goatskin. This is because too much water may damage the wooden body of the tonbak. In this case, it is better to wet the skin with a wet cloth and wait till it becomes safe to remove the skin.
After removing the damaged skin, one ought to use soft sandpaper to clean the wooden part of the tonbak where the skin was stuck. After that, one needs to rub some "wet serishom" on the wooden part prepared to stick the skin on the body of the tonbak. The tricky part is how tight one has to tighten the skin around the large opening. If it is stretched too tight, then when the skin is dry and overtight, the skin or even the body may be broken. If it is stretched too loose, the skin will not sound properly and needs to be stretched again.
Once the skin has been stretched around the large opening properly, it must be fixed with the help of 8 small pins and a cloth rope. Note that the pins used for fixing the skin must be small enough not to harm the body of the tonbak. After it has dried, the pins and the rope must be removed.
To find out what skin can be used for the tonbak, see my note The Skin and Wood of Persian Drums.
Also, check Structure of Tonbak.
[N]: Peyman Nasehpour, Personal Interview with Ostad Nasser Farhangfar, Tehran, 1990.
[S]: Mehdi Setayeshgar, Vazhe-Name-ye-Musighi-ye-Iran Zamin, Tehran, Vol. I (1995) & Vol. II (1996).
[T]: Hossein Tehrani, Amouzesh-e-Tombak (Tombak Rudiment), Tehran, 1970.
Keywords. replacement, substitution, repairment, tonbak, tombak, donbak, dombak, zarb, drum, skin.