Erhu Making - How NOT to make an Erhu!

We came across a video recently. It actually states how to make an Erhu. Most parts were acceptable, except when it talks about the most important part of the making: The Affixing of the Membrane.

Proceeding to 22:50, there are so many flaws in which we see with this portion!

1. Whoever is sacriligeous enough to fix an entire piece of skin without even removing the flesh and fat layer from the top most layer, is asking for the erhu membrane to warp with changes to the weather. Flesh and skin are 2 distinct layers, which will will expand and contract at differing rates. When the weather gets moist, or air pressure drops, the flesh will sag first, causing the erhu's tight skin to have a stage of muffled sounds, till  it sags sufficiently to have a softer tun usual mellow tone. The interim stage is when we say "the erhu got a flu". Its not a bad way of foretelling the weather. When the air gets dry, the outer skin expands first, while the flesh behind stays intact. You get a muffled sound again, but this time, if the skin dries much faster than the flesh, guess what, the skin may tear.

2. No respectable maker will apply glue while the skin is still in a flimsy form. If you ask any respectable maker, Wang Geng Xin, Hu Han Rou, Wan Qi Xing, or even EcoErhu (yes, they make using traditional based methods as well) , the skin needs to be stretched and dried on a mold of the Erhu box or the box itself to give it the shape that is needed. At this stage, the maker can adjust the tension adjust the angles, tune all corners, making sure all sides are well stretched and dried at least 2 times. During this time, the maker must even out the skin. Think of it as TuiNa massage, when you release all knots of your muscles, its done on the skin as well, 2 times. It is only after the maker is happy that the skin is in its most balanced form when he will apply the glue.

3. Stretching. Using the screw down clamp, the hydraulic jack and such methods are akin to cooking everything together in a pressure cooker. You can't control any side or corner. Whatever comes out is based on luck. True makers use this method, or a slight variation:

Corners are controlled by the twisting ropes and wooden rods, while sides are controlled using jammed in wedges. This is ancient wisdom of levers and wedges at work, and boy this is hard work. The glue holds 2000lbs/square inch, and you can easily guess how much stretching this is. This stretching is done and released and done 3 times. 

Every maker has their own concept of how to tune the "drum skin" on the erhu. No matter what, a method without tuning the 6 sides of the erhu will never be the right one. 

I hope this helps everybody to be a bit more discerning about what they watch, read or hear about.