Intro to Gouging Cane
I have decided to make this a free post because of the lack of specifics included in this post. Because all gouging machines are a little different and have their own nuances, I highly suggest you ask the maker of your gouging machine questions such as:
- What diameter cane will work best with the blade and the bed of the gouging machine
- How wide should the pre-gouged cane be to fit in the bed of the gouging machine
- How long should the cane be soaked (if at all) before gouging
- What are the ideal measurements in the middle and sides of the gouged cane
- How do you prepare cane to be gouged
- How thick should the chips that come off be
- How often will the blade need to be resharpened
- What are the necessary things to buy (oil, brush for dusting) to best take care of the machine
Many gouge makers have also posted videos and tutorials on their own website covering the basics of using their machine which I would highly recommend checking out.
Normally I use an Innoledy gouging machine because that machine is able to gouge cane quickly and requires little maintenance. This gouging machine works with dry cane so you do not have to spend time soaking cane before using it. While this machine is often times less consistent than other gouging machines, it saves me so much time that I feel that it is worth it.
Instructions come with the Innoledy machine, but I normally set the dial at 1.1mm for a center thickness, then go down incrementally to 0.58mm. On my machine, the dial needs to read 0.55mm to actually come out 0.58, but every machine will be slightly different and your machine will come with instructions. I like my last pass through of the cane to remove a chip of 0.10mm. If the last chip is more or less than 0.10mm then the cane might be gouged more unevenly so I set my second to last swipe at 0.65mm and last swipe at 0.55mm to make that chip 0.10mm.
The Opus 1 radius gauge (pictured below) has a gauge point location guide to help you find the exact center and sides of the cane (the sides are going to be where the sides of the tip will be after the cane is shaped and tied). To use it, just draw dots on the inside of the cane using a pencil where the big grooves in the location guide are. I often times do not use the radius gauge to find the side measurements because I can get a more accurate side measurement reading after the cane is shaped, but before the ears are trimmed off (see post about shaping cane). If you leave the ears on the cane after it has been shaped, you will see exactly where the sides will be on that particular piece of cane.
Often times, cane gouged from 0.57-0.60 in the center will work great, but veering off more than one or two hundredths of a millimeter in either direction will start to have noticeable consequences. Since you will not be scraping the bark all the way down to the thread, your reed needs to be balanced so that the center measurement of the cane is not too thick or thin for the rest of the reed. I have found that if the center measurement of the gouge is left thicker then you will need to scrape out less cane to keep the reed balanced. Many people find this counter intuitive and think that if cane is gouged thicker, then more cane will need to be scraped off to accommodate and vice versa if cane is gouged thinner, but I believe a proportional reed will have the best response.
Since the bark of cane is denser than the inside of cane, the process of gouging is also designed to help you get to a specific density of cane where you will finish a reed. Since cane is denser on the outside where the bark is, the thinner you gouge cane, the closer you are going towards the bark, meaning the denser that area of cane will be relative to the rest of the tube.
Quick Explanation on Using a Double Radius Gouging Machine:
A double radius gouging machine is a machine where the blade is not a perfect semi circle but rather an elipse. This shape allows greater consistency with your gouge, and also creates a thicker measurement between the center and side measurements of a gouged piece of cane (called the rib measurement). The rib measurement is located at the side of a shaped piece of cane at the height of where the top of the thread will be. Each gouging machine will come with its own intricacies so I would recommend asking the maker or seller questions like how long to soak the cane before gouging, the ideal width of cane to fit the bed, ideal diameter of cane, what type of blade it uses, and how often to flip the cane if it is a double radius gouging machine. You might be told to soak the cane for 20 minutes or up to 2 hours or it may be possible to microwave the cane in water for several minutes. The width of cane will need to fit the bed, and the diameter should be appropriate for the blade and the bed. Some machines will work better with cane that is above 10.5mm in diameter and some with a diameter smaller than that.
You fasten the cane into the bed using the clips. Start with the bed all the way on the right and quickly swipe it over the piece of cane. You should not have to use too much downward pressure to remove cane; if you need to press down, this means the blade is dull or the blade is not sticking out of the guide as much as it should. As you are swiping the blade over the piece of cane, you should try to feel like you are going 'downhill' and apply a little (very little!) more pressure as you are going from right to left. This is done really just to compensate for the tendency for people to accidentally release pressure. After about 5-10 swipes, flip the reed over and take out another 5-10 swipes. If your gouging machine is a double radius you will then need to flip the cane about every 5-10 swipes on each side until no more cane is gouged out. Often times, if I am getting measurements a little bit off from 0.58 and 0.46mm in the middle and sides, instead of adjusting the machine I will either leave the cane a little wider or narrower to see if that can account for the difference - this means I would take a razor blade or a plainer and just remove a little extra width off the sides of the piece of cane. Normally, decreasing the width of the piece of cane (relative to the bed) will create thinner sides. Using a smaller diameter of cane will also yield thinner sides. Wider cane or cane with a wider diameter will naturally gouge thicker sides and thinner middle. This will only account for a difference of 1-3 hundreths of a millimeter.
The picture on the left shows the gouging machine and the picture on the right shows the carriage of the gouging machine where the guide and the blade are. The blade sticks out very slightly from the guide to remove chips of cane. The blade should only stick out so much so that the chips of cane are only about 0.06-0.12mm in thickness.
When you are gouging, remember that your dial indicator might be off or might read a little thicker or thinner than other dial indicators. This can be due to a larger or smaller needle point or how resistant the spring is inside the dial indicator (if the spring is stronger than it will press down on the cane a little more). If the cane is soaked then it will also read thicker than if the cane is dry. For these reasons when someone tells you that cane should always be gouged 0.60mm in the center, interpret that as though the measurements should be consistent all the way up the center, but it might read 0.58 or 0.62 on your dial indicator. Measuring the sides (right next to where the ears of the reed will be clipped off) is particularly hard to get consistent readings because you are trying to measure a specific point on a curved material. The opening of your reed is largely determined by the diameter cane and by the difference between the center and side measurements of your gouge. If your piece of cane is 0.60mm in the center and 0.48 on the sides, it could be more closed than a piece of cane that is 0.60mm in the center and 0.46 in the sides.