I too was having a challenging time sharpening my micro "V" gouge. I have a belt sander with a leather stropping belt that is real good for larger tools, but the micro set offers a special challenge. Even using buffing wheels is risky because you can overheat your tool real easy due to the friction involved. It's also hard to control the shape.
Determined not to let it best me, here is what I did. Now my tool is so sharp I could shave a flea.
First thing you should realize is there really isn't much metal to be removed due to how small the tool is. You can make the job more tedious by removing too much at first or ruin the tool completely. The micro "V" gouge is particularly challenging due to the shape. The best thing to do is remove only the amount of metal required. I found a way to control the sharpening procedure for micro tools that doesn't involve anything expensive.
First you need to make some special tools to work with. Get yourself some popsicle sticks and some two sided tape. You also want some 400 grit, 600 grit, 1200 grit and 1500 grit wet & dry sand paper. Put a piece of the two sided tape down one side of the popsicle stick and stick it to the back edge of each piece of sandpaper. At less than a buck for a piece of sandpaper you can make a lot of these tools for cheap, so it should lasts for years.
Once you have your four sanding sticks ready, you will also need a scrap of wood. Fir or Pine 1" x 2" or 2" x 4" about 6 inches long will work fine. (more on the wood block later)
The First Step
Now, often "V" gouges develop a problem where they get a hook on the leading edge or one side is shorter than the other and this is the first thing to be addressed. This problem develops over time due to improper stropping. Hold your gouge with the tip pointing straight at a fine stone, or you can use your 400 grit sanding stick for this or even better, place the big sheet of 400 grit on a piece of glass. You want to square up all the leading edges so they are flat and even and square to the top edge of the gouge at the tip. Hold the tool against the abrasive surface and move it away from the point of the "V", so if the "V" points one way, move the chisel the other way. This is important because you want to keep the inside surfaces and edge of the gouge as clean as possible. Perform this step with caution because you only need to see the whole "V" shape in the new flat surface you are making. You don't want to remove too much metal if you can help it. If the whole "V" shape does not reveal itself then you need to repeat this step until it does. This will vary due to how damaged the edge is. This is going to define your new cutting edge and any repairs for width of the tool needs to be addressed now.
Once you have the tool squared off you should be able to hold it in your hand and turn the point towards you and see light reflecting off the newly formed square surface. Use a bright light for this and twist the gouge until you see the reflection off the front "V" edge. If the reflection isn't even, in other words, only one side reflects and you have to turn the tool to get the other side to reflect, then your edge isn't even and you should drag it over the abrasive again. It's much better if your new edge is flat to begin with. Sometimes holding the tool against a small block of wood helps you keep it at an even angle to the abrasive.
The Second Step
Okay, now you have the new flat square surface. Place the shank of the gouge (the part closest to the handle) in a vice, using a piece of leather or cloth to protect the tool from the jaws of the vice (not necessary if you have rubber jaw guards). You want the tool to be held firm with the "V" pointing up. You want to have it positioned so as you sit there and work on the tool you can see the light reflecting off the new flat "V" shaped surface. A jewelers loop is also a good way to follow your progress.
So with the jewelers loop (or your magnifier of choice) on and ready to go, start with the 400 grit stick and work the thickest parts of the blade first. Keep the flat surface of the stick parallel to the inside edge of the gouge.
Always move the stick down during the working stroke, never move it upwards against the gouge. Don't think moving it upwards is faster as that is false economy. Take your time and make it right the first time, you will be done sooner and be happy with the results for years to come.
Work carefully keeping the stick at about 15 to 20 degrees to the flat surface on the inside of the gouge. Keep working the 400 grit until you see the reflection is getting really small. when it gets that small, about 1/64" stop and move on to the other edge and repeat the procedure. Leave the gouge in the vice because seeing the reflective edge is all important for these steps.
Once the second edge is down to 1/64", stop and examine the point of the "V". Hold the sanding stick at the same angle as you held it for the sides of the "V" and work the point so it becomes an even 1/64 edge transition from one side around the tip to the other side. You will need to roll the sanding stick as you work it so that you don't wind up sanding a flat surface on the tip. Really take your time with this step as it is by far the most difficult.
Now your new cutting surface is taking shape it should still be square on the tip of the gouge with a flat spot 1/64" wide. Now you change to the 600 grit sand paper and start again as you did with the first side of the "V" gouge, keeping the stick at the same angle as before and keep you eye fixed on the reflection from the 1/64" flat. It will get smaller and smaller until it disappears all together. Pay close attention and stop working the surface as soon as the reflective flat surface disappears. If you continue you will be throwing your edge off square and you will need to start again with the very first step in order to get the edge back to square.
Once you have the first edge perfect, move on to the second edge and then work the point as well.
STOPPING AS SOON AS THE FLAT REFLECTIVE SURFACE DISAPPEARS IS IMPORTANT! Once again the point of the gouge is real easy to ruin on this step, so take your time and make it perfect because you are almost done and a mistake here will mean starting all over again at Step One.
Once you make it this far you will have what look like a new sharp edge, but it is not sharp enough yet.
Christopher