Here is a good way to scrape off extra solder or epoxy from the blade side of your guard (or your handle slab, if no guard). There are lots of ways to do this. This is my way. It is not necessarily the best way.
Take a handy length of aluminum angle "iron".
Hold it against your grinder so the end looks like a "V".
Now raise it to a forty-five degree angle (end still looks like a "V"). Start the grinder.
You'll be grinding off the top two points of the "V".
Hold the angle "iron" at the same angle, slowly pushing
the aluminum into the grinding belt. Keep grinding until the bottom of the "V" is ground. So now everything's at a 45 degree angle.
The point is fairly sharp. Aluminum is softer than steel so it won't scratch the blade & if your gentle, it won't scratch your guard or handle slab.
Good luck! Be sure to use common sense and always be very safe and cautious! Remember: you only get two eyes, two ears, two lungs and ten fingers. Try to make them last at least 100 years.