After boring the first few holdfast holes, I realized that I had serious issues. My holdfasts simply weren’t biting. Often, they were jumping around in their holes. I had to find a solution, and fast.
The bench top is 4-1/2 inches thick. The holdfast holes are 3/4 inch in diameter. I am using Gramercy holdfasts. They are very well made, and should survive years of abuse. I did some research and determined that the most likely cause was the thickness of the bench top. How could I resolve this with the holes already bored?
I received some excellent advice from my friends on Twitter and decided that I would counter bore the holes from the bottom with a large diameter hole. To center the holes, I inserted a piece of 3/4 inch dowel. After some trial and error, I determined that the most effective nominal thickness was around 3 inches. The holdfasts work beautifully. The solution was quick and easy.
I need to clean up the surfaces and coat everything in boiled linseed oil. Then, I will finally be able to start my first project on the Roubo. Stay tuned
You can find links to my other Roubo posts here: Project Index