Tim, I made two closed end pens using Jr Gent kit parts and had no problems. I used longer than normall brass tubes to make sure brass was as deep in the blank as possible. The only area I was concerned with was the unsupported tip. After drilling the blank I dropped a few drops of thin ca down inside the blank so the end beans would soak up the CA then as I turned the outside, I made sure the end beans were saturated with CA. I applied a CA finish as usual and the pens turned out nice.
With the beans saturated with CA, they are as strong as the alumilite itself. I also wash my beans in lacquer thinner before casting to get rid of the oils in the bean so they will adhere better to the alumilite and not "pop out" as some folks have had problems with.