You can go low tech and wrap a towel several times around a barbell or dumbbell to create a thick bar, or you can add a set of ready-made thick grips.
Another side benefit of thick bar training is reduced stress on the shoulders and elbows because it disperses the force over a greater surface area.
related posts
An ab training article for people who do more than take mirror selfies.
Are high-rep Oly lifts dangerous? Will they fail to make you strong? Here's what a variety of experts have to say.
Use the first-tension principle to build bigger, stronger arms. Here's how.
My new pastime (and how women should train)