Depends on what you call thick. I have several different varieties and the trunk size varies. I have one that has about a 1/2 to 3/4 inch trunk. I'll try to get a picture this evening. They aren't really as hard to grow as everyone says they are.
How's this one - large enough? It's a club member's tree and I can't recall the exact size but it's pretty impressive. He has began training it in 1987 I believe. The cardholder is a baseball card holder for scale.