At first I was going to say I thought 100% bonds was a bad idea until I saw this was a small enough part of your portfolio that it only reduces you from 95/5 to 80/20. That would make it a reasonable thing to do, and even more so if some of the equities are in taxable brokerage accounts. If you have a mixture of taxable and tax-deferred investments, and you have a mixture of stocks and bonds, it's better to have the (taxable) bonds in the tax-deferred accounts and the equities in taxable accounts.
"Hey, for every ten dollars, that's another hour that I have to be in the work place. That's an hour of my life. And my life is a very finite thing. I have only 'x' number of hours left before I'm dead. So how do I want to use these hours of my life? Do I want to use them just spending it on more crap and more stuff, or do I want to start getting a handle on it and using my life more intelligently?" -- Joe Dominguez (1938 - 1997)