When I ordered the base from Ken Thomas, he informed me that it would have a void on one side. No problem, I'll fix it somehow. I hate having left over putty, thats why I mix small batches at a time, so this is what I've done with the small semi-hard clumps that are not useful. The blue thing is a piece of foam board I carved to fit the shape of the void. I did this so I wouldn't have use half a tub of putty to fill it.