The rivets are a very important part of your airplane, they keep it together. I took no chances and ordered a hand riveter from Zenair (You will need it in some tight places). It turned out I can use the heads also in my pneumatic riveter. The cost is nothing compared to the cost of a kit or the work you put in a plans build. Later, just for fun, I tried to hone out some old riveter heads and the rivets never came even close to the standards set by Zenair.