February 20, 2004 - HS Priming

In the RV building arena, priming is one of the most controversial, right up there with powerplant selection or side-by-side vs tandem seating. There are two schools of thought regarding priming. One extreme is to prime everything with two-part epoxy. This approach yields ultimate corrosion protection but adds weight to the aircraft and requires a lot of effort. The other extreme is not to prime at all. No weight and no effort. There is still some protection because most of the aluminum material is alcad-coated. However, there are some non-alcad-coated parts. Reinforcers and ribs are generally not alcad-coated. Van's doesn't make a recommendation one way or the other.

I've read both sides of the issue. My decision is since I am trying to keep my airplane light, I am only going to prime the non-alcad coated material. I'm going to use Mar-Hyde, a self-etching primer with a good reputation among builders. It comes in a spray-can; in other words, it's easy to apply and there is no clean-up. It dries in one or two minutes. It's a nice shade of grey. I don't feel like etching my lungs, so I use a respirator when priming.