Title of this post doesn't make sense? Go see your eye doctor! This post is about subtle differences and small decisions. When you embark on a van customization project, you know you'll have to calculate the power draw of different lights and choose a material for the wall paneling. You might not realize, however, that you will need to decide how to cut and tape insulation to best fit the wheel wells.
As far as we can tell, most people insulate their wheel wells. Just what they use and how they go about it is under documented, however. We used Reflectix for the insulation. We stuck it to the steel wheel wells with 3M 90 Low VOC spray adhesive and Duck Brand HVAC UL Foil Tape.
QUICK FACTS Time Spent: 4 hrs Dollars Spent: $35 Products Used: * Reflectix * Duck Brand HVAC UL Foil Tape * 3M 90 Low VOC spray adhesive Tools Required: sturdy scissors Frustration Factor: moderate
Like many parts of the van, the wheel wells aren't square, and therein lies the rub. Although there are likely many approaches to dealing with the irregularities of the wheel well, we tried two. In the end, both worked. One required more finesse when attached to the wheel well; the other involved more prep time cutting a template and some awkward application of tape.
For the first wheel well (Photo A at top), we cut a rectangle of insulation roughly the size of the wheel well. By "size" we mean long enough to stretch from front to back and deep enough to touch the wall behind and the floor in front of the wheel well.
We measured the depth of the top of the wheel well, marked that on the Reflectix, and then made vertical cuts in "bottom" half of the rectangle. The idea was that we would attach the insulation to the top of the wheel well and then fold the fringe down over the face of the well to cover the entire surface.
Using spray adhesive, we attached the insulation to the top of the wheel well. Then, starting from the center, we glued each strip to the face. We minimized overlap by cutting away excess material as we progressed toward the floor. There was lots of excess, and clearing it got more and more awkward the closer we got to the floor. It worked, but it didn't feel elegant.
For the second wheel well (Photo B at top), we pre-cut the material into two pieces: one for the top ( in the diagram above), and one for the face ( in the diagram above). This method required more upfront measuring and prep, but it decreased the number of awkward cuts we had to make with the material already in place.
We cut the rectangle  long enough to stretch from floor to floor along the top of the wheel well. We added a couple notches to minimize bunching. We sprayed adhesive on the steel and the Reflectix, started at the front, and followed the arc of the wheel well, pressing the insulation firmly into place.
Next we traced the face of the wheel well onto a paper bag and cut a template. Piece  was easy to cut using that template. Again we applied adhesive to both the steel and the insulation, and we pressed the Reflectix into place. Easy peasy.
The most awkward step required by this method was finishing the front arc. We cut piece  a little wide, providing just enough material to fold down to meet piece . We taped this junction with the HVAC tape. If you're persnickety about the tape lying flat, well, good luck! (Remember, if you build a box around your wheel wells, nobody will ever see them again.)
Both methods produce satisfactory results. That said, and if we were to do this again, I'd opt for the "two piece suit" (i.e. the second) method.