You can always buy that $325 rack used for around $100. Just because they're $325 new, doesn't mean you need to pay that much.

• Check ebay,
• check used sporting goods stores,
• check the sale board at the local university.

• Go to a used car dealership that has a vehicle with racks on a topper. Offer the man $100.

• Know any friends with a welder? Welded racks are very easy to make.

  I made two--one for a Plymouth Grand Voyager, and one for an aluminum topper on a FS pickup for $80 total.
  

For your wood rack, try a steel backing plate, and some of that weatherstripping that you use between topper and truck bed would work well enough for a seal on the outside.

Shawn

: Greetings -- Saw the thread about roof racks below and it got me thinking. I
: purchased a full-sized truck w/fiberglass topper this winter, and really
: hard to fork out $325 for a set of rails and 2, 1" square cross bars.
: Thinking about making 2 sets of wooded risers (2"-3") and wooden
: cross bars. Couple of questions: (1) If I bolt them thru the roof of the
: topper, what tink of backing plate do I need on the inside? and what
: should I use to get a water-tight seal? (2) What type of wood? I was
: thinking ash, but am open to suggestions. (3) How would I rail system
: within the cross bars to mount kayak and canoe cradles? Thanks in advance
: for your help. -- Greg