How to: Repair fiberglass tunnelhulls

Radio Control Boat Modeler, Jun 2003 by Dunlap, Jerry

Resurrect your racer!

During a six-week period in the fall of 2002, I smacked two different fiberglass tunnel boats into floats at the lake where I test. The first incident occurred when I ran a 3.5cc modified tunnel at full throttle too close to a float; I flat-out drove the boat into the float. The second episode of "boat meets float" transpired because water penetrated the receiver battery connector of a new 7.5 tunnel I had flipped earlier in the session, and that caused an electrical failure that led to the collision. Water and connectors make a bad combination, and I had neglected to check the radio box carefully after the flip. What's worse is that the boat (the Van Houten Hornet 45 tunnel shown in the photos) doesn't even belong to me. It belongs to James Chambers of Tampa, FL, co-owner and crew chief of the Rinker Boats Formula 1 full-size tunnel boat. It's a good thing that I have a reliable technique for repairing broken sponson tips on fiberglass tunnel boats!

During nearly 40 years of running, racing, crashing and repairing model boats, I've had plenty of opportunities to evaluate and restore damaged hulls. Because the front sponsons of tunnel boats extend past the center section (as do those on most sport and scale hydroplanes), they tend to suffer the most damage and often crack near where the sponson joins the front edge of the center section. When wooden or wood-over-foam (WOF) boats sustain a hit, the result is usually a crushed sponson tip, but with a fiberglass hull, unless the collision is head-on, the sponson tip tends to fracture rather than crush. This type of damage might be considered a "best-case" scenario because the sponson tip, although fractured, isn't destroyed. A "worst-case" scenario would entail a complete rebuild or replacement of the sponson tip. This article deals with mending a fractured sponson. In a future issue, I'll show how to completely reconstruct a sponson tip using a WOF tunnel.

Van Houten Tunnels; distributed by Van's Racing & Design, 675 Shields Rd., Deatsville, AL 36022; SportRacer632@aol.com.