After hitting a few logs while sailing and frustrated with blowing through the bottom of slot boxes, and the lack of unavailability, I decided to upgrade my Starboard Kode Wave Twin board to US boxes.
This repair took me way to long, mostly because of the colder winter than usual and not wanting to keep my shop heated on the cold days. Here’s the basics of what I did, I’m by no means a pro, but I’ve repaired a few boards for myself, and at windsurfing centers as an instructor.
Step 1: Measuring and Removing the old slot boxes.
First thing I did was take some measurements, so I could line up the fins later, and can’t forget to measure cant, 0 degrees.
Step 2: Gluing up the boxes
First I had to shorten the US boxes, I felt I didn’t need the full range, I removed 30cm, from the front of each box and glued them back together with jb weld. Next each box I glued into divinycell with a mix of epoxy and microballoons, mixed to the consistency of peanut butter. A note here, I would maybe put old fins in the boxes, as clamping them crushed them a bit, and I had to sand like crazy for the new fins to fit.
Step 3: Cleaning up the boxes
Multiple passes with the router cleaned up the box nicely. Was very careful on the first pass to follow my markings as close as possible, then the glass worked as a template to cut the full depth. After I tested fitted the boxes, and sanded the boxes so they would fit tightly and evenly.
Step 4: Gluing the boxes in
There was some debate over whether to just glue the box in, or wrap it in glass. From the factory it had a layer of glass around the a foam. In the end I opted not to use a layer of glass, so let see how long it lasts. I mixed up a big batch of epoxy and thickened it with micro balloons to a peanut butter consistency. I spread the mix liberally around the inside of the opening in the board, and then on the boxes. It took some force to fit the boxes in, which was a tight fit.
Step 5: Glassing
I glassed the fins in with two layers of 4oz E-glass. Two small patches over each fin box, and one large patch over the tail.
Step 6: Paint
A layer of sandable auto primer, followed by black and white to match the original finish.
All done and ready to shred! Lets hope it’s windy soon.
6 thoughts on “Board Repair: Replacing a broken slot boxes for US boxes”
Nice, I’d a kept the centre box in case the twins suck or remove it to lose weight. I think u cut 3 not 30cm or mm? Off the boxes….made me pause haha. Good work yeah hope there’s wind again some day 😃Kus
You’re right, I meant to put 30mm, thanks! I thought about removing the center fin, but felt the trauma to the board wasn’t worth it to save the weight.
Very nice work Lawrence!!!
Thanks David, and thanks for the divinycell and tip on the oscillating tool!
Re: “There was some debate over whether to just glue the box in, or wrap it in glass. From the factory it had a layer of glass around the a foam. In the end I opted not to use a layer of glass, so let see how long it lasts.” … did it end up being durable without the extra wrap of fiberglass?
Yup, out lasted me and my ankle hitting a reef.