I recently reboxed a slalom fin taking it to 40 degrees from the vertical (because in the Mandurah estuary it was pretty useless and I wanted a low cost weedy). The low tech method I used was to
1) cut the fin off at the box,
2) cut the top of the fin at about 40 degrees
3) drill out the box until I could fit the fin in
4) glass the fin into the hollowed out box using resin with some mat shredded into it ( used about 40ml of resin)
Then I tested it.... it did 27 knots first try and seems good but as Decrepit says with a low thickness to cord ratio it does not provide great lift for going upwind (unless really powered.)
When fully powered it is ok so I am waiting for some wind to try it further
. I have photos of the process if you are interested!
Have used it a couple of time, done about 20 kilometers on it and it has held up fine.
