Hey, I’m ready to put in a single fin box (10.5" bahne style) and looking at that thing it looks pretty tall. It seems there is a thinner wall around the opening with a recessed smaller opening down inside. Looking at my other boards it seems that all I see of the box is this smaller opening. does that thinner wall get grinded off after it is in the board?
If I left the thinner wall the fin would fit snug into the smaller opening, but have a lot of room in that larger opening. Also, if I put the whole box in I’d have to leave a lot of thickness in the tail for it to fit properly. If indeed the idea is to grind off this ‘wall’ should I grind off some before installing the box so I can get it properly flush with the bottom, or should I wait until it is in to grind it off?
The latest style Bahne boxes use this high wall design to make it quicker and easier to install, no tape off needed. Hotcoat the board then install the box, the raised section is all ground off flush, slightly below the small “bridge” between the side walls of the box.(you are correct in thinking that the narrow opening is the width of the finished opening). I use a hardbacked 36 grit disc to cut through the exposed plastic and resin it is set in place with. As you get closer to the hotcoat level move to an 80 grit hard disc, then your normal sanding pad. Pay particular attention to the heat buildup, don’t be in a hurry and you will be fine.
Billy, that wall around the outside of the box is to prevent resin from running inside when you set it in the board. Watch out that you don’t set the box too deep. It’s difficult to see the finished box surface in comparison to the surface of the board with that little “wall” in the way. I’ve found that there is a tendency (with me anyway) to get both ends of the box right, but the middle will be a hair too deep. The more curve in the tail rocker, the more likely that is to happen.
One solution is to pregrind the plastic wall and tape off the fin slot so resin won’t flow in. Then you can see all the edges involved. Also, if you do it that way, you can set the box with only enough resin to fill half the hole, let the resin set up, then fill the rest of the space around the box later using a plastic sqeeze bottle filled with colored resin. Doug
I put in the vert fin to check the set of the box all sew a few ,ayers of glass under ,four today,and dremmeling to the box to rough it for intensifying he mechanical bond…yes that straight in the length of the box os confounding…but I am accustomed reinforcing the top of th box with glass on the top of the box ,3 layers today this has helped to take up the dip in th center of the box on the length and refreshing the curve…ambrose…lately Ive been cutting a slit in the filler glass on the ends of the box so I can see the centerline relationship is true I mark that with a pencil
Good point Doug. Since I’ve been using epoxy lately I like your method of presetting the box then coming back and finishing the fill in a second step. Always seems like with epoxy there is some little pinhole to fill in or finish work to do. Thanks.