Hi folks,

I am getting back into speedsailing, and thus have resurrected an old board by pealing off the existing bottom skin, removing the old finbox, then re-shaping the bottom as appropriate.

I am now at the stage of re-glassing. Having done it a few times about 15 years ago I am familiar with the task - however, I do remember having resin leak into the finbox/mast-track causing all sorts of problems when I went to use the board. ie: I glued them in before I glassed the board.

Rather than make that mistake again, should glass the bottom of the board before glueing in the finbox - or the other way around (finbox before glassing).

Also, how do people get the finbox to align with the rocker-line of the board, during the resin curing stage.

Note that I have read all of "The board Lady"s tips.

thanks,
Mathew

you should put in the finbox then glass
as you mentioned board lady then, kind of like this (although here it is a powerbox):
boardlady.com/jppowerbox.htm

you could put some foam/fabric/old bit of clothing, whatever in the finbox if you are scared that resin might leak into the finbox.
But also simply remember not to soak the resine too much near the finbox.

if you are in WA there's few guys like Mike BlueJ and Mike Kaos69 that could give you advice. they'll probably comment here.

good luck

amazing what u can find when u r desperate to fix something

I used to put the box in first, then glass over it, but now I prefer to put the finbox in last.
No matter how much you rough up the top surface, polyester resin doesn't stick at all well to fin box plastic, this usually means it delaminates from it, the box can then get loose with little visible evidence of a problem. If there's no glass layer over the top of the box, a crack is immediately visible and you can do something about it.
It's important to support the sideways load on the fin, especially if the blank only has light stringers. The old way of doing it was to sink much thicker timber along side the existing stringers for a few inches either end of the box.
I've used light timber or high density foam the other way up, set into the bottom of the board about 10cm wide and 3mm to 5mm thick. this allows the cloth to have a greater surface area to bond to, giving better support without much extra weight.
Use a chinook style box with a peg, I try and cut the peg to the exact length for it to bond to the deck glass, (stick a bit of fiberglass into the peg's hole).
If you want a really strong job you can set the box in with a layer of glass, but this is a bit more tricky, for a speed board you're going to want the bottom to be as fair as possible, so you need to make a .3 mm rebate over the reinforcing area before glassing. Then after you've cut the box hole, "make it loose enough for a layer cloth each side" slightly round the top edge so the cloth will bend round onto the bottom without making an air bubble. If you can find some stiff plastic, (monofilm is great!) you can use this over the top of the box when you glue it in with a weight on top, sand bags are handy if the bottom isn't dead flat.
I've done all sorts of things to keep the resin out, but wax sounds like a good idea.
If you make sure the fin area of the board is very close to level, put more resin than needed into the box, initially push box in just proud of the bottom, then the weight on the mono film will align it with the bottom, squeeze out any excess resin and leave you with a great finish.

Regarding filling any space in which you are glassing/epoxying over - be it a mast-track/finbox or whatever - childrens plasticine is very good - it is malleable - it isnt that hard to get out afterwards - the epoxy/glass doesnt stick to it - but it does have a kind of oily residue - maybe because it is petroleum based to my knowledge - so I try to keep this residue off anything I want it to stick to - including my hands - when sanding etc. But it works very well!

To stop the resin sticking to the box I use a cotton bud with cooking oil and lightly coat the inside of the box, Any resin will flick off with a knife. Put the box in 1st followed by woodys or I like to route a channel around the box and fill with Q-cells and carbon fibre or glass strands, sand flat and glass over. The channel will give a good bonding surface.