I did the same thing a while back to one of my helmets and man did I go about it the long way. Advice. If you can make a puck out of fibreglass do that instead, very easy to do and I wish I had done that. Just get some ISO P40 fibreglass and copy the pucks you have, measuring everything as best you can. If you make a mistake you can always re-sand it or build it back up.
If not this is a step by step guide of doing it the hard way.
Removing a dome puck
A dremal will work with the disk cutter but be careful and accept that you will ruin the "dome puck" but you can save the basic shape and add Isopon P40/P38 fibreglass or bodyfiller to repair it and build it up.
DO NOT TAKE THE DREMAL DOWN TO CLOSE TO THE PUCK, OTHERWISE YOU CAN CUT INTO THE DOME.
This is what I did.
1) I measured the puck approx, just so I got my dimensions correct. Such as where it sat etc.. the diameter, depth and width.
2) I got the dremal and cut the puck from a side position maybe leaving a 0.25 or half an inch from the bottom of the puck. Not advisable to cut the puck at the very bottom.
3) I slowly went all round the puck, the puck is obviously shorter in the front and more substanial and deeper at the back.
4) As the dremal's disk would not penetrate the whole thing because of the depth and width I cut the puck into 4 pieces from the TOP position.
5) I then bit by bit removed the top 4 segments which left a battered looking mangled puck left, but I still had the shape from the top pieces to form a new puck.
6) Between the grindstone and disk bits I sanded down the mangled puck that was left inside the dome. which takes ages, all the time being careful.
7) I picked up my TOP 4 pieces of puck. I then fibreglassed them to make them one whole piece with Iso P40 and let dry.
8) I grabbed my dimensions that I measured first of all and built the base and foundation of the puck up in the dome where I wanted it.
9) I then added the top of the puck which was now one piece again after fibreglassing it.
10) I fibreglassed the whole puck as one. Measured it, put smooth filler on it and then sanded it with various papers by hand.
It took 2 solid days :cryas I did it the hard way. Hope that helps?
