Just grabbed a 95 fx1 for super cheap didn't even really take a look at the ski just grabbed it. Got it home has a huge Crack in hull right under the rail about a half inch gap of light shining into engine compartment. Never dealt with fiberglass or any composite work but feel I'm capable just looking for tips on what I should be doing and how to go about it. Thanks guys. Sorry about the pictures being crappy.
Use a grinder to cut out the crack. You could open it up to only 1-2mm as long as the majority of the damage is removed. This will prevent the crack from extending after repair.
Sand down to bare smc inside and outside of the hull.
*optional step* That is close to the bond line, so now is a good time to reinforce the bond line if you want to pancake it. The reinforcement will add more weight so if you don't plan to pancake the bond rail is fine. Your decision. If you do want to reinforce, mix epoxy with microspheres and fill the gaps in the bond rail, let dry, then feather, so you have a smooth transition from top to bottom deck.
Prep your materials for the inside. You will need epoxy, a roller or 2, brushes, etc. the choice of epoxy is yours. I personally use 3:1 laminating resin with about 20 minute pot life at 80-90 degree ambient. You may want to work with a slower curing resin.
For glass you can use 1208, it will be easier to work with than 1708. If you want to reinforce the bond line, use 1 layer of 1208 that overlaps the crack by 2" on all sides and a second layer that reinforces the bond line. That is a big crack so if you want to be safe use a 3rd layer. First would be 2" on all side, second would be 4" on all sides, 3rd would be whole side for bond line reinforcement. This may be overkill as there are more steps to come.
Cut all pieces so the pretty side faces you, that is to say, the chop side faces the hull. Cut all pieces as one piece, so if you are doing 3 layers, you only have 3 pieces. If a piece is going to be too large for you to work with, then plan for a 1" overlap of the 2 pieces used for the same layer.
Next, select your filler. You filler will be put in the crack and then the glass put over it before it dries. The filler you chose will depend on the size of the ground area you made. 0-2mm use cab-o-sil or microspheres mixed with epoxy. Any bigger than 2mm, use milled fibers. Any bigger than 0.25" you should cut strips of glass and lay them up (put filler on the edges when you layup these pieces to fill any voids around the edges). I have personally not used milled fibers but they are less brittle than microspheres. There will be one more layer of glass on the outside so microspheres will be fine.
Now that you have cut your pieces and sanded, finish preping the hull.
Prep with acetone. Put a piece of packing tape over the opening on the outside of the hull. One length the full length of the old crack. Use a couple pieces (all full length) if necessary to make sure it doesn't pull away when you push on it from the inside.
This next filler step is done with the layers you preped, so be ready to do it all at once. Fill the ground out area with your filler (or strips of glass + filler if you got crazy with the grinder), the packing tape will hold the filler in place, put filler in and wipe so it is flush on the inside of the hull. Before its fully cured, layup all of your glass. Let fully cure.
Go to outside now, If you are lucky the tape pushed out and you just remove tape and sand smooth. If not, make a little microsphere filler and feather it into the hull. I would do a so-so job here, but you could just blend now and be done. I personally would do a good enough job to get the shape right, prep the outside, and reinforce my fillers with a thin piece of lightweight woven cloth, using about 1-2" overlap. Let dry, use microspheres to blend in the body work. I would not bother with this piece of glass or all that prep work if I was going to add sponsons. Just sand to general shape and add sponsons.
Tip: Don't put the hull flat on its side. If it's flat, resin will pool at the bond line. Put it at an angle that lets the resin flow from top to bottom. Put resin on starting at top, work down, roll it otu down, then collect the pooling resin at the bottom. (top to bottom I am talking about gravity, doesn't matter if you work topdeck down or bottom deck up, as long as gravity is helping you.)
