Reinforcement questions I cant find

[yz250f]

Hi guys,
I have a 2010 superjet. When i start attempting rolls I will need to reinforce. I will ride lakes only but some will have 4-5 foot waves. Im planning on doing the nose with a layer of 10 oz glass, filling the bondline and putting 2 layers of 10 oz.(4 inch strip then a 10 inch strip) on from the nose back to the fire wall. Then one layer of 10 oz on the handlepole mounting bracket. Will this be strong enough for what I want to do? When I do this I will put in footholds too. Ive been hearing theres a weak spot back by the exhaust but i cant quite figure out exactly where it is. Is it the tray thats weak? Or the actual outside hull? Also, do i need to reinforce for nose stabs?

 

[smoofers]

The bond line is usually the weakest point of the superjet hull. Without reinforcing, the hull tends to crack at the point of highest stress - where the hull curves outward at (or inside) the bond line on either the top or bottom deck (pic 1).

The second pic shows how reinforcing not only thickens the hull, but it bridges the two hull halves together and eliminates the weak spot.

As for what to reinforce with, most people (myself included) fill the bond line with epoxy thickened via glass micro bubbles or cabosil. Use 17oz biaxial cloth to reinforce the entire insides of the gunwales in the engine compartment. I generally cut my gunwale pieces so that they extend up into the nose as high as practical. Then you can finish the rest of the handlepole area with more biax or 9-10oz cloth.

Edit: As for the tray area, it isn't as important to reinforce since it's filled with foam that adds a good amount of rigidity to the glass in that area. If you feel like cutting out your tray to defoam and reinforce the tray gunwales, go for it, but it's a bit of a PITA.

 

[yz250f]

The bond line is usually the weakest point of the superjet hull. Without reinforcing, the hull tends to crack at the point of highest stress - where the hull curves outward at (or inside) the bond line on either the top or bottom deck (pic 1).
View attachment 183728
The second pic shows how reinforcing not only thickens the hull, but it bridges the two hull halves together and eliminates the weak spot.
View attachment 183729
As for what to reinforce with, most people (myself included) fill the bond line with epoxy thickened via glass micro bubbles or cabosil. Use 17oz biaxial cloth to reinforce the entire insides of the gunwales in the engine compartment. I generally cut my gunwale pieces so that they extend up into the nose as high as practical. Then you can finish the rest of the handlepole area with more biax or 9-10oz cloth.

Edit: As for the tray area, it isn't as important to reinforce since it's filled with foam that adds a good amount of rigidity to the glass in that area. If you feel like cutting out your tray to defoam and reinforce the tray gunwales, go for it, but it's a bit of a PITA.

Thanks for the reply. Now i now what to reinforce. If I was only going to be doing flatwater freestyle, how much reinforcing would be necessary?

 

[smoofers]

I'd reinforce the inside of the engine compartment gunwales and the handle pole bracket area (from the inside).

 

[djraider700]

I need to reinforce soon. Im rolling and stabbing in the surf lol. Nice diagrams smoofers!