I'm in the process of doing this, on the side, and about the same size area. I just cut out the whole piece, then bonded both pieces. Next, I'm going to attach strips of marine plywood, about 3" wide, to the inside of the hull. 11/2", sticks out. The cut out piece, sits on it, I'll epoxy it,, and clamp it. After that, I'll fill in the gaps, then cover the seem, with epoxy and clothe. I've done this before, and it worked fine. Epoxy is stronger than fiberglass, so it's better than new. I tried drilling holes, and injecting epoxy, but only on small areas.
While what you described will work it is significant heavier, more complicated, and can only be used on small local areas. Which is why I chose to drill and fill. Epoxy is not inherently stronger than fiberglass. We use both together to combine strengths and mitigate weaknesses. If you are ever only using epoxy, I would recommend adding milled fiberglass for body and strength.
I did so much delam jobs on my old 74 H16. At some point i just had enough and bough a newer boat which is solid as a rock. Sometimes its just not worth it.
good stuff, mate. Learned a lot. When you say "fasteners", I assume you're refering to long (about 30mm) coarse-thread screws? I also guess you predrill the hole in the bottom laminate to the screws can bite.
I was using self tapping machine screws. Make sure they are at least 20mm long and you coat them with a PVA mold release. I only drillee through the top laminate to ensure the epoxy didn't just go in and right out into the hull. The self tapping fastener will drill through the other side and grab onto the laminate.
Hey Mate, I am from australia and have recently purchased two catamarans 'windrush 14's" an australian edit of the american trac 14 design I belive. and one has barley any issues besides minor waterproofing with the beam connections. I just wanted to ask your informed opinion when you push down on the outide of the fiberglass on the inboard area of the hulls how much flex shoud there be in the walls of the hull (where you stand to right it after a capsize) I am 200lbs and am worried about breaking the boat in a bad situation if i capsize.
Hey, I just went out a felt a couple of the areas that I did not repair. They do not move at all when I press on them. Listen when you press to see if you can hear the core compressing, it will sounds like crackling. If so, your hulls are definitely delaminated. If you haven't checked out my video on how to map delaminations, I would recommend checking it out as that is a pretty sure fire way to see if you have a structural problem with the boat.
I thought about it, but in the end it is a question of risk vs reward. It could work, but there are multiple factors to consider: access to the inside to put the air bladder, ability to make a air bladder that would fill the entire area, ability to ensure constant pressure, but not too much pressure that you cause additional delamination. With the way I bonded this back together I was able to have better control in all areas than a bladder.
I have a Hobie 18 sx that has some ripples and waffles on the front of both hulls. Structurally the hulls are solid. Is there an email address that I could send u some pictures to get ur opinion of if this boat is worth restoring?
I have done that on all of the other repairs. I have a couple of videos on that process of drilling holes, injecting and pulling the laminate together with fasteners.
There is a Bill of Materials (BOM) in the video description.
I'm in the process of doing this, on the side, and about the same size area. I just cut out the whole piece, then bonded both pieces. Next, I'm going to attach strips of marine plywood, about 3" wide, to the inside of the hull. 11/2", sticks out. The cut out piece, sits on it, I'll epoxy it,, and clamp it. After that, I'll fill in the gaps, then cover the seem, with epoxy and clothe. I've done this before, and it worked fine. Epoxy is stronger than fiberglass, so it's better than new. I tried drilling holes, and injecting epoxy, but only on small areas.
While what you described will work it is significant heavier, more complicated, and can only be used on small local areas. Which is why I chose to drill and fill. Epoxy is not inherently stronger than fiberglass. We use both together to combine strengths and mitigate weaknesses. If you are ever only using epoxy, I would recommend adding milled fiberglass for body and strength.
I did so much delam jobs on my old 74 H16. At some point i just had enough and bough a newer boat which is solid as a rock. Sometimes its just not worth it.
Completely agree. I would only do thus again for smaller areas.
good stuff, mate. Learned a lot. When you say "fasteners", I assume you're refering to long (about 30mm) coarse-thread screws? I also guess you predrill the hole in the bottom laminate to the screws can bite.
I was using self tapping machine screws. Make sure they are at least 20mm long and you coat them with a PVA mold release. I only drillee through the top laminate to ensure the epoxy didn't just go in and right out into the hull. The self tapping fastener will drill through the other side and grab onto the laminate.
@@tridactik Ah, that's kinda what I reckoned you did. Perfect!! Thanks very much. I've got a soft spot on my Hobie 18 so I'll be doing that shortly.
Good luck! I'm jealous of the 18.
@@tridactik yes, it's a great boat, goes well with new sails, but I still haven't cracked 20 knots yet...maybe this summer!
Hey Mate, I am from australia and have recently purchased two catamarans 'windrush 14's" an australian edit of the american trac 14 design I belive. and one has barley any issues besides minor waterproofing with the beam connections. I just wanted to ask your informed opinion when you push down on the outide of the fiberglass on the inboard area of the hulls how much flex shoud there be in the walls of the hull (where you stand to right it after a capsize) I am 200lbs and am worried about breaking the boat in a bad situation if i capsize.
Hey, I just went out a felt a couple of the areas that I did not repair. They do not move at all when I press on them. Listen when you press to see if you can hear the core compressing, it will sounds like crackling. If so, your hulls are definitely delaminated. If you haven't checked out my video on how to map delaminations, I would recommend checking it out as that is a pretty sure fire way to see if you have a structural problem with the boat.
Whaat about using an inflatable air bladder inside the hull to force the core onto the laminate?
I thought about it, but in the end it is a question of risk vs reward. It could work, but there are multiple factors to consider: access to the inside to put the air bladder, ability to make a air bladder that would fill the entire area, ability to ensure constant pressure, but not too much pressure that you cause additional delamination. With the way I bonded this back together I was able to have better control in all areas than a bladder.
I have a Hobie 18 sx that has some ripples and waffles on the front of both hulls. Structurally the hulls are solid. Is there an email address that I could send u some pictures to get ur opinion of if this boat is worth restoring?
Hey Douglas, sorry for the late response. You can send the pictures to me at tridactik@gmail.com if you are still looking for a second opinion.
How much epoxy did you use?
I ended up using an entire quart kit and most of a gallon kit.
that's why they just rotomold them now
why can't you just drill small holes and inject resin with fiber bits mixed in to fill the voids? too heavy?
I have done that on all of the other repairs. I have a couple of videos on that process of drilling holes, injecting and pulling the laminate together with fasteners.