How to repair cracks in Livingston hull

[kinaiahi61]

Re: How to repair cracks in Livingston hull

Thanks again y'all!!! Hope to get to it some time next week. I might need to cut the top layer off the middle hump. Looks like there's all water in there, and I think there's some type of wood in there that might be no good. Is this a good idea or just create some drain holes and glass over everything?

 

[Yacht Dr.]

Re: How to repair cracks in Livingston hull

Any advice on joints of fabric. From what I've read long triangle joints are better than butt and overlaps, is this true? Also is there a correct way to lay the knitex in relation to layering and in relation to the weak spot or crack? Should the direction be changed after the first layer to add more directional strength? Or since its stitched just layer the same direction? Thanks

Butt joints just are not a good idea in fiberglass repairs.. you need an overlap. I have never heard of triangles but I can understand the concept behind it. 1708 is a clean cut cloth .. meaning you cut your cloth to the size and pattern that matches dimentions of the repair. However some drawback to this application would be hard edges for you to roll out in its final application ( mat side down and cloth side up ).

Your 1708 will give the best orientation for the fibers, you could lay one the other direction if you wanted, it may help a little.

The first layer of CSM helps, the rest add nothing to the bond strength. If doing multiple layers at one time the mat stitched to the fabric is sufficient (they designed it to work that way). The final mat does nothing but possibly give you a better surface profile depending on what you want it to look like.

If the resin was cheap the extra mat wouldn’t make a difference, wouldn’t help much, but wouldn’t hurt either.

In reality .. the final 1.5 oz mat will give you better working conditions when trying to roll out the glass for the final layer. So I would suggest that the final Mat does more then Nothing. 1708 is a pain to roll out when the woven side is up and the mat side is down. The woven just does not do a good job to hold in the resin ( think suction cup ). Another thing to consider is your Fairing. If you Ever have to sand on the final lam .. then it best be CSM .. or you just sanded through a few strands ( or all the way through the material itself ) to get your shape. Now if you sanded through or into the strands of biax .. then you already corrupted the integrity of that lam.

I suggest the final layer of CSM to Hide the woven look of the CSM showing on the outside of the hull. Of course by the time you use fairing material it may not be an issue. It will use more resin and as ondarvr not add much to the strength so it's totally up to you. I DO think that applying CSM as the initial layer to bare glass prior to the 1708 gives you a much better bond than the thin layer of CSM that is stitched to the CSM. Again Just my opinion and ondarvr has MUCH more experience than I do. Your boat, your decision. Either way will work just fine an yield acceptable results.

I would hope there is not too much "fairing material" .. normally you can get back to Fair using glass and resin. Sure its harder to Fair out.. but its better then puttying 1/4" lows in the repair ( Im not suggesting that Woody suggested that ). Fairing compound should only be used to fill Very low spots. If you can feel it with your hand then you should consider putting some mat/resin lams to fill those areas.

My below waterline repairs are done in All Glass/resin. I dont suggest using any fillers below the waterline in large repairs. Just me though..

YD.

 

[ondarvr]

Re: How to repair cracks in Livingston hull

In reality .. the final 1.5 oz mat will give you better working conditions when trying to roll out the glass for the final layer. So I would suggest that the final Mat does more then Nothing. 1708 is a pain to roll out when the woven side is up and the mat side is down. The woven just does not do a good job to hold in the resin ( think suction cup ). Another thing to consider is your Fairing. If you Ever have to sand on the final lam .. then it best be CSM .. or you just sanded through a few strands ( or all the way through the material itself ) to get your shape. Now if you sanded through or into the strands of biax .. then you already corrupted the integrity of that lam.
YD.

Kind of what I said, "The final mat does nothing but possibly give you a better surface profile depending on what you want it to look like." Odd isn't it.

 

[kinaiahi61]

Re: How to repair cracks in Livingston hull

If I cut the top layer off to get the water out and possibly the rotted wood, how much more layers are needed to be put back in addition to what's already suggested above?

 

[Woodonglass]

Re: How to repair cracks in Livingston hull

Not sure I understand " Cut the top layer off"?? Do you mean inside the boat?

 

[kinaiahi61]

Re: How to repair cracks in Livingston hull

Not sure I understand " Cut the top layer off"?? Do you mean inside the boat?

Yes. It seams that there's two layers. The outside is one layer, above that is a thin section of wood, and the inside is another layer of fiberglass. I don't know if this was their way of reinforcing the middle hump? There are usually little center consoles or things of the like that are mounted here. It looks like the inside and outside sandwich that piece of very thin wood. In any matter, is it better to cut out sections of fiberglass that water has penetrated beneath? Or is it better to drain, by cutting drains or drill holes then seal? I figured that the material will stay wet, and won't be able to dry if the fiberglass isn't removed, causing the materials to rot. I also believe that this runs to the transom and will eventually ruin the transom. Thank you:joyous:

 

[Woodonglass]

Re: How to repair cracks in Livingston hull

Never worked on a Livingston Hull. ondarvr has. He will prolly be along to advise. Sounds like the hull may be a wood or balsa cored hull. If so, that's another kettle of fish for doing a repair. Let's see what he has to say.

 

[Yacht Dr.]

Re: How to repair cracks in Livingston hull

Yes indeed it does sound like some kind of core .. got any more pics to show whats going on ?

YD.

 

[ondarvr]

Re: How to repair cracks in Livingston hull

Since the inside of the boat is a glass finish and not a mold finish, you can easily cut the top off the hump and remove the wet rotten wood .
Clean the old stuff out and replace it, then set the piece you cut off back in place and glass over the whole thing .

 

[Yacht Dr.]

Re: How to repair cracks in Livingston hull

Since the inside of the boat is a glass finish and not a mold finish, you can easily cut the top off the hump and remove the wet rotten wood .
Clean the old stuff out and replace it, then set the piece you cut off back in place and glass over the whole thing .

Im not sure if you have that correct .. Im sure the deck is a Mold finish.

You would have to cut the deck liner to get to the hull from the Inside .. I would think.

YD.

 

[kinaiahi61]

Re: How to repair cracks in Livingston hull

Ondarvr is right. There's a glass finish on the inside. Should I replace that very thin layer of wood or go all knitex? When I redid the floors the wood in there were just thin pieces of what looked like mahogany door skins about 4 inches wide overlapped on each other. They didn't look very structural to me. These hulls are thin!!! Thanks again for all the input. I like to have things planned out prior to doing he job.

 

[ondarvr]

Re: How to repair cracks in Livingston hull

Some used cardboard (mine do), so even thin wood is better than that.

You could replace it with wood, but I would try to find some foam, or like you said, skip the core and just use glass. A slightly thicker core will increase the stiffness, but it will create more stress on the radius, which already cracked due to flex in the two hulls, so this area will need to be strengthened slightly more too.

 

[ondarvr]

Re: How to repair cracks in Livingston hull

Located on the island of Kauai in Hawaii. Resin is $55 a gallon and 1708 is close to $20 a yd. shipping to Hawaii is usually not worth it so we need to just pay the price. What weight CSM would you recommend? Thanks for the help. Aloha

I did some work on Kauai, it was somewhere near Kuamakani, I wasn?t there long enough to do much looking around though. I had to ship in all my supplies ahead of time.

 

[Yacht Dr.]

Re: How to repair cracks in Livingston hull

Im sure the deck is a Mold finish.

You would have to cut the deck liner to get to the hull from the Inside .. I would think.

YD.

Ondarvr is right. There's a glass finish on the inside. .

So the Deck is just Raw glass ? .. or is it a finished surface ( out of the mold kinda thing ).

Got pics ?

YD.

 

[Wind dog]

Re: How to repair cracks in Livingston hull

Shouldn't holes be drilled at the end of each crack before the repairs are done? To stop the cracks from growing?

 

[ondarvr]

Re: How to repair cracks in Livingston hull

If you are leaving the cracks in place, then yes. These cracks are being sanded out before repairs are done.

 

[kinaiahi61]

Re: How to repair cracks in Livingston hull

What kind of work? That's pretty cool that you've been here. Most people just say they would love to come here. So I should put something back in, thus allowing it to flex. Or could cloth be used or something besides knitex to make a all composite middle that flexes. Therefore no rot down the road? We have a Home Depot and some hardware stores so I could put wood back if thats best. Thanks again

 

[ondarvr]

Re: How to repair cracks in Livingston hull

I've been there a few times, we built drip irrigation filtration systems and put in many on several different islands. Whether you use wood, glass or foam isn't going to make big difference, adding the extra glass to the high stress areas is what's going to help.

 

[kinaiahi61]

Re: How to repair cracks in Livingston hull

What would be the recommended way to fair out the outside. The repairs done last time were very difficult being under the boat. I used cabosil, and chopped fibers. But being that its laminating resin, do I need to add surfacing agent to sand it good. It ended up just clogging the paper last time without the agent. If I do add surfacing agent, what do I need to do to add gelcoat or another layer of glass over this last layer? Thanks

 

[Yacht Dr.]

Re: How to repair cracks in Livingston hull

Bump for ya.

YD.