Replacing wet balsa core

[minaret]

Originally Posted by phorvati

Im very pleased how the coosa and corebond came out. Deck is already very strong and i am yet to start the top skin.

Yup, that won't rot again, ever. Nice permanent repair.

[phorvati]

Originally Posted by sneuman

You need to keep things in perspective. Why did the balsa rot? Because the deck hardware was not properly bedded. How long did it last even without properly bedded hardware? How long do you expect to keep the boat? So, what if you get a fancy (and very expensive) coring material and water gets in ... you will still have water in the sandwich, it just won't rot said fancy (and very expensive) coring material. Don't waste $$. Use balsa again, but do it right this time. Btw, I re-cored my entire deck and so have some experience with this!

You wont have wet decks where coosa is the core. because core is closed cell foam impregnated with woven roving and does not retain water. What you're saying is true, if you get rid of the root cause, balsa will stay dry. But it gets more complicated. Boat design and how you use it as well as latitude has a lot to do with the root cause. Water and ice will eventually win, especially if you are in northern climates and do not shrinkwrap every year. And balsa is like a sponge, it holds water and rots.
In terms of my boat, many aspects of the design were contributing to the root cause. I had no deck drains and toerail makes a nice dam so water accumulates. All this makes the problem that much more difficult to deal with. I Re-beded all deck hardware back in 2004. Also I re-bed genoa track and windows on a regular basis, 2009, 2012, etc.. So in my experience, water will get in. And i live on the boat 6 months out of the year so I see things on a daily basis. Imagine if I was a typical owner that goes on the boat once per week or once per month. So yes you can re-core with balsa but batter make sure (1) boat design is sound so that design flaws are not contributing to water ingress, (2) stay away from winters like we have here in NE. For instance rain/sleet in the afternoon then by midnight its 0F. Also, make sure you chase down every gelcoat crack, 'cause they will let water in as well, and same cracks will get worse at 0F. Or just re-core with something not susceptible to water ingress so there is no where for water to accumulate. That amount of coosa, 13'x1' area is about 100$. Now that i've worked with it, I'll spend that especially if i'm spending 100s of hours in labor.

[minaret]

Exactly. Most boat work 90% of the cost is labor. So use the very best materials.

[malbert73]

Originally Posted by minaret

Exactly. Most boat work 90% of the cost is labor. So use the very best materials.

Hmm. Any boat building companies hear this?


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[minaret]

Originally Posted by phorvati

You wont have wet decks where coosa is the core. because core is closed cell foam impregnated with woven roving and does not retain water. What you're saying is true, if you get rid of the root cause, balsa will stay dry. But it gets more complicated. Boat design and how you use it as well as latitude has a lot to do with the root cause. Water and ice will eventually win, especially if you are in northern climates and do not shrinkwrap every year. And balsa is like a sponge, it holds water and rots.
In terms of my boat, many aspects of the design were contributing to the root cause. I had no deck drains and toerail makes a nice dam so water accumulates. All this makes the problem that much more difficult to deal with. I Re-beded all deck hardware back in 2004. Also I re-bed genoa track and windows on a regular basis, 2009, 2012, etc.. So in my experience, water will get in. And i live on the boat 6 months out of the year so I see things on a daily basis. Imagine if I was a typical owner that goes on the boat once per week or once per month. So yes you can re-core with balsa but batter make sure (1) boat design is sound so that design flaws are not contributing to water ingress, (2) stay away from winters like we have here in NE. For instance rain/sleet in the afternoon then by midnight its 0F. Also, make sure you chase down every gelcoat crack, 'cause they will let water in as well, and same cracks will get worse at 0F. Or just re-core with something not susceptible to water ingress so there is no where for water to accumulate. That amount of coosa, 13'x1' area is about 100$. Now that i've worked with it, I'll spend that especially if i'm spending 100s of hours in labor.

How did you like working with Corebond? Did you get the BPO hardener or did they tell you to use MEKP?

[phorvati]

Originally Posted by malbert73

Hmm. Any boat building companies hear this?

I feel that boat building is different from repair. On a production boat in a factory, I can see how they try to save money on materials cause everything is streamlined. Doing repairs on your own boat, is all about labor hours. Especially if you have no time, or dont want to do it again in your lifetime.

I used MEK. Like I said, coosa is great. I was able to get in two plys of 1708 biaxial last night. Rolling out and wetting 4 plys is a job for more experienced or at least those with helpers. Getting two of them was challenging enough. peelply helped a lot.

[Scott Fuller]

Some photos of the final deck prep (forgot to take photos of the hours of fairing and longboard sanding that preceded it) which involved spraying gelcoat under the stanchions and across the deck to the cabin top, then masking everything for the KiwiGrip. Got the deck sections done yesterday, and finished up the foredeck today!

[seahag]

Great looking work Scott.

Did you ever live in Brookfield? I went to school there with someone who had your name.


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[Scott Fuller]

Originally Posted by seahag

Great looking work Scott.

Did you ever live in Brookfield? I went to school there with someone who had your name.


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Yes I did - but I don't recall a Seahag?

[Stumble]

Originally Posted by malbert73

Hmm. Any boat building companies hear this?


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Sure they have, but how much more for a boat do you want to pay? Bob Perry mentioned that his new 44' carbon full keel cruiser costs about $50,000 more being built in carbon fiber/epoxy than if the boat was built in glass. For that extra you get a substantially better boat, but so what, most Beneteaus simply can't justify the extra cost.

Once mainline builders start installing proper sized winches instead of using ones that are too small to shave $500 off the cost of the boats then we can talk about using the best materials. But boat buyers are cheap and don't want to spend even that little bit extra.

Cast iron keels are just stupid, but they save thousands over using lead. But try to convince all those iron keel owners that...

[SV.Maverick]

Speaking of core that would never rot how about starboard?

[Cheechako]

Starboard doesn't bond well and is very heavy.

[BigSmile]

Originally Posted by phorvati

I feel that boat building is different from repair. On a production boat in a factory, I can see how they try to save money on materials cause everything is streamlined. Doing repairs on your own boat, is all about labor hours. Especially if you have no time, or dont want to do it again in your lifetime.

I used MEK. Like I said, coosa is great. I was able to get in two plys of 1708 biaxial last night. Rolling out and wetting 4 plys is a job for more experienced or at least those with helpers. Getting two of them was challenging enough. peelply helped a lot.

Meant MEKP, right?

[phorvati]

It's the hardener for polyester. There is a P in there for peroxide. I realized I never shared the after photo. Spring and summer just took off on me. It's so short up here in NE. I had some hard sails to wind with 150% genoa all along this track. So far no signs of any flex or cracking

[phorvati]

It's a bit dewi this morning.

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