Replacing Large Areas of Wet Hull ?

[DIY1111]

Looking at a valuable sailboat that I can buy for a bargain price due to wet core ( for the DIY'er ). I have not seen the boat yet and am doing my pre-work to assure its not more than I bargain for.

It has quite a bit of hull and deck delimitation with end grain balsa the composite material. I have done quite a bit of this type of work ( and always swear I'll never do it again ). I believe the hull delam to be extensive - 4' - 5' per side. And, in order to not remove the interior, I am contemplating doing the hull from the outside - something I have not done.

What are the pitfalls and where can I read up on this process ?

My first pass is that I would make a mold of the hull near the delam area. Then, cut outer gelcoat and skin off - remove balsa, re-bed with balsa or other material. My question - what is the simplest way to ensure I can bring the outside skin back to its original shape with minimal faring ( I was hoping the skin mold would help ) ?

Looking for someone who has 'been there, done that'. Your advice is appreciated.

 

[Scott Danforth]

replacing the core from the outside is common.

there is no such thing as minimal fairing. however if you do a good job with the core and you bag the outside, you will have close to minimum fairing. no need to try to make a mold. that is 4x the work and you still have the fairing.

cut the exterior skin off
remove the wet balsa core
blend the cut
prep the inside skin
apply core bond and core
bag the core (to hold constant thickness
apply 3-4 layers to the outside and bag it
sand the high-spots
fair as needed
spray gel
sand gel
polish gel
go boating

 

[kcassells]

Iboats should make a thread for "Thinking about buying a boat with problems, need help before I buy." Cause these threads typically go nowhere in this forum.
Million replies based on no real info, no pics, no definition, no replies from poster, then a walkaway. etc.

 

[DIY1111]

Scott - thank you. Sounds good !
KCass - would you like to add input. I could use your expertise.

 

[kcassells]

DIY, try tp put up some pics. That helps a lot to make suggestions.

 

[DIY1111]

I don’t own boat yet. Doing research before I commit. It’s a sailboat and the actual balsa damage is unknown but I suspect it’s 4-5’ on each side of the hull - down toward keel. It’s a big job. But, if do-able, could be a sweet deal. Going from inside seems like a real hassle due to finished interior components tabbed in etc.and the potential of bad core below the sole Damn shame to go from outside as it’s in really nice shape ! Catch 22...

 

[kcassells]

Make, model, year isabled to be googled and pics should be available that way. Maybe it can be decapped and approach repair that way.

 

[Scott Danforth]

I don’t own boat yet. Doing research before I commit. It’s a sailboat and the actual balsa damage is unknown but I suspect it’s 4-5’ on each side of the hull - down toward keel. It’s a big job. But, if do-able, could be a sweet deal. Going from inside seems like a real hassle due to finished interior components tabbed in etc.and the potential of bad core below the sole Damn shame to go from outside as it’s in really nice shape ! Catch 22...

sail boats are commonly repaired from the outside

start looking at sail boat forums and you will see that.

on really large boats, sometimes they do a hot-vac treatment followed by an injection of epoxy which buys a couple of years.

 

[kcassells]

Google sailboat hull repair/vids
As an example;

https://www.bing.com/videos/search?...os/search?q=sail+boat+hull+repair&FORM=HDRSC3

 

[DIY1111]

This is a rich mans sailboat - which I am not. So, the work is not typically a DIY'er thing - they pay to have it repaired. So there are no repair pix online regarding his hull. As a reference, I own a small pedigreed classic fishing boat - the amount of resto and repair info online is staggering - not so with this sail boat hull.

Since my post, I have done a lot of research. Any repair can be done. Hull repairs can be done from the outside and inside. Both have their pro's and cons. It really boils down to the amount of wet there is and what I'm willing to commit to get the job done.

The areas of wet on the hull are at least as large ( or larger than ) 3'x5' on each side. And, in my experience - it'll be worse than what is expected... Damn shame !

 

[Scott Danforth]

now you know why fiberglass boats have a 15 year life expectancy and are replaced. many sail boats have a slightly longer design life, however we are talking 20 or 25 years unless you get into the 30+ meter range then you are looking at a 50 year design life with a re-fit ever 5-10 years on most on-board equipment.

boating is the worlds most expensive hobby. I spend more on boat maintenance out of pocket per year than my buddy does racing - granted he has sponsors, however you get the point.

In post #1 you claim this is a valuable sailboat. yet in post #10 you seem reluctant to spend money to repair it.

 

[todhunter]

boating is the worlds most expensive hobby. I spend more on boat maintenance out of pocket per year than my buddy does racing - granted he has sponsors, however you get the point.

Don't tell my wife that. I just finished my race car and felt like picking up a boat project.

 

[Scott Danforth]

if your wife watches your finances, she will catch on quickly.