Reglassing 50' cat hull bottoms - overhead?!

[tevake118]

What is the existing lamination schedule on the bottom of your cat?
It just occurred to me that we have not asked you WHY you are doing this.
Did you have rampant osmosis, and you had to grind away a lot of bad fibreglass? Or something else?
Can you post a photo or two of the cat, and her bottoms please?

I used only one layer of 17 oz biax over much of the original ply skin, so am adding 3 more layers, for a total thickness of 3/16".
The design is my own, built from scratch, based on my first cat, built from plans, and lived aboard and sailed from Europe and thru the Caribbean. Then worked repairing wooden boats for some years.
I have always known that using my own ideas would require me to view this project as a prototype - improve by doing, and doing over, until it works.

 

[bajansailor]

Some photos would be very useful tevake - they are not difficult to post really.
To the right of the 'Post reply' box in the bottom right corner of where I am writing is a box called 'Upload a file' - if you click on this, you can then select a photo (or some photos) from an album on your computer or phone.

 

[fallguy]

I am guessing you have delamination? But the delam is where? So if you have delam; it needs to be removed first...

If not delam; then what is driving the decision to add glass? Just watching the hull flex or hearing it in rough seas? Or getting abrasion?

I have wetout 34' sections of triaxial glass 3' wide or so on table. I used tropical epoxy, 2 hours set time, in a controlled environment, best time took 3 people 73 minutes to close the bag to wetout, add core, wetout, add peelply, bleeder and breather. You cannot wet bag this job!!! 73 minutes was flyin, one slow guy. You will run into gelation unless you have 2 pros or tropical and outside you are in trouble. So forget bagging it unless you infuse. There is no time. My 73 minutes was 2 pieces of glass and core, but table top conditions and two tables, setup perfectly. Resin batches for bottom and tops of all 4 pieces prepped, etc. All efficiences were maximized. My only weakness was one guy of the 3 was slow, but me and the other fast guy were flyin.

You will probably run into trouble hand laminating it...sorry to say... maybe say 15 minutes to wetout on peelply and visqueen, 15 minutes to move, 15 minutes to consolidate...it is going to he close even at half wides. Things like rolling on the dirt add so much time...trying to move the large piece without making a dirty mess of it....

I still think you ought to consider infusion. It is scary, but clean work. Someone here will probably even put it into a model for you for the layout.

I have epoxy derma allergy..the crap will be splashing in eyes even consolidating without goggles. Like Jeff said, lotsa suits needed.

Glue the glass on with 3M spray adhesives, and seal the bag, and pull the resins with a pump. Whole job done in a few days, no mess, no epoxy dripping in eyes, maybe one ty suit for spraywork.

Just think how good you'd feel gluing up the glass, then putting the bag on and fixing leaks for a day and the next day pulling the resin.

My whole boat, if I started today, would be infused, even a panel at a time..

 

[bajansailor]

And this is said after thousands of hours of experience. Please take heed of Fallguy's suggestion.

 

[rwatson]

I am guessing you have delamination? But the delam is where? So if you have delam; it needs to be removed first..
If not delam; then what is driving the decision to add glass? Just watching the hull flex or hearing it in rough seas? Or getting abrasion?.

No, he explained it in an earlier post. "I used only one layer of 17 oz biax over much of the original ply skin, so am adding 3 more layers, for a total thickness of 3/16"."

I have wetout 34' sections of triaxial glass 3' wide or so on table. I used tropical epoxy, 2 hours set time, in a controlled environment, best time took 3 people 73 minutes to close the bag to wetout, add core, wetout, add peelply, bleeder and breather. You cannot wet bag this job!!! 73 minutes was flyin, one slow guy. You will run into gelation unless you have 2 pros or tropical and outside you are in trouble. So forget bagging it unless you infuse. There is no time.

Huh? Have you never heard of slow hardeners.

 

[fallguy]

Of course. But I don't believe he could do it in 60 minute gel time.

I'm still trying to understand how he arrived at needing 3 more layers of glass, that decision seems arbitrary.

 

[rwatson]

Of course. But I don't believe he could do it in 60 minute gel time.

I'm still trying to understand how he arrived at needing 3 more layers of glass, that decision seems arbitrary.

Its a bit obvious, to me. and you already spotted it
"Just watching the hull flex or hearing it in rough seas? "

"I used only one layer of 17 oz biax over much of the original ply skin, so am adding 3 more layers, for a total thickness of 3/16"."
thats
" Biaxial, 17 oz. .035" , not even ONE MILLIMETRE

Even now, he is going to end up with less than 5mm, which for a 50 foot catamaran, is ridiculous.

My Kayaks start with 5 mm ply, and have 6 oz on either side.

He is in real trouble.

 

[fallguy]

Its a bit obvious, to me. and you already spotted it
"Just watching the hull flex or hearing it in rough seas? "

"I used only one layer of 17 oz biax over much of the original ply skin, so am adding 3 more layers, for a total thickness of 3/16"."
thats
" Biaxial, 17 oz. .035" , not even ONE MILLIMETRE

Even now, he is going to end up with less than 5mm, which for a 50 foot catamaran, is ridiculous.

My Kayaks start with 5 mm ply, and have 6 oz on either side.

He is in real trouble.

Did he ever cite the ply thickness? I missed it if so. There are boats made of ply and no sheathing.

 

[wet feet]

Which leads on to asking what ,if any,sheathing was applied to the inside.