CS23 Build Config: Open Deck / Closed Transom

Power Boats only. Please include the boat type in your question.
TomW1
Very Active Poster
Very Active Poster
Posts: 5844
Joined: Sun Apr 19, 2015 10:57 pm
Location: Bryson City, NC

Re: CS23 Build Config: Open Deck / Closed Transom

Post by TomW1 »

It should all fit, if not you are making some of your overlaps to big. For example, in your last post you mentioned a 172mm overlap. Much to wide when a 148 would work just fine or 156. I did not realize that by going up that far you would not have any overlap on the other side.
Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

rsiedl
Frequent Poster
Frequent Poster
Posts: 55
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

This is what I ended up going with (just finished putting the last sheets on now) but would still love to hear your opinions.

Image
Currently building a CS23...
Build Thread
Technical Q&A

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: CS23 Build Config: Open Deck / Closed Transom

Post by fallguy1000 »

My only comment is that overlaps can replace tapes, so a generalization here would be that you have too much tape/glass on the chines/keel.

If the overlaps are consistent enough, you could theoretically eliminate a tape for an overlap.

Obviously, this is a check with designer issue, but what happens is the heights get big when you tape and overlap same places.

When the stuff cures, take a straightedge from keel to chine at 90 or 45 aft toward bow and see the gap? That will be increased by so many laps on the chine.
My boat build is here -------->

viewtopic.php?f=12&t=62495

rsiedl
Frequent Poster
Frequent Poster
Posts: 55
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

Thanks fallguy.
When the stuff cures, take a straightedge from keel to chine at 90 or 45 aft toward bow and see the gap? That will be increased by so many laps on the chine.
I certainly do see the gap but I'm a little confused. Doesn't the lamination schedule specify a thickness of:

Chine:
- 2 layers biaxial tape each side, staggered 51mm = thickness of 2
- 2 layers fabric, offset edges = thickness of 4
Total thickness = 6 layers
Minus the 2 layers across the hull make for a differential of 4 layers

Keel:
- 3 layers each side, staggered = thickness of 3
- 2 layers fabric = thickness of 2
Total thickness = 5 layers
Minus the 2 layers across the hull make for a differential of 3 layers

I've put on:
Keel: 7 layers - 3 hull = differential 4 layers
Chine: 6 layers - 3 hull = differential 3 layers

So aren't I still in the same position as if I followed the lamination schedule?

(I've actually not put on the final hull layer yet so could I potentially lay that "within" the chines and keel, so still get the added thickness on the hull but not push up the seams?)

And I guess now, how can I address that gap?
Currently building a CS23...
Build Thread
Technical Q&A

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: CS23 Build Config: Open Deck / Closed Transom

Post by fallguy1000 »

The thing is that more overlaps in the same place raise up the seam.

So, your chine shows 7 layers of glass on the bottom edge, less 3 is a differential of 4.

4 layers thickness of db1200 is about 1/8"...

Had you moved the overlaps off the chine; you could have built two overlaps on the bottom; then the chine would have been 4 and the hull bottom 5...Or chine one overlap is 5 and 4 on hull bottom I like better, then you are fairing thickness of 0.030" versus 0.125".

As it is now, you will use more fairing compound, but you did ask for a critique.

what layer is not done? Can you move the overlap off the chine? I would. But if you only have the bottom panel done, not much you can chance cuz you need 2" overlap..unless say a 1.5" overlap gets you lower..

Sometimes things are counterintuitive. 7 layers of glass on the chine is not any better than 4-5..
Attachments
FEB262A3-0C9B-4956-9184-750EC3B29B8B.jpeg
My boat build is here -------->

viewtopic.php?f=12&t=62495

rsiedl
Frequent Poster
Frequent Poster
Posts: 55
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

Thanks fallguy.

The gap is around 3 mm at it's largest.

Image

It's the final layer that isn't done.

I have 100 mm edge at chine and keel that I can overlap onto, is 50 mm enough overlap?

Image

Or is it crucial that this layer also come 150 mm above the baseline? In that case I could do this:

Image

Also, can I build up the gap with more cloth rather than compound (initially)?

Image
Currently building a CS23...
Build Thread
Technical Q&A

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: CS23 Build Config: Open Deck / Closed Transom

Post by fallguy1000 »

Cloth is of little benefit. Once you get to the designer spec; adding cloth is adding weight and expense because fairing compounds are more solids than epoxy. And fiberglass is 1:1. So, adding glass is a bad idea unless it is in a place of certain benefit. A low spot on a keel, for example, could be glass because it'd be stronger than compound. But 3mm of glass and epoxy is a shit ton. You do not have to full fill that and you can fill each edge, but I'd find the angle that makes sense and full fill, personally.

50mm is the minimum overlap for structural elements.

The goal of ending and overlapping is first strength, but never forgetting to minimize fairing. This is why overlaps are often moved off the chines as I stated earlier.

Did you ever look for any hook? I usually ask the larger boat builders to watch out for it.
My boat build is here -------->

viewtopic.php?f=12&t=62495

rsiedl
Frequent Poster
Frequent Poster
Posts: 55
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

Did you ever look for any hook?
Yep, I've been on the lookout for hook and hog from day 1 and pleased to say there is none.
Currently building a CS23...
Build Thread
Technical Q&A

rsiedl
Frequent Poster
Frequent Poster
Posts: 55
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

I have a few little areas with "blistering" beneath the glass.

Image

Can anyone suggest a good way to deal with this?

The rest of the lamination looks good.

Image
Currently building a CS23...
Build Thread
Technical Q&A

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: CS23 Build Config: Open Deck / Closed Transom

Post by fallguy1000 »

Those bubbles suck. They are caused by not enough work with a quality consolidation roller.

Any areas of air on the bottom and bottom edges to waterline need special attention because they can delam under extreme water pressure from waves and speed or both.

Any areas should be ground out and repaired or injected after drilling two holes with the perfect sized blunt needle.
My boat build is here -------->

viewtopic.php?f=12&t=62495

Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests