1990 C-Hawk 18 rebuild

[jeffrey.bean]

Hello all,

I picked up a 1990 Chawk 18 this past spring as a project boat.
The below deck fuel tank was shot, transom was wet and debonding, the deck core was saturated. The stringers don’t seem to bad, but I want to raise the deck 1-1/2”, so it self bails, so I plan on redoing them as as well. I have a 4 stroke, and with the weight of that and all soaked wood and foam, I have to plug the scuppers, while on the water.
I’ve never rebuilt a boat from the stringers up. I found this site, and followed another Chawk rebuild, lots of great knowledge and help.
The engine has been removed, waiting on help to pull the top cap off.
One question I have at this point, my boat sits on a roller trailer. I understand that I shouldn’t redo the stringers while on the trailer due to deforming the hull. How should I block it up and assure the hull is in proper shape before installing new stringers?
Thanks Jeff

 

[88 Capri (2022 SOTY)]

I didn't have the space to build a cradle so I supported the hull where I assumed it wouldn't flex but, in my rebuild I didn't remove the cap so I'm not sure it would be suitable for you.

I can say that it had been said take measurements on everything and possibly bracing so your sides don't splay when cap is removed.

If you search the forum I'm sure you'll find alot of threads on this subject and read the stickies at the top of the forum for excellent information on rebuilding your boat.

 

[jeffrey.bean]

I’ll probably go your route, and just support it the best I can.
Thanks

 

[jeffrey.bean]

Decided to block her up, now the dirty work begains

 

[jeffrey.bean]

Picked up a piece of 3/4” Coosa, made the template for the transom.
I’m gonna see if my poly tent around the boat will get me up to 65°+, if not, guess I’ll be on hold till temps come up.

 

[jeffrey.bean]

The 3 stringers in the center are double 3/4”, the outer ones are 3/4”.
Can I make the 3 center ones 3/4, or should I stay with the original thickness?
I plan on changing the layout of the stringers, by removing that dog leg, and having the 3 center ones, straight from bow to stern.
From P to S, it measures 5.5’
I’ll be using marine ply, probably glassed with chop and 1700.
Thoughts???

 

[zool]

IMO, its always better to overbuild from factory specs, than underbuilt.

Whether you hull was designed by an naval architect, or drawn on a cocktail napkin, an engineer most likely signed off on the design.

Production boats were usually built with cost savings in mind, so if 3/4 would do just fine, they would have probably went with that.

 

[jeffrey.bean]

IMO, its always better to overbuild from factory specs, than underbuilt.

Whether you hull was designed by an naval architect, or drawn on a cocktail napkin, an engineer most likely signed off on the design.

Production boats were usually built with cost savings in mind, so if 3/4 would do just fine, they would have probably went with that.

I was reading through another rebuild thread ( same boat as mine) and he did them all in 3/4”.
I like your thinking though.

 

[zool]

You have to consider length of the stringers. If more than 8', you will either need to scarf, or sister. The clearspan strength of plywood is stronger, so if the originals are dimensional lumber, then maybe the 3/4 ply is close to 1 1/2 dimensional.
Its easy enough to stager 3/4 ply overlapped by 4 foot at a time, to get the required length, so i dont see the risk being worth it, but that could just be me.

 

[jeffrey.bean]

You have to consider length of the stringers. If more than 8', you will either need to scarf, or sister. The clearspan strength of plywood is stronger, so if the originals are dimensional lumber, then maybe the 3/4 ply is close to 1 1/2 dimensional.
Its easy enough to stager 3/4 ply overlapped by 4 foot at a time, to get the required length, so i dont see the risk being worth it, but that could just be me.

Completely agree with you.
The original stingers are all 3/4 ply sistered together.

 

[zool]

In order to get the length, even at only 3/4, you would need the same amount of plywood at double 3/8, the cost savings is just not there. The other thread where they used only 3/4 may have just used butt joints, which is not a good choice and would probably lead to stress cracks from pounding under way. Do it right once and have piece of mind.