trying to fix a sagging strern?

[arhhboat]

Workn on a 19' mako 1970. Just finished cutting out the floor. I am replacing the stringers this weekend coming up. For a year and a half This boat was on a 15ft johnboat trailer. It was a sad sight. I now have it on a proper trailer for my project.
The Problem is that with the stern not being supported on the back of the trailer, it now sags even with stringers removed and a jack underneath the back. Anybody know a technique to cure this? The sagging stern really ruins the handling of the boat and drives the bow into the water when hitting a wake which almost stops the boat completly. Really need to correct!

 

[Bondo]

Re: trying to fix a sagging strern?

Ayuh,... Now would be the time to fix that Hook ya got...

To do it, you'll have to jig it up,+ push, pull, whatever to bring it back to True...
Then do your stringers,+ whatnots,... They'll hold it where it otta be after you release the jig...

 

[CheapboatKev]

Re: trying to fix a sagging strern?

Welcome aboard!
Wow it seems like ya have a major project there that I do not think is fixable easily if at all..Why wouldn't somebody support the stern?? Mind boggling what happens to boats and their PO's..

The only thing that comes to my mind is removing the entire area that is sagged..I guess a chainsaw across the last couple feet would give ya a 16 or 17 ftr..

I'd walk away myself...

Best of luck to you in whatever you choose.

 

[BobsGlasstream]

Re: trying to fix a sagging strern?

arhhboat,
Welcome to Iboats.
I am by know means a expert. I have read other threads here and the one constant I have seen to fix your problem may be to run some bracing along the bottom of your boat and on the inside. Use the bracing to force the bottom back straight.
I would assume that with the stringers out it would sag worse because the stringer are the longitudinal support for the boat. I would also think you would want to extend you bunks to support the stern when the boat is on the trailer.
Use the search function to find other threads of similar repairs. I seen some folks refer to it as a hook in the hull.
Good luck with the rebuild. I hope this helps.
Bob

 

[jonesg]

Re: trying to fix a sagging strern?

The way to fix warped glasswork is with HEAT,
halogens should do the trick if you allow enough time, it will need to be indoor or tented and warm ambient surrounding it, heat and bracing to push it back into shape, then install the stringers to lock it in place.

Think 2x4 cross braces from gunnel to gunnel (underneath), then a couple of bottle jacks pushing the hull down, use plywood pads to spread the pressure where you need it. Get the glass VERY warm and start pushing, allow more heat and increase the pressure after a few hrs, let time/heat do the work for you, only push as much as the flex will allow to prevent cracking.

Let it go cold and see if it holds position, then double check and slap the stringers in place.

Had a freind who imported polyester glasswork from China, after months in a container ship baking under the sun we saw a lot of warped peices, slow heat always worked to bring them back, usually without applying any pressure at all. 4 hrs was good but you have more mass so it might take overnite.

 

[arhhboat]

Re: trying to fix a sagging strern?

To late to walk away and I love a challenge. I'm liking the heat idea. I have an idea of tryn to strap the boat down in many spots to the trailer along the bow and mid section then trying to raise the stern slowly with a jack while applying heat from a few work lights underneath. Thanks for the help, i'll put up some pics of progress tomorrow night. Ive been documenting the project and am going to start a 19'mako project thread.

 

[Gary H NC]

Re: trying to fix a sagging strern?

Is the transom rotted too?