repairing hogged hull......

[alws55]

We have a 1958 17' Lyman.....I'm having trouble controlling her while underway.The hull is definitly hogged, it looks to be symetrical, from the transom to the knee it seems to be an inch or less difference by the time you get midway.

My plan is to put the trailer on stands, adjust the rollers so they are inline. I've adjusted them up to meet the keel for even support while trailering. Then apply 600 to 800 lbs in the form of water in 3 30 to 40 gal. trash cans on a 3x6 pc. of 3/4 plywood.I'd ptobably take measurements before and gradually add water as not to try to regain uniformity all at once. I'm anticipating 3 to 4 months. Any comments pro or con are greatly appreciated. Here is a link of some pics I restored the hull on a 1958 161/2 last year, this summer I took the finish down on the 17 till uniform, faired it out & painted by roller & foam brush.

boat pics (http://pak04.pictures.aol.com/NASApp/ygp/Login?event=ViewFilm&filmId=37381.1076.1118574516896.1&locale=en_US)

[pcford]

Thompsons and Lymans are lightly built boats and often suffer with symptoms that you describe when stored on inappropriate trailers. Roller trailers kill these boats. Also, the boat is sometimes left with the transom unsupported on a trailer with the weight of the engine pushing it down. It will develop a nasty hook which will cause porpoising at speed. Typically if the hook is in the last 3 or 4 feet, I have had luck installing on a client's boat a bronze framework to force the bottom down into place. I infer that your boat hogged a long way down the keel. I have not seen an example like this. However, it might be possible to put a stiffener down the keel, say a 5/4 x 5" white oak on edge. (?)
I am dubious that you can warp the bottom back the other way with your plan.

[ahp]

Many years ago at a Mystic Show-and-Tell someone described how they removed hogging from a hull simply by supporting at the ends and filling part way with water for seversl months. He claimed it worked although its sounded drastic. I don't recall the boat. It was not a Thompson or a Lyman.

[Victor]

IIRC someone said correcting a hog this way will probably open up the seams and shorten the life of the hull. Better to jack up the stern whenever the boat's not in use. At least it won't get worse, and it might get better.

[Bob Adams]

I straightend out a Gar Wood by turning her over and supporting her with a strongback. Took a while, but it worked.

[alws55]

Thank you for your replies.....much appreciated...

[Bob Smalser]

Originally posted by pcford:
Thompsons and Lymans are lightly built boats and often suffer with symptoms that you describe when stored on inappropriate trailers. Roller trailers kill these boats. Leaving the boat on a badly-adjusted trailer with cover on and drain plugs in....having it fill with rainwater after the cover fails....and not discovering the problem for anywhere from several weeks to a year, can hog a boat in a nice, neat, one-shot deal.

[ 09-21-2005, 09:52 AM: Message edited by: Bob Smalser ]

[Jay Greer]

One thing to consider with a hogged hull is that as the ends drop, the hull narrows as a result of deck beams crowning up slightly. Remember that is some thing is moving in one place there must be movement of other components to permit the hogging. This is the reason for such components as hanging knees, structural bulheads, compression and tie rods. Blocking the ends up and the midships area down in conjunction slightly spreading the hull and adding structural strengthening members under the deck and strenghtening the cockpit
combing can save the expense of reframing the entire deck. As has been mentioned already, Lymans are lightly built.

[alws55]

BoB.........I believe thats exactly how it developed this problem....

I talked top a fellow today, he recommended to cover the bilge with a few inches of water for a few weeks. Then drain and apply steam by pumping under a tarp covering the affected area or turn the boat over to let it rise for ??? hours then apply weight or resistance.

Any feedback on this??....thank you for you comments and ideas !!