Survey is done....not too bad but...more sister frames to put in...

[DiverDan]

Well, had my first survey of my 1970 32' Hankins that I am refitting for diving. I got her last fall, and have been repairing/rebuilding her all winter long. Finally got a survey yesterday to make sure I was addressing everything before I go back in the water.

Well.... I had missed a few things. Mainly, the fuel tanks were not propperly tied down, and quite loose. This is an easy fix, and only requires pulling half the aft deck...

The other major concer is with the frames/ribs aft of the engine. Many of them are either rotted, or starting to rot. There are quite a few sister frames already present, but still need to put quite a few more in. I plan on sistering in more frames from laminating in 1/4 ply. I know I should replace all the original frames, but except for the area where the crack is (turn of the chine) they are in fine shape and the fasteners are strong. So should the sister frame be right up against the old frame, or inbetween the two? The construction is Cedar Lapstrake over Oak frames.

Thanks,
d

[nedL]

Dan, The norm is to sister right next to the original ribs. I might add (if I saw your pics. correcty)that the norm for fastening sisters is to fasten throught the plank laps, just like the original ribs.
Also, on you fuel tanks (maybe the surveyor checked this) when you are done reseating them & fastening them down you should make sure there is an electrical grounding wire that runs from the metal fuel fill tube/cap at deck level down to the metal tank (to electrically connect the fuel fill to the tank, usually there is a piece of flexable hose in there somewhere). You want to do this because there is a fair bit of static electricity generated while fueling up & there can be a spark created if things aren't grounded. Though not as much of a problem with diesel fuel (as you have)You sure don't want any sparks at the fuel nozzle with gas!
Glad to hear that things went well smile.gif

[Donn]

"Sistering ribs is not a complicated process. Although sometimes the amount of interior you need to remove to get at the ribs is. There are 2 methods of sistering ribs. The best method is to steam a piece of white oak to the proper shape and lay it in next to the rib. Then fasten the planking to it from the outside using the same type of fasteners which are used on the rest of the boat. (ie if the rest of the boat is fastened with bronze or copper riveted then use bronze or copper.
The other method is to laminate a rib in place. Use thin layers of red oak and epoxy. The reason for using red oak for laminating is because it has a more porous cell structure and the epoxy will penetrate the pores forming a better bond and filling them. This type is best fastened with thru fasteners such as rivets or bolts and nuts with the bolt peened over."

http://www.classicboatworksofmaine.com/Questions.html

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"Add another frame next to or on top of the old frame. This is called "sistering". Attach this sister with epoxy, screws, clamps, or bolts. If the frame is curved (a bent rib) it may be possible to approximate the form from the hull's form, from an adjacent plank, or from the other side of the hull (a mirror image.) "

http://www.sailingbreezes.com/Sailing_Breezes_Current/Articles/sept99/repair.htm

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I have both types of sister ribs in my old tub. Apparently cracked ribs are common at the turn of the bilge on a soft chined hull. Whoever installed the sisters place 4 alongside the cracked ribs, and 2 right on top of the cracked ribs. In every case, the sister spans at least 3 planks.

[DiverDan]

I was wondering about sistering on top. I know that it is not what one is supposed to do, but seems to me that it would be pretty strong.

Yes, I am going to have to remove most of the aft decking. Luckly I have already taken care of the ribs that needed sistering under the cabin area. The aft deck is just 3/4 ply so removal should not be too bad. Hopefully I can get much of it done in two weekends, because I would still like to launch on May 15.

d