Refastening procedures

[davidatlantic]

Now that the weather is better here in Massachusetts I have to start refastening the bottom of my 37' Egg Harbor. Is there a standard order to refasten in? Plank by plank? Fore to aft? Garboard to top? Seems like Garboard to top makes sense as we have quite a few planks off at the turn of the bilge and I only need to go to where the big hole in the hull starts.
I looked in the archives but found nothing that applied.
Thanks guys!

[imported_Spissgatter W-9]

Dave,
It probably goes without saying that you don't want to take all the fasteners of a plank out of a respective frame lest the plank pull away from the frame. The screws will not then be able to draw back in and there is no place to clamp the plank/frame together.

When I refastened Anna Marie (about 3500 fasteners ago), I alternated down the length of a plank (top/bottom/top/bottom). Since there were two fasteners holding the plank to each frame this left at least half the fasteners in at any one time. If the plank and frame start separating despite this safeguard, you might consider also alternating frames as well.

Because the fasteners being taken out were galvenized and the ones going in were silcon bronze, and there was 60 years in between manufacture, the latter were a little smaller in diameter. So, I had to cut out little four sided pyramids (about 3" long tapering to about a 1/8" point) out of red cedar with a band saw, glue them in with thickened epoxy, then redrill/counterbore. My shipwright friend showed me out to cut the wedges out of 2 1/5" x 3" stock. So it isn't as tedious as you might think. Email me if you run into this problem and I'll send you a sketch.

Finally, the fasteners I was removing had a common head and were often rusted in place. To remove I used a 1/2" air wrench with the pressure turned way down so it kinda thunka, thunka, thunka on the screw. Most of the time this would break the screw loose. If not, I would bore a hole into the head of the screw and insert a four sided, tapered extractor (try to get the center of the head.) If the head broke off, I would then turn to the Unscrewums (there was a previous thread on that item.) I now see them in Jamestown distributors. More often than not these would end up boring down most of the length of the screw before catching and extracting leaving a nice big hole. Of course, I had my hand wooden pyramids & epoxy handy to fill.

Anna Marie is about the same size as your boat. So, you likely have quite a chore ahead. Don't over stress your elbow (easy to do pushing down on the impact wrench so it stays in contact with the screw head).

Good luck. Have confidence that the task will come to an end.

[imported_Spissgatter W-9]

Some additional thoughts:
1)Watch out for the ends of the planks springing from the stem. (Not familiar with your boat's design. Mine is a double ender the planks at the stern made quite a turn in and twist up. Did not want to behave.)
2) Where you work will also kinda depend upon access i.e. will work along level of the scaffolding. Unless looking for a good work out, may not want to work in a verticle plane (up/down/up a ladder).
3)May want to break up work so not required to stoop or bend over for extended periods. Corollary to this is don't save all the hard jobs for last. These are probably things you already know or would come to know pretty quick. Good luck

[Ed Harrow]

IMHO, it is MUCH better to remove and replace with a larger/longer size, than to simply add additional fastners. If additional ones have already been added, well what are you going to do, ya gotta play the hand your dealt.

You might find the expanding/grippy screwdriver that holds standard screws pretty tightly a useful addition to your tool box. If you have a screw that simply turns, but doesn't want to come out, one of these might do the trick. You might also get some to come out by spinning them backwards as fast as your drill will rotate and kind of "coax" them out.

If you have some messed up heads, Lee Valley sells some gripper enhancer that works pretty well.

[Gary E]

David,

I did very much the sme job many years ago on my Pacemaker, it is a lot of work. A tool that I found to work best for me was a old fashiond brace and bit, make sure the screwdriver bit fits the screw, it is very eazy to apply a lot of push to the screw and with a little efort to the turning of the brace the old screws comes out and the new one goes in. I chose to not use power tools because the screw heads could be dammaged while removing them and then I wanted the correct feel as the new screw was installed.

Good luck

G

[Dave Hadfield]

You can also use a "speed wrench", a socket wrench built in the shape of a brace, but with a (eg.) 3/8" driver at the end, onto which you put a 1/4" adaptor and then the screwdriver bit.

I agree about the hand tools. I replaced about 500 #10 x 1 1/2" galvanized screws 3 years ago and found that the control of torque was simpler with a hand tool. The "brace and bit" layout gives ample strength and speed.

You get a much better "feel".

You certainly need to use great care with the screw head. Clean out the slot with a carefully ground tool. Tap the driver in with a mallet. You only get one shot. Then, if you mess it up the project becomes tedious.

[imported_Spissgatter W-9]

David,
With regard to power vrs hand brace, the former provides a little jarring impact where the latter does not. I found that for "stuck" fasteners,the hand brace would often twist off a portion of the screw head. I agree with the others. Control is an important issue. That is precisely why the the pressure to the impact wrench is much reduced. Otherwise it will spin out of control. If the hand brace works, use it. You may wish to reserve the use of the impact wrench for the most recalcitrant of fasteners. Finally, it seemed to help by first tightening the fastener a bit then reversing and removing. Armed with all the good advice you have received from the various posts fasteners should fear you. Good luck

[imported_Spissgatter W-9]

So there is no confusion, I'm talking about the use of an impact wrench to remove fasteners. I endorse the use of the hand brace for the install. As Dave Hadfield said, one gets a much better feel. Can avoid over/under torqueing of the replacement fastener.

[davidatlantic]

I was actually thinking more along the lines of the planks drawing in and what effect the order of refastening would have. If the hull has worked enough to have loose planks (mine has some) then will the planking shift around as it is refastened? Since none of you mentioned this it seems as it may be irrevelant and I merely need to arm myself for battle. I did find a place in New York that sells new flat screwdriver bits with the square taper for a bit brace. I have also found that my favorite tool for removing old bungs is an small bore spade bit with a wood handle glued on. Now I need a few friends some Cockspur rum and a case of Red Stripe to make the arsenal complete!