plank replacement

[alankey1]

Hi new to the site and hope I can get some info
I have a 1951 ex-fishing boat converted for pleassure.some planks on starboard side are rotting(above water)can some one draw or explain a simple way to scribe the new plank to fit. The boat is a double ender with lots on curves and twists
Thanks for any advice
also looking to talk to anyone with similar stle boat :cool:

[Paul Denison]

Oooh, you are asking for it. First try the search function re: planking, spiling, ect. I know there was a good discussion of this a few months ago.

Then look on the WB store for books dealing with this subject.

[Nicholas Carey]

Originally posted by alankey1:
Hi new to the site and hope I can get some infoWelcome to the zoo!


I have a 1951 ex-fishing boat converted for pleassure.some planks on starboard side are rotting(above water)can some one draw or explain a simple way to scribe the new plank to fit. The boat is a double ender with lots on curves and twistFear not. Don't worry. It's not as bad as it looks (as the homebrewers like to say, "Relax, don't worry. Have a homebrew."

Next, order a copy of Robert M. Steward's excellent Boatbuilding Manual, 4th edition

http://covers.eppg.com/Jpeg_140-wide/0070613761.jpeg

It's available from Our Sponsor as well as all the usual places—Amazon, Barnes&Noble, etc. The ISBN number is 0070613761 and it was published in 1994.

Here's my brain dump on the basic process (Steward does a better job):

First, you'll need some gear: A sheet of doorskin or thin plywood. A pencil. and most importantly...

spiling blocks. These are, fundamentally, little blocks of wood, just large enough to slide easily along the edges of the existing planks and overlap the pattern.

</font> Remove the plank to be replaced.</font> Take doorskin or thin plywood and rip it into strips a little narrower than the plank.</font> hot-glue or staple pieces of doorskin into a shape that will fit into the space formerly occupied by the plank. It doesn't need to be a perfect fit. This is your pattern.</font> Tack the pattern into place where the plank used to reside.</font> Get out your trusty pencil (sharpen it up first) and your spiling block.</font> Lay the spiling block along the edge of the existing plank and resting on the pattern. Slide the spiling block down the edge of the plank, scribing a long with your pencil on the pattern. Repeat for the other edge of the plank and both ends.</font> You might want to pick up the bevels at each frame (using a bevel gauge) and record them on the pattern, especially if the planking stock is thick. You're going to have to reproduce those bevels on the new blank.</font> That's about all there is to it.</font>Congratulations.

You now have a pattern for your plank. It is undersized by the size of the spiling block (2x actaully, one for each side.)

Remove the pattern from the hull and lay it down on the shop floor. You'll note that the developed (flattened) shape of the plank doesn't appear to have a lot of relationship to the apparent 3-D shape of the planke. It may look S-shaped and have a lot of curve. This is normal.

Getting out the new plank.

Rummage through your lumber pile for a nice piece of Spotted Owl habitat planking stock. In the ideal world, it should be long enough and wide enough to get your new plank out in one piece.

If it isn't you'll need to make two shorter planks and put in a butt block. Or...(a fine idea from WB some time ago. Can't remember the issue.), do what a guy in England does: he uses a finger joint bit on a big router and edge-scarfs the plank stock with the finger joint bit to make a curved plank (glued together with expoxy) that fits the pattern. This eliminates the need for a butt block since the joint is so strong that the classification societies will allow the plank to be treated a a single plank.

Anyway, assuming that you've got stock to mill the plank out, lay your pattern down on the planking stock and and tack it in place. Don't want it shifting now.

Fishing that awfully handy spiling block out of your apron pocket, scribe the outline of the new plank directly on the planking stock. Doing so is the reverse of spiling the shape on the pattern. Lay your block flush against the line drawn on the pattern and trace the outline of the new plank on the planking stock while sliding the spiling block along the line.

There you go.

Take it to the bandsoar and cut out your new plank.

But Wait, There's More.

If your planking is thick or has a lot of bevel, you need to make some adjustments here. The shape and dimensions you spiled off are those of the inside face of the plank. The outside face of the plank may well be larger/wider than the inside. Remember how we picked up the bevels at each frame?

In this case the spiling is a bit different: you'll need to flip the pattern so its face-down, spile off the shape of the inside face and mark the locations of each frame on the plank. As your cut the plank you'll need to be cutting a 'rolling bevel' on the plank edge, so from frame to frame you'll make the appropriate smooth transitions from one bevel to the next.

That's About it.

If you've done this right, a little work with th e plane and your plank should drop right in place. [peanut gallery: "Yeah, Right!"] It might take a little&mdash;ok....well...a lot of horsing to get it in. But it shouldn't require edge-setting, bending the plank sideways to make it fit.

You'll probably need to back the plank (hollow the plank where it lands on the frame so the plank has full contact with each frame on which it lands.) You'll need to make/buy/borrow/steal a 'hollowing plane' or 'backing plane' to do this. It's a wooding block plane with a sole that's straight in the fore-and-aft direction and has an appropriate 'belly' in the athwartships direction.

Once you happy with the planks fit: it doesn't need or want to be snug with no gap between the planks. It wants a bit of room to allow for swelling.

And then last little thing you'll need to do is to plane the caulking bevel on the plank. Typically, when two planks meet, only one of them has a cuulking bevel...so every plank has a caulking bevel on one edge and one end.

Consult with your caulker regarding how big the seam should be if you're not sure.

Once you're happy, it's time to fasten the plank in place. So...

paint both faying surfaces (where the plank meets up with another plank or frame.) with red lead and fasten the plank in place. You might have to go up 1 screw size, though. Alternatively, you could use rivets (copper nails and roves) instead.

Then it's time to make an appointment with your caulker.

Somebody tell me (I'm sure you will) If I've left something out of this extemporanious brain dump. :eek:

[whb]

NC

This is probably a dumb question but why can't you just use the piece(s) of the original as a pattern?

Howard

[Nicholas Carey]

Originally posted by whb:
This is probably a dumb question but why can't you just use the piece(s) of the original as a pattern?Cause they probably won't lay flat&mdash;and you need to start with the flat shape.

I know the process sound complicated, but it isn't really all that tough. It's takes spiling carefully and accurately and understanding what's going on so you don't inadvertantly produce a mirror image of the plank you actually want. Of course, if you're building new, you should be able to get out planks in pairs (assuming your boat is approximately symmetrical.)

[Ken Liden]

Wooden Boat Magazine. Back issues # 16, 23, 24, 53, and 80. Look around this website to order.

[John R Smith]

Folks

I think that we all on the WB Forum owe Nicholas a big vote of thanks for one of the clearest and most detailed replies to a thread that I have ever seen. I'm going to print this one out in case I need it in the future.

Quite restored my faith in the Forum, that has ;)

Thanks again

John

[Chadd Hamilton]

I second that, John. Nicholas, I think you've certianly nailed it beautifully. If the WB forum ever had an archive or FAQ, this post should go in there.

[Cecil Nickerson]

And a very nice dump it is, my son. :D

[alankey1]

I again want to thank Nicholas for his great explaination and help with my problem.Now have to try it out ;)

[R.I.Singer30]

I too found the info valuable ,even though I don't have a grasp on it totally yet .Replanking is in my future too and I will reread this most certainly then.Thanx also to the back issue #'s. I 've been to the library in Wickford and scan there back issue's even though our host probably doesn't appreciate it . I may buy some issues if they prove to be most valuable.Sometimes I need to be told things several times and several different ways to understand things .I think it's the stubborn French Canadian in me. Dan L. smile.gif

[ 04-01-2003, 03:50 PM: Message edited by: R.I.Singer30 ]

[Nicholas Carey]

Gee, thanks :rolleyes:

I'm sure I'm missing some of the details there, but it's the best I could do off the top of my head.