Wooden clamps for lapstrake??

[BirchBark]

Can anyone point me to any pictures or drawings of clamps that I can make? I'd seen some in Chapeles - Boatbuilding but I don't own the book. I'd like to see some details and variations.

Thanks,
Chris

[dmede]

here's one:

http://www.duck-trap.com/2002oars.html

http://www.duck-trap.com/lapclmp300.jpg

ive made a handfull of these myself. very easy to do and work great for lap clamping as other clamping.

other options include glueing two peices of wood together, say 2 pcs of 1/4"x1/2"x8", with a small 1/4" or 3/8" spacer glued at one end. use a simple shim or wedge on the open end to apply the clamping pressure. I have a box of about 50 of these clamps from my last lap canoe. Greg Rossel's "Building Small Boats" has other versions and ideas as well.

dave

[ 11-29-2005, 03:54 PM: Message edited by: dmede ]

[Thorne]

Our hosts have a great book _Planking and Fastening_ that covers making various clamps, some wonderfully technical articles on woodscrews, drilling countersink holes, making bungs, and more more more! My copy more than paid for itself within a day.

;- )

http://www.woodenboatstore.com/images/325106.JPG

http://www.woodenboatstore.com/prodinfo.asp?number=325-106

[Graham Knight]

http://img.villagephotos.com/p/2004-8/804365/VSKSH-Clamp.jpg

These are what I've used for making my lapstrake skiff, very simple to make and use, finger pressure is all that's needed to insert the wedge and apply suffient clamping force.
I made a couple of dozen at first, but have ended up with about fifty of different sizes.

[BirchBark]

I just found these:
http://www.duckworksmagazine.com/04/s/articles/nippers/nipper.jpg

Planking Nippers (http://www.duckworksmagazine.com/04/s/articles/nippers/index.cfm)

Very nice. Hinge and all.
I think that I like a simpler clamp though. A leather hinge would work as well. And laminating all of those pieces would be alot of work for 20 of them.

Chris

[BirchBark]

Thank you.
All good ideas. Keep them coming.

Chris

[StevenBauer]

Not a great picture but I copied these from a picture of Norm Messingers:

http://www.imagestation.com/picture/sraid20/pcc7f309da2e683480498056c28d1f8a8/fdb9a527.jpg

Steven

[wyndham]

In a back issue there is a description of crab claw clamps? Fiddler clamps? I don't remeber the exact name but I made a few for my brother in law for just this purpose and they worked like a charm. I made patterns so I can reproduce them. I upped the size a bit and made them a little tougher than reccomended. they were fun to make and look real pretty.

[Thad Van Gilder]

I make up clamps that are crab claw esque, with rubber or leather hinges, and clamp the middle with a bar clamp.

-Thad

[Thad Van Gilder]

I make up clamps that are crab claw esque, with rubber or leather hinges, and clamp the middle with a bar clamp.

-Thad

[BirchBark]

Steven,

Was that a picture here on this site? Maybe the FAQ's?
I did search the FAQ's but didn't find anything labled "clamps".
I like your chisel plane in the picture.

Chris

[ 11-29-2005, 08:08 PM: Message edited by: BirchBark ]

[Canoeyawl]

These standard clamps are simple and work well, we made up patterns for a couple of sizes 12”, and 16’’ the larger ones being thicker and heavier. This used up most of the hardwood scraps lying around the shop! Pieces of leather belting are the padding for the planks, and the hinge. A fully threaded carriage bolt fitted so it won’t turn and an extra heavy nut with a couple of pieces of ¼” bar welded on make the big wing nut. They will clamp up the planks with a fairing batten inside and out (a bit over three inches for the smallest). These were useful for epoxy glued plywood planking.
http://www.canoeyawl.com/boatimages/1const1-600.jpg

[BirchBark]

Ya, here you go:
http://www.woodenboat.net.nz/Workshop/Workshoptips/woodclamp.jpg

:D

Those are a little rough for me. They would work though.
The only thing I wonder is whether the clamping surface ought to be rounded soas to be able to bear evenly in different thicknesses?
Thanks for the ideas.

Chris

[ 11-29-2005, 11:59 PM: Message edited by: BirchBark ]

[JimConlin]

The lapstrake boats i've built have had light (4-6mm) planking. These planks get pretty wayward, so i feel the need for close clamping. I have two sets of the clamps sketched by Graham above, about sixty of each, different throat widths. I have two bunches of wedges of different thicknesses. With this variety, i can handle a range of thicknesses.
I like these clamps because:
the price is right
they apply quickly
if using a tom hill style setup, they can be wedged at the back of the throat, too,
they store compactly.

[Mick Herron]

I will second Graham Knight's suggestion.

I built a McGregor glued lapstrake canoe. I found the clamp and wedges very practical. I went to one of those big boxes and bought a 4' x 4' piece of 1/2" plywood and several packs of scrims. I mad over 50 clamps for less than seven dollars.

[gert]

I also made about 40 like G Knight's but in 3/4 MDF, the "soft" edge of MDF is very kind to expensive plywood strakes, it's not like you want a lot of clamping preasure with epoxy. It's important the inside crotch be drilled so the stress is distributed, the MDF ones were also more springy than the plywood ones, so make both.

they're good enough

after all this is about building boats not tools ;)

[ 11-30-2005, 10:31 AM: Message edited by: gert ]

[Brian Palmer]

I built a glued lap canoe and used 1-inch wide sections of 4 inch PVC pipe that were slit to form a spring "C" clamp. I got the idea from the CLC web site. Cheap and easy to make, glue doesn't stick to them. Downside is that they do not have a lot of bearing surface on the wood, so they may leave a mark, and they don't apply much pressure to really thin work.

-- Brian

[wyndham]

PVC pipe makes great clamps. You can alter the strength and clamping pressure by cutting the pipe at an angle so the contact area at the slit is smaller than the opposing side. I have made a variety of PVC pipe clamps from pipe up to 10 inch. There are lots of cut offs at most home building sites and the dumpsters are full of the stuff. If the contact area on a 4" piece of pipe is 1" as described above and the opposing side is 2" there is considerably more pressure being applied at the "jaws".

[Graham Knight]

Another way to increase the clamping pressure of PVC "C" clamps is to double them up, cut and slit two pieces and slip one over the other, it works like a leaf spring, you could glue them with PVC pipeweld too.
Or try just using thicker walled pipe, or the harder stuff they sometimes use for buried pipes, it's expensive but you can usually blag some offcuts from the workmen if you see them laying pipes somewhere.

[BirchBark]

I found another style of clamp in "The Workshop Book" Taunton Press.
It looks like a large spring clamp.
8/4 stock x about 20" or so. The spring looks like a piece of steel bent in half and attached to the handles.
http://home.earthlink.net/~cnebarker/BoatClamp.jpg

Chris

[ 11-30-2005, 09:59 PM: Message edited by: BirchBark ]

[Greg Luckett]

These are pictured in "The Evolution of the Wooden Ship" and I have been using this clamp design to build a lapstrake lobster skiff. It works well and is simple an inexpensive to make. The ones pictured are made from pine 2x4s....common lumber, much can be had from construction scrap piles too.

Oops, I cannot figure out how to post the pic. Would someone please tell me how this is done?
Thanks.

[ 03-05-2006, 11:35 AM: Message edited by: Greg Luckett ]

[Dave Fleming]

http://pic4.picturetrail.com/VOL780/3097474/6292566/132040986.jpg

[Dave R]

Dave, I wondered where that drawing had got to. :D

[Dave Fleming]

Dave R, I have saved that to CD plus a copy on the hard drive.
Got the other image too.

Good Job!

PS: sorry I did not give credit but, I forgot who sent it to me. redface.gif

[Dave R]

Thanks Dave. No worries on the credit. ;)

I hadn't seen this thread before and was a little surprised to come across the photo Birchbark had posted.

Out of curiosity, do you have illustration of how I made those out of plywood?

[Dave Fleming]

Dave R, don't think so just the CAD drawing showing completed clamp but, will check on it.

[Dave Fleming]

http://pic4.picturetrail.com/VOL780/3097474/6292566/132040989.jpg

[Todd Bradshaw]

Somebody who has the WoodenBoat CD - look up the "Brenne" clamp from an issue about 25 years ago. Similar in concept, but designed for one-hand operation using a built-in wooden cam. Elegant and simple to build.

[Dave R]

That's it Dave. Thanks. I think I can do a much better drawing of that clamp today if anyone wants it.

Todd, I have something on the Brenne clamp in a book and would have made them that way but for my use these were fine and actually ended up being a little bit lighter. In the application I had, the planks were only 1/8" thick so weight of the clamps was a big consideration.

[Tom Robb]

An idea I saw at one of the WB shows in Mystic, I think,on a glued lap ply hull was very small sheetmetal screws like tinners use. After cure they'e removed and round toothpicks glued in the holes, then sanded flush.
They called them microtrunnels :D
You'd still need some clamps to get the plank to lie correctly, just not nearly so many of them.
And yes, they're obviously useless on traditional clinker.
The plywood C and wedge work and are nice and cheap if you forsee only building one hull. Does anyone stop at one?

[BirchBark]

Dave R,

I found the picture and an article on those clamps on the Duckworks site.
I hope you don't mind my posting it.

Chris Barker

[Dave R]

No problem Chris. I was kind of surprised to see that picture because I didn't think anyone thought much of my design. Seems to me I posted something about them when I made them but didn't get much reaction from anyone.

If you're interested I can show the method I used to make them. I think it took me about two hours total to make a dozen of them

[Antonio Majer]

Just to show you my clamps. The jaws come from a dead stock of wooden flooring, I got some fifty pieces gratis, some years ago. I used a ¾’’ thread box for the wooden screw. Since these “flat” jaws are slightly flexible, they are able to adjust themselves to the different angles of the clinker planks, and they cannot damage the wood. Moreover I have the sensation that a wooden screw “holds” its position better, thanks to the friction between wooden screw and wooden bolt, even if you don’t close the clamp hardly.

http://img507.imageshack.us/img507/6140/16tu1.th.gif (http://img507.imageshack.us/my.php?image=16tu1.gif)

This is a possible variation for both clinker and caravel planking, to clench two different thicknesses.
http://img507.imageshack.us/img507/9686/30ms.th.gif (http://img507.imageshack.us/my.php?image=30ms.gif)