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View Full Version : Mr Hoppity, the bearded rabbet



Big Red
08-24-2004, 02:44 AM
I am wondering if there is rule of thumb? How wide should the plank-land be, compared to thikness of the plank in a rabbet?

PeterSibley
08-24-2004, 06:52 AM
I may be missing something here ,but isn't the width set by the angle at which the planking meets the stem or what ever ?

Big Red
08-24-2004, 08:07 AM
Sure that would be correct, if you made a stem from some plans that was the right width, or perhaps depth is a better word. Then when you cut the rabbet, it would work out.

But work out to what? How wide, whats the minimum. There are just too many rules in boatbuilding for there not to be one.

Bob Cleek
08-24-2004, 02:50 PM
The bearding face has to be wide enough to permit your fastenings to be far enough back from the plank edge that they don't split the plank. I'd say about twice the thickness of the plank, maybe, but it depends on how prone to splitting your planking stock is. It's worth doing a little experimenting, actually. Problem is, the width of the bearding face is going to be decided by the scantling of the backbone pieces, the angle at which the plank meets the rabet and the thickness of the plank... which is why decent plans by good designers are worth the price.

[ 08-24-2004, 03:53 PM: Message edited by: Bob Cleek ]

Venchka
08-24-2004, 04:23 PM
Originally posted by Bob Cleek:


... which is why decent plans by good designers are worth the price.

AMEN!

Wayne
In the Swamp! :D

PeterSibley
08-24-2004, 05:23 PM
On a stem I'd say twice plank thickness would definitely be the minimum.I'd prefer two rows of fastenings ...scale it out on a sheet of paper.Are you building from purchased plans or going it alone?

Big Red
08-24-2004, 08:19 PM
Well Peter, I would say just curious is all. I have lofted out the Catspaw from WB 110. More as an exercise than the likelihood of building it. Well it lets me feel like a boat builder. Unfortunately the house renovations come first. :(

I am working on the details, that aren't included in the table of offsets such as keel dimensions and stem dimensions. Though perhaps Bob's advice should be heeded and I will spring for the plans.

A question for you guys, I can get some WRC from the local hardware, about 1 1/2" x 3" at US$3.50/meter. Also they have some nice Meranti (Phillipine Mahogany) 1 5/8" x 5 1/2" at US$11.20/meter. How does that compare to stateside prices? Wood just seems terribly expensive to me.

PeterSibley
08-25-2004, 05:04 AM
Hoop pine is pretty good stuff and local too.I can buy excellent quality for A$1500 per cubic metre...thats around A$4.50 per m for your 3"x1 1/2" and say A$9.00 m for the other .

Big Red
08-25-2004, 05:46 AM
Where are you at Peter? I'm in Brisbane.

You use the hoop pine for framing and such? Or planking?

PeterSibley
08-25-2004, 05:54 AM
Murwillumbah...or about 25 k outside in the hills...abut 120 k S of you .Hoop is good for most anything in a small boat .If you were building a carvel hull for voyaging etc a hardwood backbone would be good, and probably spotted gum for ribs.For a small boat hoop is fine for most things.

Big Red
08-25-2004, 09:07 PM
Oh your a hippy Pete :D Been round that area a few times, nice smile.gif I have been out through Benarkin twice (hoop pine plantations) and past the mill there. If I wasn't on company time...

Is it grown locally in your area? How do you get it by the cube?

Paul Frederiksen
08-26-2004, 01:29 AM
When you work it out make sure your minimum land is figured for the place where the sheer meets the stem. The gain changes as you move down (or up if you are building from the keel up). The planks near the keel will have much more than the sheer plank due to the changing angle that they approach the stem from.

PeterSibley
08-26-2004, 03:19 AM
You could ring Pelican Slipway down at Redland Bay.Tell them I gave you their name,they have a supplier who does very nice stuff for the $1500 cm .I worked there a while ago and they had just bought some 6m x 250x 40 , very nice material.

And yes...an old hippy ...been here 25 years. Where do you live...what kind of work? smile.gif

Big Red
08-26-2004, 05:56 AM
Actually I live in Ipswich Peter, I'm sure you know where that is. Sparky by trade. You live near the river down there? How far from the sea?

Hmm, I gotta get over to Boat Craft Pacific for some supplies, might head out to Redland Bay as well...

6m huh? Perhaps its time I got a proper table saw and a router. Sounds like they'd make good strips... sigh :(

PeterSibley
08-26-2004, 04:59 PM
Hmmm.700 feet up in the hills ,about 40k from Tweed Heads .Lovely place to live,up the end of a long dirt road.

Ive got a couple of mates in Ipswich..nice place if hot.