Scarph question(s)

[Nanoose]

We've been unable to find a suitable timber to make a new mast for Nanoose. The issue seems to be the length needed. You'd think in BC it'd be easy to find a 32 foot piece of wood but, no such luck so far. I have been able to find lengths up to 24 feet so I'll likely scarph to length.

Question 1.) Which is preferable, a "simple" long scarph at 12:1 or so or a clothespin scarf? I know the straight scarph is going to be a lot easier for me to do but I don't know if the clothespin scarph is inherently stronger.

Question 2.) Does the scarph end in a feather edge or is it preferable stop at a half inch thick or so and butt it the last bit? I know what I'm trying to say but can't figure out how to articulate it...hope you can figure out what I mean.

Question 3.) How should the scarph be positioned? is it best to have it fore and aft or athwartships?

Thanks for the help!

Dave

PS. Yes, I've considered a birdsmouth spar...for a number of different reasons I'm not going to take that route.

[cjp63]

Though I don't know the answer to your question, you articulated it very well. I can't wait for the answer as I am just plain old curious.

[SV Papillon]

Question 1.) Which is preferable, a "simple" long scarph at 12:1 or so or a clothespin scarf? I know the straight scarph is going to be a lot easier for me to do but I don't know if the clothespin scarph is inherently stronger.

Question 2.) Does the scarph end in a feather edge or is it preferable stop at a half inch thick or so and butt it the last bit? I know what I'm trying to say but can't figure out how to articulate it...hope you can figure out what I mean.

1&2

We have a solid mahogany foremast that has a long scarf. There was some rot below the scarf so we had it re-cut and glued. Long scarf with a straight horizontal small butt on the end. Jensons motor boat co in seattle did the repair. Their assement was that the original scarf was a Anchor scarf, the small butt on the end is cut as a wedge helping to lock the ends in. Unfortunatly on the bottom if the seam opens at all this makes a cup at the bottom of the seam for water or moisture. The soft spot on out mast was just below this, and the seam had opened.

Question 3.) How should the scarph be positioned? is it best to have it fore and aft or athwartships?

Our scarf is at the spreaders. Most of it just above where the gaff sits. The scarf seam is athawtships. It seems that most of the load will be fore aft at small angles. I am not an expert but loading of the joint perpendicular to the glue seam, seems like a much better way to go than in line with it.

Finally Tad Roberts is in the process of locating some suitable lumber for building our new main mast. You might try to give him a call.

Jake

[John B]

Its just about maximising glue surface area so
#1 depends on the timber you can get. I'd do one long scarf in whole pieces but clothespin type when the 'short' end is in halves. If you were buying the whole lot in halves you'd possibly stagger the scarfs.or not.
#2 I really don't like the idea of that nib, its much harder to do plus the reason above,and the clincher.... theres this really satisfying period when you shape down and get that beautiful radiused taper showing out of the spar.
#3 I'd do a full scarf so that it ( the flat surfaces)was across the beam because thats even distribution. I've done clothepins both ways but I get a disquiet about it when its across the beam. I feel better when the flats... the joints ,are fore and aft. Besides, you get to look at that beautiful feather edge you made on the sides of the spar.

[Stephen]

Try contacting Sheane at Ravenwood in Sechelt. He has supplied big timbers for many tallship projects in the US and found a very nice 8"x8" x 30 foot FOH piece of fir for my boom. He brokers for several yards - one of which can cut up to 50' in length.
http://www.pilotcutter.ca/images/titlebar-split.jpg

http://www.ravenwoodservices.com/

[Nanoose]

All the replies make sense, and I feel more sure about making a straight scarph now. And Stephen, thanks for the lead. We've got a few feelers out for timbers on the island but nice to know there are alternatives not too far afield.

Dave

[Nanoose]

We finally found a timber for our new mast. It was only about 25 miles away but it was a trick to figure out how to get it home. Yes, we probably could've had a flatbed trailer with a crane bring it to us but where's the fun in that?

In case you're curious...our timber is 32 feet and that just happens to be the aisle length in a 48 passenger school bus. Deb is a teacher and was able to get "permission" to use the bus this weekend. Here are some of the photos of trying to get it out of the bus and onto sawhorses in our driveway. Enjoy,

Dave

Sliding the timber out of the bus. I'm (Dave) on the left, my buddy Jim is to my right and Lynn, looking tres chic in his gumboots drove the bus.

http://www.imagestation.com/picture/sraid225/p66a9baea564a5d76060b9dae2b9849d4/e951f97b.jpg

Lynn and Eric lower the light end of the log...

http://www.imagestation.com/picture/sraid225/p0c8ecf5df4a3c887316c7cb2047a895e/e951fa0a.jpg

We ponder our next move...

http://www.imagestation.com/picture/sraid225/p0e5e5d52ee92caa26855c98a845d913a/e951f9e1.jpg

Lynn is about to drive down the driveway and we're debating whether we'll be strong enough to hold the log as it slides out the back (we were)...

http://www.imagestation.com/picture/sraid225/pca7b65fbe37cbc1ec24e0a93a1fd81c0/e951f96b.jpg

A few final "tweaks" to get it lined up...

http://www.imagestation.com/picture/sraid225/pb2dd3e219fbefce579d4d54e4e031ef6/e951faff.jpg

You can see there is a slight twist to the grain and few knots.

http://www.imagestation.com/picture/sraid225/p04a749cc8048cc7216521ade8ae3a63e/e951fb00.jpg

With the old mast on the left you can see we've got a bit of wood to remove

http://www.imagestation.com/picture/sraid225/p362b08243a90b7106643abd176214eb8/e951fb02.jpg


http://www.imagestation.com/picture/sraid225/p31f479c5e2808985af7faababcd52b42/e951faef.jpg

[paladin]

The scarph should be a continuous long scarph at 12 to 1 or better. I don't have all my drawings finished, but I'm putting something like that together right now, with drawings.....so.....you're heading in the right direction....start whittlin'...and make some of those toothpicks large enough for BBQ skewers......

[Nanoose]

I should have said that with a timber this long I won't need to scarph.

Dave

[Jim Ledger]

You're going to be knee-deep in chips but I imagine that Deb's got a plan. I notice the drop cloths are already under the horses.:D

This should be a good thread.:cool: