Warped mast

[capt jake]

Dave, that is a sweet idea! Simple, strong and allows for wiring (which I don't have). Pre-engineering the taper into it is also a nice idea!

:)

[Dave R1]

Thanks Jake.

Tell me. Did my suggestion of the guide nailed to the blanks and guided along a raised fence on the tablesaw make sense to you?

I've been thinking of making a new mast and although I've been leaning toward a birdsmouth spar, I've started thinking of doing a square stick instead.

A few weeks ago there was a short discussion of putting the gaff and mainsail on a track up the mast. This is intriguing to me. Not very traditional but I like the idea. I just need to engineer a different hinge so that the track can extend over the joint and align properly when the mast is raised.

[capt jake]

Tell me. Did my suggestion of the guide nailed to the blanks and guided along a raised fence on the tablesaw make sense to you?

Yup, just one of many tricks to be used. I have several taper guides also, but what you describe would work best on this application.

[Jan Williamson]

Dave,

I would like a more detailed raised fence explanation. Thanks for the great drawing.

[Dave R1]

Jan, Make a T that will be clamped to the fence of the saw. The leg of the T extends toward the blade and the top is clamped to the fence. The leg of the T should be parallel to and about 7/8" above the top. Make it a convenient length such that a guide board nailed of screwed to the stock can run along the raised edge. In this case, the guiding edge would run immediately above the blade.

The leg of the T needs to be long enough so that the waste can be cut off without trapping it between the blade and the fence.

I'll make a drawing for that if you like but it will have to wait until Sunday afternoon or evening.

Have a great weekend.

Dave

[Jan Williamson]

Thank you Dave. I look forward to it. Doing the taper would be 80 % of the job for me.

Thanks

[Dave R1]

Jan, here you go. This fence thing doesn't have to be fancy. It does have to be securely clamped to the fence and the edge needs to be parallel to the line of the saw blade. If the edge of this fence is perfectly aligned over the blade, the guide nailed or screwed to the top of the work should be positioned right over the cut line. Keep in mind the was would be to the right of the blade so your cut needs to run along the right side of the line. Make the horizontal part of the fence wide enough so the waste can't be trapped between the blade and the fence. If it did get trapped, ti could become a projectile and give you a piercing you don't want or need.

[Frank Hagan]

Not sure what I am seeing in your tapered fence drawing.

For a bird's mouth mast, I found the easiest way was to cut the staves, cut the bird's mouth in the staves, and mark the desired taper on the un-cut edge of the first stave. Then I planed down to that line with a power planer. That stave then became a taper jig for the others by using some double sided foam tape to stick them together and run them through the table saw using the standard fence.

To taper a 16' stave with a tapered fence, don't you need a 16' tapered fence?

[Dave R1]

Sorry for the confusion Frank. The fence isn't tapered. I suppose the perspective in the drawing makes it look that way. This isn't for making a birdsmouth mast although I guess you could use it for cutting the staves.

The idea with this fence is that the waste can slide underneath the fence while a guide screwed or nailed to the work runs against the edge which is aligned with the blade.

The guide is effectively a template for the cut.

I drew this up for Jan so that she could see how to cut the tapers for the box mast I drew and posted on page 1 of this thread. she was concerned about the time it would take her to, a. make a birdsmouth mast or, b. taper a solid piece. I drew up a quick to make square box with a long taper. All she needs is a straight piece of something she can attach temporarily to the work.

Screws or nails would be fine as long as they don't pentrate the opposite face--the face with the holes could be on the inside of the spar and there don't need to be many holes anyway. Double stick carpet tape would actually be the way I would go because it is secure and doesn't leave holes. The adhesive might need to be cleaned up with mineral spirits, though.

The stick I drew could be made from 3 twelve foot 1x4s since the narrow sides could be cut from one piece.

This fence design is also useful for removing a live edge from a plank or for cutting odd shapes that don't lend themselves to be cut agains the normal fence or with the miter gauge. Polygonal (i.e. triangular, pentagonal, hexagonal, etc.) tabletops come to mind. It is quick to make and not fussy at all. The guide or template is also easy to set up since its edge aligns right on the cut line.

Hope that clears up any confusion.

Dave

[Frank Hagan]

Thanks, that does clear it up. I was wondering if it was the perspective I was seeing in the drawing (I love those drawings, by the way ... I've never been any good at all at CAD programs).

[Dave R1]

Frank, I'm happy that cleared it up for you. I've never found any 3D CAD programs that were what I'd call intuitive. I've been drawing with a program called SketchUp and have found it incredibly easy to learn.

[Jan Williamson]

So this is clamped on to the existing table saw fence? And it sits at least the height of the thickness of your work piece (like the 7/8". You attach a straight stick to your piece along the taper line, I'm still not clear if the edge of the T is right above the blade, does the stick you've attached run under the leg? Or? :oops:

[Dave R1]

Jan, you have it correct. The T is clamped to the existing fence. The leg sits high enough to clear the stock you are cutting. The edge does indeed align with the saw blade. In this case, the left side of the blade.

The guide is just something stiff and straight that you attach to the work. The edge of the guide is positioned right on the line you wish to cut. If the fence is positioned correctly and the guide is right on the cut line, you'll cut right to the line.

You could use a long piece of aluminum angle stock for the quide although you'd want to put thin spacers under it to reduce the risk of hitting it with the blade. Aluminum can be sawn with a carbide blade but there's no point in ruining the edge guide.

If you think more drawings would be useful, let me know.

Dave

Edited to add a drawing.

[Jan Williamson]

Dave,

I almost have it. But which side of the blade does the attached guide get fed into?

[Dave R1]

The "template" is to the left of the blade. It rides against the edge of the guide. Attach the template to the work on the "keep" side of the cut line. The waste side will end up under the guide. As I said before, make sure there is space below the guide so that the waste does not become trapped. If it does, you can get kick back which is very dangerous.

[Craig]

Dave is this to make the taper or to cut off the warp?

[Craig]

Cj over on TSBB was talking the other day about taping the surfaces on two opposing joints on the bird's mouth mast and the glueing the others up. This gives a perfectly formed mast blank that can receive the internal hard point fillings and wire runs with ease, then the two halves are glued and your are done. I thought it was a slick trick....

[Dave R1]

Craig, the tablesaw auxillary fence is for cutting long tapers. Jan was talking about making a new mast but didn't want to do a birdsmouth right now. She also found that a dry D.fir 4x4 was going to cost a fortune.

I suggested she make a square hollow tapered mast. There is a drawing or two on the first page of this thread showing the mast construction.

Craig, that is definitely a good trick for a birdsmouth spar. It makes fitting plugs easier, too.

[Konrad in Lincoln]

Hells-bells, I can't read all of those replies, but let me say this:

My mast has been warped that much since the day I made it 6 years ago, and the Vacationer doesn't give a dang.

Seriously, quit worrying and go sail.

[Guest]

I gotta story for you. most if not all of the local spritsails have mast that are just plain sloppy in their thwarts. Most, if not all, including mine, deal with wedges, and strain that changes and throws the wedges out, and its too dang ruff to mess with it. The sails just continue to perform and the boat continues to go ahead. Warping mast, as long as they do not become delaminated, which is unsafe in most cases, is just part of being wood. Use it till you can build a spare, and, or till your off season.