PDA

View Full Version : Hollow wooden spars...



mdevour
07-11-2005, 07:27 PM
If I were to make a hollow wooden spar, 16 ft long and about 2 1/2" diameter, or thereabouts, would it be proper for the interior to be completely sealed, or must there be at least a small vent hole in it? How big?

It'll probably be made from two halves hollowed out before gluing them together. The outside will be smeared with epoxy before being varnished.

Hit the inside with epoxy before sealing it up?

My son has consented to let me build the mast for his Gypsy while he's doing the hull. ;) I'm thinking of taking the opportunity to get some experience with something new. :cool:

Mike D.

kc8pql
07-11-2005, 07:56 PM
I'd seal the inside with epoxy (because you'll never see it again to inspect it) and leave a drain hole open at the foot so leaks, condensation or whatever can get out. I'd just varnish the outside (no eopxy) so the wood can dry out if it does get wet.

StevenBauer
07-11-2005, 08:06 PM
It'll probably be made from two halves hollowed out before gluing them together. Yikes! That would sure be the hard way to do it. Have you thought about using the birdsmouth technique. Much easier, faster, stronger, more forgiving of less than perfect stock, need I go on.

Steven

mdevour
07-11-2005, 08:29 PM
kc8pql,

That sounds pretty sensible. What size drain hole are you thinking of? Thanks.

Stephen,

I know about the birdsmouth technique and I'd like to try it someday. I could do it here...

So far I've been thinking of a rounded over rectangular or square section rather than round. I suppose that box construction would also make sense?

Mike

StevenBauer
07-11-2005, 09:31 PM
Birdsmouth spars don't have to be round. If you make two opposing staves a little wider than the others you get an oval. If you make every other stave a little wider you get a rounded over square. You could even taper every other stave in opposite directions and get a spar that was oval in one direction at one end and the other direction at the other end. I've seen that for high performance oar shafts. Fool around with some 6" long pieces. Spars are really fun to make this way. smile.gif

Steven

Bob Cleek
07-11-2005, 09:42 PM
Well, one of the odd things about the internet is that just because somebody posts something, they don't necessarily know what they are talking about. Pretty amazing that the hardest thing for some to say is "I don't know."

Building a HOLLOW sixteen foot spar two and a half inches in diameter is going to be sort of like building a hollow bamboo fly fishing pole. It's two and a half inches at the heel, right? What does it taper to, and inch and a half, maybe? What does the designer specify?

If you lay up a two and a half inch "birdsmouth" spar, eight sided, you will be working with sixteen foot strips of wood maybe 3/4" wide, at most. Think about it. DUMB idea!

This sort of spar is best dealt with by simply planing down a nice straight grained piece of Sitka spruce, or if unobtainable, a similar piece of close grained, straight Douglas fir.

However you do it, the wood should be sealed all over with CPES (Clear Penetrating Epoxy SEALER... NOT epoxy resin) and varnished or painted. There is no reason to put drain holes in a spar like this. It's just a stick of wood. Even if you glue it up, why put a hole in it? If it is glued properly, water isn't getting into it anyway.

RodB
07-11-2005, 11:17 PM
I never get tired of reading Bob's posts...

smile.gif
RB

[ 07-11-2005, 11:44 PM: Message edited by: RodB ]

paladin
07-11-2005, 11:38 PM
Yup...he beat me to it...I wuz gonna suggest three pieces of 1 x 4 by 16 feet all glued up and shaped....

mdevour
07-12-2005, 12:31 AM
Bob, Paladin,

I agree I don't have to make the spar hollow! tongue.gif This is only one of Bolger and Payson's "Instant Boats" after all. They specify a 2 1/2" square section made out of 2x4's.

In defense of the idea, though, I was at a friend's house a couple days back. We were out in his shop, where he handed me the boom from one of his sailing canoe rigs. It was made from two halves, carved hollow before they were glued together. It was feather light, stiff as you could want, and a work of art. :cool:

So, I'm pondering putting in some extra work in exchange for a (slightly) lighter spar for my son's boat and the chance to try some things I haven't done before.

Silly? Foolish? I suppose so. But I'm thinking about it as fun! So long as it isn't dangerous I can't think of why not?

Mike D.

[ 07-12-2005, 01:50 AM: Message edited by: M. G. Devour ]

StevenBauer
07-12-2005, 12:34 AM
The staves would be about 1" by 1/2" before tapering. I don't see the problem. The ones I've made were only 12' long but I don't think 16' would be much different. The cool thing with this method is the wall thickness doesn't change when you make your tapers. It would definitely save time, too.

Steven

wyndham
07-12-2005, 09:46 AM
Making a birds mouth spar of these dimensions sounds like a great way to lose a fingertip in the table saw quite frankly. If you must build a hollow spar, and if your doing it just for the hell of it why not, I would use a router with a half round coring bit and hollow out the two halves that way. One simple set up.
Seems like a long run for a short slide though. How much weight will you really be saving?

Gary E
07-12-2005, 09:56 AM
I agree on the router idea and if you want a core larger at the base than at the top, make a tapering jig.

Keith Wilson
07-12-2005, 09:56 AM
In this case, Bob's dead wrong, and I can attest to that from personal experience.

The rig in the Gypsy is the “Universal Bolger Rig”, a 59 sq ft sail with a sprit boom that is used in many of Bolger’s smaller boats. The mast is designed to be made out of two carefully-selected 2x4s, and tapers from about 2-1/2” square at the partners to about 3/4” square at the top. It’s designed to be somewhat flexible, particularly at the top to spill a bit of wind in a gust like the old New Haven Sharpies. Bolger’s Gypsy is a very nice boat BTW. It was the first design I ever built, and I got to sail in it this weekend. It’s still going strong after fifteen years, despite being made with polyester resin out of ACX fir plywood. My Gypsy had the Bolger mast, 2x4s and all, and has worked fine despite having to be reglued with epoxy; the Weldwood failed after twelve years.

A couple of years ago I built another boat that used the same rig. My intent was to make a boat that would be very easy to rig and sail off the trailer, and to that end I wanted to make the mast as light as possible, and to experiment with building birdsmouth spars. I also wanted to make the mast a little more rigid than the Gypsy’s original. I made a round birdsmouth mast that’s about 3-1/4” dia. at the partners, tapering to maybe 1-1/4” at the top and 2-1/4” at the foot. I cut strips from the local lumberyard’s finest spruce 2 x 12, and the walls are about 1/2” or perhaps 5/8” thick. There’s a short plug at the partners, at the point the snotter block attaches, and at the foot. The hole in the mast pretty much disappears at the top. I added a little tab on the aft end of the mast to hold the peak grommet of the sail; I never liked way the Gypsy sail looked lashed to the hole in the mast.

This mast has worked even better than I though it would. It’s incredibly light, maybe half the weight of the original design, significantly more rigid, and I think stronger as well. I can step the mast with one hand. The birdsmouth technique allowed me to make it out of pretty ordinary (and very cheap) wood, yet end up with a straight-grained spar perfectly clear of knots. Construction was very easy; I ripped and tapered the staves out of a 2x12 with a Skilsaw, hand planed them more or less straight, cut the notches with a router, and glued it all up with System 3’s T-88. If I were to build another boat with this rig, I would certainly do it again.

A couple of rigging suggestions: Since there’s no halyard, luff tension on the sail comes from the tack downhaul, and it’s hard to get enough tension on it. I rigged up a 3-part downhaul with a couple of tiny Harken blocks which works admirably. I never liked the snotter arrangement in Dynamite’s book ,and replaced it with a block and eye strap screwed to the mast. A piece of line with a stopper knot at either end goes from the slotted forward end of the boom, through the block, then to a cleat low on the mast. Also the sheet arrangement shown in the book seems unduly complicated; I tied the sheet to the clew grommet, and the put a stopper knot about three inched along the rope. The slotted after end of the boom hooks on the sheet between the sail and the stopper knot; very simple.

Anyway, have fun with the Gypsy. IMHO it’s one of Bolger’s best taped-seam designs, and convincingly disproves the idea that stitch-and glue boats can’t be beautiful. A hollow mast on this boat is neither silly nor foolish.

http://www.instantboats.com/images/gypsyprof.gif

[ 07-12-2005, 10:06 AM: Message edited by: Keith Wilson ]

PVanderwaart
07-12-2005, 10:38 AM
If you lay up a two and a half inch "birdsmouth" spar, eight sided, you will be working with sixteen foot strips of wood maybe 3/4" wide, at most.Sixteen?

I'm not sure how you lay up the mast out of 2x4's. When I made my Elegant Punt mast, I used a flat 16' Douglas Fir board, that was ripped in two. Laminated together, the blank was the right dimensions at the base. Note that although Bolger uses the same sail for various small boats, the masts may differ; a boat with more stability calls for a stronger mast. For example, the same sail is used as the mizzen on Centennial, and there is a note about the mast on the plans.

Bob Cleek
07-12-2005, 01:43 PM
Hey, if you want to play with making a hollow spar and don't mind going to the trouble, go for it! In such case, I'd opt for the router method. If you want to do a birdsmouth and have some fingers to spare, fine. BTW, in these sizes, I'd suggest you use one of the new birdsmouth router bits and a router table. I'd think it would be safer than cutting them on a table saw.

Keith Wilson
07-12-2005, 01:52 PM
Yeah, I wouldn't like to run those long skinny staves over a table saw either. I used a V-groove router bit with a little homemade jig that bolts to the router base and holds the bit centered on the stave. It's certainly close enough for epoxy.

Bob Quick
07-12-2005, 02:27 PM
With all due respect to the nay sayers and freely acknowledging that I am as much of a novice as anyone on the forum, I have found the method that I am going to use.

In the last 3 months I have built 2 masts and 4 spars using the bird's mouth method. The masts are 11 and 13 feet long and 2 1/2 and 2 inch in diameter. The spars are from 8 to 10 feet long and 1 1/2 inch in diameter. Each has a taper on one or both ends. I rough cut the staves on the table saw, used the planer to trim to dimension and cut the mouth on a router table with a big box V cutter. I layed them up with epoxy and hose clamps. The first one took about 6 hours not including finish but the last one about 2 hours.

The masts and spars are for a Penobscot 14 and a Skunk Island Skiff. They weigh 1/2 to 2/3 of a solid spar and are varnish finished. I have cut staves for a 21 foot mast and it wasn't any harder. The only problem is my spar bench isn't long enough.

You can say what you want about solid versus hollow versus bird's mouth but after having done at least one of each, I threw away the first two away and kept the last.

The hardest part was making the tapered plugs for the ends.

Don't see why you would do anything else.

My 2 cents.

Bob

mdevour
07-12-2005, 03:00 PM
Thank you for the great discussion, gents!

Keith, I appreciate the inspiration. I showed your post to my son, who is as encouraged as I am that the Gypsy is a good craft for him to build and own.

On bird's mouth construction... Some careful fixturing is in order to make cutting out the staves simple and safe. I would definitely use a router, not the table saw, for cutting the grooves.

Well, I will think things over some more. Simply routing out the halves, I have no doubt I'll be able to do, do well, and be done in time for launch.

The bird's mouth method, though more elaborate, is intriguing.

Back to my original questions:

Does anybody object to CPES in and out, followed by varnish to finish? Since I happen to have inherited some CPES I may as well try it out.

Again, vent/drain hole, yes or no? How big? Where? Reasons pro/con?

Thank you again, folks. I always appreciate the diversity of opinions :D and the depth of experience hosted by this forum.

Be well,

Mike D.

waterside
07-12-2005, 03:03 PM
I built two birdsmouth masts, a 16'x3.5" mainmast and 14'6'x3.5" foremast, for my Bolger Light Schooner, and I believe that the extra work was worth it.

Regarding the original question: Definitely seal the mast inside and out before or during assembly. This will keep the moisture level of the wood relatively constant across the mast section. If you don't, then rapid humidity changes can cause checking and splitting as the wood shrinks and swells unevenly. This happened to an un-sealed test section that I glued up in the muggy heat of August, and left sitting around all winter in the dry, heated shop: http://watersideboats.com/split/tn/split.med.jpg (http://watersideboats.com/split/split.jpg)

Regarding stave-cutting on a tablesaw:

My experience was that if you need to have your fingers so close to the sawblade that they are at risk, then you probably don't have enough support for the staves to get a clean and accurate cut anyway. I think the same thing goes for either a tablesaw OR a router...

I used lots of support on both sides of the saw to prevent sagging, and a homemade jig (see http://watersideboats.com/bolger/masts) so that the staves would lead fair into and out of the blade. My fingers never got within 8 feet of the blade when cutting the staves or milling the V-groove.

Frank Wentzel
07-12-2005, 03:05 PM
I used a birdsmouth bit from Lee Valley on a small tabletop shaper to make my 2.5 inch spar. Using proper fixturing (held in place with spring clamps) the "birdsmouthing" was quick, easy, and safe. The spar went together almost by itself. Once you clamp one end (I used hose clamps) the rest of the spar almost 'snaps' into place. I didn't plane and sand it to a fully round shape. I left it as a "relaxed" octagon. It looks great!

/// Frank ///

Keith Wilson
07-12-2005, 06:31 PM
I didn't put in a drain hole and it's worked fine so far. IMHO you're better off without one. I did not seal the inside, and finished the outside with Cetol (actually West Marine's knockoff, it's a prettier color) over CPES, and painted the top 2 feet white. No problems so far.

StevenBauer
07-12-2005, 06:40 PM
Sorry, but I fail to see the safety issue with cutting the birdsmouth on the tablesaw. You tilt the blade to 45 degrees, set the depth of cut to half the thickness of your stave, clamp a finger board to the fence and another one to the table, lay the stave on it's side and run it through, flip it over and run it through again. After the birdsmouth is cut you can taper the top and bottom with a simple jig. Mine uses two of those toggle clamps and a scrap of plywood.
I made two spars a day or two apart last summer. The gunter (upper part of the 2-part mast) was hollow, the boom was solid. It took less time to make the birdsmouth hollow gunter than to make the solid boom. With the solid spar you have to taper both ends, (four sides) then plane it to eight sides, at which point you are where you are when you take the clamps off the birdsmouth. All the milling for the birdsmouth staves took about an hour. Less time than marking and planing the tapers on the solid spar. The birdsmouth technique is faster and easier, the spar is lighter and stronger, and it's more forgiving of less than perfect materials. But ymmv. :D

Steven

kc8pql
07-12-2005, 07:07 PM
For a small spar that won't spend all it's life out in the weather, you probably don't need a drain hole. I have one in my mast because it's 50' long and has thru bolts for stay tangs, and wire exiting for lights and antennas, all potential places for leaks sooner or later.

http://tinypic.com/72qfxz.jpg

Philip Maynard
07-12-2005, 08:25 PM
For my 16' hollow birdsmouth unstayed mast, I was concerned about the short 10" distance between the deck and the foot of the mast and I wanted a good reinforcing plug at the butt end. I cut 8 triangle sections about 30" long (think of an orange) with the outside of the orange contacting the inside of the hollow octagon mast staves. After getting about 16 - 18" above the foot of the mast - past the point of maximum stress where the mast passes through the deck, I then tapered each of these pieces starting at the center - at the acute angle (the center of the orange) and extending the taper to a feather edge at their top end at the inside of the staves. It goes from a solid plug to nothing, tapering from the center out. I relied on thickened epoxy to assemble and hold the plug together and glue up and the staves all in 1 operation. I coated the inside of the staves with epoxy as I was doing the glue up. I myself found it a surprising amount of work as it was the only one I have made and I really do not have a shop set up for this kind of work but I enjoyed building it and would recommend any hollow spar. Light weight masts are a joy every time you go sailing.

BillyBudd
07-12-2005, 09:27 PM
Like so many other respondents, I've had my first go at a birdsmouth mast (13.5'x3" to 1" dia. one way, and 3" to 2" the other way--all in native eastern spruce with scarf joints as needed) and found it a great adventure in woodworking and so far an astounding mast. But I do think that interior reinforcing plugs at potential stress points are critical. And I think the idea that water will someday somehow somewhere get in there and need a way out is key to lowering the potential for rot. So, following others who've given advice here, I gathered the staves with epoxy in the joints, but put wax paper (saran wrap might be better) across the mast's interior middle. The next day it was then easy to split the mast in two and clean out the split joints for re-epoxying. With the 2 halves opened, one can coat the interior with epoxy (twice); and one can shape plugs (each with a central drain hole) where needed. Bed the plugs in epoxy, mush them in place, coat the joints, and put it all together. Later, if mushed in for solidity drill out the bottom for a moisture escape hole.

I plan multiple coats of Captain's varnish for the protection of the epoxy joints.

Not easier than shaping a solid stick, but lighter, and probably more reliable with the clear grain, but with the risk of lots and lots of joints that may not be perfect and that someday might separate.

If WB would fix its search engine (what's the big deal about getting it to work like it used to work, you guys?) you would finds simply tons of materials and photos on the making of hollow masts.

On fingers and table saws on these fine strips of wood, I used wood flexible finger boards top and side to get it right and run the strips through. A bit of testing on scraps was needed. I treasure my fingers and keep them far from the blade. This setup allowed my fingers to be some distance from the blade.

Philip Maynard
07-14-2005, 09:20 PM
This is what I was trying to describe, the drawing is of 1 section of 8 that would make up a butt end plug. DRAWING (http://www.pmaynard.lunarpages.com/temp/core2.jpg)

kc8pql
07-14-2005, 10:23 PM
I feather internal plugs like this. The one shown is a solid plug for the masthead. The feathers are made by making vee cuts to the center of each flat of the octagon. Small plugs like this are cut on the bandsaw. I make large plugs for the foot, partners and spreaders birdsmouth style, sized to fit inside the mast. That way the hole for wiring and drainage is built in. If they're to long to handle on the bandsaw, I cut the feathers with a skillsaw.
http://tinypic.com/8wkpz9.jpg

Philip Maynard
07-15-2005, 06:37 AM
that's much easier to make than what I did.

Carlsboats
07-15-2005, 08:15 PM
Can't agree with Bob Cleek's bias against samllish spars made birdsmouth style. I just made spars for a new boat, including a gaff about less than 2" in dia.,11' long. Earlier, I made a mast
for a Shellback that way. The strips were a cinch to mill and went together with no fuss. Best of all, the spars were not only light but very strong and rigid --just what you want.
Yes, in this case, you could clap together two piece of fir or spruce with a groove down the center. That makes a good spar too. But I wouldn't turn away from birdsmouth construction
without giving it a try.

ion barnes
07-16-2005, 02:38 PM
I watched a gentleman at the Port Townsend Woodenboat Festival four years ago build birdsmouth shafts for oars and spars. Incredable!

Solid wood is a waste of wood and if you have inferior wood or less wood, you can make better use of it. If you dont have 16' staves or they have defects, you can scarf joint to the desired length, alternating the joint spacing.

I always try to do something different on a project, I guess its the experimental phase of building, and its should not be discouraged. Yes if its a need to get it out the door, go find a pecker pole that will do the job but if time permits, try something you have wondered about.

Doug Wood
07-18-2005, 10:05 AM
As an FYI, Aime Fraser is scheduled to demo the building of birdsmouth hollow spars at the WBS in August - 12:30 on Friday.

George Roberts
07-18-2005, 12:19 PM
I have made 1-1/4"dia x10'long bird's mouth paddle shafts and have made similar in solid stock.

While it is easy enough to make the sawing safe, I expect most people will not do so if they are making a single mast, spar, or paddle shaft.

For small diameters even with defect free wood there is too much waste of material to make the process cost effective. For small diameters there is not enough weight for the savings to be important.

It looks like the spar will be only 15-20 pounds. Hardly worth the time and effort of making a hollow spar. 2 hours of time if you don't count the time at the lumber yard.

mdevour
07-18-2005, 02:22 PM
Originally posted by George Roberts:
While it is easy enough to make the sawing safe, I expect most people will not do so if they are making a single mast, spar, or paddle shaft.
I must not be "most people," George, because all of my thinking towards the idea has been centered around the fixturing for cutting those strips. ;)

The process is appealing enough that I hope this wouldn't be the only time I use the fixtures I make. We'll see.



For small diameters even with defect free wood there is too much waste of material to make the process cost effective. For small diameters there is not enough weight for the savings to be important.
Well, if it allows me to use well selected but cheap lumberyard wood rather than clear specialty woods like Sitka, it kind of makes up for itself at least a little.

As for the weight... I guess it's a matter of taste, whether it's going to be worth it.

I have solid spars on my 16' skiff, and they're fine. In fact, I remember the remarkable sensation of hefting the mast for the first time after getting the rough blank cut and routed to shape. I was astonished at how "alive" it suddenly felt, balanced in my hands, compared to the dead weight it seemed before.

I can imagine how it would feel if it was 40% lighter? :cool:

Well, since my son has realized we won't have the boat ready for our upcoming vacation, we're easing back to a more comfortable building pace. So now I have the time to devote to more tinkering and maybe trying it.

I do wish I had a band saw to make those beautiful feathered plugs. Hmmm... Wait, I have a very nice 20" scroll saw that ought to do very well since I'm building on such a small scale.

Cool! We just might have something here... :D

Thank you everyone.

mdevour
07-18-2005, 02:32 PM
Originally posted by Keith Wilson:
I added a little tab on the aft end of the mast to hold the peak grommet of the sail; I never liked way the Gypsy sail looked lashed to the hole in the mast.Keith, is there any chance you can post a picture or a sketch of this modification? I'd like to know what it looks like and if it has worked as you hoped it would.

Thanks!

Mike

Bob Smalser
07-18-2005, 03:05 PM
Originally posted by M. G. Devour:
I must not be "most people," George, because all of my thinking towards the idea has been centered around the fixturing for cutting those strips. ;)

The process is appealing enough that I hope this wouldn't be the only time I use the fixtures I make. We'll see.
http://pic3.picturetrail.com/VOL12/1104763/7099973/104971463.jpg

No need to buy anything fancy to cut bird's mouths on your average size spar.

Any cheapo TS with two garden-variety feather boards that'll take you all of 8 minutes to make will do the job very well and very safely.

Add roller stands fore and aft, and doing a 15' spar all alone isn't difficult.

I have the entire picture sequence of the uncomplicated method I use to make these spars...

...will it help you for me to post it?

I largely agree with Bob Cleek about smal spars and strongly recommend mast bands instead of solid blocking.

By the time I gandered at all the blocking I'd need for my latest set of spars, the weight gain of hollow spars was largely negated and I coulda gone solid in a lighter scantling and achieved about the same thing.

[ 07-18-2005, 03:20 PM: Message edited by: Bob Smalser ]

George Roberts
07-18-2005, 04:28 PM
It looks like it takes 4 clamps to hold the stock down and keep one's hands away from the blade.

I would use 2 pieces of solid stock rather than 2 feather boards but that is a personal issue.

For better or worse getting that much stuff together is often not done for just 8 passes on the table saw.

Bob Smalser
07-18-2005, 06:53 PM
16 passes on the TS.

8 on the shaper or router table.

Both work just fine.

Any 90-degree V-bit will work in the shaper....you don't need anything special.

Both require feather boards for an accurate job single-handed.....and I use them when I have an offbearer, too. Saves mistakes and the attendant stock.

http://pic3.picturetrail.com/VOL12/1104763/7099973/105008869.jpg

[ 07-18-2005, 07:02 PM: Message edited by: Bob Smalser ]

Stephen Hutchins
07-18-2005, 07:49 PM
Hmmmm... That V groove router bit is interesting. I wonder if we could rig a router to rout the top of a plank?

Bob Smalser
07-18-2005, 07:53 PM
Originally posted by Stephen Hutchins:
Hmmmm... That V groove router bit is interesting. I wonder if we could rig a router to rout the top of a plank?I've done them with the TS like in the pics above.....with a common router v-bit mounted vertically into a sacrificial fence on a router table....and with a shaper and v-bit mounted horizontally using the stock shaper fence.

Lotsa ways to skin this cat, depending one what tools you have access to. All require feather boards.

[ 07-18-2005, 07:54 PM: Message edited by: Bob Smalser ]

Keith Wilson
07-18-2005, 11:37 PM
Oh Lordy - I just posted a reply to Dennis Marshall in the bilge’s evolution thread here by mistake. Sorry, folks. This is what I meant to say.

I was trying to answer the question about the Gypsy mast. No digital camera, so no pics, alas. Anyway, there are two little tabs extending back from the masthead. They are made of 6mm marine plywood and are about 1” x 1-1/2” or thereabouts, epoxied into little notches cut on either side of the masthead. The front end is rounded to match the contour of the mast, and the back end of the tabs is rounded in the other direction. There’s about ½” between the tabs, and after gluing it up I drilled a ¼” hole through both of them. The peak grommet goes in the fork, between the plywood pieces, held with a pin.

I’d certainly do it again. It’s a very minor point, but the sail sets a little better, and there isn’t a wrinkle at the peak like you have with Bolger’s arrangement.

I did the V-notches in my staves with a hand-held router and a v-grooving bit. I made a little guide that bolts to the router base and keeps the bit centered on the work. There are lots of ways to do it.

[ 07-18-2005, 11:48 PM: Message edited by: Keith Wilson ]

Philip Maynard
07-19-2005, 01:29 AM
It seems that a table saw with feather boards can cut the grooves without to much trouble, what I found more difficult was an easy way to taper these 16' lengths to get a 2-1/2" or 3" base dia to a 1-1/2" top diameter - and its not a straight taper, it would be gently increasing curve, tapering more quickly towards the top. What would be an easy way to jig that with limited space to work in?

Keith Wilson
07-19-2005, 09:14 AM
I cut the taper on the band saw, then planed it to a fair curve by hand, If you clamp carefully, you can plane all six staves at once. Perfection is not necessary; epoxy fills small gaps very well, and any lumps can be taken out as you make it round.

Bob Smalser
07-19-2005, 09:23 AM
Originally posted by Keith Wilson:
I cut the taper on the band saw, then planed it to a fair curve by hand, If you clamp carefully, you can plane all six staves at once. Perfection is not necessary; epoxy fills small gaps very well, and any lumps can be taken out as you make it round.Even for a straight taper, making and handling alone a taper jig that size for the TS is a bit of a challenge.

http://pic3.picturetrail.com/VOL12/1104763/7099973/105076030.jpg

http://pic3.picturetrail.com/VOL12/1104763/7099973/105076026.jpg

[ 07-19-2005, 09:50 AM: Message edited by: Bob Smalser ]

Keith Wilson
07-19-2005, 01:34 PM
Geez, your workmate is almost as pristine as mine! ;)