CS17 #226

[Roger Peterson]

Par,

Thanks for the Router table fence detail. Much simpler than I made it in my minds eye. I think I'll give it a try this afternoon when I get home from work.

I have a Selway-Fisher Waterman canoe I built a few years ago with a soild mast and I have been wanting to make a birdsmouth mast for it for a long time.

I just bought a new Table saw (Steel City Hybrid) and have been thinking about using it for the birdsmouth mast but I'm a little scared of it. I removed my right thumb on a tablesaw about 25 years ago and it's taken me awhile to cowboy up. I've been using hand saws and jig saws to build boats with but with a home remodel project looming, I really needed a table saw.

The worst part is the  ZZZINGGG  sound when I make a short cut....

Anyway, Thanks for another way to get the job done in case I "chicken-out" with the table saw.

Roger

[Charlie Jones]

Won't look as classy???

On Pilgrim you can't tell which is aluminum and which is wood, once they were painted. Nor can you on the CS 20 I did.

On the table saw- I just kick the blade to 45, set up a finger board- I have the table saw table drilled and tapped on both sides for those. Then slap on a hold down, run the stave through, end for end it and run it through again. 2 minutes per stave and the mouth is cut.

I found that the dado blade sometimes chipped out chunks of wood, and occasionally ruined a stave. So I stopped using those- also in the time it takes to change out the blade and set it up, make the cuts and change the blade back, I can have 8 staves cut.

Don't make cutting the mouths a big deal- it really is simple. And fast.

And use a push stick- then any oopsies happen in that instead of fingers. I don't cut on a table saw without one unless it's a WIDE rip.

[Apteryx]

True, nothing ugly about Pilgrim, not by a long shot.  More options for mounting hardware to aluminum too - you can't pop rivet spruce.

How do you taper the staves?  Band saw?  Tapering, a new-found interest of mine... 

[Hirilonde]

I've had zero confidence in anything free-hand, but last night I tapered my first seat stringer.  Amazing.  I think I took 20 minutes with a jack plane, cutting down to a pencil line, and the taper is only barely short of machine precision.  A metal straightedge appears to fit precisely.  Looking closely, there is some variation but the surface undulations are probably no more than a few thousandth's of an inch.  I'm cool with that!

;)

With all the wonderful advancements in tools nothing has even pretended to replace the hand planes.  Many people think only old timers or highly experienced woodworkers can use them.  You have just proven that with a little care and attention this is wrong.  They assure you only remove a little at a time and you can correct your approach as you go with little chance to ruin your piece unless you rush.

How do you taper the staves?  Band saw?  Tapering' date=' a new-found interest of mine...  Smiley[/quote']

Lay out taper, rough cut with table saw, band saw, or whatever makes you comfortable, then dress it off with your new favorite tool  ;D

[PAR]

A few rectangles, some text and arrows, no big deal, 5 minutes.

I taper staves with a saw guide, that is a long, fairly heavy piece of T shaped aluminum stock. I clamp or screw it down over the work, with the amount of back set I need for what ever tool I'm using, which often is a laminate trimmer and a straight bit.

[Ken_Potts]

I taper with a hand held jig saw well outside the line and then a plane for the accurate stuff.

[Charlie Jones]

I taper witth one of my band saws, then set that edge facing up, clamp the staves together and

Are you ready for this?

Plane the edges smooth all together.

AFTER I cut the birdsmouths

I have a few planes- LOVE using them- wonderful tools

[Apteryx]

I got excited over the scarf joint in my keel batten in another thread - there's pictures somewhere of my freehand tapers.  Or, I should say, of my plane's tapers.  I just skidded the thing back and forth while the tool did the precision part of the work.  ;D

The plans say the keel batten doesn't need to be shaped, but I decided to start with a 9 degree vee the full length of the batten.  I don't want to have to worry about voids in the epoxy underneath a simple 1x4.

The vee rip-cuts go through that scarf, of course, so I got to see a little of how it looks inside.  The way I made the joint is I wetted out the wood with unthickened epoxy, unhurriedly so it would have time to penetrate the wood a bit.  Both surfaces got about a 1/32 inch coating of thickened epoxy and I placed the two pieces together.

Clamping was done with two 15 pound barbells standing on end on the joint.  That seemed enough to promote good squeeze-out but left a glue line.  Sighting the length of the board helped align the pieces, and the finished part required no fairing, just a few passes with a sander to clean up the glue.

Although I want a good fit I left a flat spot on the batten.  My thinking is a fillet down the point of the vee, between the batten and the hull, is better than wood fitted to a point.  This way there's no spot on the wood where force would be concentrated in any flexing.

There won't be much filler under the batten, though.  For some reason I didn't get a perfectly repeated cut with my table saw, and, oh darn, I have to use my new favorite tool (the mighty hand plane!) to make it right.  ;D

[Hirilonde]

Someone is having way too much fun with planes.  Next will be a draw knife and spoke shave.

[PAR]

I have to admit I prefer using a hand plane too. I have quite a few and find it easier to control the cut. I just tapered some booms and used a #4 Bailey. A power plane would have been faster, but they can remove so much wood, so quickly, you can easily cut more then you want.

[Apteryx]

I've been looking for 16 ga. stainless wire but I haven't found any.  Baling wire is available locally.  Somehow the sound of holding my boat together with baling wire is unappealing, but it's strong stuff.  Generally always oxidized, though, and I would hate to contaminate the epoxy coating.

Any suggestions where to find appropriate wire?

[Ken_Potts]

  I bought a few feet of some big (2/0?) multi-strand copper wire and used that - I stripped the insulation off and unwound the individual strands.  Some people have reported success using cable ties but I haven't tried that.  If you use wire you can (should?) remove it once you've got the panels epoxied together.

  A tip for the future, if you haven't heard about it yet - Wire slides right out of cured epoxy if you heat it a bit with a soldering iron or even a cigarette lighter.  That's one of many things that I've learned from the fine folks on this board    It's pretty cool that even the most stuck wire slips right out when heated.

  So it's probably just fine to use the galvanized stuff since you don't have to leave it in the boat.  Just don't heat it enough to make it give off fumes (it doesn't take much heat to lubricate the epoxy).

[PeterP]

Ken just beat me on  this post. So I'll just sort of belabor the point. Bailing wire is the ticket for wiring the panels together. If that is what you want it for. It gets pulled out by most builders.  While back Charlie had a post about using 12V battery to heat up the wire to facilitate extraction. I just managed to pull mine using end nips. If you end up with a bit of wire buried in the wood it will most likely end up under a layer or two of tape, epoxy, paint etc etc. out of sight out of harm. Stainless would be a total waste here. Save the money for where it is going to be seen. PeterP

[Ken_Potts]

That probably means your instructor doesn't build stitch and glue boats  ;D

[Peter HK]

My Marine electrician instructor went ballistic when I mentioned using a jumpstart battery to touch off the tie wires to facilitate removal.

He's probably never seen the technique of starting a campfire with the sparks from shorting leads from the 4WD battery either

Peter HK

[tom151]

When I built the masts for the Princess 22 I weighed the aluminum lowers and the wooden upper halves separately- the wooden uppers were lighter than the lowers by a few pounds- not enough to get excited about really, but lighter.

Charlie,

Would you provide some details please...

for the wooden uppers: what was the finished dimension OD?, ID? and what was stave thickness before rounding/tapering?

for the equivalent alloy tubing: what was the diam?, wall thickness?, alloy specification?

Do you have specs for all-wooden birdsmouth masts for the P22? or is it only spec'ed as alloy lower sections?

Thanks a lot,

[Norman Colter]

My set of plans included specs for all wood birdsmouth from Graham.

easy to make, light, flexible. Looking forward to Spring.

Norm

[Apteryx]

Thanks for the wire comments - I found 16 ga. galvanized last night at the local chandlery (Tractor Supply).  It's galvanized but not rough and is rated for a minimum breaking strength of 100 pounds.  Aluminum was rated for 30 pounds for comparison, and I don't think I want to trust zip ties.

Concerning birds-mouth masts, how do you clamp them?  My guess is a ribbon of plastic topped with a constrictor knot seizing would do the trick, maybe one every six inches or so.

I don't know if I posted this elsewhere or not, but Hefty contractor garbage bags work well for clamping.  There is absolutely no adhesion between epoxy and the plastic they are made of.

[Charlie Jones]

;D ;D

TomH- You have got to be kidding

;D ;D

I built that boat 5 or 6 boats ago. I don't recall what the exact sizes were- just that they all came out to the spec'd size of the mast aluminum tubes and they were tapered.  I THINK the masts were 3 inch, maybe 3 1/2. Whatever the plans called for. I'd have to go dig the old plans out of the store room, where ever they wound up, to see the exact sizes.

I don't even have a picture on this computer anymore- they've all been dumped to CD and stored, and I'm not close to the CD''s right now.

I'm sure the staves were 3/4 inch thick, probably 1 inch wide or close to that. Frank Hagan over on the boatbuilding half of this forum has a website with a formula for sizing birdsmouth masts though. I printed that and use it for all my calc's- it does give you a tad oversized spar so then you plane off a tad more.

Apteryx- I use bicycle inner tubes cut apart so they are one long strip. I get them from a bike shop in town for free- old ones that they don't want to patch. I wrap them around them selves to start, then in a long spiral, then tie off and add another as needed. I've also used hose clamps, but the inner tubes seem to give just the right pressure. Again, I've got pics, but not where I can get to them immediately.

Ray- just goes to show you- instructors don't necessarily know it all, particularly on things not in their field.

[Charlie Jones]

Well, since all you are doing is "popping" the wires. Takes longer to say "popping" than it does to do it, I seriously doubt the battery ever knows the difference. We're talking micro seconds of short here, cause if you do it longer, the wire gets too hot and burns the wood.

For the time it saves yanking wires, I could afford a new Jump-it every 4 or 5 boats (or more)  though.