jib track placement

[Rico]

Hey Marcelo,

Your 30" track COULD be sufficient for your boat provided it is in the right location for ONE of these sails... Either the 135% OR the 150% depending on where the track is...

I highly doubt that it would give you enough range to properly trim a 135% AND a 150% jib.

It is hard to say much without actually seeing the sails at work on your boat.

Proper sail trim depends on the specific sail (cut, shape, etc.) and the conditions (especially with a furler as they can adopt a strange shape under load when not fully unfurled...), as well as the location of the cars, AND the location of the track itself on the boat.

I've read a bit on the subject and found that Ivar Dedekam's short & sweet book "Sail & Rig tuning" nicely illustrated the basic points.

There are MANY discussions on the web, but many are confused and contradictory. It is all Physics, but there seems to be all sorts of opinions... The books help keep the focus on the topic succinct & to the point.

The right answer inevitably depends on the conditions... Wind direction, wind intensity, and intended course relative to this. As well as The sails, sheet geometry and the boat... it is not a very hard subject - just one that takes a bit of skill and 'art' as it depends on many variables.

[ebb]

Going to own the Dedekam book, Thanks for the tip.
Reviews are ALL positive, if not ecstatic, about his explanations and great diagrams.
Amazon samples one page of colored graphics that alone makes this book look really exceptional.

Local Barnes and Noble store don't have it in stock.
But they'll get it delivered to me for $19.32 in four days.

[commanderpete]

I try not to partially furl the genoa. The boat performs better with a reef or two in the main instead.

My genoa tracks don't run forward enough for a partially furled genoa either. I've experimented with using a "barber hauler" made up of snatch blocks on a short line attached to padeyes on deck. (like the small picture below). This way I can use the same genoa sheets and still pull the sheet down and inside a bit when the genoa is partially furled.

There is a pretty good general discussion on genoa sheet leads at the UKHalsey website with a few diagrams

http://www.ukhalsey.com/LearningCent...clopedia5b.asp

I'll reproduce it here in case the link fails



UK-Halsey's Encyclopedia of Sails
-- Genoa Trim

Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Main Sail Trim
Genoa Trim
Sailing to Telltails
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 10

[vanguard64]

I will be purchasing Ivan Dedekam's book promptly. Great suggestion! The barber hauler is an interesting concept. How well do they work? When you say that you rather not furl the headsail and instead reef the main, what size genoa are you flying? Do you have any pics of the barber hauler setup on your boat?
Thanks,
Marcelo

[commanderpete]

Hi Marcelo

I have a 135 furling genoa on my boat. I don't have any pictures of the barber hauler set up. But, you can use any sort of block. The idea is just to deflect the angle of the sheet without running the sheet through a permanent lead block.

Sometimes a barber hauler is called an "inhauler." You also use these when flying a spinnaker and they call them a "tweaker" or "twing."

My idea with using a barber hauler was to get a little better shape and pointing ability out of the partially furled sail.

How well does it work? I really cant say how much it helps. If I'm rolling up the genoa I've already got two reefs in the main so its blowing like stink. I probably dont feel like pointing as high as possible. I'd rather foot off a bit in the waves and to keep from getting soaked repeatedly bashing to weather. So, I'm not sure I really need to pull the lead inboard. Besides, a partially furled genoa doesnt point as well anyway with the disturbed leading edge. Pulling the sheet down may help, but you still want the lead set aft so the top of the sail can twist off in strong winds.

Just something I've played around with.

You mentioned having a problem with your furler. Shouldnt you be able to partially furl the sail to any size with a CDI , regardless of sheet lead position?

[vanguard64]

The furler is working fine. My two main concerns are being able to adjust the trim as the clew moves forward and the fact that when the sail is furled the un-reinforced sections of the sail now have to bear the chafe and pressure of the wind. It seems more apparent as I think about this that the best for the health of the sail is to not use the furler as a reefer even though CDI claims you can reduce sail area upto 70% and still maintain a decent shape as long as you have a "padded" luff. There have been times when I have had to take in 1 reef in the main and keep the 135 but sooner or later I will find myself needing to take more in and this is what I am preparing for. I haven't tested her with the 135 completely furled and just 1 reef in the main but on my previous boat, a Pearson Vanguard, the main didn't have much drive and you found yourself being overpowered by the waves themselves.

[manderson]

I'm working on Commander 94 and am planning on installing longer jib sheet tracks on the toe rail (boat has life lines). I just read/skimmed through the older thread on the subject but still had a question about bending the track. I would like to install a 6' section of 1" stainless steel track (similar I believe but longer than the original track used on these boats). this track seems to be quite stiff and am having doubts of whether it can be bent to follow the rail while installing. I was thinking the schaffer track referenced in the older thread in most cases may be the newer style aluminum extrusion and easier to bend?

Does anyone have experience with bending the 1" ss track? Can this be done?

I very much enjoy reading the technical forum here as I come up with qestions and develop my own plans for the boat.

Best regards,

Mark

[ebb]

Search using google
jibtrack placement [Archive] - Pearson Ariel Association

[manderson]

Thanks Ebb. I skimmed through the thread and see reference to both ss and aluminum track, but nothing specific about the difficulty or ability to bend the stainless track. I'm thinking the comments regarding bending may all be related to the aluminum extruded track.

Still wondering if anyone out there has been able to install 1" ss track on the toe rail or if bending is too difficult.

thanks,

Mark

[ebb]

It's difficult. Guys who talk about it on forums never want to do it again!

They say do it 'incrementally'. Start at an end, fasten, then bend, fasten, etc.
If you are going to do it this way, C-clamp (2 or 3) the end with 6" to 10" long pad sides (like below here) to totally immobilize the T-track.
Having two of these. One for the end, and a second as a clamp moving forward might be all that's needed to mount the track....

One thing to be aware of is that when you have successfully created a cold curve in something as stiff as T-track,
the ends of any metal strip stay straight - impossible to curve. Have to try and fool it.
So thinking about this: I'd have the track a foot or so longer than necessary at both ends. May not have to.... but that will allow the extra track to be temporarily fastened to the rail creating a fair curve in the track that is to remain.
After it's caulked & installed, cut the ends to spec. Add extra closer together fasteners at ends, as keepers. Also install track END stops.

Something to think about:
The rail essentially has to have all holes drilled and chamfered before the CAULKING goes on. How can we do that?

Can see long 3/4" hardwood strips on both sides of the track - and a whole bunch of C-clamps.
First visualize BENDING THE WHOLE TRACK into final position between two temporary walls of oak.
Radius the bottom interior edge of the oak strip on deck to get it to lay flat against the fiberglass rail.
Because the inside of the toerail leans out about 25°, this strip has to be milled into a truncated profile (wider on top) to give the clamp heads some flat and equalized landing - otherwise they'll slip or pull the strips out of line. Another reason to stabilize the wood strips with carpet-tape.
The top of the rail in relation to the outside is approximately 90°. Might need two people to do the initial clamping
Can see carefully sized smaller strips of the same wood that are slipped under the T on both sides
- and are actually used to center and stabilize the T-track on top of the toe-rail.....in the clamping process.

Maybe this is too complicated, maybe not. The actual bending curve of the rail along the A/C cockpit is not too radical.
Whatever style of track, it's still going to be very stiff and quite long.
But T-track is being bent onto many boats, which has no doubt been taken into account by the manufacturer. Not THAT stiff!
Maybe it's left partially annealed to take a set. Imco, our toe-rail curve is too mild for track to keep a bend. It'll spring back when released.
Manufacturers sometimes prebend curves for customers.

T-track, oak strip and spacers is a lot of stuff to keep organized while bending.
Might also carpet tape the wood spacers onto the underside of the T, attempting to keep them attacht.... so that after the holes are drilled AND chamfered (extremely important for waterproofing and keeping salt out), the clamp-up can be disassembled AND put back together again after the caulking is applied, have to see. Clamped back into a fair curve, matched to the new fastener holes. Using butyl tape means you can have squeeze-out without making the disaster polysufide promises. Butyl sealant tape is already 'cured' and squeeze-out comes off clean.***
Keep the track extra long until after complete install. Then cut, dull edges, and buff.
One thing the A/C has going for them is that the rail is bent to a single plane.
Fiberglass** carpet tape is a temporary stickum. Difficult to remove, but it does come off..... Keeps wood from slipping.

Probably have a problem with what you are going to do with the cove inside the rail - how and where to attach nuts and washers. If your track is going aft by the cockpit, you might have to hire a midget to get under there to backup the fasteners properly.
The top of the rail on A338 is pretty thick. You may only going require a regular washer inside there.
Most forum responders say they never had a problem with that. INSIDE of the toerail on top is curved. A thin washer will bend a little when tightened, creating a nut lock. Fastner holes must drill in dead center top of the toerail.
Others have blocked the backup out to make a wider pad for nuts, longer bolts, and better access.

A simple job made complicated??? Maybe it'll go on 'incrementally'. Try it that way first.
Just throwing this out to get discussion going.
.................................................. .................................................. .................................................. ...............................................
*The extra longs can temporarily be fastened to the rail FROM THE TOP by tapping for machine screws. The toerail is (on A338) at least 1/4" thick and will tap coarse thread for MS. May not need to do this, but possible. Fill holes later. Maybe tempted to use this as lagging to attach T-track. NO!
**double-sided FIBERGLASS CARPET TAPE refers what the adhesive is backed with . Cheap hardware stores don't stock it. Fiberglass allows tape to be pulled off after you've used it. hardly ever all of it at once - but you can't pull the cheaper stuff off at all. Naptha cleanup. Put it on in pieces, not strips.
***3M makes a very expensive 3/32"h X 1/2"w black butyl tape expressly for installing T-track called WEATHERBAN (Jamestown). Squeeze-out using this stuff will be minimum

[Bill]

Bending SS Jib Sheet Track merged with jib track placement

[Ariel 109]

Harbor Freight sells this tubing roller that with the purchase of an addition die-set will curve rectangular stock on end, like a jib track. This machine is well made and a good value for a backyard workshop.

http://www.harborfreight.com/tubing-roller-99736.html

http://www.harborfreight.com/3-piece-die-set-66598.html

[ebb]

Looks like a great tool, Ben!
How to hold T-track on its side to fit the groove in the die will take some experimenting.
Maybe hardwood filler strips will work.
Or machine-shop altered rollers (cutting in a deep groove on one side of the appropriate (2)die channels) that'll track the wings of the T.
Or a two part jig attached to the bending machine that holds and feeds the T-track on edge going in and coming out.
Again with woodstrips to guide the track in the channel of the roller die while it's bending. Mild bending, but a lot of pressure.

It would indeed be great to prebend the track so that it can be placed onto the rail without dislodging the butyl tape.
.................................................. .................................................. .................................................. ..............................................

It'll be difficult.
Reassembling straight track that requires that hardwood jig, mentioned above, to get it to curve
means that some method is needed to hold the bend over the the toerail with the caulking tape attached
(either to the rail OR the track) AND lowering it without scuffing the tape out of place.

To me that means some kind of temporary longer straight round rod inserted probably in each or every other drilled bolt hole
just to guide track & caulk to locate correctly for the fasteners.
It is important for butyl to get compressed into every chamfer. So some measure of finesse is going to be needed.
Haven't thought this move through yet!

[Bill]

It would seem to me, that unless you're looking for something that will last over 40 years, using aluminum track should be an acceptable solution. I believe that all the AC yachts, where the track was placed on the top of the rail, used aluminum track. For eg, see A-100.

[Ariel 109]

Using Delrin plastic for the die-set on a tubing roller would great for curving aluminum track. The Delrin won't mess up the anodisation on the track. You can buy the Harbor Freight tubing roller at their stores for around $60 without a base and clamp it on a workbench.