I want to install a CDI furler on my boat. My headstay length is 31.5' pin to pin. I am shopping the used sail warehouses. What is the maximum luff I should look for to allow space for the upper bearing and the furling drum. I ask this question because the sail will come first and later the furler.
- Status
- Not open for further replies.
K
Kevin
Check CDIs web site
Don, I seem to recall that CDI had pretty good specs and installation info on their web site. Kevin
Don, I seem to recall that CDI had pretty good specs and installation info on their web site. Kevin
J
J Cianflone
If the sail comes first
it will need to be modified anyway. My sail guy had me install the cdi furler and then take my measurements. You will need to cut the furler to fit when you install it. With the furler installed I hoisted my tape measure up the unit. Bob Johnson in Dunedin did a great job.
it will need to be modified anyway. My sail guy had me install the cdi furler and then take my measurements. You will need to cut the furler to fit when you install it. With the furler installed I hoisted my tape measure up the unit. Bob Johnson in Dunedin did a great job.
R
R.W. Landau
J...
If you buy a CDI Furler, Don't cut it to spec. CDI allows for owner error. In other words, you can make your luff foil length longer than they spec. If you have been sailing your boat and are happy with your mast rake,( weather helm or lee helm corrected) try this first. Lay your forestay on the ground. Lay the luff foil with the drum connected next to it like it is to be connected. Cut the foil so that the top bearing rolls on the swag fitting and not the cable forestay. This does about three things. The bad thing first. Your forestay will then not be adjustable. To remove the mast you will need to do all the loosing at the backstay. The good things: first, you can max out your jib luff. Second, the furler will roll on the swag fitting and not the wire so the chance of unwinding your wire forestay is much less if something hangs-up. I do think that CDI has the best system going. There is no halyard wrap, the luff can actually support more sail in light air due to the even load on the luff foil, and there are almost no moving parts to go bad! The important thing is to have a sail made for the furler. If you set your traveler right, trimming the sail is easy in all weather. I would use a sail loft that knows your boat and the furler system. If I were you, do them both at the same time. To have a sail made then have it fitted with luff tape and UV cover may compromise the sail design. r.w.landau
If you buy a CDI Furler, Don't cut it to spec. CDI allows for owner error. In other words, you can make your luff foil length longer than they spec. If you have been sailing your boat and are happy with your mast rake,( weather helm or lee helm corrected) try this first. Lay your forestay on the ground. Lay the luff foil with the drum connected next to it like it is to be connected. Cut the foil so that the top bearing rolls on the swag fitting and not the cable forestay. This does about three things. The bad thing first. Your forestay will then not be adjustable. To remove the mast you will need to do all the loosing at the backstay. The good things: first, you can max out your jib luff. Second, the furler will roll on the swag fitting and not the wire so the chance of unwinding your wire forestay is much less if something hangs-up. I do think that CDI has the best system going. There is no halyard wrap, the luff can actually support more sail in light air due to the even load on the luff foil, and there are almost no moving parts to go bad! The important thing is to have a sail made for the furler. If you set your traveler right, trimming the sail is easy in all weather. I would use a sail loft that knows your boat and the furler system. If I were you, do them both at the same time. To have a sail made then have it fitted with luff tape and UV cover may compromise the sail design. r.w.landau
B
Bayard Gross
My experience with CDI furler
I have a CDI FF2 furler on my Catalina 22 that I installed by myself. Noting your forestay length, I believe you may be getting this same furler or the FF4. I do not know what you know about this furler. However, while it is relatively simple too install, uses the common number six luff tape and is robustly built with negligible maintenance, its self contained halyard which produces a flat extrusion is not a good design. While this feature eliminates halyard wrap, getting good tension on the jib luff when hoisting the jib becomes problematic. Please see my recent response entitled “CDI FF2 furler modifications” under the question “Knots” in the Ask All Sailors menu. (Link below) In addition to this difficulty, the flat extrusion aligns differently on windward to wind abeam port and starboard tacks with the furler’s counterclockwise furling and clockwise unfurling, usually the norm as most furling jibs have their sun protection on the starboard side. On a port tack with the sail out fully, the furler drum easily turns counterclockwise as it “pushes” the furling line wrapped about it back out. This means the flat extrusion actually has its flat side facing forward and it creates a large curve in the luff of the jib. This condition itself is not bad, but it does have some effect upon sail trim. Neither adjusting the jib sheets or the jib cars will eliminate this condition. (And no, the furling line cannot be adjusted, as I have not found a way to push lines, only pull them.) On a starboard tack with the sail out fully, the furler aligns more directly into the wind. This is because the drum turns clockwise and then stops when it pulls against the secured furling line or otherwise fills up in the drum sufficiently to where its bulk rubs against the inside of the drum and prevents it from turning clockwise any further. Thus, a slightly different sail trim than on a port tack. While not actually horrible, it is annoying. Now compare this to a furler with a round extrusion. While drum rotation would be the same, the round extrusion has a uniform surface against the wind. As such, it does not generate the same curvature in the jib luff on a port tack as the CDI does. Further, the round extrusion will have a starboard tack luff similar to the port tack, while on the CDI there is this difference. Therefore, instead of the CDI, I think you may wish to examine the Schaefer Snap Furl. While this unit does not have the round extrusion as on a Harken unit, it is not nearly as flat as the CDI. Hence, I think it may not have the similar problems with different tacks as described above. However, I do not have any experience with this furler so I cannot say with conviction. In addition, the Schaefer Snap Furl requires a number five luff tape that is smaller than the more common number six as CDI uses. This can be a disadvantage if you decide to use a used furling jib which will more likely have a number six luff tape than a number five and hence need to have a number five tape installed. Further, sail makers that keep furling sails pre made in inventory for quick shipment, will usually have number six luff tapes on them. So for a new sail with a number five luff tape, you may need to wait to have a number five tape installed. Another item on furlers in general is that nearly all furler manufacturers recommend the addition of a toggle at the top of the forestay in addition to the one at the bottom due to the side loads that the furlers effect upon the forestay. Thus, in addition to a new furler, you may wish to obtain a new forestay with this top toggle. It is the same length as your current forestay but shortened to accommodate the additional length of the toggle. Nevertheless, as at this point you have not totally committed yourself to any particular jib, I would like to make one important suggestion when you install whatever furler. Most furlers have an extrusion that is separate from the drum. By this the extrusion can be lifted off and up above the drum exposing the forestay. However, the only way this may be performed is if the furler extrusion is cut short enough from the top to permit about eight to ten inches of upward movement. Now, why is this ability to lift the extrusion sufficient to expose several inches of forestay important? So you can check forestay tension with your Loos gauge. Unfortunately, many furlers are installed with the extrusion too long to allow it to be moved up to check forestay tension. This is because furlers with a swivel (not the CDI which has an internal halyard), the closer to the mast exit of the jib halyard the swivel is located, the less the opportunity for halyard wrap. Hence, I think it is very desirable to cut the extrusion at a point that will allow you to lift it up to check forestay tension, provide sufficient hoist for the jib, and avoid halyard wrap. In addition, of the three, I think avoiding halyard wrap at the expense of loosing the ability to check forestay tension is more important. Nevertheless, there are devices placed on the front of the mast that are below where the jib halyard exits from the mast truck that give the halyard a more perpendicular angle to the forestay. This prevents halyard wrap and thusly permits cutting the furler extrusion short enough to allow for checking forestay tension. This brings us back to CDI with its internal halyard, which despite the difficulties aforementioned, does by its nature, eliminate halyard wrap and therefore allows easy cutting of the extrusion to a point that meets your hoist needs and allows the extrusion to be lifted for forestay tension checks.
I have a CDI FF2 furler on my Catalina 22 that I installed by myself. Noting your forestay length, I believe you may be getting this same furler or the FF4. I do not know what you know about this furler. However, while it is relatively simple too install, uses the common number six luff tape and is robustly built with negligible maintenance, its self contained halyard which produces a flat extrusion is not a good design. While this feature eliminates halyard wrap, getting good tension on the jib luff when hoisting the jib becomes problematic. Please see my recent response entitled “CDI FF2 furler modifications” under the question “Knots” in the Ask All Sailors menu. (Link below) In addition to this difficulty, the flat extrusion aligns differently on windward to wind abeam port and starboard tacks with the furler’s counterclockwise furling and clockwise unfurling, usually the norm as most furling jibs have their sun protection on the starboard side. On a port tack with the sail out fully, the furler drum easily turns counterclockwise as it “pushes” the furling line wrapped about it back out. This means the flat extrusion actually has its flat side facing forward and it creates a large curve in the luff of the jib. This condition itself is not bad, but it does have some effect upon sail trim. Neither adjusting the jib sheets or the jib cars will eliminate this condition. (And no, the furling line cannot be adjusted, as I have not found a way to push lines, only pull them.) On a starboard tack with the sail out fully, the furler aligns more directly into the wind. This is because the drum turns clockwise and then stops when it pulls against the secured furling line or otherwise fills up in the drum sufficiently to where its bulk rubs against the inside of the drum and prevents it from turning clockwise any further. Thus, a slightly different sail trim than on a port tack. While not actually horrible, it is annoying. Now compare this to a furler with a round extrusion. While drum rotation would be the same, the round extrusion has a uniform surface against the wind. As such, it does not generate the same curvature in the jib luff on a port tack as the CDI does. Further, the round extrusion will have a starboard tack luff similar to the port tack, while on the CDI there is this difference. Therefore, instead of the CDI, I think you may wish to examine the Schaefer Snap Furl. While this unit does not have the round extrusion as on a Harken unit, it is not nearly as flat as the CDI. Hence, I think it may not have the similar problems with different tacks as described above. However, I do not have any experience with this furler so I cannot say with conviction. In addition, the Schaefer Snap Furl requires a number five luff tape that is smaller than the more common number six as CDI uses. This can be a disadvantage if you decide to use a used furling jib which will more likely have a number six luff tape than a number five and hence need to have a number five tape installed. Further, sail makers that keep furling sails pre made in inventory for quick shipment, will usually have number six luff tapes on them. So for a new sail with a number five luff tape, you may need to wait to have a number five tape installed. Another item on furlers in general is that nearly all furler manufacturers recommend the addition of a toggle at the top of the forestay in addition to the one at the bottom due to the side loads that the furlers effect upon the forestay. Thus, in addition to a new furler, you may wish to obtain a new forestay with this top toggle. It is the same length as your current forestay but shortened to accommodate the additional length of the toggle. Nevertheless, as at this point you have not totally committed yourself to any particular jib, I would like to make one important suggestion when you install whatever furler. Most furlers have an extrusion that is separate from the drum. By this the extrusion can be lifted off and up above the drum exposing the forestay. However, the only way this may be performed is if the furler extrusion is cut short enough from the top to permit about eight to ten inches of upward movement. Now, why is this ability to lift the extrusion sufficient to expose several inches of forestay important? So you can check forestay tension with your Loos gauge. Unfortunately, many furlers are installed with the extrusion too long to allow it to be moved up to check forestay tension. This is because furlers with a swivel (not the CDI which has an internal halyard), the closer to the mast exit of the jib halyard the swivel is located, the less the opportunity for halyard wrap. Hence, I think it is very desirable to cut the extrusion at a point that will allow you to lift it up to check forestay tension, provide sufficient hoist for the jib, and avoid halyard wrap. In addition, of the three, I think avoiding halyard wrap at the expense of loosing the ability to check forestay tension is more important. Nevertheless, there are devices placed on the front of the mast that are below where the jib halyard exits from the mast truck that give the halyard a more perpendicular angle to the forestay. This prevents halyard wrap and thusly permits cutting the furler extrusion short enough to allow for checking forestay tension. This brings us back to CDI with its internal halyard, which despite the difficulties aforementioned, does by its nature, eliminate halyard wrap and therefore allows easy cutting of the extrusion to a point that meets your hoist needs and allows the extrusion to be lifted for forestay tension checks.
J
Jim LeBlanc
Get the furler first
You should definitely get and install the furler first. If you have a suitable head sail with hanks, it would need to be modified to fit the furler. If an new maximum size head sail is to be purchased, it should be fitted to the actual measurements of the installed furler. I was very impressed with Bayard's analysis of the CDI and of it's drawbacks. His suggestion of considering a Shaefer Snap Furl is also a very good one. He is mistaken however, the extrusion is in fact round (it is formed in two halves out of a very tough plastic which snap together over the head stay) and does not have problems with different tacks that he mentions for the CDI. I installed a Shaefer Snap Furl on my S2 7.3, with a forestay length of 29' 9.5 ", and I love it. Whereas, I installed a system similar to the CDI on my previous Catalina 30 and did not like it. In addition to being relatively inexpensive for a boat in the mid 20 feet range, the feature I liked best was being able to install the Snap Furl with no modifications to the headstay, i. e. no cutting, no new pieces, no filing on turnbuckles, no nothing. Since the original jib halyard is used, it is easy to adjust halyard tension. I did have to install a deflector (Shaefer makes those too) about one foot down from the top of the mast to ensure that the jib halyard is held away from the rotation of the upper end of the foil, but that was no big deal. The Snap Furl works great, running on upper and lower plastic ball bearing, and is both easy to install and to use.
You should definitely get and install the furler first. If you have a suitable head sail with hanks, it would need to be modified to fit the furler. If an new maximum size head sail is to be purchased, it should be fitted to the actual measurements of the installed furler. I was very impressed with Bayard's analysis of the CDI and of it's drawbacks. His suggestion of considering a Shaefer Snap Furl is also a very good one. He is mistaken however, the extrusion is in fact round (it is formed in two halves out of a very tough plastic which snap together over the head stay) and does not have problems with different tacks that he mentions for the CDI. I installed a Shaefer Snap Furl on my S2 7.3, with a forestay length of 29' 9.5 ", and I love it. Whereas, I installed a system similar to the CDI on my previous Catalina 30 and did not like it. In addition to being relatively inexpensive for a boat in the mid 20 feet range, the feature I liked best was being able to install the Snap Furl with no modifications to the headstay, i. e. no cutting, no new pieces, no filing on turnbuckles, no nothing. Since the original jib halyard is used, it is easy to adjust halyard tension. I did have to install a deflector (Shaefer makes those too) about one foot down from the top of the mast to ensure that the jib halyard is held away from the rotation of the upper end of the foil, but that was no big deal. The Snap Furl works great, running on upper and lower plastic ball bearing, and is both easy to install and to use.
- Status
- Not open for further replies.