Luff tape

All U Get

All U Get

.
Oct 2, 2008
3,810
Pearson/ 530 Strafford, NH
Hi all,

We have a Hood Yacht Systems furler called Seafurl and would like to know the size of the extrusion groove so we can order the luff tape from Sailrite. Being a 1985 vintage boat I’m guessing the extrusion style didn’t change and I emailed Hood an inquiry. Sailrite carries several different sizes so we’re hoping someone might know.
 
DrJudyB

DrJudyB

.
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
All U Get said:
Hi all,

We have a Hood Yacht Systems furler called Seafurl and would like to know the size of the extrusion groove so we can order the luff tape from Sailrite. Being a 1985 vintage boat I’m guessing the extrusion style didn’t change and I emailed Hood an inquiry. Sailrite carries several different sizes so we’re hoping someone might know.
Click to expand
If you know the model number of the Seafurl, you can look it up and be confident you’ve got it right. If you don’t know the model number, the only way to get it right is to test fit some sample tapes, or compare some samples to the luff tape on the old sail. Don’t guess, it could be an expensive mistake!

Ask Sailrite to send you a 6” long samples of some #6, 7and 8 tape. It’s one of those sizes. Test fit it in the furler. The tape should fit and slide easily, not too tight. If you choose a tape that fits too snugly, there will be too much friction to hoist and drop the sail in the extrusion.

Judy B
Retired sailmaker.
 
  • Like
Likes: JamesG161 and rgranger
capta

capta

.
Jun 4, 2009
4,902
Pearson 530 Admiralty Bay, Bequia SVG
Ours are #6 or 6mm depending on where the sailmaker is.
 
All U Get

All U Get

.
Oct 2, 2008
3,810
Pearson/ 530 Strafford, NH
DrJudyB said:
If you know the model number of the Seafurl, you can look it up and be confident you’ve got it right. If you don’t know the model number, the only way to get it right is to test fit some sample tapes, or compare some samples to the luff tape on the old sail. Don’t guess, it could be an expensive mistake!

Ask Sailrite to send you a 6” long samples of some #6, 7and 8 tape. It’s one of those sizes. Test fit it in the furler. The tape should fit and slide easily, not too tight. If you choose a tape that fits too snugly, there will be too much friction to hoist and drop the sail in the extrusion.

Judy B
Retired sailmaker.
Click to expand
I also have a short piece of mine to send them somewhere on this boat. Can’t find a model number, must be from the era where they thought this is as good as it gets.


capta said:
Ours are #6 or 6mm depending on where the sailmaker is.
Click to expand
Seems like I heard that from a sailmaker in Maine a few years ago. Sailrite says #6
  • Hood Seafurl (all except New A, Old B, Old C)
 
DrJudyB

DrJudyB

.
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
capta said:
Ours are #6 or 6mm depending on where the sailmaker is.
Click to expand
.

No, a 6 mm tape is not the same diameter as a #6 tape. A standard #6 tape varys between approx 5.3 mm to 5,5 mm in diameter

The Metric sizes are quite a bit different from English system sizes, enough to make a functional difference. The metric equivalent to a #6 luff tape is a HL55.

The English system is weird, it’s the cord diameter in 32nds of an inch, plus an unspecified allowance for the Dacron cloth wrapped around the cord. It can fraction of a mm depending on manufacturer or cloth. a #6 tape has a 6/32 cord (4.8 mm) wrapped inside Dacron sailcloth. The Dacron adds between .3 mm and .7 mm depending on weight. Average total diameter is around 5.4 mm for a #6 tape.

The luff tape needs to be about 1 mm smaller than the extrusion groove to reduce friction.... or so.

I looked back in my records. Some of the really old Seafurls used a 7.5 mm diameter ( equivalent to a heavy duty 8, non standard size) on the models for big boats. Some used 5.5 mm (equivalent to a #6 regular)

The Safest thing to do is check a sample of the new tape In The furler.
 
Last edited:
  • Like
Likes: SG
capta

capta

.
Jun 4, 2009
4,902
Pearson 530 Admiralty Bay, Bequia SVG
DrJudyB said:
.

No, a 6 mm tape is not the same diameter as a #6 tape. A standard #6 tape varys between approx 5.3 mm to 5,5 mm in diameter

The Metric sizes are quite a bit different from English system sizes, enough to make a functional difference. The metric equivalent to a #6 luff tape is a HL55.

The English system is weird, it’s the cord diameter in 32nds of an inch, plus an unspecified allowance for the Dacron cloth wrapped around the cord. It can fraction of a mm depending on manufacturer or cloth. a #6 tape has a 6/32 cord (4.8 mm) wrapped inside Dacron sailcloth. The Dacron adds between .3 mm and .7 mm depending on weight. Average total diameter is around 5.4 mm for a #6 tape.

The luff tape needs to be about 1 mm smaller than the extrusion groove to reduce friction.... or so.

I looked back in my records. Some of the really old Seafurls used a 7.5 mm diameter ( equivalent to a heavy duty 8, non standard size) on the models for big boats. Some used 5.5 mm (equivalent to a #6 regular)

The Safest thing to do is check a sample of the new tape In The furler.
Click to expand
I haven't noticed the difference as both seem to work equally well.
 
capta

capta

.
Jun 4, 2009
4,902
Pearson 530 Admiralty Bay, Bequia SVG
All U Get said:
I also have a short piece of mine to send them somewhere on this boat. Can’t find a model number, must be from the era where they thought this is as good as it gets.




Seems like I heard that from a sailmaker in Maine a few years ago. Sailrite says #6
  • Hood Seafurl (all except New A, Old B, Old C)
Click to expand
What are the chances your sail was made to metric standards?
 
All U Get

All U Get

.
Oct 2, 2008
3,810
Pearson/ 530 Strafford, NH
capta said:
What are the chances your sail was made to metric standards?
Click to expand
Nooooooooooo I hope knot. That doesn’t seem likely if the sails are from North Sails. I’ll make phone calls Monday. Too many free spirits building sailboats.
Now that the coffee is kicking in I’m thinking this boat was built in RI and used mostly local suppliers for parts. I made this to clean the groove so I can send them this for a good match. Thanks for all the help everyone.

. image.jpg
 
Last edited:
SG

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
All U Get:

Are you putting this on a sail whichhas a different luff tape, or no luff tape, or? Are you cutting down another sail? You say it’s a North Sails built sail?

This is the picture that you posted

1587913616855.jpeg


The answer to you question is probably Best summed up by DrJudy: get a couple of short pieces of tape and make sure.
 
Last edited:
  • Like
Likes: DrJudyB
DrJudyB

DrJudyB

.
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
All U Get said:
Nooooooooooo I hope knot. That doesn’t seem likely if the sails are from North Sails. I’ll make phone calls Monday. Too many free spirits building sailboats.
Click to expand
I wouldn’t worry about it. Every sail loft knows that a #6 tape = HL55 tape , just like 25.4 mm = 1 inch.
 
You must log in or register to reply here.

Top Bottom