My wife wanted christmas ideas for me so the 8:1 blocks came to the top of my list. This 8:1 system using Harken 2631 and 2632 blocks appear to be a very popular combination. I see the 2632 block is a triple 57mm with a single 40mm block and the 2631 is a quad block. Here is a link to one place to buy it.

https://store.catsailor.com/pc/viewPrd.asp?idproduct=7971

My questions are:
The 2632 recommends a max line of 3/8 where the 2631 has a max of 7/16. I am guessing the limiting factor is the 40mm single? Have people used 7/16 in these blocks or am I better off going with the 3/8 (10 mm) line?

Are these blocks as nice as they sound? Currently using 25 year old original H18 blocks with 3 upper single blocks.

Are there other 8:1 options out there that are similar?

--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
--

A tapered mainsheet would fix the diameter running through the smaller block pretty easily.

I think the 3/8 recommendation is b/c of the ratchet, though, not the size of the sheave of that extra block.

They certainly look like a serious upgrade to the 6:1's it sounds like you have. The one thing you might want to remember is the amount of mainsheet you need, and the amount you'll have to sheet in or let out will all increase.

--
Rob
OKC
Pile of Nacra parts..
--

Scott,
Yes, they are as nice and if you have never used this setup, it will be nicer than you will ever expect. The key though, is get a quality sheet, smaller and taper it. You will wonder how you ever lived with out it!

I'm using 8mm (5/16") Racing Sheet tapered down to 3/16" Amsteel and it is plenty big. My traveler end is tapered with a 1/8" Amsteel tail. Put your money into the mainsheet.

--
Philip
--

i purchased a triple top to replace the 3 single blocks that come stock on the Hobie 18. I had put them on hanging s hooks for easy removal but they would get tangled up.

i eventually upgraded the base block (on the traveler) and i liked it, but after about 1 year... i realized the Auto ratchet wasn't working so i called harken and sent it back. they replaced the ratchets (no questions or receipt needed) and returned it to me. This year i upgraded to the quad top.

I do very much like the system but completely agree with Philip... get quality line (like Robline racing sheet).

PS i use 10 mm racing sheet (8 was to small in heavy air and my local guys didn't have 9mm) and it runs great!



edited by: andrewscott, Dec 02, 2009 - 09:47 AM

I use a 7:1 and started out the 7/16" but it ran poorly through the blocks in light winds. I switched it out for 3/8" and couldn't be happier even in heavy winds even without a taper. I think the key is to purchase good quality main sheet with good grip properties (i.e. Robline, VPC, etc), that is more important in my mind than the difference in diamater 7/16 and 3/8. That being said if I sailed solo for 10 hours a time like Andrew I might change my mind.

Regards,
Dave

--
Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
--

Also look at Salsa line. it is VERY soft, decent price, made in the USA (i think) and cleatable (unlike regular dyneema).

So does the robline racing sheet not cleat well? I am looking for a good main sheet that does cleat. Sounds like I will go with the 3/8 now just need to determine what type and brand.

--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
--

I use 10mm Salsa tapered to 1/4" vectran. Works great. The single braids are incredibly easy to splice. I can vouch that the salsa is incredibly soft, but I'm not familiar with the other dyneema blended single braids to know it compared to the others.

--
Rob
OKC
Pile of Nacra parts..
--

what technique do you use to taper from 10mm to 6.5mm (1/4") or do you purchase it?

Scott,
you can also consider a strippable double braid made for the purpose, like Endurabraid. It also will work great. All you have to do is strip the 10 feet of cover and bury it. So easy a caveman can do it. . . .

--
Philip
--

dont foget a lock stich with stipped / buried cover

Can cave men thread a needle with them big Barney Rubble thumbs?

personally, I whip it. That transition point turns through the blocks continuously. I do not whip any other buries, though.



edited by: mummp, Dec 02, 2009 - 02:53 PM

--
Philip
--

Most dyneema blends cleat fine, pure dyneema braids don't cleat well. Most web sites will tell you whether they are recommended for Main Sheet applications. Unless you are really serious I wouldn't worry about tapered lines too much. They roll nice but 3/8" line should be fine, and simpler (I'm not big on splicing myself).

--
Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
--

Wolfman

Most dyneema blends cleat fine, pure dyneema braids don't cleat well. Most web sites will tell you whether they are recommended for Main Sheet applications. Unless you are really serious I wouldn't worry about tapered lines too much. They roll nice but 3/8" line should be fine, and simpler (I'm not big on splicing myself).

I probably wouldn't have looked into splicing mine, but I needed a new mainsheet and I was in a cast for a few weeks this summer. I figured it was a good time to look into upgrades. Only about 7 or 8 feet (iirc, out of town atm) of the tail is tapered, and it definitely makes a difference on how well the line runs through the blocks. I have a 7:1 system; I'd have to have a higher ratio to use a longer taper. I actually think it would be better if I had a foot less of the vectran, but I'm not willing to cut it a foot shorter to experiment.

I don't agree with one line or another being 'simpler'. Once its tapered, you move on and enjoy the benefits...its just more work to get there in the beginning. It's not like I have to taper it every time I put the blocks on the boom.

I agree that 3/8's runs through 57mm blocks just fine, but I suggested it b/c the blocks in question also have that 40 attached, and the 40 should be the first sheave of the lower block that he uses....perfect setup for a tapered sheet.

Anyway, not trying to be argumentative, Wolf, but I'll stand behind the tapered sheet here. He needs a new one anyway.

andrewscott

what technique do you use to taper from 10mm to 6.5mm (1/4") or do you purchase it?

Technically, I used the yale instructions for the most part:
http://www.yalecordage.com/pdf/yale_endforend_hi.pdf
IIRC, I used NE Ropes' instructions b/c it has illustrations instead of pics, which were easier to follow, but where they differ I followed Yale's instructions (which i think just differ in that yale has you pull the two through each other once or twice more than neropes.)

I lock stitched the splice, although it was my first time to do that, and it ends up in the cleat on occasion, and its pretty ugly now. If I ever notice it fray or start to come apart I'll replace it with a nicer stitch.

I also whip locked each end of the main sheet for whatever that's worth.

Another thing - I just bought end of spool sale lines with a focus on a thinner high modulus, and a thicker dyneema blend. There were quite a few options, which made it relatively cheap.

--
Rob
OKC
Pile of Nacra parts..
--

Yurdle, no problems. I just thought that it was easier to order one type of line over tapering. I glossed over the part about the 40, a 5/16" line would run better through that than 3/8". My blocks are all 57s so it doesn`t matter as much for me, but in this case a tapered line would have some definit benefit.


--
Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
--

Quote

Technically, I used the yale instructions for the most part:

cool thanks for the data.

There is NO DOUBT tapered lines are wonderful!

I really want to move to a tapered main... but need to replace my 90' spin halyard with a tapered line first (as my current one burns holes in my spin every time)

So basically the tapered line runs through the blocks smoother while allowing you to hold on to a more substantial diameter line? I am new to the idea of using tapered lines, but presume if I buy my line from a good source they will do the splice.

I was looking at the APSltd site. Looks like I could taper to an amsteel line and then put an eye splice in the end of the amsteel to connect to the block without a knot.

I presume a good splice between line diameters runs through the blocks fairly well.

--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
--

Quote

So basically the tapered line runs through the blocks smoother while allowing you to hold on to a more substantial diameter line?

Yes

Quote

if I buy my line from a good source they will do the splice.

Yup, for a fee

Quote

I was looking at the APSltd site. Looks like I could taper to an amsteel line and then put an eye splice in the end of the amsteel to connect to the block without a knot.

exactly

Quote

I presume a good splice between line diameters runs through the blocks fairly well.

a good splice will have a nice long tail/tuck that has been correctly tapered and the transition is extremely smooth.

this is critical because HM line like dynema (amsteel/spectra,vectran,and others) lose up to 50% of their strength if tied in a knot (inside face of line holds no tension so the outside has double the load) or have a sharp curve to the (i.e. a non tapered tail/tuck would be a hard edge at the bitter end).


If you are also new to splicing... this HM line is single braid, 12 strand (there are others) and the easiest line to splice. its a good way to get started with splicing. I would have them do the end to end splice (taper) and do the eyesplice yourself (get some extra line to practice with if you are new..)

Let me add my 2 cents. Don't bother putting an eyesplice on the end. You will end up cutting it to the proper length after you sail it a couple of times. Don't worry about losing strength with knots (no disrespect Andrew)'cause it ain't going to matter. The stuff is so strong you could hang a tribe of cavemen with it, even if it were to loose 50% breaking strength. Tie the bitter end with a bowline and go sailing. Once you get the length right you can put the eyeslice on if you like. You can use the trimmed piece to practice you eyesplice with over and over until you get your confidence.

Let me add, the load on the bitter end that you will tie off or eyesplice is minimal, I repeat, it is an insignificant load. An added benefit is you can quickly remove the sheet for rinsing, drying, washing, storing, etc.

To put the knot nonsense in perspective, spin boats are knotting the spin bridals, as they are constantly being adjusted. The bridals are 1/8" HMPE and they do carry much more intense and significant loads.

Not calling you out Andrew, as knots and strenght are indeed important, but they don't really apply here.

--
Philip
--

andrewscott

I really want to move to a tapered main... but need to replace my 90' spin halyard with a tapered line first (as my current one burns holes in my spin every time)

Andrew, you might be in luck, if your current spin has a HMPE core you can taper it. I did it on a used spin halyard and liked it so much I used it. I can give you more details if you like. So easy a caveman can do it. . .

--
Philip
--

Thanks Philip ...
I am currently using 90' of xls (i think its Dacron jacket and polycore but unsure). I may strip the cover anyway.

Robbie D showed me how he strips and burys 5mm robline dingy control line (for his spin halyards) and i did it for my martingales (pole bridals)

Quote

Let me add, the load on the bitter end that you will tie off or eyesplice is minimal, I repeat, it is an insignificant load. An added benefit is you can quickly remove the sheet for rinsing, drying, washing, storing, etc.

Good point Philp, you are correct. Each line in the block has the same force, and that force is equal to what you have at the cleat. So if you can pull the line coming out of the block that is about the same force every line in the block has on it. The connections from the block to the crossbar and the boom are totally different then the force on each line in the block.

I was just thinking an eye splice would make a really clean connection that wouldn't come loose over time, but I see your point about likely having to trim to length the line once I use it. Guess I just need to check the knot periodically.


--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
--

andrewscott

Thanks Philip ...
I am currently using 90' of xls (i think its Dacron jacket and polycore but unsure). I may strip the cover anyway.

milk back one end and inspect the core. If it has a good tight braid open it up and put a sample bury in it and see how it looks. Some cores are crap for burying that have a loose parallel braid. It's worth a look . . .

If you buy a new halyard you will only need about 55-60 feet. Endurabraid would work well and is reasonable $$.

--
Philip
--

its true you dont need to worry about the strenght of 4mm amsteel (around 1000lbs depending on which amsteel) but i still like an eyesplice at the end. it's only held to the blocks with a little becket and 1 pin.. not hard to remove if you want to wash your sheets.

and most important of all.. it looks cool!!!! (and no body will ever see it there if you dont point it out) but its cool!

edited by: andrewscott, Dec 03, 2009 - 04:11 PM

Quote

If you buy a new halyard you will only need about 55-60 feet. Endurabraid would work well and is reasonable $$.

i am seriously considering going with 4mm robline racing sheets for my halyard.. no taper needed (dynema blend) and i have a friend with a discount... :) but i will also look at Endurabraid

Quote

and most important of all.. it looks cool!!!! (and no body will ever see it there if you dont point it out) but its cool!

I had the same thought. As long as I was getting a custom tapered mainsheet I would be using for a long time, might as well spend the little extra for the cool factor. The fact it is technically a better connection is a bonus.

--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
--

Quote

If you are also new to splicing... this HM line is single braid, 12 strand (there are others) and the easiest line to splice. its a good way to get started with splicing. I would have them do the end to end splice (taper) and do the eyesplice yourself (get some extra line to practice with if you are new..)

Holy moly that looks complicated! Do you guys really do a lot of this tapering/spicing? Still always though provoking! I'll never look at ropes again the same way.

smfinley

Quote

and most important of all.. it looks cool!!!! (and no body will ever see it there if you dont point it out) but its cool!

I had the same thought. As long as I was getting a custom tapered mainsheet I would be using for a long time, might as well spend the little extra for the cool factor. The fact it is technically a better connection is a bonus.

Scott, like I said before, you WILL trim to length, then you can add the eyesplice. It really is easy, . . . . and you will be . . . . COOL!

--
Philip
--

Andrew, regarding the issue with burning holes in the spin:

This is caused by the hard round covers on today's quality sheets, especially the popular double braids. It is when you pull hard that the round firm surface of the halyard pinches the spin between and against the hoop. So, how do we illuminate this problem. Two ways, one is with the douse technique, the second is to change the douse part of the halyard. The idea is to get rid of this hard firm round surface that is doing all the damage to the spin, which can be accomplished in many ways. In your case, you can fix this problem without replacing your halyard, if it is a double braid. How? Remove the core about 25-30 feet (for your boat) on the dousing end. This allows the cover to lay flat against the spin and hoop when dousing, rendering your burn problems a thing of the past. The added advantage is that when the spin is set in very light air, the dousing end of the spin is much lighter and has less effect on the shape of the spin.

If you have a stripable double braid now, rather than remove the core, just milk the cover back 25-30, bury the cover, and walla!, you now have a tapered spin halyard. Core for the head (less windage), cover only for the douse (lighter weight, no burns). So easy a caveman can do it!

So, with all the money you will save on a new 90 foot halyard, you can get that new tapered mainsheet and buy me a rummy.

--
Philip
--

interesting.. i hadn't thought about stripping the core to get a flatter sheet... i thought it was the Dacron jacket that did the damage...i thought stripping the jacket was the answer. let me mull over this a bit..

At this time, i am trying to NOT spend money on my cat (isn't working) as i have just moved into a new house and its emptying my bank account... so the idea of NOT buying a new halyard is appealing (also not getting a tapered main at this time.. i will SUFFER with my racing sheets :)

Philip.. your rummy is waiting for you at my cooler...

Quote

Holy moly that looks complicated! Do you guys really do a lot of this tapering/spicing? Still always though provoking! I'll never look at ropes again the same way.

--
Larry Smith
--

Hahah.. if you are refering to the end to end splice link above,.. that is a bit complicated but a simple eyesplice is very easy to do (in 12 strand single braid like spectra/vectran etc)...

i saw a friend had a real soft line (amsteel) as his 4way adjuster (that goes accross the tramp) and i hated my steel cable (cheeze grader) so he showed me the basics of splicing and i got some fids.. i was all gung-ho on it for a month or so.. but in the end.,, i find HM line NOT all that useful on my cat... dynema creeps (stretch over time) so it needs to be somewhere creep doesnt matter (or re-adjusted) and vectran has no creep but is not soft. I have only found a couple of places where a HM line/splice have any actuall value (besides the cool factor)

I will make spectra trap lines when i need to replace my current ones.

Perhaps i will make a video showing how easy a simple eye splice is to make

Quote

I was looking at the APSltd site. Looks like I could taper to an amsteel line and then put an eye splice in the end of the amsteel to connect to the block without a knot.

This is what I'd planned to do, but when it came time, the HM lines required so much of the tail to run back up inside itself that it actually doubled the thickness of the sheet over halfway back to the end to end splice....so it was stiff and worthless.

I ended up putting a whiplock on the end, tying a bowline, and burying the bitter end back into the loop of the bowline just to clean it up.

The loads on the sheet don't matter to the 1/4" HM line at all.

The 12 strand single braids seem so easy to splice end to end, that my guess is that you can have a fairly large difference in diameters. They are kind of like chinese finger traps - if you just keep working two points towards each other the diameter grows and grows. If I had to do it over I'd try 3/16 or even 1/8 on the smaller one instead. It would make for a very ugly splice but I don't think it would be functionally affected at all.

Don't forget I've done the end to end all of 1 time in production, so take it FWIW.


--
Rob
OKC
Pile of Nacra parts..
--

andrewscott

a good splice will have a nice long tail/tuck that has been correctly tapered and the transition is extremely smooth.

Mine is fugly but works perfectly. Its very malleable. I was concerned that I'd have a stiff spot in it that wouldn't run well but its not an issue at all.

--
Rob
OKC
Pile of Nacra parts..
--

Quote

the HM lines required so much of the tail to run back up inside itself that it actually doubled the thickness of the sheet over halfway back to the end to end splice....so it was stiff and worthless.

You're doing it all wrong. Use a brummel splice and bury a few inches after tapering it. You only need to taper a few inches.
.
.
.
. . . for Pete's sake, how in the hell do you add a picture without hosting it to a website??



edited by: mummp, Dec 05, 2009 - 07:56 AM

--
Philip
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mummp

You're doing it all wrong. Use a brummel splice and bury a few inches after tapering it. You only need to taper a few inches.
.
.
.
. . . for Pete's sake, how in the hell do you add a picture without hosting it to a website??edited by: mummp, Dec 05, 2009 - 07:56 AM

Oh, I used Yale's class 2 eye splice, which has about 6 fids of line in the tail after the eye. I'll have to look for a brummel splice.

I don't know that you can upload a pic. I let picasa host most of mine....free and easy to use and easy to link to.

--
Rob
OKC
Pile of Nacra parts..
--

brummel splice - http://www.precourt.ca/brummel_splice.pdf

and
http://www.newenglandropes.com/SPL_12Strand_EyeSpliceBrummel.aspx

Oh. Thanks.

I made one of these in my first and only attempt at a soft shackle. I didn't have instructions, though, so I pulled the entire length of line through the knot to make it work. This looks much more practical.

--
Rob
OKC
Pile of Nacra parts..
--