34 rig tuning (again)

[Sefuller]

Before launching this spring I ordered a Spartite kit, which I have yet to install. I thought I may do it today, but then had second thoughts.

I have fought heavy weather helm on our boat for as long as we have owned it. I have tried numerous things to get rid of it - some of which have helped, but never completely solved the problem. In anything over 10 - 12 knots going to weather it takes more than a little effort at the helm, and I can't get the boat balanced on anything much higher than a beam reach.

I have replace the non-functioning pin stop traveler with a Harken traveler that we use regularly, purchased new sails, and use mast bend, vang and cunningham to flatten the main.

Today I decided to take some of the rake out of the mast. I have had the rig tuned with about one mast's depth of rake, so today I partially dismantled the Harken furler and shortened the forestay so that I now have about 2" of rake. Unfortunately, we had 2 knots of wind today so I have not had a chance to test my work, but I am anxious to see if it makes a noticeable difference.

Information on tuning the 34-35 rigs is sparse, but I did find some information on 30s and 34s that I had not seen before which said that the original specification of 8" of rake was prior to the change to iron keels, and a shift of the mast forward in the boat.

--
Scott

 

[jibes138]

How tight are your shrouds? If the mast is hooking off to leeward it might cause a little weather helm by moving the center of effort further to lee? How much heel are you experiencing over 12 knots of wind? As the boat heels the center of effort also moves to lee and causes more weather helm. Also as the boat heels the rudder loses efficiency as much of the force is directed downward versus horizontal. Best to reef your main and keep her on her feet. What size headsail are you using?

 

[Sefuller]

I have a 142 Genoa with a higher clew which was new last year. I have had the backstay and cap shrouds at 17 - 20%, the forward lowers 10 - 12, and aft lowers 8 - 10. I have a Loos gauge so I have checked and reset them each year. Not much detailed info on the 34/35 tuning. One poster in another thread seemed to indicated his rigging was all the same size, I have 9/32" cap shrouds and stays, 1/4" lowers. Going to weather it gets helmy between 12 - 15 degrees of heel and I've got probably 8 - 10 degrees of rudder. I replaced the 30" wheel with a 36" wheel and it takes more effort to hold course than on any of the other boats I sail on. Usually over 15 knots the top of the wheel will be between 4 and 5 o'clock, and around 15 is where we reef the main, after full out haul and traveler down. Our main is loose footed so it's easy to tension the outhaul.

 

[jibes138]

Using the loos gage gets you in the ballpark but you should tune your shrouds under sail so they stay tight on the lee side in 12 knots of wind. Go for a sail and if the leeward shrouds are loose take up a turn on each shroud. Then tack and do the same thing on the other side. Keep tacking and taking up the slack until they stay tight in 12 knots. The backstay should be tightened to keep the headstay from sagging. I use a 130 headsail as my largest and a 110 for heavier conditions. I found a 150 was too much sail for the boat as a general purpose sail. Only good in really light winds and always rolling it up a bit as winds increased making for a terribly shaped sail. Better to use a smaller headsail if your average wind speeds are 10 knots or more.

 

[njlarry]

My manual says 8 inches of rake. Can fax it to you if pm me a fax number. Did you find the rubber wedges around mast collar could be reused?

 

[Sefuller]

My manual says 8 inches of rake. Can fax it to you if pm me a fax number. Did you find the rubber wedges around mast collar could be reused?

The rubber wedges are definitely re-usable, however ultimately I will replace them with SparTite.

I read somewhere else that the 8" specification was for earlier boats with lead keels, and that subsequently they changed to cast iron (lighter) and re-positioned the mast in the boat. In that case the 8" would be too much. I find that with the 2" I have now the situation is improved but not what I would call great.

I noticed another very strange thing when centering the mast. I ended up measuring inside the boat as well as above deck to make sure there wasn't something faulty with my method. On my boat, the port chainplate (inside the boat) is one inch further from the mast than the starboard chainplate. The hull liner is molded to position the chainplates, so it isn't like someone moved one of them. If I measure (inside the boat) from the aft lower chainplate rods to the mast, the dimensions are the same port and starboard. Above deck, the same thing is true, and if I measure from the forward lowers to the mast that dimension is the same port and starboard. Curious if anyone else can confirm this? @jibes138 , @njlarry ?

 

[jibes138]

Not sure your comment about cast iron on later boats? Mine is lead for sure! I sanded mine to bare lead and sealed it with West epoxy so I am positive!

 

[njlarry]

Will check measurements over the weekend.

 

[njlarry]

Hi Sefuller, did take the measurements and wrote them down only to leave them on the boat but.....as I remember there was a difinenate difference.
The measurements were the same to the port and starboard rods, but the measurements from the mast center to the innner edge of the main chainplate bracket were different by one inch. I think the port was the shortest. It is definitely not a builder error as they both are perfectly positioned in the molded cutouts of the overhead liner. It may well be that chainplate brackets are identical with the stay attachment point offset to the same side so by moving one bracket an inch to the side they are symetrical at the deck.

 

[jibes138]

Makes more sense to measure from the mast to the shroud turnbuckle or the u-bolt above the deck. Lack of adjustment makes the measurement kind of moot anyway. Maybe they were providing more space to walk past the mast below?

 

[Sefuller]

@njlarry I did measure topside originally, and found the same one inch difference. The inside measurement is a little easier to get accurately which is why I asked folks to check that. Thank you for confirming it is not an anomaly!

 

[jibes138]

I measured from mast to aft u-bolt thread inside the boat and it was 5/8 difference. Port side was shorter