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Nacra DS rod and sleeve

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tim nell
(@tnell)
Posts: 358
Mate
Topic starter
 

Ok, there's been a lot of talk about dolphin strikers lately, and I KNOW my DS rod/mast step bolt is bent in two directions. I don't think it's necessarily weaker but I'm gonna change it anyway. However, I'm quite concerned that it's gonna be seized to the sleeve. Here's what I need to know:

Does the sleeve completely pass through the main beam or does it fit inside? Another way of asking is the hole in the beam equal to the inner diameter or the outer diameter of the sleeve?

Thanks, I just want to know what to expect when I go in.

 
Posted : July 27, 2017 9:41 am
(@leeboweffect)
Posts: 484
Chief
 

The sleeve (called a compression tube) fits inside the crossbar. The sleeve ID is the same as the diameter of the hole in the crossbar that the DS post goes through.

Hope this helps.

 
Posted : July 27, 2017 10:06 am
tim nell
(@tnell)
Posts: 358
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Topic starter
 

I think so....so if it's stuck, it's REALLLY stuck

 
Posted : July 27, 2017 10:29 am
(@dmgbear55)
Posts: 258
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Further to NacDaddy this tube is installed and removed through the outside end of the main beam. So once you get the DS rod through this tube you get to get that compression tube out through the end of the beam (or if it looks OK just leave it in place). That is followed by even more fun reinstalling this little tube. The trick is to tape it to the end of a stick or something that is about 5' long and then maneuver it back into place. It really helps to have another pair of hands for that part of the project when you are reinstalling the new DS rod.

There is a good chance that someone coated this rod before making the DS assembly so you may only have to deal with getting the bent rod extracted. There was a good thread a while back that dealt with a difficult removal of the DS rod. Maybe someone will remember it or figure out a good keyword search to find it again.

 
Posted : July 27, 2017 10:36 am
(@leeboweffect)
Posts: 484
Chief
 

tnell wrote: I think so....so if it's stuck, it's REALLLY stuck

Yes, and PTL I've never had to deal with one like that,,,,YET.

 
Posted : July 27, 2017 11:39 am
tominpa
(@tominpa)
Posts: 624
Chief
 

I did this replacement many years ago to replace a bent rod. Needless to say, the DS is not something to pull on when loading the boat to a trailer or onto a beach. I think even back then the assembly was over $175, and we're talking around 1990. Once you have replace one, you will never damage another. I used a piece of 6-foot 1x2 furring and simply attached the tube with a rubber-band. I needed a second person to guide the tube into place, and used a screwdriver to line it up, then inserted the DS from the bottom. That was when I lost my front beam end-caps...don't lose those either.

 
Posted : July 27, 2017 11:44 am
(@nohuhu)
Posts: 274
Mate
 

We dealt with this on a 5.2 for awhile. Bent 2 rods.

The danger is not the bent rod breaking, it's the off-axis mast ball stripping and being pushed off. Recipe for getting demasted at any time.

I don't think the rod is as likely to corrode/seize to the sleeve as it is to the beam. The sleeve is fairly loose. But once the rod gets bent on top, it may bind inside the sleeve. The aluminum sleeve deforms easily though.

One could always pound or pry the bar straighter on top and cut it off there. Grease things up and try to thread it down.

One issue we had is that the newer rods were too tall (more likely to bend) and needed to be trimmed down.
Issue #2 was was corrosion and forces opening the holes in the aluminum beam.
Issue #3 was not using loctite on the ball

 
Posted : July 27, 2017 12:10 pm
(@dmgbear55)
Posts: 258
Mate
 

nohuhu I would be surprised if the new DS rod was actually too long. But if you don't put the preload into the beam that is required, the top of the DS rod will look and be too tall. When you do the preload you use up a lot of that top thread just below the mast ball. The entire DS assembly is prestressed to move the center of the main beam upward. I think the number that Ed has used is 3/8". To get that amount of prestress you need to crank the nut on the bottom side of the main beam upward and doing so will bring the mast ball much closer to the beam. The top nut is essentially a lock nut.

 
Posted : July 27, 2017 2:07 pm
Edward Hilliard
(@Edchris177)
Posts: 2531
Captain
 

Does the sleeve completely pass through the main beam or does it fit inside? Another way of asking is the hole in the beam equal to the inner diameter or the outer diameter of the sleeve?

sorry, don't have time to read the entire thread...here is everything you need to know.(How I did my 5.7). Apologies if it has been answered.
https://www.thebeachcats.com/pictures?g2_itemId=73301

E C Hilliard

Nacra 5.7
Bombardier Invitation

 
Posted : July 27, 2017 2:14 pm
(@nohuhu)
Posts: 274
Mate
 

Thanks Guys. Good info.

The Nacra rods that Murrays shipped were longer that the originals. So after quite a few turns tensioning, we had a ball sitting about an inch too high. That one bent on the next hard sail.

Before it failed completely, we ordered another and cut off about 3/4" at the base. That worked better.

All the tensioning was done following the 5.2 manual at the time. I'm funny that way.. 🙄

 
Posted : July 27, 2017 3:00 pm
tim nell
(@tnell)
Posts: 358
Mate
Topic starter
 

Thanks everyone for the quick replies!! Sometimes this place is silent for days but not this time! Here's my plan of attack...

I don't mind buying all new parts from Murrays or Salty Dog so that's not an issue.
My main concern (and I may be overthinking it) is that I will find the DS rod frozen in the compression tube.
I searched and could not find again one solution which as I recall was...
Loosen the bottom nut to gain some working room, then turn the top nut down thus raising the DS rod.
If I can move it that way, I know it's not frozen and I should be able to proceed with cutting the bent part
And then removing it like Edchris said to do. Once it out I'll make sure everything is well greased so the
Next time I bend one I know it will come out easily.
Comments or suggestions?

Thanks again guys!

 
Posted : July 27, 2017 3:07 pm
tim nell
(@tnell)
Posts: 358
Mate
Topic starter
 

Upon further review....apparently as stated earlier in this thread (thank you leebow) the I.d. of the compression tube is 5/8 and this jibes with Murrays info. The rod is 9/16 so with that much slop I can't see how it could be stuck too bad.

 
Posted : July 27, 2017 3:23 pm
Andres Chianale
(@Andinista)
Posts: 880
Chief
 

My main concern (and I may be overthinking it) is that I will find the DS rod frozen in the compression tube.

I vote for overthinking, I would just have WD40 at hand, I doubt it's even needed.
I would be more concerned about the nuts, they get stuck where the rod is bent, even if you straighten it, or the thread might be dented, so most likely you will have to cut the rod. Not a problem if you have enough room to cut. I don't have mechanical skills, some somebody else may tell you how to deal with this if it happens, what I did learn after two replacements is that forcing the nut won't fix the thread, it ends up totally stuck.

Edited by Andinista on Jul 28, 2017 - 09:34 AM.

 
Posted : July 28, 2017 3:00 am
Andres Chianale
(@Andinista)
Posts: 880
Chief
 

To put the new compression tube the following might work too, I haven't tried:
- Get a thin (cheap) line longer than the beam, pass it through the beam holes and tie one end.
- Make a hook with a wire and the tiller to get the line out of the beam
- Cut the line, pass it through the compression tube and tie again
- Recover the line and tube from the beam center
- Use a screw driver to align it
- Etc

 
Posted : July 28, 2017 3:49 am
John Schwartz
(@JohnES)
Posts: 797
Chief
 

I am going through this very thing right now with the $100 Hobie 20 I just got... same scenario, bent mast post rod. For getting the compression tube lose I first dowsed it with boiling water, and then used a mix of 50% acetone and 50% Automatic Transmission Fluid... I was skeptical of this at first, but it worked, and a few persuasion hits later it came lose. For those that have been here a while, do not use "buckets of acetone... you just need a 1/4 cup or so 😆

When reassembling it be sure to use gobs of copper paste. I replaced the main beam on my 5.8 due to the corrosion cause by the stainless to the aluminum main beam and had it done at the factory... The most post was literally floating with a 1/16 to 1/8 gaps caused from corrosion. When reassembling it they used gobes copper paste on the mast post bolts. Also do the same with the bolts that hold the beam to the hulls...

Also, something you may want to check every year, losen the bolts, clean and re-paste them, and reassemble. Again for those of that have been around here a while this was referred to as "exercising the nuts." 😆

Edited by JohnES on Jul 28, 2017 - 12:23 PM.

 
Posted : July 28, 2017 4:15 am
Edward Hilliard
(@Edchris177)
Posts: 2531
Captain
 

and then used a mix of 50% acetone and 50% Automatic Transmission Fluid..

That little gem was passed on to me decades ago, by an old school mechanic. It works as good, or better than any commercial penetrating oil. Just make sure you keep the mixture in a tightly sealed container, or the acetone evaporates...& don't smoke!

When reassembling it be sure to use gobs of copper paste.

Anyone who has done there own brakes may well have this product, Permatex is the most common. If you have it, the silver stuff works just as well. The copper product is speced for high temp applications,ie brakes.

E C Hilliard

Nacra 5.7
Bombardier Invitation

 
Posted : July 28, 2017 5:01 am
John Schwartz
(@JohnES)
Posts: 797
Chief
 

At Pep Boys for $10.99

Edited by JohnES on Jul 28, 2017 - 12:21 PM.

 
Posted : July 28, 2017 6:20 am
Edward Hilliard
(@Edchris177)
Posts: 2531
Captain
 

As far as I could find, this was the only one Permatex recommends for salt/marine use. Cheaper too, $7.49
https://www.permatex.com/products/lubricants/specialty-lubricants-anti-seize/permatex-anti-seize-lubricant-3/

Edited by Edchris177 on Jul 28, 2017 - 01:27 PM.

E C Hilliard

Nacra 5.7
Bombardier Invitation

 
Posted : July 28, 2017 7:25 am
(@nohuhu)
Posts: 274
Mate
 

I should get some of that for the trailer too. Mahalo Ed.

 
Posted : July 28, 2017 1:41 pm
(@nohuhu)
Posts: 274
Mate
 

I just wanted to add that Penetrating Oil, in my recent experience, attacked my aluminum clear coat and began to etch my mast and beams. Made the long sanding and refinishing process even more of a PIA.

Use an inert lube (Silicone) where you can and don't leave this stuff in place on any surface that doesn't need it. Especially the sun exposed areas.

I was using the Liquid Wrench brand.

 
Posted : July 28, 2017 2:08 pm