400: Lagoon 400 turnbuckle / rig replacement

[Beach View]

Greetings Lagoon owners.

Well, I neglected preventative maintenance on my turnbuckles, and they are now seized up tight. I’ve tried penetrating oil and a lot of leverage, but they refuse to move. My rig is loose, and I need to resolve this one way or another. On each side, there are two bottle jacks joined by a length of threaded rod (more on that later…). Attached are a couple of photos, with measurements below:

• Overall length of the assembly as currently adjusted is 116 cm
• The pins on each end are 22 mm
• The jaw width of each tang is 27mm
• The capshrouds are 17mm
• The chainplates are 20 mm thick.

Now my questions for the forum:

Could I use moderate heat (i.e. light touch with a torch) to help loosen up the turnbuckles? I certainly don’t want to compromise strength here….

Does anyone have a source and/or part numbers for replacement turnbuckles?

Why would Lagoon fabricate such a complicated setup—why two bottlejacks + threaded rod instead of simply making the caps shrouds longer and use only one bottlejack?

My rig is now 9 ½ years old—should I replace the standing rigging—and if so should I use only one turnbuckle on each side?

Thanks in advance for your input.

Regards,

Bill

[Celestialsailor]

Maybe tell us what type of metal is the body and the threaded piece. Yes, a propane torch will do wonders. Heat then oil then try to move ever so slightly then heat oil and repeat.

[Beach View]

Thanks Celestialsailor.

The bodies (female threaded parts) are bronze, the threaded rods in the center and threaded jaw ends (male threaded parts) are stainless.

Any idea on how hot I can get the bronze parts without any strength loss?

Bill

[SailingHarmonie]

Are you SURE that is the factory design? There is no (good) reason for such a design. There is no way there is so much stretch in that wire you would need this much thread to take it up.

If both male threads and female are stainless steel, you might be screwed so to speak. Unfortunately, this is common, because it is the cheapest.

Here is what happens: when sliding past each other under very high pressure, the protective chromium oxide layer on the surface of stainless steel can be rubbed off, exposing very clean, virgin metal underneath. When two pieces of very clean metal are under very high pressure they can literally "melt" together, sometimes called "cold welding." When this happens to threaded parts it is usually called "galling." Once this happens, there is no way I know of to undo it short of a cutoff wheel in an angle grinder.

There are a couple of way to prevent this. One is to not use male and female threads out of stainless steel. In rigging screws the turnbuckle should be bronze. Chrome plated bronze if you really need it to be shiny. At least one company is now making stainless body turnbuckles with bronze inserts that seem to work well. The other solution is to be sure parts are assembled with high pressure antisieze lubricant that will keep them separate. In the professional rigging world this is usually Tef-Gel, but others work.

Now, it might be possible that your turnbuckles ARE bronze. The photos are not clear enough to be sure. If they are bronze, the parts are NOT galled, and can be disassembled with more torque. There is no way you can break these parts with normal hand tools, so feel free to pull on them as hard as you can.

My final advice to you is to seek the advice of a local professional rigger who can put eyes and hands on the parts in question. That will be worth a LOT more than all the advice you can get on the internet. Mine included.

[Celestialsailor]

Originally Posted by Beach View

Thanks Celestialsailor.

The bodies (female threaded parts) are bronze, the threaded rods in the center and threaded jaw ends (male threaded parts) are stainless.

Any idea on how hot I can get the bronze parts without any strength loss?

Bill

Most likely there has been created an oxidization layer between the bronze male thread and the stainless female thread. You would be heating the stainless steel area only as you want that to expand away from the bronze threaded rod and then add the penetration oil to slip into the crevices.

You should not let the bronze get over 500F. It is unlikely that would happen anyways with a sweat type propane torch and especially heating the stainless only. I usually use the spit on the finger test. I heat it up until the spit sizzles on the stainless which would be over 212F, then heat for another 10 seconds or more. Immediately add the oil and soon there after try moving it but be gentle, not forcing things. You only need small movement to start. Add more oil and let cool down to the touch and repeat a dozen times. If it still is not budging, time for new turn-buckles.

[neilpride]

They never grease the threads at the factory.
My advice after release hundreds of these disgusting turnbuckles.
1/ Preheat with a torch the top and bottom part of the turnbuckles , just at the area where the thread its visible.
2/ Soak the hot area with PB Blaster, let the PB work few minutes, wipe the area, and heat torch again, don worry for the heat.
3/ With the hot turnbuckle, try to move it back and forth, if it moves a little ,repeat the process 1 and 2.

If you don't have luck with this, you just have to cut them.

[Beach View]

SailingHarmonie—Indeed, they were installed this way by Lagoon (we bought our boat new from the factory). I haven’t personally looked at turnbuckles on other L400s, but all the photos I found on the internet show the same “two turnbuckles with center threaded rod” setup. I am perplexed at this (seems like a waste of money with increased opportunity for failure), but Lagoon built hundreds of L400s, so they must have had a reason... Also, the rods are SS, barrels are bronze so perhaps galling is not an issue, just salt, dirt, and corrosion.

Celestialsailor—thanks again for your input. Actually the threaded rods are SS, the barrels are bronze, which may work in my favor. I looked up the coefficients of expansion for bronze and SS. Bronze expands a bit more, so if I heat the barrels and quench the rods (along with penetrating oil) they may loosen up.

Neilpride--I'll try your method, but after ignoring them for ~10 years I don't have much hope...

[AKA-None]

What I have noticed is that once you start turning don’t stop or it could seize

YMMV