Another sign of the top build quality/assembly? or normal?

[Paul S]

We had the boat out sailing this past weekend. I noticed the starboard rudder making a racket. Everything was working OK.

Took the boat out of the water. Took a look at the rudder..the nut was holding onto the bolt by one or 2 turns only. It was not snug down to the nylon end. The port rudder was tight as a drum.

For all these years using nyloc nuts..I never had one come loose. This is 2 on this boat alone (first was the steering linkage nut worked out).

I tightened it up real snug..should not be a problem now..but will keep an eye on it.

While I am at it..I think I should look at the swivel bolt in the mast base..to ensure that is snug. Don't want that puppie coming loose.

Do the rudder bolts have a tendancy to work loose...or is it another case of poor dealer assembly?

Paul

[Dimitri-2000X-Tampa]

I've found that the nyloc nuts only hold well if they are screwed all the way down onto the threads...ie, the nut is completely on the bolt. Of course, who knows, as much rattling as that thing does when it is being trailered, I've heard of a lot of stuff coming loose....but in the case of a bolt with a fully attached nyloc, you would think the bolt would turn before the nut did. I'm gonna get my tires balanced which hopefully will reduce the rattle somewhat.

[kmclemore]

Never, never, never, never, never re-use a Nyloc nut for any critical fixing. Use once, and throw it away if unscrewed. They work fairly well right out of the box (if not heated), but are increasingly less reliable on multiple use, and can indeed be horribly unreliable if re-used repeatedly.

IMHO, if you want things to *stay* put, use Loctite. I always keep vials of 243 (Blue) and 272 (Red) in my boat's toolbox.

In general:
Purple: Can be removed with hand tools
Blue: Can be removed with hand tools
Red: Apply heat to remove
Green: Apply heat to remove

Loctite Usage for Popular Types:

222 - Purple "Thread Locker" - Low strength threadlocker, designed for precision metal fasteners under 3/4". Designed for the locking and sealing of threaded fasteners which require easy disassembly with standard hand tools. The product cures when confined in the absence of air between close fitting metal surfaces and prevents loosening and leakage from shock and vibration. Particularly suitable for applications such as adjustment of set screws, small diameter or long engagement length fasteners, where easy disassembly is required without shearing the screw. Protects threads from rust and corrosion. Removable with hand tools. Temp range -65 to 300 degrees F. Cure Speed 20 min. Full 24 hrs.

242 / 243 - Blue - "Nut and Bolt Locker" - Designed for the locking and sealing of threaded fasteners which require normal disassembly with standard hand tools. Product cures when confined in the absence of air between close fitting metal surfaces and prevents loosening and leakage from shock and vibration. Particularly suitable for applications on less active substrates such as stainless steel and plated surfaces, where disassembly with hand tools is required for servicing. Medium strength threadlocker for fasteners up to 3/4". Cures reliably even on stainless steel. Tolerant of oil and other contamination. Protects threads from rust and corrosion. Parts can be disassembled with hand tools. Temp range -65 to 300 degrees F. Cure speed 15 min. Full 24 hrs.

262 - Red - "Permanent Threadlocker" - Permanent strength threadlocker for fasteners up to 3/4". Designed for extreme enviromental/chemical conditions. Typical applications include the locking and sealing of large bolts and studs, and especially useful for holding tight Grade 5 and 8 fasteners. Protects threads from rust and corrosion. Localized heating and hand tools required for disassembly. Temp range -65 to 300 degrees F. Cure speed 30 min. Full 24 hrs. (note: Not good for Stainless Steel - requires 72+ hours for cure and only develops 50% strength on that material)

271 / 272 - Red - "Stud Lock" - Hi-temp/hi-strength formula. Suited for temperatures up to 450 degrees F. Fast cure on most surfaces including "as received" fasteners. Recommended for bolts up to 1 1/2" in diameter. Heat and hand tools required for disassembly. Temp range -65 to 450 degrees F. Cure speed 60 min. Full 24 hrs.

290 - Green - "Penetrating Threadlocker" - Penetrating formula works in between pre-assembled parts. Designed for the locking and sealing of threaded fasteners. Because of its low viscosity and capillary action, the product wicks between engaged threads and eliminates the need to disassemble prior to application. The product cures when confined in the absence of air between close fitting metal surfaces and prevents loosening and leakage from shock and vibration. The product can also fill porosity in welds, casting and powder metal parts. For fasteners ranging from #2 to 1/2". Localized heating and hand tools required for disassembly. Temp range -65 to 300 degrees F. Cure speed 60 min. Full 24 hrs.

[dclark]

I can only speak as an X owner, but I'm not sure there is a differance in this respect...

I think you are talking about the bolt that holds the rudder on to the bracket. On the X if it is too loose, the rudders kinda click back and forth a little and do indeed make a noise.

Ideally you'd tighten them all the way down. BUT if you do that, the rudders won't drop and you'll need to push them. Too tight and you won't even be able to do that. So you want them as tight as you are willing to deal with. For me that is just barely loose enough to drop.

Nylon lock nuts shouldn't move. I'd guess your dealer didn't tighten them enough on installation. I know, I know, you want to blame MacGregor. They might be installed at the factory, I'm not sure but I'm pretty sure no. Put yourself in the factories shoes...why install something that is liable to suffer damage in transit when you can just pack them along and have the dealer do his job? I live in Costa Mesa and I've seen those boats leave the factory and trust me, they are bare. What ever happened to John Mason. He bought an X as it came from the factory and assembled it himself. He must have been on here for 6 months asking questions before he had it readyu for the water.

[Paul S]

Not blaming the factory.

I snugged it down enough that the bolt now extends past the nylon part of the nut, like the port rudder. The rudder itself is in a bracket and moves quite well up and down. It should be OK now. But I will keep an eye on it now.

I just assume the installer did not tighten them enough. They should not come undone in the first place.

Not a lot surpises me anymore.

Paul

[Chip Hindes]

Never, never, ...

As a mechanical engineer, I've been seeing and hearing this unofficially for as long as I can remember. Knowing that the nyloc feature does not add substantially to the torque required to screw or unscrew a properly torqued nut, I've been ignoring it for just as long. So I decided to see if I could find it anywhere.

In fact, I found an FAA document on certificated aircraft which states "DO NOT reuse a fiber or nylon locknut, if the nut cannot meet the minimum prevailing torque values." The prevailing torque values are given in an accompanying table.
FAA Document

So in essence, they can be reused forever as long as they still work. If the FAA lets you reuse them on ceticficated aircraft, they should be OK on our boats.

Although the table doesn't cover the small 1/4" and 3/8" sizes used on the Mac, I can tell you the prevailing torque limits for the larger nuts cited are quite low; as an example, for the smallest nut, 7/16", it is is just 8 lb-in, whereas the suggested tighening torque for such a nut would be 1190 lb-in.

I have a full box (originally 100/box) of each size of Nyloc nut. That being said, there are only five nuts on the boat that are regularly removed, and one of those (the one on the mast crutch) is pretty much superfluous. I've been using and reusing the same ones for more than three years. I don't notice that they ever get any easier to remove. I've trailered over 8000 miles, and I have yet to lose one or even find one loose. Inspecting these is part of my once per hour walk around when I'm trailering long distances, along with lug nuts, trailer ball and chain security, brake and hub temps.

The only key is that the bolt be long enough for the nyloc portion to fully engage, so that one thread is showing past the end. Going past this point, you're actually being conterproductive because it's the wear of installation and removal which eventually wears them out.

[kmclemore]

Well, as another Mech-E with almost 30 years of experience, I beg to differ.

As the FAA says in their document:

"Self-locking nuts should not be used with bolts, screws, or studs to attach access panels or doors, or to assemble any parts that are routinely disassembled before, or after each flight."

It would appear that the FAA agrees with my statement that they "...are increasingly less reliable on multiple use", since they disallow their use on "routinely disassembled" parts.

Further, they reveal their lack of faith in self-locking nuts, and agree with my statement that "never re-use a Nyloc nut for any critical fixing" when they state:

Self-locking nuts should not be used with bolts or screws on turbine engine air-planes in locations where the loose nut, bolt, washer, or screw could fall or be drawn into the engine air intake scoop.

Personally, I'm OK with using Nyloc's for non-critical items that you pull on and off, as long as, as you say, they have a limited amount of resistance remaining. But when it comes to things that are mission-critical like attaching the rudders (as the original poster stated), or the engine or mast, I believe very strongly in the 'use once' rule with Nyloc's... and frankly, I use them with Loctite if it's really critical.

[Chip Hindes]

kmclemore: I won't argue with your additional quotes from the FAA document nor your interpretation of them. However, none of these alters the key point of the original statement, as I paraphrased: Self locking nuts may be reused indefinitely as long as they still self lock.

[Sloop John B]

I don't think there is anything critical on the Mac, including the rudders. My rudders were under the aft berth with all the rigging, etc., when I brought my boat home. Same dealer John Mason used. You drive up, hitch it up, and away you go. Got the new 2002 for $11,995 that way.

If yours were mounted, then the dealer hired some 10 year old for $3.00 an hour to get it ready. The nut didn't come loose.

The PTO and blade nuts on my lawn machine spin very fast. The manual emphasizes using new nyloc nuts each time or it will chop off your nose.

[sailpsych]

For those of you who are REALLY concerned or have experienced catastrophic failure as a result of unsecured fastening devices, you may want to do like NASCAR, NHRA, and AMA pro's do and lockwire your nuts to secure them.

Another option would be to have castle nuts with cotter keys. Motorcycle axles use this technique regularly to ensure loss of axle does NOT occur.

I'm a bit aprehensive about using lock-tite except where there is no other option. After reading about torque values, I have to wonder if the locktite acts as a lubricant and affects the appropriate torque values? Thoughts?

[Don T]

Hello:
I feel the need to chime in here. I have owned my boat since 1995 and have never had a nylok nut back off. I use worn nuts on the mast crutch and tabernacle that I can barely turn on and off by hand and they have never backed off while towing or sailing. I use nyloks exclusively and have scores of them on the boat in sizes ranging from #6 to 3/8."

[Sloop John B]

On third thought I think I'll lockwire my nuts and add a cotter key.

[kmclemore]

Actually, when I worked for Lotus Cars, Ltd., we used to safety-wire quite a few of the bolts. Colin Chapman didn't trust Nylocs either.

[Chip Hindes]

kc: I agree that safety wire is much more effective than Nylocs, but Brit cars? I've owned 'em, I love 'em, but the idea you would present them as examples of the way things ought to be built; well, that's truly hiliarious. Especially Lotus

[Jack O'Brien]

My 2000 X had 1/4" x 20 shoulder bolts in the port rudder bracket that were too long. The nut stopped at the shoulder instead of holding the bracket fast to the hull. Starboard side was ok. Go figure. How about the length of the hinge bolts on the head door? 3 X longer than needed.