Stuffing Box Problem

D

DBBRanger

Well-known member
Joined
Mar 31, 2013
Messages
262
Fluid Motion Model
R-25 Classic
Vessel Name
Still Crazy
I haven’t adjusted my stuffing box since I bought the boat over 7 years ago - because I didn’t need to. The drip rate was always good. Well, I decided to replace the packing since after all that time, I expect the packing is pretty dry and needs replacing. I definitely had a difficult time removing the old stuff. Because I couldn’t move the nut away very far, a cork screw wouldn’t work and because the packing was so hard, a dental tool wasn’t strong enough. So I used a hose removal tool that has a u-shaped tip that fit perfectly in the nut. With a lot of effort, I was able to remove it all. But after I tried to screw the nut back on to check to see if the threads were clear, I found the nut would not turn after about 3/4 of a turn. The only reason I can think of is that using the tool scored the threads. I would not have thought that possible, but I have no other reason. It’s not cross threaded. My question is whether I should power through and try to clear the threads - maybe adding a little anti-seize. It won’t be easy though since the base of the box would have to be held and there’s not a good place to get a wrench on it.

I’m afraid I may have to replace the box and that doesn’t seem easy.

Any words of wisdom?
 
This would be my attempt to repair the damaged threads. I would use thread cutting oil. Apply a small amount of oil to the threads in the nut and the gland. Thread the nut onto the gland until it stops. Then back it off a 1/4 turn repeat, thread until it stops then use a small ball peen hammer, tap the nut, top and sides turn the nut about 1/8 turn, tap the nut again then back it off. Repeat this procedure moving the nut further on to the gland. After you get it to thread on to the gland about a half turn farther unthread it and apply some more cutting oil to help prevent galling. This procedure takes patience. If the threads are not damaged beyond repair this will clean the damage. Use the hammer after each time you draw the nut further on the gland shock it then back off. ( Old Millwright trick for removing nuts from damaged threads on studs)
 
I hope Brian’s suggestion works for you. If not, you can replace the packing nut(s) without replacing the entire stuffing box. I had to do this on our R-29 when I found I was unable to adjust the packing nut due to damaged threads. It’s not an easy job. The shaft must be disconnected from the gearbox and pulled far enough back to allow removal of the flange. On the R-27 there may not be enough space to do this without removing the propeller. On the R-29, there is just enough room. A new nut can be ordered from Marine Hardware.

I think confirmation of the ability to adjust the packing nut should be on every marine surveyor’s checklist.

Gordon
 
BB marine":17ds1s2m said:
I would use thread cutting oil. Apply a small amount of oil to the threads in the nut and the gland.
Click to expand...

Brian,

Thanks for the detailed suggestion. Since I don't have strictly thread cutting oil, would anti-seize or any oil work as good or is the magic is in the oil?
 
knotflying":3muruo44 said:
If it works, don't fix it!
Click to expand...

Yeah....That's what my wife said, but.....
 
I would not use anti seize. If you do not have cutting oil use WD 40 or a light penetrating oil and keep the threads wet with lubrication when dressing and cleaning the threads. If and when you get the threads cleaned. I do not recommend using anti seize on the threads. I recommend using an anti corrosion marine grease on the treads to help stop them from galling.
 
Success! I was able to clear out the threads with the technique that Brian detailed. The nut now travels by hand most of the way in although the last turn requires a light wrench. No need to replace the cap. Thank you Brian!
 
Splashed Gayle's Faerie on Monday. I checked the bilge and found the stuffing box is dripping at 15 drips per minute. Did my homework on Tugnuts but can't get the lock nut loosened. Here is the illustrated version...

1. Before doing anything:
https://share.icloud.com/photos/098SL1QMaoyuzfxxzcd0-FILw

2. Sprayed with PB Blaster and let sit overnight. Sorry, not worth the picture.

3.Did some wire brush cleaning first (those spaces between things look bigger than they really are):
https://share.icloud.com/photos/0abs9Ia7TmuO0HiDtYkV6FWQg

4. Wrench setup. I'm stabilizing the packing nut with a sink basin wrench wedged tight with some wood and I bought the offset pipe wrench recommended by others:
https://share.icloud.com/photos/037AhGhCNmVkMfjRTGW_1rfwg

5. Obviously, my strength on the wrench was not enough and everything stayed in place, i.e. the wrenches didn't slip or anything. I hit the packing nut and the lock nut with a small ball peen hammer and then the lock nut with a nail punch going clockwise looking aft. Didn't want to force anything so I got a bigger hammer.

https://share.icloud.com/photos/0a92sPzQ84YoyhITuewTxjjRQ

6. Not wanting to break the bigger hammer I got a 2.5 foot roll under car jack handle and applied pressure to the offset pipe wrench handle (clockwise looking aft). Nuh-thing. I noticed the large black hose connected to the stuffing box was starting to rotate so halted all effort. Sprayed with PB Blaster, found another project and resolved to let the team take it from here.

https://share.icloud.com/photos/0a06RKTSlXlD15EDNjnmo3vLw

All I can think to do from here is just keep repeating the above. Now some people would say doing the same thing over and over in hope of getting different results is "insane", but for some reason mechanical things don't always follow that rule and persistence sometimes wins over obstinance.

I'm open to and would appreciate any and all suggestions/corrections. Gary
 
Well, usually if the boat has been out of the water for a while the packing dries somewhat and the stuffing box will leak much more until he gets remoistened. this can take a few days after it is in the water and used a bit. I would wait and see if the flow subsides. With that said, how many hours on the stuffing box material? If it is close to replacement I would consider a little heat on the lock nut first. Also, sometimes alternating tightening and loosening gets an initial break in the seal created between the threads.
 
...how many hours on the stuffing box material? If it is close to replacement I would consider a little heat on the lock nut first.
Click to expand...
Don't know. I'm the 3rd owner of a 2012, so it could be ten years. I'll try a heat gun and see if that helps.

Also, sometimes alternating tightening and loosening gets an initial break in the seal created between the threads.
Click to expand...

Will try that too. Thank you.
 
It looks clean enough. The issue is the threads have green oxidation in them and filling in the voids in between the threads. A good penetrating oil soaked into the threads may help lubricate the threads. Using a rag saturated with penetrating oil may help the lubricant soak into the gland threads. Use a oil absorbent pad under the gland to catch the run off penetrant. Throughly soak the gland then wrap it with the rag. let it soak for a while. Use a hammer to shock the packing nut and locking nut. If you have a bearing race installation punch you may get a better shot at it and not damage the nut when hitting it.
https://www.google.com/url?sa=t&rct=j&q ... 6vChq3B_Lu

By the looks of the threads left on the gland you are close to needing to repack the gland. There are a couple threads left so you may be able to get another adjustment out of it. I'm not a fan of backing the packing nut off but you may have to to free the threads. Don't back it off much maybe 1/8 turn if it loosens then work it back in forth in that small window of 1/8 turn. While doing this continue to apply penetrating oil to break up the green oxidation. If either the locking nut or packing nut break loose. Do this repeatedly until it the crud breaks up in the threads.

GaylesFaerie":t2o4yclf said:
All I can think to do from here is just keep repeating the above. Now some people would say doing the same thing over and over in hope of getting different results is "insane", but for some reason mechanical things don't always follow that rule and persistence sometimes wins over obstinance.
Click to expand...

You are spot on with this statement. Persistence will prevail!!! I once spent a week drilling 8 bolts out of a machine to remove a seal. This was a large extruder in a polymer plant. It was as bad as watching paint dry but at the end, the seal that two contracting companies could not remove was removed. Persistence and patience will prevail. Many time there is no secret method. The method is starring you in the face.
 
Years ago, Practical Sailor did some testing and claimed that the best penetrating fluid was a 50/50 mixture of ATF and acetone.

Barry Thompson
TOUCAN, R-27 Classic
 
...50/50 mixture of ATF and acetone.
Click to expand...
Interesting. I have another back up method. Thanks, G
 
Update: decided to take the boat for a shake down cruise and see if that changed things. After splashing the boat, I only idled less than 1/4 mile to the dock. After docking that's when I noticed the 15 drips per minute. On shake down I ran the boat through its paces up to cruising speed at 3750 RPM, docked and had a cocktail. This morning at the dock, I'm only getting 1 drip every 45 seconds. That was easy. I think I'll save getting that lock nut loose for another day. In the mean time its real clean and shiny and I coated it with T-9 to help keep it that way.

On an aside, I mentioned the issue to a dock mate and he suggested pulling the hose leading from the exhaust elbow to the stuffing box and pumping Salt Away in with one of those hand squeeze siphon bulbs to dissolve salt crystals that may have formed in the packing after haul out. Sounds like a good idea but I don't know if one can get enough pressure to overcome the water pressure coming from the cutlass bearing. Perhaps that technique is better suited when on the hard before launching.

G
 
1 drip every 45 seconds is not bad if the engine is running and in gear. That was the way I kept my packing adjusted. More than 3 drips in 1minute with the engine running and in gear it was time to adjust. I did it three time in 650 hours. I loosened the locking nut once a season to make sure I could adjust it if needed. If it is leaking 1 drip every 45 seconds with the engine not running and in gear in my opinion too much. It should not leak when at the dock without being in gear. I would check the packing when cruising at higher Rpm. I will bet there is a fine mist of water getting flung off the shaft. I personally would want the ability to adjust the packing at a moments notice. You never know on older packing when you will need to adjust it. The way the gland is set up in the Ranger 27 a leaking packing is not going to sink the boat but all the salt water getting flung around in the compartment will really make a mess if it does start to leak. I would continue to soak the gland and work it, give it a few raps with a punch from time to time. Just my opinion.

I'm not sure if the salt away is going to do much. Most of it is going to just run down the shaft log and drain out. Whatever amount that the packing is leaking is how much salt away will get into the packing. If the packing is leaking 5 drips a minute that is how much salt way you will flush thru the packing in a minute 5 drips!
 
Good points Brian. Last season (my first full season with the boat) I consistently had 3 drips a minute at the dock with the engine off. I have not yet done a check with the engine on and in gear which presumably would drip more often. That said, oddly I do not have any noticeable spray or dry salt accumulation anywhere in the engine compartment or bilge that a wet rotating shaft may throw.

Over the winter when reading about stuffing boxes on Tugnuts I saw a post about fabricating a shaft shield of sorts to deflect any spray back down into the bilge. I created a simple one out of the flexible plastic used for roll up cutting boards. It lays nicely on top of the coupling back to the shaft log and across to the engine stringers. A simple cut out half way down the middle allows it to fit past the stuffing box hose and keep it in place. I'll post a picture later.

I will keep working on that locking nut (I despise frozen corroded anything on a boat or otherwise) but I'm feeling less urgent about it now that the per minute drip rate at rest has gone from 15 to 1.3.

Gary
 
The shaft shield installed...
https://share.icloud.com/photos/06b9ti7 ... xMHFWuGXNQ

When I have time I'll add a flap that is glued (4200) on one side of the cut out to cover the 5" of open slot. Gluing on one side will allow me to flip the flap up and slot the hose and then let the flap fall and cover most of the slot opening.

HTH, Gary
 
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