My stuffing box decided to start leaking (2 drips per second) while I was warming up the engine to change the oil! So I came home and studied everything in the archives about stuffing boxes and have a couple questions about my '87 Hunter 31: (The attached photo is not mine, it's just a similar stuffing box I googled) When I put a wrench on either of the two nuts on the shaft and wiggle gently, it causes the rubber boot to move also. From this I deduced that the whole stuffing box assembly is just clamped to the rubber boot with the 2 hose clamps. Correct? My stuffing box assembly is rather green.... other than spraying it with PB Blaster, is there anything else specific that I can/should do to clean it? It appears that the aft-most nut on the threaded shaft is the lock-nut and the forward nut is the compression nut that holds the packing material in place. They appear to be threaded onto the same threaded shaft. Am I correct? It between the two nuts, there is a smooth piece with a tab. Am I right in assuming that this is part of 1 of the nuts? (This might be obvious when I clean some of the corrosion). If I get the locknut loose first, how do I hold the shaft in place while working the compression nut loose? Two possibilities occur to me: either put a wrench on the threaded shaft, or back the lock nut all the way down the threaded shaft and grip that. Does anybody know the right size packing for my boat? I didn't think to measure the shaft. I suppose I'll buy both 3/16 and 5/16 packing and return the size I don't use. Am I an idiot for thinking to do this in the water on a Sunday when the boatyards are closed? I've got to believe I can keep the boat from sinking, even if I screw it all up. Also don't feel like worrying about it all week and want to sail next weekend. OK, enough random ramblings from me. Thanks in advance for the advice and wise counsel..... even from those of you who tell me I'm an idiot!!! Cheers, Bob s/v X SAIL R 8
Stuffing box stuff
- Thread starter BobW
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Ahoy Bob
I will try to answer your questions one by one. Yes the stuffing box is just clamped to the tube. You need 2 wrenches to loosen it. Do not twist the hose!!!! I have never seen one that is not green. LOL. They all turn green in a short time. You can take it off and use a wire wheel to clean it if you want to. If you try this in the water have plenty of rags to stuff around the shaft, to keep the water from rushing in. You are correct the aft nut is a jam nut, and the forward big nut is where the packing is placed, and are on the same threaded shaft. The smooth part is part of the large forward section. There are just 2 parts the lock nut, a narrow nut and the big packing nut. YOu would be supprised how easy it will turn after the locking nut is loosened. Usually you can turn the bigh nut by hand. If it is to tight you can grap the aft end of the threaded portion with a pair of channel locks with a rag on the jaws to protect the threads. I am not sure of your packing size, it depends on the shaft diameter. Why do you want to change the packing? Loosen the jam nut and tighten the packing nut until the leak stops. Don't tighten to tight, while the shaft is turning you should have about a drop a second. The water lubricated the shaft. If to tight the shaft will get hot and burn up the packing and score the shaft. If you want to replace the packing, you will need some tools to get the old packing out. Packing picks or dental picks work well. You will have to replace the packing with 3 pieces of new packing cut to the diameter of the shaft and placed so the cut parts will not line up. I hope this helps and fair winds Cap'n Dave
I will try to answer your questions one by one. Yes the stuffing box is just clamped to the tube. You need 2 wrenches to loosen it. Do not twist the hose!!!! I have never seen one that is not green. LOL. They all turn green in a short time. You can take it off and use a wire wheel to clean it if you want to. If you try this in the water have plenty of rags to stuff around the shaft, to keep the water from rushing in. You are correct the aft nut is a jam nut, and the forward big nut is where the packing is placed, and are on the same threaded shaft. The smooth part is part of the large forward section. There are just 2 parts the lock nut, a narrow nut and the big packing nut. YOu would be supprised how easy it will turn after the locking nut is loosened. Usually you can turn the bigh nut by hand. If it is to tight you can grap the aft end of the threaded portion with a pair of channel locks with a rag on the jaws to protect the threads. I am not sure of your packing size, it depends on the shaft diameter. Why do you want to change the packing? Loosen the jam nut and tighten the packing nut until the leak stops. Don't tighten to tight, while the shaft is turning you should have about a drop a second. The water lubricated the shaft. If to tight the shaft will get hot and burn up the packing and score the shaft. If you want to replace the packing, you will need some tools to get the old packing out. Packing picks or dental picks work well. You will have to replace the packing with 3 pieces of new packing cut to the diameter of the shaft and placed so the cut parts will not line up. I hope this helps and fair winds Cap'n Dave
A little more info
The smooth part is actually part of the jam nut. The packing goes inside the housing in this type of setup not in the nut itself. The packing will overflow the housing and this is where the end nut comes into play; it compresses the packing causing it to tighten against the shaft. Be sure to inspect the hose before doing this. If it appears dried out and easily cracked then you really need to haul and do an overhaul. If you do this, make sure you use a proper packing shaft hose that is reinforced. Automotive heater hose is not strong enough. Double clamp both ends. As far as acceptable dripping, 2-3 per minture will suffice. Also, you can buy teflon based packing that should allow you to virtually eliminate the dripping. You will probably hear some people suggesting dripless units. I do not recommend these as when they fail you will be in deep water(pun intended). That said, I agree with Dave. Adjust it now and wait for your next haulout to rebuild the whole unit. Good time to replace the cutlass bearing as well. Tim R.
The smooth part is actually part of the jam nut. The packing goes inside the housing in this type of setup not in the nut itself. The packing will overflow the housing and this is where the end nut comes into play; it compresses the packing causing it to tighten against the shaft. Be sure to inspect the hose before doing this. If it appears dried out and easily cracked then you really need to haul and do an overhaul. If you do this, make sure you use a proper packing shaft hose that is reinforced. Automotive heater hose is not strong enough. Double clamp both ends. As far as acceptable dripping, 2-3 per minture will suffice. Also, you can buy teflon based packing that should allow you to virtually eliminate the dripping. You will probably hear some people suggesting dripless units. I do not recommend these as when they fail you will be in deep water(pun intended). That said, I agree with Dave. Adjust it now and wait for your next haulout to rebuild the whole unit. Good time to replace the cutlass bearing as well. Tim R.
My 2Cents
Clean off the threads with a stiff wire brush so you can tell which way the nuts will move when you try to loosen them. Typically, I hold the Cap nut side furthest from the shaft log with a large aircraft wrench and using a plumbers wrench , back off the inside locknut counterclockwise. Then turn the cap nut counter clockwise hand tight. If you can't move it by hand, adjust it 1/4 turn at a time, hand tighten the lock nut and check the drip rate. I/d wait till the boat is hauled to replace the flax if you haven't done it before.
Clean off the threads with a stiff wire brush so you can tell which way the nuts will move when you try to loosen them. Typically, I hold the Cap nut side furthest from the shaft log with a large aircraft wrench and using a plumbers wrench , back off the inside locknut counterclockwise. Then turn the cap nut counter clockwise hand tight. If you can't move it by hand, adjust it 1/4 turn at a time, hand tighten the lock nut and check the drip rate. I/d wait till the boat is hauled to replace the flax if you haven't done it before.
2 drops a second, no sweat.
Mine has been leaking at a rate of 3 or 4 per second for the past year. Just keep the bilge pump in good working order.
Mine has been leaking at a rate of 3 or 4 per second for the past year. Just keep the bilge pump in good working order.
Drip Rate
Benny, surely you mean 'drops per minute' not per second. My Yanmar book and Nigel Calder both say a couple of drops a minute are adequate...any more is a plan old leak.
Benny, surely you mean 'drops per minute' not per second. My Yanmar book and Nigel Calder both say a couple of drops a minute are adequate...any more is a plan old leak.
Even Better
Ahoy Bob; I got you some pictures and a little pdf. file for you. It is a stuffing box man. http://www.practical-sailor.com/newspics/charts/886stuffingbox.pdf Fair Winds Cap'n Dave
Ahoy Bob; I got you some pictures and a little pdf. file for you. It is a stuffing box man. http://www.practical-sailor.com/newspics/charts/886stuffingbox.pdf Fair Winds Cap'n Dave
Frozen solid
I verfied the direction of the threads and put my two big wrenches on the nuts........ nothing, even after repeated applications of PB Blaster. I even broke my large Channellocks in the effort, and I've put as much torque on those nuts as I care to with the boat in the water and not being an emergency..... as well as being a Sunday and no lift available. So Plan B is to have the engine mechanic give it a try when I get him to come out to change the motor mounts. If he can't get it loose, it'll mean hauling, but I'm counting on his 40 or so years of experience to give him a few tricks we don't know. My real annoyance at the moment is that the water doesn't drain straight into the bilge - it goes into the engine 'drain pan' and then through the hole in the side (where the water hoses go through) and into the space between the hull and inner liner. It looks like it will accumuate about a gallon or two before it gets high enough to drain through another hole into the bilge..... I"m not sure what that salt water will do in the intra-hull space, but I don't like the design. Oh, well, enough grousing. Thanks for all the helpful advice. More on the saga follows! Cheers, Bob s/v X SAIL R 8
I verfied the direction of the threads and put my two big wrenches on the nuts........ nothing, even after repeated applications of PB Blaster. I even broke my large Channellocks in the effort, and I've put as much torque on those nuts as I care to with the boat in the water and not being an emergency..... as well as being a Sunday and no lift available. So Plan B is to have the engine mechanic give it a try when I get him to come out to change the motor mounts. If he can't get it loose, it'll mean hauling, but I'm counting on his 40 or so years of experience to give him a few tricks we don't know. My real annoyance at the moment is that the water doesn't drain straight into the bilge - it goes into the engine 'drain pan' and then through the hole in the side (where the water hoses go through) and into the space between the hull and inner liner. It looks like it will accumuate about a gallon or two before it gets high enough to drain through another hole into the bilge..... I"m not sure what that salt water will do in the intra-hull space, but I don't like the design. Oh, well, enough grousing. Thanks for all the helpful advice. More on the saga follows! Cheers, Bob s/v X SAIL R 8
Water in the engine compartment
I had the same problem. There is likely dirt under the engine "box" restricting the flow to the bilge. Use a flat metal probe to clean the restriction. The water avenue on my boat was to the side of the engine box not directly under it. You will need to poke around to free up the area. I am putting in a bilge pump in the engine compartment to pump out the area as even with the under the engine box clear, the water flow is not as fast as it needs to be. I will be writting up my last two week experience with my deteriorated bronze stern tube almost sinking the boat. If you have an older boat with a bronze stern tube, please check it when you next pull the boat.
I had the same problem. There is likely dirt under the engine "box" restricting the flow to the bilge. Use a flat metal probe to clean the restriction. The water avenue on my boat was to the side of the engine box not directly under it. You will need to poke around to free up the area. I am putting in a bilge pump in the engine compartment to pump out the area as even with the under the engine box clear, the water flow is not as fast as it needs to be. I will be writting up my last two week experience with my deteriorated bronze stern tube almost sinking the boat. If you have an older boat with a bronze stern tube, please check it when you next pull the boat.
Update on stuffing stuff....
So I called the mechanic and he came over....sans tools! He took a look at my stuffing box and asked me for my big Channel locks. Gripped the locknut and turned.... and the whole assembly turned in the hose *yks Asked me for my pipe wrench and had a go at turning both nuts.... no go. Asked me for a hammer *yks I handed it to him and he disappeared back into the quarterberth...... Wham WHAM WHAM... I'm cringing with every stroke... then..... 'Got it!' Guess all those years of experience ARE worth something ;D No drips, no water in the liner, no worrys, mate! Cheers, Bob s/v X SAIL R 8
So I called the mechanic and he came over....sans tools! He took a look at my stuffing box and asked me for my big Channel locks. Gripped the locknut and turned.... and the whole assembly turned in the hose *yks Asked me for my pipe wrench and had a go at turning both nuts.... no go. Asked me for a hammer *yks I handed it to him and he disappeared back into the quarterberth...... Wham WHAM WHAM... I'm cringing with every stroke... then..... 'Got it!' Guess all those years of experience ARE worth something ;D No drips, no water in the liner, no worrys, mate! Cheers, Bob s/v X SAIL R 8
BFH!
Never leave home without it! I went through the same routine earlier this summer! The fresh water filling my bilge on a regular basis for a couple weeks really cleaned it up. After that, it was dusty in my bilge until October. Endless rain and some minor leaks and I find a little water in the bilge once again!
Never leave home without it! I went through the same routine earlier this summer! The fresh water filling my bilge on a regular basis for a couple weeks really cleaned it up. After that, it was dusty in my bilge until October. Endless rain and some minor leaks and I find a little water in the bilge once again!
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