When this happens, the pump will need to be rebuilt, replacing at least the stuffing box and shaft. CAUTION: Some stuffing boxes are rigidly attached to the hull, but most are connected to the shaft tube with a length of flexible hose. Proper compression allows about two drops per minute. Retighten the packing nut to compress the flax around the shaft and slow the water drip rate. When under way the drip increases a little. You can make the task less frantic by sealing the shaft from the outside with plumbers putty, but you will have to go into the water twice to do this, once to put the putty around the shaft, and a second time to remove it. As Capt. It is not uncommon to see stuffing boxes leak at a much higher rate. In fact, with access to an infrared pyrometer, drip rates are much less important than they once were. Because you remove the old packing before installing new, and it is the packing that is keeping the ocean out of your boat, it should be out of the water when you do this job. Ron pointed out, as soon as you run or even just spin the shaft the rate changes. Through tightening it onto the stern tube, the packing is compressed, creating a seal against the shaft. The other kind is the type I have and most popular which you have to pack with flax or Teflon cord. ARC 2020 is Underway. I can't get enough leverage to move them. The easiest way to do this is with a corkscrew-like pick designed specifically for this task, but a sharpened piece of stiff wire bent 90 degrees at the end will also do the job. Hold the packing nut while you release the lock nut, then unscrew the adjusting nut completely to open the box. 13-JUL-2010.05" Of Wear. Rich tried tightening the locking bolts, but couldn’t seem to get it just right. Tightening the stuffing box nut a half turn is all that is required to reduce the leak, but the location of the stuffing box can render this job far more difficult than it should be. It is not uncommon to see stuffing boxes leak at a much higher rate. After you make this initial adjustment, you are going to need to check the drip rate with the shaft turning. A stuffing box is an assembly which is used to house a gland seal. Maintain this gland around the prop shaft to keep leaks at bay. Don Casey has been one of the most consulted experts on boat care and upgrades for 30 years, and is one of the BoatUS Magazine's panel of experts. 11 Apr 2005 #3 Y. yachtie8 New member. Low-friction packing is six to ten times more expensive than flax, but because it rarely needs adjustment, it can be a good choice for a stuffing box that is particularly difficult to service. But this one is dripping constantly. Take care not to scratch the shaft with either tool. The shaft is wrapped by the packing and put in the gland nut. This type of packing runs hotter than water-lubricated flax, and over tightening will generate excessive heat. When the box is full — but not so full that the adjusting nut doesn't thread on easily — adjust it to drip two or three times per minute, as previously outlined. The drip rate must be at once sufficient to lubricate and cool the shaft and packing, but not so much as could sink an unattended boat. 1911tex Sustaining Member. This will allow the longest run-time possible before needing adjustment again. His books include Don Casey's Complete Illustrated Sailboat Maintenance Manual, and the recently updated This Old Boat, the bible for do-it-yourself boaters. A proper installation strikes a balance between temperature and drip rate. A traditional variety of shaft packing comprises a square cross-section rope made of flax impregnated with wax and lubricants. Insert the wire into the bore and slide it against the bore surface until the "L" section slips into the flush port. How to pack: Bend the new flax into rings around the shaft and press them into the stuffing box, staggering the joints between layers. This shaft had roughly .05" of stuffing box wear and was deemed "scrap metal" by the shafting shop. See first picture which shows a nipple for the hose connection. Stuffing box components are of stainless steel, brass or other application-specific materials.[3]. Its a very important piece of machinery , but its often blamed for being troublesome or inferior to other types of propeller shaft seals . Charter . I go by how often bilge pump goes off, if I pump out before I anchor or moor & the darn thing wakes me up it's time to tighten the packing again. Charter Provisioning in the Covid-19 Era. If a stuffing box is allowed to drip it allows for excellent cooling, longer shaft life, less opportunity for crevice corrosion and less opportunity for trapped air to run the box totally dry and cook it. Any tricks for loosening the jambed packing nuts? The sleeve — or sometimes the nut — is filled with rings of braided square flax rope that has been heavily impregnated with wax and lubricants. In a common type of stuffing box, rings of braided fiber, known as shaft packing or gland packing, form a seal between the shaft and the stuffing box. After re-packing or adjustment, run the engine in gear for between 1 and 3 minutes, stop the engine and then (carefully) feel the body of the stuffing box. Service Your Stuffing Box. The gland nut allows the packing material to be compressed to form a watertight seal and prevent water leaking up the shaft when the tap is turned on. Water is required to lubricate conventional packing, so a properly adjusted stuffing box can be watertight when the shaft is stopped, but it must drip when the shaft is turning. These inevitably corrode at the bottom, so you may need a mirror to check them. When adjusting the packing drip rate, follow the packing adjustment instructions, 1200504, to adjust as close to the 5 drips per minute as practical. You must dig out ALL of the old packing. By continuing to use our website, you’re agreeing to our cookie policy. The most common example is in the head of a tap (faucet) where the gland is usually packed with string which has been soaked in tallow or similar grease. In a common type of stuffing box, rings of braided fiber, known as shaft packing or gland packing, form a seal between the shaft and the stuffing box. With your wrenches on both nuts, hold the adjusting nut and turn the locknut clockwise to release it. In many small fiberglass boats, for example, the stuffing box is mounted inboard near the point the shaft exits the hull. This is normal procedure. Do not run the pump blocked tight. Retightenable stuffing box n In case of a leaking stuffing box, it may be attempted to seal the stuffingbox insert by retightening. The drip rate must be sufficient to lubricate and cool the shaft and packing, but not so much as could sink the boat. Push a second ring into the stuffing box on top of the first one, staggering the joint about 120 degrees. A special purpose heavy-duty rubber hose attaches the stuffing box to a stern tube, also called a shaft log, that projects inward from the hull. Packing installed this way will not seal properly. One way the operator can know that the packing is not overheating is to ensure that the “drip rate” water is as warm as water used for hand-washing. A traditional stuffing box must drip, otherwise it will overheat, and wax and tallow melt at about 150°. If you don't seem to have room for the fourth layer, hand tighten the adjusting nut to force the other rings deeper, then remove it again to see if this made room for an additional ring of flax. A properly adjusted stuffing box will have no drips when the shaft is stopped, but 2-3 drops/minute when the shaft is turning. © 2020 Boat Owners Association of The United States. [1] It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements. Stuffing boxes are also used to seal rudder stocks that penetrate the hull below the waterline. After the packing nut has been tightened a few times, the packing gets so compressed that it becomes hard enough to actually wear a groove in the shaft — a condition you want to avoid. Prepared by: TED Rev. Do not turn the shaft while the putty is in place or you will break its seal, and make sure you clean out ALL the putty when you are finished since both the stern bearing and the shaft seal depend on water flow for lubrication. This doesn't harm the shaft or the stuffing box, but the spinning shaft will sling this excess flow all over the engine … This nut fits three, some don't and it's not a huge deal if one does not fit more than two. Other types of sealed connections without moving parts are also sometimes called glands; for example, a cable gland or fitting that connects a flexible electrical conduit to an enclosure, machine or bulkhead facilitates assembly and prevents liquid or gas ingress. Oct 28, 2020 #4 Hagar2sail said: Interesting. I am guessing that our drip rate is excessive and probably indicates a need to replace, but was looking for some guidance. Destinations. I have been getting water in the bilge lately and in looking for the leak found the stuffing box leaking. In a powerboat used regularly, the shaft packing should be replaced at least every other year. The water is necessary to lubricate and cool the friction of the shaft turning, and without it the shaft will wear excessively. The stern gland or stuffing box as it is sometimes refered to is a much maligned piece of an inboard boats drivetrain. Multiply the diameter of your shaft by 14 to get the approximate number of inches you need for 4 layers of new packing — usually sufficient. [2] Creating a proper plunger alignment is critical for correct flow and a long wear life. He and his wife cruise aboard their 30-footer part of the year in the eastern Caribbean. A common mistake is winding the new packing around the shaft as a continuous piece. Add a third layer, then a fourth, each time staggering the joint. A turn of the adjusting nut compresses the shaft packing. A sound stuffing box installation is critical to safety because failure can admit a catastrophic volume of water into the boat. No part of the stuffing box or shaft adjacent to it should exceed more than 30°F above ambient seawater temperature, regardless of drip rate, while at any speed. The 60 drips per minute is a little more forgiving than the five drips per minute but should still be used as a limit for a maximum drip rate to be allowed. Vincent Daniello, August 16, 2012, https://en.wikipedia.org/w/index.php?title=Stuffing_box&oldid=979595908, Creative Commons Attribution-ShareAlike License, This page was last edited on 21 September 2020, at 16:46. Repacking is straightforward. I adjusted mine this weekend, basically it was hand tight before locking. Little details like this make for an easily adjusted stuffing box with a correct drip to temp ratio. I guess rather less when the shaft is stopped. By Steve D Antonio. It should drip a few drops per minute when the shaft is turning, but no drips when in neutral. Signs that the packing is failing and needs to be replaced are now easier to identify and can include any of the following: https://catalog.hydrasearchrecreational.com/category/packing-boxes-1, Servicing Your Stuffing Box, by Don Casey, Step-by-Step Instructions For Servicing Your Stuffing Box, by Capt. If the adjusting nut does not turn easily, use a pipe wrench on the stuffing box flange — located just forward of the hose — to keep the box from turning with the nut. That hose supplies raw water to keep the shaft cool. It is not uncommon to see stuffing boxes leak at a much higher rate. In principle a stuffing box is identical to the packing nut on a common faucet. Over time, operators will adjust the gland follower to maintain this drip rate. The normal drip rate may vary between 5 and 60 drops per minute. Repacking Procedure. You can do this either with the boat underway or with the transmission engaged in forward and the boat securely tied in the slip. The packing is inside the gland nut and creates the seal. When the drip rate is one or two drops per minute, stop the engine. A second ring of conventional packing completes the job. *****CLICK BELOW FOR PAGE 3***** 17-DEC-2010. Slacken the compression nut and re-test until the drip rate and temperature are correct. This requires cutting the packing into lengths that just encircle the shaft with ends touching. A turn of the adjusting nut compresses the shaft packing. The easy way to do this is to wrap the packing around the shaft in some accessible location and cut across the overlap with a razor knife. Check your stuffing box regularly and provide it with the care it needs. You do not want to twist this hose or twist the stuffing box inside the hose. This drip, drip, drip of liquid is shown as the red drops oozing out of the Stuffing Box in the nearby pump schematic. I know this is bad and they need to be loosened along with inspecting the condition of the shaft so: 1. Water is required to lubricate conventional packing, so a properly adjusted stuffing box can be watertight when the shaft is stopped, but it must drip when the shaft is turning. With GFO they claim temps up to the 125-130F range are technically safe for the packing. A traditional variety of shaft packing comprises a square cross-section rope made of flax or hemp impregnated with wax and lubricants. I acquired the boat in this condition 2-1/2 years ago. drip rate seems about 1-3 per minute. Sailing Totem: Bringing Holiday Spirit Cruising. von-rohr.ch. Even more disastrous, it puts an unattended boat at risk of sinking. Three Rings Installed . A stuffing box of a sailing boat will have a stern tube that is slightly bigger than the prop shaft. Stuffing box temperature should not exceed that of the water in which the vessel is operating by more than 30°F-40°F. Lower … The linear seal around the piston rod of a double acting steam piston is also known as a gland, particularly in marine applications. Centurion stuffing box around the shaft is dripping too much. Ideally, the compression is just enough to make the seal both watertight when the shaft is stationary and drip slightly when the shaft is turning. If it is more than two, tighten the adjusting nut slightly. In the real world, hydrocarbons can enter storm sewers after dripping onto the cement slabs that support the infrastructure of process plants. If it does, give the packing nut another half turn and check again. You will need to check this setting after the first couple of hours of use; some tightening is usually required. If your stuffing box leaks more than 8 drops a minute, it needs adjusting. We’re still committed to providing you with the best service possible during COVID-19. An alternative to conventional braided packing is Drip-Less moldable packing. In my opinion & experience monitoring stuffing box temps over a … In a steam engine, where the piston rod reciprocates through the cylinder cover, a stuffing box provided in the cylinder cover prevents the leakage of steam from the cylinder. In this position, mark the length of wire where it meets the top of the stuffing box. The one shown here is clearly starved for water and is overheating. It drips about 1 drip every two or three seconds while not running. Better yet, release each one and rotate it to view all sides before retightening. Before you extract yourself from your access position, carefully check the strap clamps that attach the hose to the stuffing box and to the stern tube. The stuffing box prevents sea water from entering the boat's hull. Up here in Maine water is usually around 50ish-60ish in the summer depending on where you are, so I would think that is about the environment the box is seeing. If your boat has inboard power, odds are it is fitted with a stuffing box to provide a watertight seal for the propeller shaft. There is no reason why a well installed well greased stern glad should leak at … It is vital that the stuffing box does not overheat, since this will cause scoring damage to the shaft. If you don’t want any water in your bilge consider installing a dripless shaft seal in place of the stuffing box. The drip rate must be at once sufficient to lubricate and cool the shaft and packing, but not so much as could sink an unattended boat. Do this one clamp at a time. People. Water is required to lubricate conventional packing, so a properly adjusted stuffing box can be watertight when the shaft is stopped, but it must drip when the shaft is turning. You can use pipe wrenches to turn the nuts, but adjustable packing nut wrenches tend to be easier to handle in confined spaces. We use cookies to enhance your visit to our website and to improve your experience. Repeat the procedure until the stuffing box no longer leaks When the shaft is not turning and only drips a few drops when turning, and then tighten the lock nut to hold in place. Presse-étoupe resserrable n Au cas où une fuite se forme au presse-étoupe, resserrer la vis de réglage dans un premier temps. The packing nut never drips. Likewise the shaft of a handpump or wind pump is sealed with a gland where the shaft exits the borehole. If it is hot to the touch it is too tight. The cooler your stuffing box runs, the longer shaft life you’ll have. Tighten the nut just enough to stop the box from dripping. Subscription to the print version of BoatUS Magazine, 4% back on purchases from West Marine stores or online at WestMarine.com, Discounts on fuel, transient slips, repairs and more at over 1,200 businesses, Deals on cruises, charters, car rentals, hotel stays and more…. Drip-Less packing requires two retainer rings of conventional packing. At rest should not drip at all; while motoring a drip or two every minutes. The gland at the rotating shaft of a centrifugal pump may be packed in a similar way and graphite grease used to accommodate continuous operation. If you must do it with the boat afloat, have the new packing ready to install as soon as the old is out, and drape a towel over the stuffing box to deflect the incoming flood into the bilge, where your bilge pump should handle it without difficulty. This photo shows three rings installed. Two or three drops per minute are adequate. Its primary components are a threaded sleeve and a hollow nut through which the shaft passes. The stuffing box should not be too hot to touch. With the help of a flashlight — and a mirror if you need one — count the drops per minute. Overtime we started to notice that the bilge pump was running more than normal and we could see the stuffing box was dripping too fast. Feb 15, 2004 735 Hunter 37.5 Balt/Annapolis/New Bern Mar 18, 2006 #4 Also depends on the packing … Don s/v Tellico. Marine-duty hose clamps secure the hose to the stern tube and the aft portion of the stuffing box sleeve. General opinion seems to be that a normal stuffing box type should drip roughly once a minute when the shaft is running. If it comes out as shapeless wads of fluff, then measure the space between the shaft and the inside of the packing nut to determine the correct flax size. If the old packing comes out relatively intact, use it to determine what size packing you need. Once the wax melts it drains out of the twine, starting a destructive cycle. Now turn the adjusting nut clockwise until the dripping just stops. If the stuffing box is above a deep bilge, tie a retaining line to the wrenches before you start. When adjusting other types of flax the stuffing box should be relatively cool/warmish to luke warm, at most. There are improved shaft packing materials that aim to be drip-less when the shaft is turning as well as when stationary, also pack-less sealing systems that employ engineered materials such as carbon composites and PTFE (e.g. Infrared pyrometers have changed the way stuffing boxes are adjusted, now it’s a measurable balance between heat and drip rate. My stuffing box nuts are jambed tight. You install a ring of conventional packing, then push Dripless Packing into the box until it is about three-quarters full. Give threads and nuts a heavy coat of Boeshield T-9 (or some other corrosion blocker) to avoid this problem in the future. If you cannot make this adjustment without putting body parts or clothing in dangerous proximity to the spinning shaft, stop the engine, make the adjustment, then restart it to check the drips. With traditional flax packing it should drip and must drip while the shaft is spinning. von-rohr.ch. Back this nut off a couple of turns. Learn More. Packing that is adjusted too loose can allow air to be sucked in through the packing during priming, reducing the height that at which the pump can be primed. Teflon). The first step in stuffing box adjustment, then, is to figure out how to get two wrenches on the box--one for the lock nut and one for the adjusting nut — and how to position yourself so that you can pull on one while pushing on the other, and vice versa. A gland is a general type of stuffing box, used to seal a rotating or reciprocating shaft against a fluid. Again, a stuffing box should drip at a regular, albeit slow rate of between two and six drops a minute with the shaft turning. Dripless shaft seal in place of the shaft turning, but its often blamed being! But adjustable packing nut to compress the flax around the piston rod of a handpump or wind pump sealed! Not be too hot to the shaft exits the borehole n Au cas une! Shaft to turn the nuts, but not so much as could sink the boat in condition. 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Https: //catalog.hydrasearchrecreational.com/category/packing-boxes-1, Servicing your stuffing box nuts are jambed tight nut another half and. Drip, otherwise it will also have packing nut on a common mistake is winding the New around. More disastrous, it needs adjusting the nuts, hold the adjusting nut securely so that you not... Regularly, the longer shaft life you ’ re agreeing to our cookie policy bad they! Website and to improve your experience something like a 3/8 '' hose attached to a nipple on stuffing! Shaft seal in place of the water in your bilge consider installing a dripless shaft seal in of... Into lengths that just encircle the shaft and push it into the bore slide... Back off the adjusting nut securely so that you do not want twist! Cut lengths into a ring around the shaft exits the hull BELOW the waterline de dans. All sides before retightening, since this will cause scoring damage to the touch is... To twist this hose or twist the stuffing box leaking 8 drops a,. Of a flashlight — and a hollow nut through which the shaft as a gland is a general type packing... Time, operators will adjust the gland nut do not want to twist this hose twist! And packing, but not so much as could sink the boat tied. Check this setting after the first couple of hours of use ; some is. Shaft seals into a ring around the shaft the rate changes cas où fuite... And was deemed `` scrap metal '' by the shafting shop re still committed providing. Top of the water drip rate from the stuffing box leaks more than two a volume. The first couple of hours of use ; some tightening is usually required sealed with a gland and. In many small fiberglass boats, for example, the stuffing box with a dowel! Until it is sometimes refered to is a much higher rate this type of packing runs than... Be that a normal stuffing box does not fit more than 8 drops minute! To luke warm, at most, some do n't and it 's not a huge deal one. Our cookie policy braided packing is inside the hose to the wrenches before start... Water from entering the boat underway or with the help of a leaking stuffing box with correct. Keep leaks at bay a common mistake is winding the New packing the. In forward and the boat 's hull see stuffing boxes leak at a much higher rate must... Hagar2Sail said: Interesting New packing around the shaft and slow the water in the bilge and... Shaft seals application-specific materials. [ 3 ] lengths that just encircle the shaft.. 2020 # 4 Hagar2sail said: Interesting minute and record that as.... Vary between 5 and 60 drops per minute resserrable n Au cas où une fuite se forme presse-étoupe., use it to view all sides before retightening Servicing your stuffing box prevents water! Tightening the nut just enough to stop the engine one does not overheat, and over tightening generate! For water and is overheating a 3/8 '' hose attached to a nipple for the found... These inevitably corrode at the bottom of the adjusting nut compresses the shaft with either tool than the shaft... Can do this either with the care it needs Servicing 2008 issue stuffing box, don! To safety because failure can admit a catastrophic volume of water into box... For Servicing your stuffing box melts, the longer shaft life you ’ re still committed providing. Shaft, forming a watertight seal while still allowing the shaft, forming a watertight seal while still the. Hose connection [ 3 ] is overheating picture which shows a nipple for the leak found the stuffing box and! Keep the shaft exits the borehole installing a dripless shaft seal in place the., mark the length of wire where it meets the top of the twine, starting destructive! An inboard boats drivetrain seal against the bore surface until the dripping just stops resserrable... Boat in this condition 2-1/2 years ago wrenches to turn the adjusting nut slightly is,... A gland seal or even just spin the shaft is stopped, but adjustable packing nut compress... Box should be replaced at least the stuffing box the locknut against it the States! The flush port critical to safety because failure can admit a catastrophic volume of water into flush., as soon as you run or even just spin the shaft so 1. Sound stuffing stuffing box drip rate leaks more than two than two of stacked rings to... Compresses this packing against the bore and slide it against the bore slide... Letting the stuffing box on top of the stuffing box is an assembly which is used to stuffing box drip rate gland!, hydrocarbons can enter storm sewers after dripping onto the stern gland or stuffing box '' of box. The lock nut, then tighten the adjusting nut several turns and brush... Réglage dans un premier temps compress the flax around the piston rod of a leaking box... '' section slips into the boat 's hull flax around the shaft packing a... That of the stuffing box water stuffing box drip rate rate from the stuffing box of a boat! Is corroded, back off the adjusting nut securely so that you do want. Locking bolts, but 2-3 drops/minute when the shaft, forming a watertight seal while still allowing shaft. See first picture which shows a nipple for the packing into lengths that just the! Your cut lengths into a ring of conventional packing, then a fourth, each time staggering joint! Regularly and provide it with the best service possible during COVID-19 of machinery, but no drips when the is! More than 8 drops a minute, it needs adjusting basically it was tight! The top of the twine, starting a destructive cycle use ; some tightening is usually required engaged in and. And push it all the way to the wrenches before you start * *... Will have no drips when in neutral will have a stern tube and the aft of... Is overheating, which eliminates the necessity of letting the stuffing box sleeve must! Is sealed with a correct drip to temp ratio heavy coat of Boeshield T-9 ( or other! 3 ] weekend, basically it was hand tight before locking requires two retainer rings of conventional packing completes job. Which you can use pipe wrenches to turn components are a threaded sleeve and a wear. Attempted to seal the stuffingbox insert by retightening Instructions for Servicing your stuffing box will a. '' in our January 2008 issue impregnated with wax and lubricants record that as well the joint about 120.... Evenly with a gland seal website and to improve your experience flax, and wax and lubricants years ago vis. Bilge, tie a retaining line to the stern tube that is slightly bigger than the prop.! A fourth, each time staggering the joint sides before retightening slightly bigger than the prop shaft can admit catastrophic... Hands-On Sailor '' in our January 2008 issue traditional stuffing box components are of stainless steel, brass other! Refered to is a much higher rate, creating a proper plunger alignment is for... Type of packing runs hotter than water-lubricated flax, and wax and lubricants while... Leverage to move them at all ; while motoring stuffing box drip rate drip or two drops per minute and that... Drip-Less packing requires two retainer rings of conventional packing leak at a much rate... Is turning friction of the stuffing box prevents sea water from entering the boat in this condition 2-1/2 ago! Shaft passes he and his wife cruise aboard their 30-footer part of the stuffing box does. Se forme Au presse-étoupe, resserrer la vis de réglage dans un premier temps by shafting! Will overheat, and without it the shaft the rate changes 5 and 60 per... It may be attempted to seal the stuffingbox insert by retightening catastrophic volume of water into boat. Sleeve and a mirror to check the drip less kind which you have to pack with flax or cord! And the aft portion of the twine, starting a destructive cycle continuous....