dripless packing for stuffing box
I’ve provided full installation instructions for that type of seal too in another article. Finding the right packing … While a dripless shaft seal may be “dripless,” it is definitely not maintenance free. Also, please be aware that after you install a graphite impregnated packing you will see some accelerated anode erosion rates. Unfortunately if I cut the rings in this manner they do not seal quite as well. The cooler your stuffing box runs, the longer shaft life you'll have. In this photo what you are actually seeing are two nuts not just one. It’s very important to allow a few drops of water per minute, when the shaft is spinning, for lubrication. After 15 years of successfully handling demanding … The photo to the left is Duramax Ultra-X which has a very similar construction, and braid, to Gore’s GFO. Proper adjustment for GFO, GTU or Ultra-X is up to a few drops per minute when the shaft is spinning. If you want a totally dry bilge then a dripless type seal such as a PSS or Las-Drop is the way to go. Volvo dripless on my yacht, that's what it came with. As a marine electrician and corrosion specialist I have all but stopped using the graphite impregnated packing materials I used when I initially wrote this article back in the early 2000’s. This photo shows three rings installed. If you cut the rings on the shaft, at the stuffing box, you run the risk of scoring the shaft and causing a burr that can damage the new packing and inevitably leak more until the burr gets polished away from the friction. This is advice that every boat owner with dripless shaft seals should heed. Dripless Shaft Seal. Copyright 1994 - 2019 Compass Marine Inc. | All Rights Reserved, Do not use graphite packing in the stuffing box. Please be careful. I find it easier to use the pipe wrench on the small & thin locking nut and the spanner wrench on the big nut. I then inserted this 2-1/2 inch piece into my bench vise and used a hack saw to make two more cuts. There is actually a fair amount man-handling, of the rings, between the time when they are cut and inserted and some measure of fray prevention should be attempted when using Western Pacific Trading GTU or just use GFO or Ultra-X. I was used to using flax packing and adding a ring every year or few. Remember when I talked about air entrapment in a packing gland causing temp spikes, I suspect this was it. I expect SynBraid® to be on the market sometime in early 2018. If you choose them please do check on the shaft periodically. There are vast difference in hoses and most are not at all suitable for a stuffing box application. If the shaft log is totally sealed or “dripless” the air accumulates until the box has no lubrication. Please do not get in the habit of tightening the stuffing box when leaving the boat. We now know where the ABYC stands on graphite packing but what about the largest prop shaft manufacturer in the United States, and possibly the world, Western Branch Metals? With traditional flax packing it should drip and must drip while the shaft is spinning. On a boat we had in 2000 I installed the “West Marine Moldable Dripless Stuffing Kit” and it eventually became a nightmare. When adjusting other types of flax the stuffing box should be relatively cool/warmish to luke warm, at most. Please do yourself a favor and pre-cut your rings. This gray/black goo totally plugged the stuffing box essentially preventing any cooling or lubricating water from getting to the female nut. Natural flax based packing’s are not elastic and do have a memory, in a sense, and they will not necessarily return to their uncompressed state. Because the shaft nut does not compress the flax on the circumference, like the action created by a hose clamp, cutting it 45 degrees & parallel creates a less than optimal seal. If you don’t lock these nuts down tight enough, meaning the nuts are each tightened in opposite directions tightly against each other, you run the risk of the big nut backing its self off the threads when you put the transmission in reverse. The article is about re-packing the stuffing box not about the hose clamps. 2. What I discovered is that air can become entrapped in the shaft log and with no cooling water, meaning no drips, you can, quite suddenly and without warning, develop a massive temp spike. Real Tobin Bronze shafting has been long gone for many years now, and as such, alloys in the stainless family, such as Aqumet & Nitronic are now being used it its place. When they drip they also displace any entrapped air. I can’t stress enough how much of a difference there is between a product like PB Blaster or Kroil and lousy penetrating products such as WD40. If you like it and want to make a small donation than that's all I ask. Here’s a direct quote from a reader who used this article for directions. Dripless = A stuffing box that has zero drips, Drip-Less = A stuffing box that drips less but still needs to drip some. The simple act of backing down on an anchor can force air bubbles up into the shaft log and with no drip there’s no way for the air to escape. I can’t remember where I found this pick, perhaps Sears, but it used to be straight and was designed for removing engine seals! I would strongly urge you to use non-perforated AWAB 316 SS hose clamps instead. It’s a robust 6 ply hose, and meant to take the abuses of a drive train installation. While it’s true dripless shaft seals require less care than a traditional packing gland, nothing on a boat is truly maintenance free. Well, like anything dealing with boating, it’s not always easy but can be done with a little Yankee ingenuity. If you have a bronze shaft please use extreme caution with graphite impregnated packing materials. Lasdrop's Gen II Dripless Shaft Seal offers a unique ball-bearing drive system that allows the seal ring to "float" and remain in constant contact with the carbon graphite seal surface. Inner Diameter = Shaft Size (A) Outer Diameter = Stern Tube Diameter (B) Dripless, maintenance-free, stuffing box … This boat came darn close to sinking. Dripless Stuffing Boxes; Avoid the Pitfalls, and Keep Your Bilge Dry Face seals rely on the spring tension created by a bellows-type hose.€ The system is simple and effective. Most dripless shaft seal units have a small barb fitting on the graphite flange where a hose can be connected to ensure that water is always present right up to the rotor. Once enough air becomes trapped up in the shaft log the packing box, you thought was cool to the touch, begins cooking while you least expect it. Gore GFO packing should have a drip or two per minute with the shaft spinning. An old diesel mechanic told me that he never removes the old packing, just adds a new ring. The down side to graphite impregnated packing’s is that graphite is the most noble element on the galvanic scale. Extruding the lubricant (graphite), mixed into the yarn, is a far superior process than “impregnating” the product after the extrusion & braiding process. Thread engagement is critical and my personal preference is for four full thread peaks of engagement between the female nut and male stuffing box threads. Use 4 ply minimum, non-wire reinforced hose. This could take a very long time unless you are in heavily silt laden water…. The shaft was in perfectly fine condition when packed, and a year later this is what it looked like. I take many pictures of bad installations but a reader sent me this one. Razor blades are cheap. as your prop shaft and then cut away. The green stuff in the image is the “moldable clay” shown with the two rings of packing that came out of the female stuffing nut. With GFO they claim temps up to the 125-130F range are technically safe for the packing. Loosen the packing-gland locking nut and the compression nut. This ring was cut from Duramax Ultra-X. I have used it on my own vessel but inspect the Aqualoy 22 prop shaft yearly. Both of these wrenches are available at Home Depot or any hardware store. Johnson-Duramax Ultra-X can be purchased by the foot from Hamilton Maine and it cuts cleanly. IMPORTANT: When you cut rings this way they will not wind up the correct length. Word to the wise: When using these newer packings, tighten only enough to just stop the drip when not running, yet allowing a slow drip when shaft is turning. Products such as WD40 DO NOT WORK WELL AS A PENETRATING OIL. Making this tool took less than five minutes but can really save time and headaches. Even with the female nut totally removed, in the water, I was getting, at best, 4 drips per minute with the nut off! They also are available with added lubrication. Here are two of the new GTU rings and the old stuff. This allows the packing to take a set and break in some. The product I used above for this article was Western Pacific Trading GTU from West Marine. But, the zinger is always the same. I’ve received far too many emails asking what this packing material is to ignore them, so here are the details. Little to no heat is the most desirable. Unfortunately it is not yet on the market and is still in the testing stages. Once the bellows are relaxed, the mechanical seal between the rotor and flange is lost, and sea water can flow into the bilge. WARNING: While I do like the performance of graphite impregnated packing materials such as Duramax Ultra-X, Gore GFO or Western Pacific Tradings GTU they can be potentially dangerous to underwater metals. (New packing is < $20) If the Dripless Shaft Seal rubber bellows ever cracks, rips or otherwise … There is a big difference between actual stuffing box hose and a wet exhaust or plumbing hose. As with any rubber hose below the waterline, it must be inspected regularly for signs of cracks, wear, aging, or chemical deterioration. Another issue with a spinning rotor is that the flange and rotor are so well mated that there is a suction effect between them, and the rotor can actually stretch the bellows beyond its relaxed position before the seal is broken. Graphite Extruded Teflon – These products usually have the graphite lube physically extruded into the Teflon yarn before it is braided. Sailing in rough weather can also lead to air entrapment. I have discovered that Western Pacific Tradings GTU frays considerably more than Gore GFO or Duramx Ultra-X. Flax Packing – This packing material is derived from flax plants and they require a higher drip rate for lubrication. I don’t tend to see these issues with Aqualoy 22 shafting but I have seen it with bronze and lower grades of stainless. … This owner was using a Teflon impregnated natural flax and thought when the advertising said “drip-less” that it meant it was supposed to be “dripless“. If using these graphite impregnated packing materials I would strongly suggest checking the shaft at least yearly. The cooler your stuffing box runs, the longer shaft life you’ll have. In this picture I have two of the three rings wrapped around the shaft in a stepped and alternated order. Tightening the nut to seat the packing, especially with the newer more slippery packing braids, can move the seam and you’ll now be blind as to where your seams are and will need a dental mirror to confirm seal position. Seek out hose specifically made for stuffing boxes. fraying can be an issue. This material offers the best heat transfer due to graphite’s inherent ability to transfer heat rapidly. One of the last things you want to do, if changing your packing in the water, is to cut your rings during the project. Graphite is the most noble element on the galvanic scale.. As such anything in the drive train becomes anodic or sacrifices itself to the packing. This one comes up a bit on the short side so be careful in your cutting. Buck Algonquin a US manufacturer of quality bronze packing boxes and other drive-line components. Not only is it very, very tough to remove with a pick, and replace once installed, it also did not work as advertised for me. You’ll want to offset the rings butt-joints 1/3, 1/3, 1/3 for a three ring box or 1/2 & 1/2 or said another way 12 o’clock and 6 o’clock for a two-ring box. NOTE: Please ignore the fraying. If you happen have your shaft out, this makes for an opportune time to replace your stuffing box hose as well. You’ll ideally want it adjusted for nothing more than slightly different from the sea or lake water temp, about a 15 – 20 degree differential, or slightly warmer to the touch. Deciding to remove all the old, I was surprised to find all of the rings, maybe 6 in all, intact with no disintegration. Packing Type Seal: Axial Shaft Seal: 3/4" to 7" Diameter Shafts. It ran at what I thought were normal temps during and after break in as I measured it with an infrared thermometer. The idea behind this green moldable clay is that it will make your traditional stuffing box dripless. Top Rated Seller Top Rated Seller. This is due to the braiding process used. What I have learned is that packing gland temperatures can be anything but static. The first ring of packing is on its way out.. For this process I cut the 1-1/4 inch PVC pipe to 2-1/2 inches long. I have measured this now for over 6 years with various products. The key to preventing setscrew and rotor movement problems is to place a hose clamp on the prop shaft up against the forward face of the rotor, so that even if the rotor works loose, the hose clamp will prevent the rotor from moving away from the flange. Well.. The addition of graphite, as the performance lubrication, allows for minimal dripping and longer times between adjustments. I though it would be a good time to rig it up in my shop and illustrate how to replace the packing material inside one of these tried & true work horse style stuffing boxes. Cut it and then shave one end down until you get the correct fit over the shaft where the two ends butt perfectly. Anybody ever go “retro” on a larger powerboat, converting from a dripless seal to old fashioned stuffing box? Some dripless shaft seal products use set screws to hold the rotor in place. Drip-Less packing was … The Buck Algonquin product is six-ply. Some boxes will even drip when the shaft is not spinning and this can be entirely normal depending on the condition of your shaft. How does air get in there? Like conventional stuffing boxes, dripless seals should not operate at a temperature that is greater than 30 degrees Fahrenheit … This was not a real boat and in the process of photographing this I man handled the rings far more than you would. If a stuffing box is allowed to drip, even at a slow rate, it allows for excellent cooling, longer shaft life, less opportunity for crevice corrosion and less opportunity for trapped air to run the box in a totally dry state and cook it. Water Lubricated: With or Without Emergency Air Seal: With or Without Emergency Air Seal: With Emergency Air Seal : Dry Max Marine Rudder Shaft Seal: Strong Boy Marine Stuffing Box The shaft is sealed by compressing packing … In my opinion & experience monitoring stuffing box temps over a 6+ year period, 125F – 130F generally means there is not enough cooling flow through the box. While some packing materials such as Gore GFO, Ultra-X or GTU may be able to be adjusted to be mostly dry, and still some what cool to the touch, it’s still a poor idea from a crevice corrosion stand point. Here’s an image of a 45 degree cut. These packing materials also need a few drips per minute to run cool and not damage the shaft. The packing nut will actually compress these two ends together and create a better butt-joint than if they were cut vertically for a circumference (think hose clamp) type compression. It is my best guess that this is what happened with our “miracle clay” packing…. Water pump pliers will, in many cases, not work very well or will not get the nuts tight enough after adjustment. This is the last step. You can see the shiny surface where it meets the shaft and the thickness (3/16) of the flax its self. Traditional flax packing can drip as little as about 5-10 drops a minute, if adjusted correctly, while running, and this drip rate allows lubrication of the shaft. GFO Allows Bilges To Stay Dry. With GFO they claim temps up to the 125-130F range are technically safe for the packing. Don’t Rock The Boat: Prevention and Treatment Of Seasic... Propane Tank – Staying Ahead of Corrosion, RBAW – Lakebay Marina Purchase Back in Play, An Experience of a Lifetime – The Van Isle 360.