Leaking black tank August 24, 2009, 11:49:55 pm Yahoo Message Number: 105229Hi Group, While exercising my 2005 26ft MB, I noticed a slight drip, drip, type leak coming from the black tank. The source of the leak seems to be right where the outlet pipe comes out of the black tank. It looks like there is a flat collar that sits right on the tank, around the outlet pipe that extends out maybe a 1/2 inch. The leak seems to be coming from under this collar. Is there some way for me to re-seal this collar? I'm thinking something like silicon caulking, but is there some other product that would work better? At least temporarily until I can get it serviced properly? I was actually at Camping World in San Martin when I discovered this. Unfortunately, the wouldn't touch it unless the tank was empty and they didn't have a dump station for me to use.Thanks, David G.
Re: Leaking black tank Reply #1 – August 25, 2009, 12:21:40 am Yahoo Message Number: 105232David, I wrote about a procedure I came up with to fix just this problem. Should be in the archives. If you can't find it, let me know. Basically you make a tip for a Weller transformer type soldering gun out of a piece of 10 ga copper wire. (the Weller may also come with a "hot knife" tip that can be shaped to do the job. The tip should be shaped like a knife blade, thin and sharp front and back. This will be used like a hot knife to re-weld the flange by sticking it in the crack before the leak area and then slowly moving it around the flange, through the leak area and beyond. Hot melted plastic flows around tip and back together as blade passes. When done, use the hot tip to "trowel" the plastic back into place and smooth. It'll be better and stronger than new. I suppose it should be obvious that the tank wants to be empty and clean before attempting this repair. Note that the flange is "spin welded" or friction welded by spinning it in place against the tank to heat the plastic when the tank is assembled. LD will tell you you need to come in and drop the tank and spin weld a new fitting in place. Both expensive and unnecessary.bumper
Re: Leaking black tank Reply #2 – August 25, 2009, 12:28:10 am Yahoo Message Number: 105234Quote From: bumperm To: lifewithalazydazerv@yahoogroups.com Sent: Monday, August 24, 2009 9:16 PM Subject: Re: [LD] Leaking black tankDavid,Forgot to add: When using the "hot knife", it is important to modulate the heat by clicking the trigger on and off. You want the tip hot enough to easily melt the plastic so it flows smoothly around the tip, but not so hot that the plastic starts to smoke as this will degrade and weaken the plastic at the "weld" - - - you are, in fact, welding the plastic with the hot iron.bumper
Re: Leaking black tank Reply #3 – August 25, 2009, 11:31:47 am Yahoo Message Number: 105250Thanks, bumper. I thought I'd remembered reading something about your fix, but couldn't remember the details. A search of the archives did indeed turn up the fix. I believe I can get my hands on a soldering gun and will try this out.Best,David G
Re: Leaking black tank Reply #4 – August 25, 2009, 11:55:17 am Yahoo Message Number: 105252You might try a product called "JB Weld" --- I have used this product for many different uses, including patching a hole
Re: Leaking black tank Reply #5 – August 25, 2009, 11:58:17 am Yahoo Message Number: 105254If you would like further info, here is the website for JB Weld... http://www.jbweld.net/index.phpEd Klaus 94 LD MB
Re: Leaking black tank Reply #6 – August 25, 2009, 12:12:36 pm Yahoo Message Number: 105256Hmmm, Looking into this, the website claims JB Weld will not bond to either Polypropylene plastic, or Polyethylene plastic. Not sure what the tanks are made of, but I think it is Polyethylene plastic. But thanks for the suggestion.David G.
Re: Leaking black tank Reply #7 – August 25, 2009, 12:42:13 pm Yahoo Message Number: 105259David,Great! Let us know how it works out for you.Bad new is that black water leaks, even small ones, are yucky! Good news is the plastic involved is all ABS thermoplastic - - eminently weldable.Have as much fun as you can (g).bumper
Re: Leaking black tank Reply #8 – August 25, 2009, 12:57:38 pm Yahoo Message Number: 105263You are correct. JB Weld will not work in this application. JB weld is nothing more than epoxy with a filler added. From the way some mechanics use it, you'd suppose it works well on everything with the possible exception of hemorrhoids. But you gotta remember that most epoxies cure fairly firm, with not a lot of flex, and their thermal coefficient of expansion is not gonna be the same as many of the substrates they are used on. Unless there's a strong mechanical bond, they can fail when used on things that flex and move. There are special (read expensive) epoxies made specifically for gluing "hard to glue" plastics (small kit was over $20 from McMaster-Carr IIRC). I bought this when I had my leak, but then after more research, and after talking to the factory about how the tanks are assembled, decided that plastic welding was the obvious best solution. Note that Vince at the factory told me the only workable fix he was aware of was to bring it in and have them try to either re-spin weld the fitting, try to install a new one, spin welding it in place, or replace the tank (as he said you could only spin weld it a couple of times). None of these procedures, as I posted earlier, sounded very appealing. The plastic welding fix, once the tool is in hand and the insulating foam (if any) is removed, is quick, simple, and amazingly easy and effective. Now, when I say that, I am not meaning to imply that working on any back water tank is what I yearn to do in my free time . . . . but you probably knew that.bumper Yonder Minden "leak free" Nevada
Re: Leaking black tank Reply #9 – August 25, 2009, 01:08:34 pm Yahoo Message Number: 105265Hey Bumber I was thinking after the "fusion" job is finished, it might be a good idea to slap a couple of small dabs of abs glue on the area. Back in the days when I did plumbing we did this on small leaks and the glue had a chemical effect on the pipe/joint. Most of the time this was successful. John 85 FL.
Re: Leaking black tank Reply #10 – August 25, 2009, 01:11:14 pm Yahoo Message Number: 105267Most epoxies do not bond well to plastics, that being said West Systems has a new product, G/Flex that does bond with most plastics. Here's the info on it: http://tinyurl.com/llpqguNeal
Re: Leaking black tank Reply #11 – August 25, 2009, 01:22:29 pm Yahoo Message Number: 105269JB Weld is ordinary epoxy glue with a bit of powdered metal as filler. It is somewhat heat-resistant, but otherwise, it won't do anything that a regular epoxy wouldn't do. The company also makes fast-curing and putty versions that are similar to other commonly available epoxy products. See this Wikipedia page for a hype-free description:http://en.wikipedia.org/wiki/J-B_Weld> For repairing a leak at a holding-tank joint, Bumper's welding method is the best way to go.Andy Baird http://www.andybaird.com/travels/
Re: Leaking black tank Reply #12 – August 25, 2009, 02:30:42 pm Yahoo Message Number: 105273If you are hesitant about repairing the tank yourself, let a pro do it. Many RV shops and all plastic fabrication shops have professional-grade plastic welding machines. An experienced welder can make a repair superior to the solder-gun method. At work, we used a local plastic shop for repairing damaged thermoplastic tanks. When done right, the repairs are almost invisible and are as strong as originally.Make sure tank is super clean before taking it to the shop.Larry
Re: Leaking black tank Reply #13 – August 25, 2009, 07:58:36 pm Yahoo Message Number: 105277"Most epoxies do not bond well to plastics, that being said West Systems has a new product, G/Flex that does bond with most plastics. Here's the info on it: http://tinyurl.com/llpqgu"Neal Thanks for the link. I had not seen this new epoxy from West Systems. Their pre-thickened epoxy looks like the perfect item to include in my kayak/motor home repair bag. The ability to apply it to a wet surface, even underwater, is impressive. http://www.youtube.com/watch?v=5l4ZB9UyrDw> I have carried a conventional epoxy and fiberglass repair kit in my sea kayak for years and always worried about how to get the boat's hull perfectly dry before making a repair. This product eliminates the moisture problem although the epoxy still must be warmed for it to cure properly.Larry
Re: Leaking black tank Reply #14 – August 25, 2009, 08:37:27 pm Yahoo Message Number: 105278Larry YW, West produces a good product! I'm a System Three retailer, they too have similiar products, but the GFlex looks best for the tank repair. I've been building S&G boats for years. Here's a link to my boat building site, www.skiffkits.com (Group Mom, sorry for the off topic shameless plug) :-) Another great adhesive/sealant that cures very strong & is long lasting - 3M's 5200. Their 4200 is good too, it's the same product just faster setting, hours vs. days for 5200. The 5200 can sometimes be found at HD,
Re: Leaking black tank Reply #15 – August 25, 2009, 11:45:23 pm Yahoo Message Number: 105282"Another great that cures very strong & is long lasting - 3M's 5200. Their 4200 is good too, it's the same product just faster setting, hours vs. days for 5200."Neal I have been promoting 3Ms polyurethane adhesive/sealants on this site for years, its good stuff. There is always a tube or two of it in the LD and at home. I have never had something sealed with it fail as long as the surfaces were properly prepped. Your website is interesting. I had no idea that 'tortured plywood' kits were available for boats as large as your 24' skiffs. These are real boats made for heavy and foul weather. How much does a fully equipped 24' skiff weigh? Hmmmm, I wonder if the wife would mind giving up her garage parking spot for the next year or so?LarryFair weather boater, most of the time.
Re: Leaking black tank Reply #16 – August 26, 2009, 02:23:44 am Yahoo Message Number: 105286Quote From: lw5315us To: lifewithalazydazerv@yahoogroups.com Sent: Tuesday, August 25, 2009 11:29 AM Subject: [LD] Re: Leaking black tank"An experienced welder can make a repair superior to the solder-gun method. Larry"Larry, I'm not sure I agree. In this case, the tank fitting has a flange that's perhaps 3/8" to 1/2" deep.. There is no access to anything but the outside of this flange if one were using a plastic welding machine (I have one BTW, though it's not an expensive one). I suppose our experienced welder could cut out a "V" with a router and then fill that in to get some body and depth to the weld, but most would probably just put a surface bead on the outside of the flange, getting at least some penetration that way. In any case, I seriously doubt that the weld produced would be as strong as the weld obtained using the soldering gun *with* the hot knife tip. The soldering gun, with a tip that is made like a knife blade, sharp on both front and back, will penetrate the flange nicely to it's full depth. Then as it's moved slowly through the area to be welded, the plastic is heated to molten and then flows back together to cool and bond at the back edge of the hot blade as it passes by. Unlike the shallow depth weld one might obtain with a plastic welder (unless the flange were routed out etc), the weld obtained with the soldering gun is as strong, probably stronger, than the original "spin weld". My tank flange failed about 3 years ago when I bonked it against a curb. The repair has performed flawlessly ever since.bumper
Re: Leaking black tank Reply #17 – August 26, 2009, 03:44:20 am Yahoo Message Number: 105287"I suppose our experienced welder could cut out a "V" with a router and then fill that in to get some body and depth to the weld"bumper That's how our welder repaired broken plastic tank outlets. He treated them the same way he would a steel tank. A die-grinder was used to open up the joint into a nice 'V' shape.. We had a fleet of electric floor scrubbers that suffered from broken outlets and drains. Once they were re-welded, they rarely broke again. The welder did have the advantage of having the tank on a bench and access to the correct plastic welding rod and a pro-grade welding machine. There is no reason why the solder gun method would not form a strong joint, especially in capable hands. My main concern would be weld contamination from the solder-gun tip. I guess a new blade-tip would not be a problem unless they too come pre-tinned, the same as the soldering tips. Which method is the strongest? Who knows? It would take a $100,000 of destructive testing to find out Larry
Re: Leaking black tank Reply #18 – August 26, 2009, 10:33:34 am Yahoo Message Number: 105288Quote From: lw5315us To: lifewithalazydazerv@yahoogroups.com Sent: Wednesday, August 26, 2009 12:43 AM Subject: [LD] Re: Leaking black tankThere is no reason why the solder gun method would not form a strong joint, especially in capable hands. My main concern would be weld contamination from the solder-gun tip. I guess a new blade-tip would not be a problem unless they too come pre-tinned, the same as the soldering tips. Which method is the strongest? Who knows? It would take a $100,000 of destructive testing to find out LarryLarry,I made the "hot knife" tip that I used, so there was no solder contamination. I know you know this (g), so the following is just for clarification for those reading this who may not. The "Weller" inductive type soldering gun is really a step-down transformer, with the heating tip a single turn secondary of the transformer. When the gun is on, lots of current flow at low voltage through the tip, and this results in heat - - and quick! To make a tip, one has only to obtain a scrap of 10 ga solid copper wire. Any electricians shop would likely give you a chunk for free, or buy a foot or two at Home Depot. To make the tip, simply fold over a length of bare wire, with the fold squeezed into a tight bend. Now use a ball peen hammer (or similar) against an anvil or similar piece of flat metal and beat the snot out of the wire end to form a flat blade of suitable dimension. Follow this with a shaping, smoothing and sharpening of the blade on a small belt sander. Install in you Weller gun and you're ready to go at that tank!all the best,bumper
Re: Leaking black tank Reply #19 – August 26, 2009, 10:42:08 am Yahoo Message Number: 105289For those not needing the quality and expense of a Weller solder gun, the cheap Harbor Freight alternative will likely do nicely - 10 bucks. One could form one of the included tips into a hot knife using hammer / sander method. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=4328all the best,bumper[Non-text portions of this message have been removed]
Re: Leaking black tank Reply #20 – August 26, 2009, 01:03:10 pm Yahoo Message Number: 105291--- In lifewithalazydazerv@yahoogroups.com, "lw5315us" Your website is interesting. I had no idea that 'tortured plywood' kits were available for boats as large as your 24' skiffs. These are real boats made for heavy and foul weather. How much does a fully equipped 24' skiff weigh?24 footer with full cabin & Suzuki 140 less than 3000lbs.Now back to LD's :-)Neal AncAk
Re: Leaking black tank Reply #21 – August 28, 2009, 08:33:31 pm Yahoo Message Number: 105339I attempted the repair as per bumper's instructions. My results were less than good. It pretty much went as bumper explained; I prepared a soldering tip by flattening it with a hammer and it did indeed slip underneath the flange. But it was difficult to move it along the edge and I had a problem with the tip digging into the black tank material.After I felt I had it done, I tested it and it leaked
Re: Leaking black tank Reply #22 – August 28, 2009, 08:55:08 pm Yahoo Message Number: 105342Quote From: lightight2003 To: lifewithalazydazerv@yahoogroups.com Sent: Friday, August 28, 2009 5:32 PM Subject: [LD] Re: Leaking black tank" I attempted the repair as per bumper's instructions. My results were less than good. "David, Sorry it didn't go so well. Is the leak at the bottom of the flange and/or easily accessable? PPL motorhomes has a rubber gasket fittings (not welded) available, so replacing the tank is likely not necessary. http://www.pplmotorhomes.com/parts/rv-toilets-tanks/rv-holding-tanks.htmI mispoke the other day when I said the tank was ABS - - if it was, gluing would be easy. Rather it's polyethelene, so almost all glues won't work, as previously discussed. I wouldn't think Eternabond tape would work either, unless it's rated for underwater applications and will stick to polyethelene.bumper
Re: Leaking black tank Reply #23 – August 28, 2009, 10:44:26 pm Yahoo Message Number: 105347but I wanted to ask those who might know if they thought attempting to seal it with EtenaBond would be a good idea. Does this tape bond well to the black tank Polyethylene plastic? Should I wait a period of time to let it cure before testing it?try Rescue Tape: http://www.rescuetape.com/?gclid=CIbKpfHqx5wCFRUwpAod3ygxKQ I've used it on several leaking things and worked well...Jerry 2000 30 IB
Re: Leaking black tank Reply #24 – August 28, 2009, 11:13:44 pm Yahoo Message Number: 105348Hi bumper, Yes, the leak is at the bottom of the flange, but I'm not sure if I'm up to really disassembling the fittings to try to do the repair myself. Hopefully, wherever I end up taking it for the repair will be able to do it without replacing the tank. BTW bumper, I just want to tell you how much I appreciate the suggestions you've made. Your ideas and knowledge are top notch. It was a very imaginative thought to re-weld the fitting and I can only say that if I had a bit more knowledge of such things, this would have worked for me as well. I am always willing to give things a try. I've not given up however. I'm going to try again tomorrow to re-weld the flange. I had to wait for it to dry out again. If I get a better result, I'll let you know.David G
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