| Author | Message | ||
| CoryDaneRTS Rating: N/A |
The water tank connection under water level is my biggest problem when concerning leakage. My tanks came with no holes. Thus the beginning of a learning experience. One manufacturer sells a "doughnut" that fits in the tank, in a tight hole where your fitting or pvc is inserted, the tight fitting of the pcv pipe is supposed to make the doughnut go tight against the tank material and seal leakage. When asking about using the "doughnut" method, I was told that they don't work well under water and may leak..... just what I want to do, dry out a bus floor and cabinetry while on a trip. ok, so I am now looking at a more direct seal which seems to be a postive seal system.... How do you feel about this Boats use a "thru the hull" fitting, connected to the bilge pump to expell any water that has gotton on board, that fits through a hole from the outside, has a rubber fitting on both sides and a nut/washer to tighten the leak proof fitting. Some have a valve built in, I think. In our case, the side of the fitting that would be outside of the boat would be inside the tank for the bus. As I am installing a snap in "deck plate" (marine) for instrumentation, inside access and cleaning, installing from the inside will be of little concern. Its the leak-proof ness I am after. This seems to be a very positive type seal with barbs on the outside for connecting hose to the system. WHAT SAYeth THEEE? Yea or Nay? cd | ||
| TWODOGS (Twodogs)
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the donut...is kinda for the inlet....out of toilet into tank...have no idea what you are contemplating...tanks inside the bus ?? | ||
| R. Steve Nichol (N4rsn)
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The fitting you are talking about is a bulkhead fitting, and you can buy those, any size you want, at an industrial supply, or any place that supplies tanks for industrial use. http://www.aquaticeco.com/index.cfm/fuseaction/listings.categories/ssid/327 Hope this helps Steve | ||
| Marc Bourget Rating: N/A |
Corey, What are your tanks constructed of? Plastic, if so, why not weld in a threaded fitting? | ||
| CoryDaneRTS Rating: N/A |
2D's I am talking about the Potable tanks and Grey tanks. The Donuts are for all fittins, according the to mfgr.... My potable tanks are inside the bus to try to save compartment tanks. Marc, the tanks are that white plastic, almost see through. Very tough. I don't know how to weld plastic and with my luck, the weld would let go. I found the through hull fittings and thought the fitting lips would make the seal/grip/support extra strong, actually stronger than any weld or screw in fitting. Obviously, with the tanks INSIDE, we really don't want any leaks, and I have already thought that the donuts are inferior to the through hull device. Steve Yes thats the area of thought right now. I think it may work quite well, just looking for some other opinions. I kinda think that might be the way to go unless a better comes up. Thanks cd | ||
| James Maxwell (Jmaxwell)
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Cory: They make the bulkhead ftngs. that Steve speaks of in slip and threaded configurations also and in a variety of materials. The compression donuts are not recommended for under pressure or water use. My 3" toilet inlet weeps a small amount just from sloshing when the tank is near full. They are strictly intended to be up top and I have seen them leak when used on the sides or ends of tanks. Since u plan to have access to the inside I think that a screwed flange bulkhead ftng. would be about the best seal you are going to accomplish short of welding. I used a self-fabbed 3" bulkhead fitting for my dump valve ftng. and it works good with no leakage. I used the inlet hole that weeps for drain ftng. inside flange access. I was unable to master the art of plastic welding and didn't know anyone else that could either. | ||
| Marc Bourget Rating: N/A |
CD, Sorry, with my experience with plastic injection molding, I didn't stop to consider the understandable caution of someone lacking that familiarity. Too bad you ain't close! I have a standing offer with Grant Gould for his conversion. All he has to do is supply the material and measurments and I'll do the "Gumpy" thing! Onward and Upward | ||
| John Bessette (John_bessette)
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cd mine all leaked had to go back in and weld them in dont waste your time. John 4106 | ||
| CoryDaneRTS Rating: N/A |
John, what did you install? Any ideas about the leaks? I was looking at two things when I found the Through Hull fittins 1. the compression fitting should seal well due to the pressure applied when installed. 2. The fittings should be stronger since they have mounting flanges and the washer with a wide area to attach to the tank. The screw on types seem to move around and appear weak, too much movement. I'd be interested in what you had done. cd | ||
| FAST FRED Rating: N/A |
The usual method is to shape a plug that will fit in the fitting and in a 1/2 + hp router. A hole is cut in the tank of the proper size and the fitting is simply spun at high speed. In about 15 seconds the area under the fitting is melted and when it cools the fitting is welded in. Absolutly no big deal , unless your tank has many different SIZE outlets , that would require many plugs to spin each sized inlet/outlet. 2in fill , 2 in vent , 2 in outlet and a low 2 in dump for FW . the same for the black/ grey with a large discharge fitting to get rid of the waste quickly (Chicago Bridges are SHORT!:-) FAST FRED | ||
| CoryDaneRTS Rating: N/A |
FF Didn't you hear????? Getting rid of waste over the side of the bridge brings on bad OMENS. AND ABOUT A $150,000 fine (so far). BESIDES, if you have an electric pooper valve, the bridges in Chicago are on a Grate, stop for the traffic, look to make sure the PO-lice are not behind you then "accidentally" hit the switch with your knee. LOLOL Oh, better look below to see that there are no tour boats to catch your water. For some reason, they frown upon that. HAHAHAHAR HAR HAR Ha Ha ho har ho ho hah ha lololol cd | ||
| Tim Brandt (Timb)
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Cory, Those marine bulkhead fittings are not what are used for a thru hull fitting below the waterline. The ony good seal you can get on a hull is with a regular mushroom shape thru hull fitting caulked with 3M 5200. Most freshwater and holding tanks I have seen in the marine industry come with threaded bungs built in | ||
| Gary Stadler (Boogiethecat)
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Cory, Like Fast Fred said, the best way to make the connection is using a technique called "spin welding". The EASIEST and most safe way to do this is simply take your tank to an RV place that will do it for you, and have them do it. The fittings they use are standard manufactured items. So are the tools they use. It won't cost much, the equipment will be right, and they will have the skill to do it right. If you've never done it, it's not hard but it does take some practice to get it right, it definitely takes the right tools, and probably you won't "get it" correct the first or tenth time you ever try it. Bulkhead fittings will work but they are mechanical. They will fail. Spin welded fittings are welds, they won't fail. | ||
| CoryDaneRTS Rating: N/A |
Well, how can something sound so easy and be so tuff to get done? LOL Well the thru hulls sounded like just the ticket but maybe it sounds too easy. I think I found someone that can spin weld up in Wisconson, think I'll take a ride up there sometime soon. Ya all been great cd | ||
| John Bessette (John_bessette)
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cd That is what i did was take it to a rv place that could weld new fitting in the holes that were leaking. Which was just about all of them. John4106 | ||
| FAST FRED Rating: N/A |
"The ony good seal you can get on a hull is with a regular mushroom shape thru hull fitting caulked with 3M 5200" Sorry but this is NOT the way its done on inspected boats. The Seacock is bolted and gooped to the hull. The thru hull is screwed into the seacock thru the hull with soft non hardening goop. I prefer old fashoned Dolphinite. The reason is the thru hulls will be pulled and inspected every time the boat is hauled (with the Coasties watching) , then reused if in OK shape. Just sticking a thru hull thru the hull , placing a nut on it and then a Home Depot valve is OK on uninspected boats , but NOT aqllowed where more than 6 will be drowned at once. FAST FRED | ||
| Tim Brandt (Timb)
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I understand where you are going Fred and I do agree I was trying to point out that his premise that a bulkhead fitting with a rubber washer is what boats use for through hull was wrong. All my hulls have been steel so that is a whole other type of attachment with an isolator between the valve and the hull.....and no no home depot parts on my boats.  |