Terry, Had this same problem only with a rectangular one. It seems that Marine Trader used very thin plastic electrical conduit elbows to exit the tank, and when one broke, I was faced with replacement that required an access plate as it could not all be repalced from outside. provided the only solution. We used a screw plate access port glued in place with 5200, but the rub, of course is your round surface. Any way to go in through the top? Only other way I can think of might be to cut a piece out, and glass in a flat chord to hold the access plate. Good Luck with this one. Steve and Dayna Smith Partners'-Ship" 1990 Marine trader 34 DC at Solomon's Md Spring Cove Marina drplanet@mindspring.com

I have a 50 gal holding tank, some kind of plastic material, cylindrical and set on-end. The head sits directly on top, with the floor dividing the two, and is gravity fed. When all this was put together, the vent was also mounted on the top portion of the cylinder, but is now clogged due to corrosion. It is in a location that is not accessible. I have not been able to ream out the vent line and need to put in a new one. I am looking for a way to mount a fitting on the side of the tank near the top portion. Flexible bladder tanks allow you to cut a hole and slip in a fitting with a backing plate that can then be tightened. Any ideas on how to do this with rigid plastic? I am not looking forward to cutting an access port that would allow me to reach inside since the surface is curved, it would be difficult to seal up. As usual, any help would be appreciated. Terry Hoy Meridian Kalamazoo, MI

Sounds like trying to build a ship in a bottle ! If your holding tank is plastic and the outlet fitting and vent line are the same....why not try a little muratic acid in the original vent line to try to clear it? It will not hurt the plastic but it might dissolve the obstruction. Of coarse using all precautions to protect skin, eyes, nose and any metal parts it may come into contact with. Bob & Jeannie Clinkenbeard To accomplish a great task you must act....and dream. TWIN SCREWS Enterprises * 1964 Chris Craft Roamer 56 Photos http://albums.photopoint.com/j/AlbumIndex?u=163724&a=1673119 ----- Original Message ----- From: Terry Hoy <THOY@TELE-CONNECT.COM> To: Trawler World List <trawler-world-list@samurai.com> Sent: Monday, July 10, 2000 3:15 PM Subject: TWL: Holding Tank Fitting > I have a 50 gal holding tank, some kind of plastic material, > cylindrical and set on-end. The head sits directly on top, with the > floor dividing the two, and is gravity fed. When all this was put > together, the vent was also mounted on the top portion of the cylinder, > but is now clogged due to corrosion. It is in a location that is not > accessible. I have not been able to ream out the vent line and need to > put in a new one. > > I am looking for a way to mount a fitting on the side of the tank near > the top portion. Flexible bladder tanks allow you to cut a hole and slip > in a fitting with a backing plate that can then be tightened. Any ideas > on how to do this with rigid plastic? I am not looking forward to > cutting an access port that would allow me to reach inside since the > surface is curved, it would be difficult to seal up. > > As usual, any help would be appreciated. > > Terry Hoy > Meridian > Kalamazoo, MI > >

One more idea......get a small plastic mushroom head thru-hull fitting and cut the hole in the tank the same size as the head you have to pass through the hole. Buy or make a flexible plastic washer with the same inside diameter as the thru-hull and the outside diameter larger than the drilled hole that you can fold into the tank. I would pass a stiff piece of wire through the thru-hull and the washer with a slight bend on the inside end to hold it all together while you assemble. (You could pull it out after it is all assembled) I am no engineer but I am sure the flexible plastic washer would hold because of the surface area it would cover. Try it on something that doesn't matter to be sure. The investment would be about $ 5. Bob & Jeannie Clinkenbeard To accomplish a great task you must act....and dream. TWIN SCREWS Enterprises * 1964 Chris Craft Roamer 56 Photos http://albums.photopoint.com/j/AlbumIndex?u=163724&a=1673119 nip-snip-snip > I am looking for a way to mount a fitting on the side of the tank near > the top portion. Flexible bladder tanks allow you to cut a hole and slip > in a fitting with a backing plate that can then be tightened. Any ideas > on how to do this with rigid plastic? I am not looking forward to > cutting an access port that would allow me to reach inside