Re: top gun holding tank
 

I just had to cut the one out of the Gun that I am re-doing. It was too big to fit through the hole but I could get a sawzall in there. I spent the next weekend with bleach, lysol and a hose! It`s much better now though. I think that a larger tank could be custom fitted in there, little taller at least.
If I do replace all the components I will fab one up myself out of 0.125 5052 aluminum instead of the 0.90 that was in there. I have been considering cutting down the area where the head was mounted and putting in and enclosure so I could mount a porta potty in there. I guess that there is just something about hauling around a sewer system that I don`t like.
Here are a couple of pictures. One is of a gun that I looked at a couple of years ago that had been converted and one of my nightmare.

Re: top gun holding tank
 

Docmanrich37 came up with a 25 gallon bladder for his Active Thunder. Our ATs came with 6 gallon holding tanks that you have to pump out. Apparently he needs more than that. :D :D I think he paid $300 for the bladder and it is about as thick as a car tire.

Re: top gun holding tank
 

I replaced one in a 93 gun and yep, you have to cut it out and RDS does still make them. Jabsco I think makes the pump. We redid the whole thing except the bowl.

I put in an access door so if anyone ever had to replace it they could remove the door and get the tank out. That had to be the worst designed system ever. Rather than replace it going to a porta potty and hooking into the pump out would have been the way to go.

Sink drains out the side of the boat..

No holding tank for sink, the head there is, you can pump out at a marina by sucking it out from the hull fitting, there is also a dump out hull but not supposed to do that unless 12 miles offshore..

another question on this topic...is there a valve on the waste water tank that would allow water to drain into the bilge? Tried filling it with antifreeze only to have it drain into the bilge...or is it likely rotted and need to be replaced? It drained fast which made me think that there was possibly a valve that was open.