Replace Holding Tank in 1989 Prestancia

[Commisatone]

I have a problem I wouldn't wish on anybody - a leaking holding tank!
Has anyone out there had to go through this with a Prestancia? From what I can see it would appear I have a crack in one of the welds.
My problem is that some genius put the tank in, then placed the fiberglass seating/support for aft cabin bed in, I believe the fiberglass will have to be cut out as the access hatch is too small for the tank to go through but I'm looking for advice on the best way to do that and it still be usable as a bed.
Has anyone used flexible bladder type holding tanks? I could possibly cut the tank up in situ then fit a flexible tank in the space.
Any help would be appreciated

 

[CHIEF915]

Re: Replace Holding Tank in 1989 Prestancia

I had to replace mine last season, its a PITA. The fiberglass seating does unbolt, you have to cut the silicon around the base and reseal it when done. I didn't have to take the fiberglass all the way out, I was able to lift it from the starboard side once I took all the fastening hardware out. It lifted just enough to pull the old tank out and insert the new one. Make sure you measure the old tank when buying a new one. I got one that just barely fits, wished I would of gotten it about an inch smaller in height. I bought a tank monitoring system that sticks on the side of the tank as I didn't have room for the old sending units. I had to replace mine as I had a guest flush a whole box of baby wipes down the head. I recommend replacing all the sanitary lines as well if you are taking on this project, it helped the smell in my boat.

 

[Commisatone]

Re: Replace Holding Tank in 1989 Prestancia

Thanks for taking the time to answer Chief915, by the sounds of your job Doral may have changed things between the two years. The fibreglass for my seats are all one piece with the floor and, as I have to be standing on that whilst trying to access the tank, I am fairly positive I won't be able to move it enough!
Do you have any tricks for running the new sanitation lines - I was thinking I was going to replace them at the same time, but it looks like an even bigger PITA than the tank. Can I attach old to new with a coupling and then just pull it through?
Again, any help is appreciated - the kids are getting restless about not going out on her

 

[CHIEF915]

Re: Replace Holding Tank in 1989 Prestancia

I'm not going to lie to you it was a pain. I ran the new hoses by opening the bottom of the cabinet in the head behind the head. The bottom lifted with a hinge allowing me to get in somewhat. Also I had to remove some of the cabinet and floor in front of the hot water heater. The biggest pain was that the hoses are clamped on the bottom of the fiberglass frame for the bathroom, just took a lot of jerking and convincing to get to break loose as I could not get anthing in there. I didn't think the fiberglass piece would lift either as it is all one piece and goes under the closet and hot water heater. But it is seperated on the starboard side. All the seats and bedding had to be removed. I have replaced just about everything on mine. I gutted it out and redid all the carpet on the walls and ceiling and reappolstered the cushions, replaced the hot water heater, frige, head and some of the plumbing. Also changed out all lights to LED and rebuilt/upholstered the cockpit as well.

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

if you can get to the leak using 3M Scotch-Weld DP8010 acrylic adhesiveis will seal it works amazing

 

[Commisatone]

Re: Replace Holding Tank in 1989 Prestancia

if you can get to the leak using 3M Scotch-Weld DP8010 acrylic adhesiveis will seal it works amazing

Will this work on an aluminum welded joint?

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

if the joint can be cleaned well and is aluminum then jb weld is a better choice the 3m adhesive is for plastic such as polypropylene, and polyethylene. both areas should be clean and dry. dont use petroleum based cleaner it will leave a residue .sandpaper should be used to prep area also.

 

[Commisatone]

Re: Replace Holding Tank in 1989 Prestancia

So I shouldn't try chewing gum then

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

gum is the way to go LOL but the prep is very important . i would try repair first (much cheaper ) if that doesnt cut it then like chief says start the tear down, losts more work but guarenteed to work.

 

[Commisatone]

Re: Replace Holding Tank in 1989 Prestancia

I've taken your advice, Goose25, and used the JB Weld. I'm now waiting for it to cure and I'll test it tomorrow, so fingers crossed.
If that works then I'm going to replace the hoses which by Chief915's description is going to be a real PITA, so I probably shouldn't have the kids with me when I try that! Any other advice on running the hose would be appreciated!

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

the kids might be helpful (long skinny arms ) . the hose goes from the toilet,through the leftside of the fiberglass of the floor and then under the stairs. i would buy a new piece of hose 6 inch to long and connect to the old piece at the tank and pull both through the fiberglass floor into the head. good luck this doesnt sound like fun. i replaced the old jabasco this year and the hoses where no fun .

 

[twobits]

Re: Replace Holding Tank in 1989 Prestancia


Well fellow Doral owners. We just completed the replacement of our waste holding tank. We removed the silicon around the base of the seat; made 3 cuts to just remove the front of the seat so we could slide the old tank out. Worked like a charm and we cut the fiberglass in such a way that you will barely notice the repair. Removing the tank was relatively easy in comparison to replacing the hoses. The worst of which was the vent hose, because we had to replace the vent itself. That took some doing indeed. The old tank was aluminum and had 5 holes in it. A lovely mess to clean up and the hose accesses through the stringer....the bottom one was rotted away and full of you know what. We cleaned it out and sealed it up. All odours have been eliminated completely thanks to finally identifying the source. Hoses were tough to manage but well worth it in the end. LOVING OUR BOAT!!!!

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

hi twobits, where did you get the new tank and what are the dimensions ? Also did your vent have any filter on it and did you replace the tank level monitor
thanks

 

[twobits]

Re: Replace Holding Tank in 1989 Prestancia

We ordered and installed a 12 imperial gallon tank to replace the original tank which was 23 imperial gallons via the marina. I believe the tank came from a supplier in Newmarket. The new tank is plastic and does not have a level indicator. We did replace the hoses and including the vent which is a little larger than the old one. The vent outlet was the most difficult part of the installation lol.

 

[Doralprestancia89]

Re: Replace Holding Tank in 1989 Prestancia

hey back, the tank installed in twobits boat isI was 24 1/4 x 15 1/4 x 8 3/4 high... The boat did not have a vent filter so we did not install one.. We don't notice any fumes yet.. We don't plan on going for long times without a pump out and most of the time we just use the marinas bathroom so the size of tank is more than adequate...

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

thanks all,
how did you attach the new tank in place or is it just loose

 

[Doralprestancia89]

Re: Replace Holding Tank in 1989 Prestancia

The original tank was held in place by 3 pieces of 1x2 approx 8" long positioned to prevent side to side movement. I reused them ( in gray) as you can see in this picture. The were fastened to the floor with 1 1/2 " screws.. I used slightly shorter 1 1/4" screws to mount the new tank as I felt very nervous driving screws into the floor however there is lots of space under the floor.. Up and down movement is prevented by the fiberglass casing around it.. Note that the is a drain on each side of the tank in the floor.. We had a tough time cleaning them out as when the old tank leaked.. It went down these drains and held up... We flushed a lot of water down them and recovered it with a shop vac.. This worked well.. Hope this info helps you out... Cheers

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

thanks again,
my tank isnt leaking yet but is in rough shape so this fall iam going to replace it. a local shop in ottawa has the same tank you used so thats easy and sounds like the hoses are the tough job. did you epoxy the fiberglass cuts back together?

 

[Doralprestancia89]

Re: Replace Holding Tank in 1989 Prestancia

I have only just applied sealant to the cuts for now for asthetics and you barley even see them as most is covered with the cushions on. The piece is bolted to the floor on the starboard side and is pretty tight, I may use a backing plat and fasten the port side down with screws to add more strength and stop any movement but is fits pretty snug now anyway.. I want to leave this piece removable for any future work so no expoxy was used..

 

[goose25]

Re: Replace Holding Tank in 1989 Prestancia

thanks for the help i let you know how it goes this fall