Compromising Hull Integrity??

[RonRelyea]

I'm contemplating relocating the holding tank in my Hunter Vision 32. A friend from this site sent me tank dimensions for a Ronco tank that another Vision owner has had installed in his boat.

The tank would go under the aft berth. I would have to remove a portion of the berth platform (hull liner) to make room for the tank. In the attached picture, it would be the area inside the red outline. The area below the red outline is totally empty - there are no supporting braces or anything like that.

Am I weakening my boat in any way by removing that part of the hull liner and installing the new 20 gallon holding tank?

Does anyone have any other input about what to watch out for or things to consider? I'm just wary of cutting up my boat and don't want to screw anything up!

Thanks!

 

[Tim R.]

Can you not remove that section, install the tank and then put it back? It may not be structural but I would check with Hunter if you want to cut it out.

 

[SamLust]

I did exactly that sort of cut-out on my H33(C) several years ago for the same reason. I too left the portion where the vertical wall angles over to horizontal, that is the strong point. As long as you leave that inch or so perimeter you'll be fine. Have had no problems at all. I did mine on a 10 degree Sunday afternoon with a circular saw with the boat in the water. I suggest you find a better (safer) method. If you are careful enough with a narrow enough cutting tool you can re-use the cut out deck piece. Might be a good application for a multi-tool. Good reason to buy one.

 

[RonRelyea]

Sam .. thanks for the quick reply! I was thinking of getting one of those new Dremel Multi-tools. Looks like they have a narrow kerf ... then I'll take you up on your suggestion of re-using the cut-out!

 

[Barnacle Bill]

You should be able to remove the area as described in your photo to install the tank and it is obvious that you have to replace it or you won't have any support for your berth. You could screw it in place with many screws using lengths of wooden strips below the cut (better yet, through bolt it). If you you use enough screws you should not compromise the integrity of what ever strength this section gives you.
Another alternative is to buy a bladder tank which will fit into the existing holes without making any cuts and then it will expand to the area in which it is contained.

 

[Steve Dion]

Ron:

Where is the current tank located?

What size is your current tank?

Have you checked to see if you can find a tank that would fit the current location? Ronco will locate the fittings where ever you want them so that is not an issue if the tank will fit.

 

[RonRelyea]

Vision 32 Holding Tank

Ron:

Where is the current tank located?

What size is your current tank?

Have you checked to see if you can find a tank that would fit the current location? Ronco will locate the fittings where ever you want them so that is not an issue if the tank will fit.

**********************************************************
Hi Steve ...
the current tank is located under the shower seat - it wouldn't surprise me if Hunter installed the tank to the hull and then plopped down the hull liner on top of it. It's that inaccessible. The only potential access to the current tank without cutting up the shower seat is through the side of the seat that is under the head sink. The way that is put together, I don't think I could get the old one out of there without cutting it up. Then it would be next to impossible to get a new solid one in place. I guess I could use a bladder but the current location is only 12 gallons. How durable / reliable are bladders compared to a ronco solid tank?

 

[Ed Schenck]

Same installation as the H37C. You are right, they tab in the aluminum tank and then drop in the inner liner. You really do not want a tank under that shower seat. A few guys have cut the front of the seat open and installed a big hatch for storage space. I have the hatch but never cut the hole. My tank is gone, taken out through the side as you suggest. Peggy would not approve of the bladder idea. I think your cutout would be fine. I would glass in a couple of stringers just for peace of mind. Probably 3x1s.

 

[sailingdog]

Obviously, cutting out that big a piece from the hull liner will weaken it to some extent. However, if you can cut the liner piece cleanly enough, and make the cuts at an angle, you can probably re-seat the piece you cut out fairly easily and use it as a basis for the repair of the area.

Ideally, if you can get your hands on a Fein Multimaster or similar oscillating multi-tool, that would probably be the ideal tool to use to cut out the liner.

 

[BobM]

Vote for the oscillating multi-tool

Obviously, cutting out that big a piece from the hull liner will weaken it to some extent. However, if you can cut the liner piece cleanly enough, and make the cuts at an angle, you can probably re-seat the piece you cut out fairly easily and use it as a basis for the repair of the area.

Ideally, if you can get your hands on a Fein Multimaster or similar oscillating multi-tool, that would probably be the ideal tool to use to cut out the liner.

I used one to cut a hole in my cockpit bigger and the precision is great. I agree on cutting, replacing and then tabbing the whole thing back together as the best option.

 

[higgs]

I am curious as to why the old tank needs to be replaced.

 

[RonRelyea]

It's a leaking 20 year old aluminum tank

It's a leaking 20 year old aluminum tank

I am curious as to why the old tank needs to be replaced.

 

[Steve Dion]

Ron: I see your problem. This is similar to the Hunter 37C (like Ed indicated). Is there a chance you can get it out through the cabinet?

One thing you want to keep in mind if you move it is that you will not have about an additional 160 lbs when the tank if full located in another area. Of course you current one will relieve you of 70-80 lbs.

Once you get a poly tank properly installed your problems "should" be resolved.

If you end up cutting the shower seat to remove the old tank it can be reglassed in place and be just as strong as it was originally. I have seen where they have cut a hole in the side of the hull to remove an engine and replaced it. When these glass guys know what they are doing, they can do most anything.

 

[SamLust]

I used 1 1/2" aluminum strips to attach the floor over the tank. Drilled close fitting clearance holes through the aluminum on fairly close centers and mounted with lots of #8 X 3/4" SS sheet metal screws. Works just dandy for years now. Would not dream of using wood strips. Too much chance splitting or of holes opening up if the hull was working. Yeah, I know, there are lots of exotic strong woods out there, and they're all a lot more money than the aluminum from Ace Hardware. I think the pictures are in my latest post about the holding tank on the Cherubini owners forum. I'm at work and can't post them from here.