I’m not looking fwd to this but I need some help

[ageless]

I’m not looking fwd to this but I need some help

The ER of my 55c has the (4) AC units mounted on a heavy steel shelf over the starboard batteries outboard of the engine. The 3/4” plywood floor the battery boxes and this shelf are mounted to is rotted and beginning to sag. I intend to make bahama runs soon but won’t do it with this situation as it is. I’m not much on the engineering side of things but proficient on the application side so I’m looking for suggestions how to approach this as the shelf is too big to be removed in one piece, even through the salon floor. As it is, the rotted floor will have to be cut out and replaced in pieces as the entire section is too big to finesse one piece in. One option would be an A-frame in the salon that I could suspend the shelf from, cut out the shelving and weld it back in, or my preference would be to build something lighter to replace it. What do others have their AC units mounted on?

 

[Photolomy]

Re: I’m not looking fwd to this but I need some help

Mine are on an aluminum shelf, attached to the aft wall. I doubt the shelf weighs much.

 

[Captain Ralph]

Re: I’m not looking fwd to this but I need some help

Please send some pictures.
Without a good reference and I have a similar project coming just for one condensing station, suspend from above, work under them..

 

[Briankinley2004]

Re: I’m not looking fwd to this but I need some help

Mine are mounted in the same type frame as yours but it sits on the deck that is about level with the bottom of the engine. My starboard batteries are located in the engine room aisle parallel to the stringer. Moving yours would probably involve more than the repair. Without pictures of the batteries under it etc it is hard to tell. I have had to suspend a/c condensing units before to pour concrete under them. We would rig up beams, etc spanning past them. I am thinking in your case, with all the glass work to do etc., it may be easier to pump them down and remove them. If they are flare fittings that will make it even easier.

 

[Pascal]

Re: I’m not looking fwd to this but I need some help

Need pictures

Are you sure the shelf is steel and not alum? AFAIK Hatteras always used aluminum frames for the AC shelves with a plywood insert

A good alternative to plywood is either glassed divinicel or Coosa. Depending on the size you may not even have to glass the Coosa and can just roll white epoxy on it.

When I removed my old air cons and installed chillers I built two shelves using Divinicel and glass. They re epoxied along the bulkheads and hull sides rating on 2x2 with an aluminum leg for support. Lightweight and will never rot

 

[dottieshusband]

Re: I’m not looking fwd to this but I need some help

Admittedly, I don't have a good mental image of your setup, but I'm thinking the metal shelf could be supported from the hull with studs. after clearing the plywood, cut a few sections out near the sides. You might have to glass in support blocks, then run studs up to support the metal shelf. Cut out the rest of the rotten battery shelf, and replace with new end supports and multiple shelf pieces, then remove the temp supports and glass in the new battery shelf. Hey, Just a blind idea.

 

[racclarkson@gmail.com]

Re: I’m not looking fwd to this but I need some help

Second the request for pics. Mine are as per Brian above so I won’t have a similar situation on my 55.

 

[rsmith]

Re: I’m not looking fwd to this but I need some help

Just throwing it out there but a metal shelf is going to transmit noise and vibration.

 

[ageless]

Re: I’m not looking fwd to this but I need some help

Here’s a couple pics to get an idea of what I’m dealing with. I need a new evap unit in the master so I may just replace with a self contained to eliminate one unit In the ER https://photos.app.goo.gl/Wpc1JCeDP9RofjjM6

 

[Captain Ralph]

Re: I’m not looking fwd to this but I need some help

Suspend the condensing stations and replace the plywood shelf with Coosa, or similar fiberglass panels.
If you ever wanted to improve the battery installation, this would be a great time also.
Looks like a bear getting those batteries out of there.

 

[kelpy]

Re: I’m not looking fwd to this but I need some help

Makes one appreciate having a chilled water system.

 

[ageless]

Re: I’m not looking fwd to this but I need some help

Suspend the condensing stations and replace the plywood shelf with Coosa, or similar fiberglass panels.
If you ever wanted to improve the battery installation, this would be a great time also.
Looks like a bear getting those batteries out of there.

Ralph, it's not the shelf the stations sit on that needs replaced, it's the floor under the batteries

 

[Boatsb]

Re: I’m not looking fwd to this but I need some help

It's not going to be a simple in and out but when you do it dont cut corners.

Coosa with proper laminating (not a coat.of resin) will last a lifetime. Its strength is less than plywood as a shelf but with 2 good layers of something like 1708 it will not flex or crush.

You can bring in a few pieces if they join on a support and glass them in place and seal them up.

 

[racclarkson@gmail.com]

Re: I’m not looking fwd to this but I need some help

Thanks for the pics. I would consider saving what’s there by painting it, top and bottom, with epoxy if it has any integrity at all. Then I’d overlay it with 1/4” epoxy sealed plywood or synthetic material and go back with the battery boxes. You ought to be able to suspend the rack enough to slide the new material under without disturbing the lines. You could cut the rack if necessary to remove the battery box. It would be a simple fix to reattach the front legs. Unless the deck is a total loss, you’ll save yourself a major headache and be plenty robust.

 

[Captain Ralph]

Re: I’m not looking fwd to this but I need some help

Ralph, it's not the shelf the stations sit on that needs replaced, it's the floor under the batteries

Still suspend all from above, plus a couple of inches. Rebuild the deck under the batteries.
Wish you were close, This project could be fun.

 

[ageless]

Re: I’m not looking fwd to this but I need some help

Still suspend all from above, plus a couple of inches. Rebuild the deck under the batteries.
Wish you were close, This project could be fun.

I sure wish I had established some relationships since my relocation in Jan where I could get some help, thank you for the offer.

Another Hatteras owner had recommended I use this product to replace the plywood floor, I am liking what I have read about it so far. I am also considering removing the metal unit all together and building a light weight shelf that mounts to the starboard wall to hold the AC units

https://www.strongwell.com/products/structural-building-panels/

 

[ageless]

Re: I’m not looking fwd to this but I need some help

Thanks for the pics. I would consider saving what’s there by painting it, top and bottom, with epoxy if it has any integrity at all. Then I’d overlay it with 1/4” epoxy sealed plywood or synthetic material and go back with the battery boxes. You ought to be able to suspend the rack enough to slide the new material under without disturbing the lines. You could cut the rack if necessary to remove the battery box. It would be a simple fix to reattach the front legs. Unless the deck is a total loss, you’ll save yourself a major headache and be plenty robust.

The flooring is completely rotted and sagging under the batteries. My other concern is how it ended up rotted and the integrity of structures under it. I have searched pretty hard for a potential source of the water intrusion but haven't located it

 

[Captain Ralph]

Re: I’m not looking fwd to this but I need some help

The flooring is completely rotted and sagging under the batteries. My other concern is how it ended up rotted and the integrity of structures under it. I have searched pretty hard for a potential source of the water intrusion but haven't located it

Water from the condensing stations would be my first suspect.