Ram Promaster Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
115 Posts
Discussion Starter #1 (Edited)
Hot water heater install (pics included!): Help with sealing

Hi all,

I made the leap and cut the hole for my hot water heater. Photos attached. After much thinking, mocking up, and creating a interior platform, I decided on a cut location knowing that I'd have a gap at the top of the role around the door flange because of the undulation in the side van wall panels.

I'm currently working on how to seal/adhere this frame assembly to the van skin. It needs either a. a shim piece or b. some kind of rigid expanding foam.

For a shim piece, I'm thinking about something that I can vary the thickness with-for ex. layers of waterproofing adhesive foam strips or butyl tape strips. The gap is pretty significant, so I need to fill it to create a level platform to silicone/sikaflex/window weld the frame onto the body so that it is watertight.

Does anyone have any tips/suggestions on getting this done? I probably should have had a firm plan on this before cutting the hole, but it was extremely tough to visualize what kind of gap I would have.

It's hard to gauge gap dimensions from the pictures. It is flush on the sides, approximately 1/8" or less away on the bottom edges, and 1/2" max along the top/upper corners.

Thanks!
 

Attachments

·
Registered
Joined
·
808 Posts
I haven't tried it yet, but I've been looking into cast alumilite (urethane resin) or cast silicone to solve problems with mating irregularly shaped surfaces.

You can see some of the stuff you can do on their site at this link.

https://www.alumilite.com/

You can build molds out of foam board or cutting board and pour urethane resin or silicone directly on the parts you want to mate with if you spray them with mold-release spray. Hot melt glue or tape is used to seal the edges. You can even embed bolts within the molds and resulting castings can have working threads once you release them.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #3
I haven't tried it yet, but I've been looking into cast alumilite (urethane resin) or cast silicone to solve problems with mating irregularly shaped surfaces.
Sounds intriguing, but pretty complex.

Anyone have opinions on why NOT to use some sort of expanding waterproof foam or just fill the cavity with sikaflex or some sort of thick caulking product and then caulking the perimeter to seal? As in using a foam/caulk/glue filler instead of a rigid shim piece?

Not sure which product to use, either.
 

·
Registered
Joined
·
808 Posts
Sounds intriguing, but pretty complex.
Maybe, but the prospect of fabricating irregularly shaped parts out of wood or metal seems infinitely more complex and time consuming to me. The thought is once I get the technique down, I can use this wherever an odd angle or funky-shaped surface gets in my way. Could turn into a golden hammer, but the material costs would likely make me more judicious.

More standard weatherstripping and sealing may be an option, like butyl rubber and silicone and such as you say. Is this intended as a one-time seal? I was initially thinking you'd want to remove this periodically for some reason.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #5
More standard weatherstripping and sealing may be an option, like butyl rubber and silicone and such as you say. Is this intended as a one-time seal? I was initially thinking you'd want to remove this periodically for some reason.
Yes, one-time seal.
 

·
Registered
MMXVI - L2H2 in IN
Joined
·
4,282 Posts
When the water heater is running is there any heat generated in the area that you are filling? Take the heat into consideration when choosing a filler.

Make sure it's a paintable product, it will blend in better.
 

·
Registered
Joined
·
808 Posts
Phil has a good point. I'd also take in account that this is a vertical surface, so you may have to do more than you do for your average roof seal to route water around rather than down into your gap. Might need a lip around the top. I'd look at door seals in cars and see what they do there. Have you considered non-leveling Dicor? That's a go to for sealing roofs and such. Comes in colors that may blend, but can be messy.
 

·
Registered
2017 159, w/dual sliders. SF Bay area
Joined
·
1,006 Posts
I'd look at something like Apoxie Sculpt. It is a two part epoxy that you mold to shape. When set, you can sand and and file it to refine the shape.

It will adhere, so I'd use plastic wrap as a barrier during molding.
 

·
Premium Member
Joined
·
641 Posts
I've seen adapters for sprinters that follow the contour of the body, but not for the promaster yet.
 

·
Premium Member
Joined
·
8,814 Posts
CNC machined plastic? I’d do it by hand, starting with a section of cutting board and my woodworking tools. Many trial fittings. When fit I’d use butyl tape and non leveling Dicor to seal.
 

·
Registered
MMXVI - L2H2 in IN
Joined
·
4,282 Posts
or someone with 3-D printer.

I like RD's cutting board route, laminate it up, only the top and sides matter, the inner cut can be rough.
 
1 - 12 of 12 Posts
Top