Community Forums

Steverino · 06-22-2022, 11:37 AM

Okay, so here's a fun one:

Our MH has rotomolded plastic basement compartments. It also has a leaking black water tank flusher - meaning that when I connect to fresh water & flush the tank, the flush line (or fitting near the tank - I can't see) leaks fresh water. This all is situated above an inaccessible bay area that I can see from the adjacent bay but cannot access in any meaningful way.

I could just continue (and have been) living with the situation - the bay does have drain holes, so the water makes its way out. The only way I can think of to even attempt to access (and get eyeballs on, hopefully repair) the area is to cut out an access in the floor of the rotomolded bay.

I'm looking for suggestions as to how to then repair or close up the opening. Unlike a regular bay, the floor doesn't carry any weight - it is just an enclosure essentially. I'm thinking I could use the cutout piece and make some type of frame (flat aluminum bar?) or flange for it that would overlap the cut line and maybe use screws to reinstall? That would allow for future access.

What adhesives would stick to rotomolded plastic? I could use adhesive to bond a backing strip to the inside and then screw into that...

Any ideas welcome!

carybosse · 06-22-2022, 01:54 PM

I am thinking that the plastics they typically use for rotomolding are not going to be conducive to any type of adhesive/glues/epoxies. I would think the vibrations of the road would pop them loose.

I am thinking I would build a frame around the cut out hole, probably 2 frames, one on the inside, one on the outside of the compartment, creating a sandwich, with the wooden frame as the bread, and the the cut edges of the plastic as the meat. I am thinking wood, but some aluminum flat stock would also work. You want the bolt heads and washers to be on your frame (bread) and you want to have minimal stress applied to the plastic (meat) as I could see the screws ripping the plastic holes.

I am thinking you attach this with screws. Rivets would probably work if you use some aluminum straps for the frame, but since you went into it once, I expect you will go there again.

ROUGHRIDER3 · 06-22-2022, 02:15 PM

Get a piece of alumimum at home depot big enough to fit the bottom of the compartment and use small bolts and nuts with fender washers on both side. drill a few drain holes. Will now have a lumimum floor.

carybosse · 06-22-2022, 02:17 PM

What ever you do, we need pictures for the next guy.

astrnmrtom · 06-22-2022, 06:21 PM

One thing I used to do was maintain playground equipment, some of which is rotomolded polyethylene. Never found any glue or epoxy that would stick, not even epoxies listed for plastic. Hot air plastic welding was about the only way to repair it. I second making a hatch plate out of aluminum. When you cut out the opening be sure to drill a round hole at each corner then cut from hole to hole. This will reduce the tendency of the plastic developing stress cracks in the corners.

Good luck.

Dutch Star Don · 06-22-2022, 08:05 PM

Install another back flush nozzle in a spot where you can access the black tank. Reroute the flush hose to the new flusher and leave the leaking one in place.

Bill Gail · 06-22-2022, 08:31 PM

Why not install a round boat deck plate .

They are available in varying diameters and can be purchased at any marine supply store or online .

Cut a round hole , run a bead of silicone around the hole , drop in the rim and drill for attachment bolts .

Then simply screw the round deck plate into the rim .

Water tight seal , easy future access and simple installation.

Steverino · 06-23-2022, 05:06 AM

Thanks everyone for all of these great ideas and tips - this is exactly what I was looking for! Now I'll have some options in mind as I assess the location and can better map it out.

Unfortunately won't be able to get to the project for at least a week or two but I will try to remember to let you know how it worked out and hopefully share some pics.

carybosse · 06-23-2022, 07:33 AM

Quote:

Originally Posted by astrnmrtom

One thing I used to do was maintain playground equipment, some of which is rotomolded polyethylene. Never found any glue or epoxy that would stick, not even epoxies listed for plastic. Hot air plastic welding was about the only way to repair it. I second making a hatch plate out of aluminum. When you cut out the opening be sure to drill a round hole at each corner then cut from hole to hole. This will reduce the tendency of the plastic developing stress cracks in the corners.

Good luck.

Great suggestion on the drilling holes in corner. One of those tricks of the trade that I had long ago forgotten.

Yes, haven't dealt with much in area of rotomolded plastic, but with polyethylene in general, nothing will stick to it, including paint.

Quote:

Originally Posted by Steverino

Thanks everyone for all of these great ideas and tips - this is exactly what I was looking for! Now I'll have some options in mind as I assess the location and can better map it out.

Unfortunately won't be able to get to the project for at least a week or two but I will try to remember to let you know how it worked out and hopefully share some pics.

Glad to hear our ideas has your mind rolling. I agree, you need to assess the location and choose an option that works for this particular situation. I have only the vaguest of notions as to what you are dealing with, will be interested to see your solution.

PanJH · 06-26-2022, 05:03 AM

Here's an option --- https://www.amazon.com/Plastic-Machi...33486262&psc=1

Winemaker2 · 06-26-2022, 05:28 AM

Quote:

Originally Posted by Bill Gail

Why not install a round boat deck plate .

They are available in varying diameters and can be purchased at any marine supply store or online .

Cut a round hole , run a bead of silicone around the hole , drop in the rim and drill for attachment bolts .

Then simply screw the round deck plate into the rim .

Water tight seal , easy future access and simple installation.

[emoji106]
https://www.amazon.com/SEACHOICE-Pry...55945506&psc=1

Ray,IN · 07-06-2022, 01:47 PM

Quote:

Originally Posted by Steverino

Okay, so here's a fun one:

Our MH has rotomolded plastic basement compartments. It also has a leaking black water tank flusher - meaning that when I connect to fresh water & flush the tank, the flush line (or fitting near the tank - I can't see) leaks fresh water. This all is situated above an inaccessible bay area that I can see from the adjacent bay but cannot access in any meaningful way.

I could just continue (and have been) living with the situation - the bay does have drain holes, so the water makes its way out. The only way I can think of to even attempt to access (and get eyeballs on, hopefully repair) the area is to cut out an access in the floor of the rotomolded bay.

I'm looking for suggestions as to how to then repair or close up the opening. Unlike a regular bay, the floor doesn't carry any weight - it is just an enclosure essentially. I'm thinking I could use the cutout piece and make some type of frame (flat aluminum bar?) or flange for it that would overlap the cut line and maybe use screws to reinstall? That would allow for future access.

What adhesives would stick to rotomolded plastic? I could use adhesive to bond a backing strip to the inside and then screw into that...

Any ideas welcome!

That sounds like a good plan to me.

Use SST hardware or rust will soon look ugly.