Community Forums

Hit_the_Rhod · 08-06-2020, 06:41 AM

Best solution is to replace the tank, BUT, if you cannot do that, and plan to go ahead with the repair, I suggest you do the following. Purchase a roll of stainless steel wire, Aviation Safety wire is my recommendation, .020" thickness,

https://www.ebay.com/i/152596075577?...hoCmRoQAvD_BwE

drill small holes on each side of the crack, especially on the bottom of the tank where stress of loaded tank may cause the tank to "flex" rendering the epoxy useless as the load would be in shear with the epoxy bond to the tank. "lace" the safety wire through the hold, like you would if sewing two pieces of fabric together, in and out along the crack, side to side, pulling tight after each wrap. When finished "lacing up" the crack, follow through with your epoxy to seal the crack, the safety wire, and the holes your safety wire laces through.

The weak point here is finding an epoxy/sealant that will bond to the tank. Another suggestion I would make is to use marine 5200 sealant instead of the epoxy over the "laced" repair. Will stay pliable, withstand flexing, and since the tension forces attempting to pull the crack apart will be taken up by the safety wire, you don't have need for great strength.
Keep us appraised of your progress please

jimknoll · 08-06-2020, 04:22 PM

Hey, thanks for the input! I had thought about trying to mechanically fasten the 2 sides together, to prevent fatigue failure, but I don't really have room on the bottom side to reach in to pull a wire through. It sits flat on a sheet of plywood, so I hope that the shear load would be absorbed by that. To distribute the forces along the crack, I had planned on using fiberglass drywall tape under the epoxy, but in reading your comment, I might try to find something stronger, like the pet proof screen door material, and use like a 6" strip. While I would love for this to permanently repair this, I'm REALLY hoping to get through this season with it. I'll keep the pics and updates coming.

twogypsies · 08-06-2020, 07:30 PM

Quote:

Originally Posted by jimknoll

The inside is not nearly as smooth / slippery as one might hope, they may be when new, but there was a buildup of chemicals over the whole surface.

That's why the only thing we ever used was just water and plenty of it.

jimknoll · 08-15-2020, 08:32 AM

Well, structural repairs to the floor and wall of the tank are working, at least after the first 500 mi. I only siliconed and screwed the access panel on the end of the tank, so I can inspect the repairs when we get back.

I used marine tech- flex set epoxy as the primary repair. It's like $25 for a small 2 tube kit, so I used 2 of them to penatrate the crack, and cover a 12" wide strip of fiberglass screen. After curing,I tested it for leaks, and everything was tight and dry. The instructions for use with HDPE are very specific. You have flame treat the area just prior to applying the epoxy. I hope that I got that part right. I still wanted more of a liner to cover a bigger area, so out comes the 3M 5200. It's never failed me yet, so I spread a generous layer of it over as much of the floor as I could reach with a short board as a trowel.
To close it up, I will epoxy and screw the white PVC trim in place, then epoxy and screw the panel back in. Currently it's just temporary sealed against leaking for this trip.