Strapping in VTS grey tanks. How tight?

[chilipepper]

I have installed 2 of the grey tanks from VTS and I'm wondering how tight the staps should be? I have them tightened down until the sides just start to bulge right now. Is that too tight? I have a piece of polyisocyanurate insulation above it that it is tightened up against but I do not want them moving around? If they shouldn't be that tight can I just back off the stainless 1/4-20 bolts with nylock nuts or should I re-drill so I can bind down on the nuts? Thanks!

[chilipepper]

Front tank... For some reason it's only letting me upload one photo per post...

[chilipepper]

Not a great picture but I'm trying to show the side of the tank that is tightened down.

[perryg114]

I would think you would want a frame around the bottom and run your straps over that. What you have now are point loads and when the tank is full all the weight is going to concentrate in one spot. Eventually, the strap might wear or cut through the tank. The tanks are not strong by themselves. Normally there is a steel pan that is lined with styrofoam. This provides cushioning and even support.

Perry

[chilipepper]

I had asked that of the guys at VTS and they said straps would be fine as they are only 15 gallons and there really isn't that much weight even when full. I'm not sure there is room there to add a frame around these without them hanging below the frame. The way they are now they will nicely fit within the belly pan. I'm certainly open to suggestions though and chose to do it this way having followed a few others installing them this way. Do you feel they will sag and cause pan problems like this?

[perryg114]

Put something at the corners under the straps to keep them from biting into the tanks. Something like a piece of rubber or inner tube etc.

Perry

[chilipepper]

I have the straps wrapped in rubber adhesive flashing. Do you think I need more?

[AirConditioner]

They look great. What did you use as strapping??

I'm doing the same with my 72 Overlander, but I'm planning to use Simpson TA9Z angles covered with the rubber at the strap points to avoid the point load.

How are you planning to tie the tanks into the plumbing to the dump valve or do you have an alternative approach. I've been considering using a pump to fill the tanks from a low collection point in the rear.

[chilipepper]

Thanks and I used some galvanized strapping with the holes in it from the hardware store. I bent it to fit and then covered it with the rubber window flashing. After quite a few conversations with the VTS guys and others we felt that three straps would be more than adequate for the max load of 150 lbs or so with the weight of the tank and full of water. If you look at my blog post from the 8th of May (msstreamy.blogspot.com) I have a link to the plans that I sent over to VTS. For the plumbing I basically went for drains and connections lines on the lowest points of the bottom corner of each tank on the curb side. This put the drain line out of the back of the aft tank right on the side of the black tank pan. I put the 1.5" dump valve there before I made the corner and along the back of the black pan to tie into the main dump there.

TennTex, McCrosti and I have been discussing things over on TennTex's thread here.

So far on the first outing I've been pretty pleased. I didn't have a lot of grey water since I didn't have the bathroom water hooked up. But I filled all the tanks with clean water to test and it works good. With the VTS tanks you'll never be able to drain them fully as the fittings just can't be on the bottom of the tank. I figure in the fall during my winterizing project, I'll jack the tongue of the trailer up and then maybe give it a bit of a slope to the curb side and I should get a pretty good drain.

Good luck and keep us posted!