VerMonsterRV
Gotta Be Nuts
Duraweld, the place I got the custom tank from also sells some premade tanks (rotomolded). They had a pretty good selection and I will likely order the gray water tank from them as it is a simple cube.
Material for fresh water tank
- Thread starter VerMonsterRV
- Start date
Alloy
Well-known member
I bought 2
I needed 4-120g tanks for my build. Two for freshwater and one each for the grey and black water.
Roto tanks for RVs are thin while roto tanks for boats are heavier.
I bought one 3/8"-1/2" marine PE roto tank for test fitting. Glad I did because the manufacturer's drawing didn't show the cross ribs on the bottom. Ribs are OK for a black tank in a boat that is pumped but not a RV tank that gravity drains.
Shipping the tank back was going to cost $300 so I bought 1 more to use for FW then had custom tanks made for the black and grey. These were made with 3/8" HDPE and the bottom sloped 1/4" per foot in 2 directions to a 3" drain fitting in one (side) corner. The bottom and sides of these tanks were welded inside and out and the top was welded on the outside. The metal support frame was made to fit the bottom of the tank.
The FW tanks with no slope were installed in a flat frame over the axles with beveled insulation at a 1/4" per foot slope to 3/4" fittings in the (bottom) corner. Side fittings in FW tanks do not drain all the water...or the sediment .... from what I've seen this is a good place for things to grow.
All the tanks have stainless rotary nozzles for flushing.
As mentioned the tanks are support by metal frame. A steel frame on 4 sides with a bolted aluminum plate supporting the bottom. The tanks are removed from the bottom. Inside the frame there is 2" Formular 200 insulation and 3" heat ducts controlled with valves so warm air only blows at the tanks when the thermometers located at the bottom of the tanks show heat is needed.
I had the 3" drain fitting installed in the custom tanks but I wasn't sure where the rest of the fittings would go. After test fitting I used a 3hp router along with aluminum mandrels that I made to spin weld the fittings.
Another issue was the tank level guage. I started with a SeeLevel system only to discover the "moda technology" is erratic on material over 1/4". Ended up switching to an iSeries from TechEdge Mfg. They put the moda sensor inside 3/4" PVC pipe that screwed into the top of the tank.
The TechEdge system can be customized for 6 tanks including 2 - 90ohm inputs for fuel/propane while the tanks on SeeLevel panels are preset. Both are really good systems.
I needed 4-120g tanks for my build. Two for freshwater and one each for the grey and black water.
Roto tanks for RVs are thin while roto tanks for boats are heavier.
I bought one 3/8"-1/2" marine PE roto tank for test fitting. Glad I did because the manufacturer's drawing didn't show the cross ribs on the bottom. Ribs are OK for a black tank in a boat that is pumped but not a RV tank that gravity drains.
Shipping the tank back was going to cost $300 so I bought 1 more to use for FW then had custom tanks made for the black and grey. These were made with 3/8" HDPE and the bottom sloped 1/4" per foot in 2 directions to a 3" drain fitting in one (side) corner. The bottom and sides of these tanks were welded inside and out and the top was welded on the outside. The metal support frame was made to fit the bottom of the tank.
The FW tanks with no slope were installed in a flat frame over the axles with beveled insulation at a 1/4" per foot slope to 3/4" fittings in the (bottom) corner. Side fittings in FW tanks do not drain all the water...or the sediment .... from what I've seen this is a good place for things to grow.
All the tanks have stainless rotary nozzles for flushing.
As mentioned the tanks are support by metal frame. A steel frame on 4 sides with a bolted aluminum plate supporting the bottom. The tanks are removed from the bottom. Inside the frame there is 2" Formular 200 insulation and 3" heat ducts controlled with valves so warm air only blows at the tanks when the thermometers located at the bottom of the tanks show heat is needed.
I had the 3" drain fitting installed in the custom tanks but I wasn't sure where the rest of the fittings would go. After test fitting I used a 3hp router along with aluminum mandrels that I made to spin weld the fittings.
Another issue was the tank level guage. I started with a SeeLevel system only to discover the "moda technology" is erratic on material over 1/4". Ended up switching to an iSeries from TechEdge Mfg. They put the moda sensor inside 3/4" PVC pipe that screwed into the top of the tank.
The TechEdge system can be customized for 6 tanks including 2 - 90ohm inputs for fuel/propane while the tanks on SeeLevel panels are preset. Both are really good systems.
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