I wouldn't use rivnuts - if one starts slipping whilst trying to tighten everything up you are buggered. I would make a ring with a slot cut in it with properly threaded holes or nuts welded on to go inside the tank. The slot cut through should allow you to thread the ring into the inside of the tank. Tie a piece of string to it whilst doing that in case you drop it. Have an extra threaded hole so you can secure it with a small counter sunk bolt in position, then it should be easy to put the external gasket and cover on.csk rivnuts.
boat is in Fermanagh
Or...fit a diesel dipper...
Diesel Bug and the Diesel Dipper
Ignore the references to diesel bug, I believe it is actually asphaltenes that were in our tank and likely yours also...
Does the job amazingly. We had the same issue, no access to the tanks, It will also future proof your fuel supply.
Yes agree,I wouldn't use rivnuts - if one starts slipping whilst trying to tighten everything up you are buggered. I would make a ring with a slot cut in it with properly threaded holes or nuts welded on to go inside the tank. The slot cut through should allow you to thread the ring into the inside of the tank. Tie a piece of string to it whilst doing that in case you drop it. Have an extra threaded hole so you can secure it with a small counter sunk bolt in position, then it should be easy to put the external gasket and cover on.
I think you are taking the right approach, the only way to be sure both now and in the future to to be able to physically clean the tanks by way of some decent inspection hatches. Preferably in the top, but through the side is perfectly acceptable if engineered properly as you are.
If your polishing pump and facor pick up from the very bottom then it will hoover up any water, dead bug and asphaletenes that drop to the bottom. In fact if you have a valve in the circuit to discharge into a bucket you can pump all that crap out till you get clear diesel the flip the facor back into circuit.
I think it will work well, which is why I am planning to do exactly the same as you, I am lucky in that I have enough access to the top of my tanks to put my hatch/lids in there. My tanks are 600 litres a side of GRP and structural to the side s of the boat. It's 30 years old and never been cleaned/accessed so I am expecting a complete horror show.
now that was a long but interesting read. Wonder where the NVO diesel debate is now in 2022?When an external lab tested the sticky residue it revealed the problem was caused by sterol glucoside and monoglyceride particles. These substances can drop out of bio diesel components and the problem’s made worse at low temperatures. They can also easily accumulate as they don’t melt back into the fuel as the temperature rises.
"Sticky Diesel" stops several canal boats - General ...
www.canalworld.net/forums/index.php?/topic/109029-sticky-diesel-stops-several-ca
I'm sure there is but with all things boat its likely to be a fortune.Lovely Lough Erne? Crazy to think with all the boats and farm machinery round these parts that no one offers tank cleaning services.
Good luck with the job. May do something similar myself some day.
D