Gas Tank External Drain

A drain plug used to be a standard feature of vehicle fuel tanks. A drain valve sticking down would, IMO, be a bad idea, too much chance of it getting hit and broken off. A valve at the bottom, on the side, maybe.
Installing a drain plug or valve is not a problem. Drain the tank, clean it thoroughly, and flood it with CO2 before welding.
OR, go to your local airport and get fuel tank sealant from the parts department of the Fixed Base Operator, along with some fuel tank Cherry Rivets. Put the drain plug in a plate, then apply the plate to the bottom of the tank with liberal amounts of the properly prepared sealant, and rivet it in place with the sealed Cherry Rivets. It will not be inexpensive, (the rivets are about $2 each, and the sealant about $100 a pint), but it WILL work.

rgatijnet1 wrote:

gbopp wrote:

dons2346 wrote:
Why not use a Oklahoma Credit Card?

Could you PLEASE, explain this response. :@

Siphon hose.

Thank you, I've never heard that term.

I would suggest wiring up a way to hotwire the fuel pump, and splice in a bypass on the fuel line. Not only is it safer, but much more convenient to use. Install a valve and let the fuel pump pump the fuel out of the tank into your car or lawnmower. No thief is going to be smart enough to figure out you have an extra hose connected to the fuel line. Most auto parts stores sell a dual tank valve. This way, when you turn on the pump, it closes the fuel off to the engine and switches to your extra hose. Simple and easy to use.

Oklahoma Credit Card?

Garden hose (about a six foot section) and a portable fuel container. Known as the cheapest way to tour America!

gbopp wrote:

dons2346 wrote:
Why not use a Oklahoma Credit Card?

Could you PLEASE, explain this response. :@

Siphon hose.

If you want a way to drain the tank put a tee with a valve after the fuel pump.

I have had 2 friends almost killed modifying gas tanks. Unless you have a chemical tank to boil the tank the only way to clear the fumes is to run exhaust through a tank for a few hours. My true advise is just don't do it. Not worth dieing for. PS no glue is going to safely seal the tank.

dons2346 wrote:
Why not use a Oklahoma Credit Card?

Could you PLEASE, explain this response. :@

I wouldn't do it! When your RV is outside your prone to fuel theft! And if you should hit road debris (tire casing etc.) it could damage the drain valve which could cause a fuel leak! And to preserve your fuel either don't put in more than you will need or buy Stabil to keep your fuel fresh. JMHO

Putting in a drain valve is not a bad idea to use up the old gas, HOWEVER, I suggest you not do it yourself. The tank will be full of gas fumes and the electric arcing done by an electric drill could cause the fumes to ignite and explode. I would not attempt it even if it was filled and flushed with water. This is something that is best left to the professionals who have the equipment and knowledge to safely handle the fumes and get the valve put in.

What I do is to have my MH tank at 1/8 tank or less at the beginning of winter. When I take it on its monthly drive I add about $10 of fresh gas and more fuel stabilizer, at least twice what is recommended. This seems to work well as we have not had problems. Of course being in AR we do not have the bitter cold of below zero temps that can cause problems with nearly empty fuel tanks. BTW I use the marine version of Sta-Bil.