heater fuel tank on radar arch?

K

Kushtaka

New member
I have a gravity fed heater, and like that it uses no power, but it's mounted low and in my cabinet, and I'd like it out in the open, but don't want the electrical draw associated with a fuel pump.

Has anyone ever put a small tank on their roof? I'm thinking about one on a radar arch, and running the fuel line to the heater inside the tubing, and through the roof.

I think the downside would be the extra movement and possible mixing of water and fuel, Otherwise, I don't see much of a downside.

Anyone ever seen this done or done this themselves?
 
I've never done anything like this, but just to throw another thought into the ring, I spent quite a bit of time on a sailboat with a Sigmar "gravity fed" diesel heater. I think the typical ways were to have the tank above the heater (but not practical on this boat) or to have a fuel pump (undesirable for other reasons). But what this boat owner did (not my boat) was to put the diesel tank in the lazarette and plumb a fuel bulb into it. It was not really "below" the heater, but not really above it either (instead it was close to the same level, and about 20' aft). When first starting a new tank, he'd give a couple of pumps on the bulb (like we do with our outboards) and that would take care of it for the duration of that tank fill.

Now, thinking back, I have no idea if all of the piping/tank/lines were correctly setup for below-decks installation and diesel appropriate (I was not as aware back in the day); but I can say the concept worked, and perhaps it could be done to better standards but using the same theme.
 
I had this system on an old boat. The heater was diesel (actually a full-sized stove with oven). I actually took the cabin top tank off and put in a cheap automotive ticker type of pump running from the main tanks. Partly for looks, partly because I already had 140 gallons of diesel on board, partly because I didn't want to mess with filling another tank, partly I didn't like the looks, and partly because I wanted to get 100# of fuel off of the roof.

That system worked fine because the carb and the float bowl never gave me any problems. But I have been in situations where the carb doesn't seal perfectly and after a few days/weeks (if the fuel isn't shut off after every use), you get into an over-fuel situation. Scary on shore and really scary on a boat.

I've had this happen several times. Drop a match into the bowl (Dickenson type stove) and just when it's too late you see that the bowl is flooded. Best case is the match goes out and you drain the carb and clean it out. Worst case you sweat it out while the stove roars for 15 minutes. This could also happen with a ticker pump if left on for a few days.

It is nice to have absolutely no mechanical noise at anchor, but that's the only real advantage. The amount of electrical use is really minimal. It could probably run for weeks.

Mark
 
If the tank could be small and you are handy enough to built a decent looking box to contain it, the whole plan seems feasible to me. Adding more weight up high is always something to seriously consider and a small pump with perhaps some added battery weight down low, may be another more viable solution. The sloshing from wave movement might be problematic depending on the pickup as well.

Greg
 
I have a four gallon tank now, it was a little less than half full when I bough my boat three years ago, and it has about 1/8 tank left. I'm thinking that a half gallon to a 1 gallon tank would keep me warm for a month.

I know that the power draw is minimal, but it's something, and where I anchor there is no noise but what I make. The pump would be the loudest thing in the world. I don't want one. And above all, other things can drain the battery, and if that happens, no heat, which could mean that I freeze while I wait for help. My stove needs no electricity, so if I can gravity feed it, I can stay warm no matter what else isn't working on my boat.

In the end, I think I'll build the stovepipe and the fuel tank into the arch, or at least supports for the stove pipe. I want to make sure it stays away from the dinghy and the fuel tank.

The sloshing is really the thing though. My heater isn't very fussy, but it won't burn water. I think that the way to do it will be to build a tank with baffles and maybe an angled bottom with a drain down low so catch water and crud, and angle the baffles like louvers to this section so heavy contaminants and water would easily find their way in there but wouldn't find their way out.

Ok. Keep it coming!
 
The biggest problem I see is what Marco Flamingo alluded to - accidental siphoning. I dug a bunker into the side of a hill to install a diesel generator and put a 300gal. oil tank above it at ground level. The thought that a fuel line failure could result in all that fuel ending up on the ground was scary! I installed a "normally off" solenoid in the fuel line above the tank. They are made by "Red Hat"- this would defeat your purpose though because it requires power to remain open. There is another method that can be used to prevent siphoning without using power but it only works when a fuel pump is used in the system. At least install a shutoff valve at the tank.

If you are going to build a custom tank - and are not concerned about your air draft - how about a more vertical style(pipe maybe?) to limit sloshing.

Regards, Rob
 
A vertical pipe is a great idea. I never thought of that.

I'm not the least bit worried about siphoning. I have a gravity feed system in place now, and it all works just the way I want, it's just that the tank is mounted below my starboard cockpit window, and the heater on the other side of that wall, inside my cabinet, and I want the heater up higher, so the tank has to go up higher. My current setup can siphon as well, but there is a fuel/water separator and a shutoff valve and I intend to keep both.
 
Aurelia":37ya2rm7 said:
Vertical tank is simple and may be perfect. It would look like some of the tubular radar reflector designs.

Greg
Click to expand...

That is pretty smart right there! I love it when my boat stuff multitasks!! I used to not even allow anything to live onboard if it only did one thing. Except the engine, bilge pumps and fuel tanks, and now I can kick the fuel tanks off the list. Those big boys on the stern better learn some new tricks pronto!
 
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