1973 196 rebuild question

[RickK]

I was looking at the forward rigging trough. If you were to install a bulkhead just ahead of the tank I think you would have to make it lower than the top of the stringers to allow the fill hose and vent hose . I'm not sure that would be a bad thing though. Assuming you're mounting batteries inside the console, you could also route heavy cables up forward under the deck, to power a trolling motor. As for the tank support you could build ledges along the sides that the tank can sit on. Maybe like a 90 degree (or less) corner that you would glass into the stringer and hull bottom. Maybe make a bracket like the letter pi and glue them onto the bulkheads near the upper part of the tank and also along the sides of the tank. You can purchase 1/4" foam rubber to cushion the tank. People have put foam rubber along the bottom and then it sat in water which caused corrosion and pitting. Up on the brackets should be fine. You can use the slot in the brackets to route what you'll be using to tie the tank down. Just thinking aloud.

[dbiscayne]

Where does the vent need to be in relation to the fill and fuel pick up etc

Always thought the vent should be a little lower than the fill so that it spits fuel out of the vent before it backs up and spills from the fill tube but maybe thats just a coincidence that most I've had are setup this way? Probably doesn't matter much if the tank vent fitting is at the front vs. back.

I relocated the pickup to be at the rear of my tank, figured that would be the lowest point if I were to ever get down to runnin on fumes.

[Duffy1470]

You mentioned a ledge. Look at the pic on the right side. Your idea or some variation was exactly what I was thinking based on there is already a small ledge built there. You bring up the vent and fill also.  I was simply copying what was there but that is probably a bad idea considering the tank was loose in the bottom. Makes me question what I am doing.

You've participated in many of these discussions, where does everyone else put the fill, vent, and supply?

[Duffy1470]

Also, the tank isn't built yet, so I can put the vent, fill, and pickup wherever.  For whatever it's worth, I am having four baffles put in the tank. Can only see two from the hole I cut and estimated 2 more. Does anyone know different on the number of baffles?

[RickK]

As you've mentioned, the notch out in the stringer ahead of the fuel tank was where AS ran the fill hose and vent hose from the tank to the starboard hull side and were mounted to the top of the cap. You might want to orient the fill pipe toward that side.

[Duffy1470]

Definitely going to run them that way. I am making what I believe to be rash assumptions about the fill, vent and supply line location on my tank. Am I over thinking this? I assumed this was the original tank, but that's stupid. No way tank 50 years old is still in there. Anyone know if it matters or where the original positions of these tank elements were located.

Think I am going to copy dbiscayne on locating the pick up to the rear and take Ricky's advice and angle the fill 30 degrees to the right. Ricky, I am sorry my spell check keeps calling you Ricky. That is not my doing.

Dumb question, what does the sending unit do? Is it a fuel pump or just a fuel gage? Can't believe I don't know that.

[Duffy1470]

The 222 I used to fish had a clear inspection plate and a manual fuel gage on top of the tank. Bet I can't get that anymore. Was that the sending unit?

[dbiscayne]

Yes that was a very simple mechanical sending unit w gauge mounted on top and I think you can still get them. My first gauge was a stick. Most sending units are either a vertical shaft with a float that slides up and down but you need to get the right length for your tank depth, or it will have a hinged rod that sticks out with a float at the end that moves up and down with the fuel like the old style toilet tank float, this style is more easily adjustable to different depth tanks. The rod magically converts its position to an electrical signal for the gauge. They all seem to have the same 5 screw mounting pattern.

https://www.moellermarine.com/product-category/fuel-accessories/fuel-senders-gauges/mechanical/

[Duffy1470]

So the sending unit doesn't send anything anywhere. That's fun. Well I guess it sends information. Thank you for the info. I looked at the link and sure enough, mechanical sending unit. Think I will forego the sending unit. Most of the boats I have run in the past either didn't have one or the one it had didn't work.  Tank is 50 gallons. I bet I end up getting 2 mpg or about 10 gph running. Anyone have rough fuel burn numbers for these hulls with 115 4stroke? 9gph seems high. Did I do the math right?

[dbiscayne]

If you're having a new tank built I'd at least have the hole drilled and put a sending unit in. Gauge is up to you but I wouldn't want to drill that hole later on with the tank full of gas.

[RickK]

I would like to be able to see how much fuel I have left, rather than guess. Even my RV uses a mechanical sender (hinged rod) that uses resistance to limit current provided by the gauge. I had to replace it after 20 years due to bad spots in the resistor - read wrong from full to about 1/2. Below half it was ok. Senders are cheap and if I were you I'd get one installed near the aft, by the builder. One less thing to worry about later.

[Duffy1470]

Roger that on the sending unit. Surely most of the new electronics have a plug in for the sending unit. I will research that and maybe save the console from having another hole drilled in it. 

I am having trouble uploading picks of my rigging tunes but the question is an easy one.  Are the tubes usually glassed in or is there some other way they are attached/stabilized? I guess it would be easy enough to use aluminum straps to bolt or screw them to the stringer sides or glass them.  Rick, I know yours were run through the stringers thus stabilizing them that way. Any thoughts or is that about the gist of it?  Here is what I picked up from the site so far:
   >  dremel the edges out of pvc joints/turns
   >  avoid 90 turns if possible
   >  run the fuel line in its own tube
What else am I missing?

[Duffy1470]

Something like this

[RickK]

I couldn't get the outboard control cables through a "90" I had to use a "45". Might want to go with 3" pipe and it was tight getting the cables to get around the bend.

[dbiscayne]

I used electrical conduit at my bends, 45 and 90 degree bends both worked out just fine. Can get the shift cables through the 1.5" diameter, steering cable went through a 2" conduit 90 degree pretty easily.