Fuel Tanks for Skiff

[kmorin]

Here are some details of the gas tanks on our daughter's skiff. Both tanks are forward the console and outboard laying to the topsides under a narrow guard deck or sheer clamp.

The tanks are 1/8" 5052 bent to a 'leaned out' parallelogram end shape. This photo is of the aft outboard upper corner of the starboard tank.



Here the top after corner has the fill doubler and vent and draw fittings.



This is an illegal drain fitting in the lower after inboard corner of each tank (tank is tipped on end here) and the 1/2" NPTfem coupler is flush to the outer tank wall. Then TIGged to the end of the tank and fitted with a socket recess SS pipe plug- it is unnoticeable by even the most keen-eyed Coastie. I don't believe its acceptable to have fittings below the top surface (?) but then I don't like water in the tank bottoms either.



Just a weld seam, using Pulsed TIG on the Miller Dynasty 300 DX you can penetrate the parent metal and sag a good back weld into the tank while maintaining a good pace and bead uniformity.



Here's the top of the tank as it is installed we're looking outboard to the starboard side so the fuel line in the right side is the tank draw and running aft.



This is the fuel filter and selector valves on either side, and the on deck fire extinguisher mount too.



Opposite the fuel filter above is the old refurbished 'Hynautic' (brand) pressure tank for the hydraulic steering. All the tubing is SS using Swagelok fittings and ball valves all tube wall is 0.035" 316 which is much heavier than needed, its just what we have for work so we use it for everything.

I'll try to take some shots of the tanks from a few feet to show them installed and make sense of this whole post.

cheers,

[JETTYWOLF]

May Hynautic steering.....rest in peace.

[Ironwoodtuna]

Kmorin,

Those welds look nicely done, perfect penetration from what I see. What is your experience in aluminum welding, are you a boat builder, fabricator or what??? I know its not approved but I like the drain plug in a tank to get it dry of water should you get a bad batch of fuel, I like the stainless steel like and stuff. WHat boat is that in, have you posted it here? Maybe I missed it. mty

[kmorin]

Ironwoodtuna,

I did build commercially for years, and still build for fun. The tanks and fuel system are in the Daugther's Skiff, but since these were more or less details I figured they'd post in this area more than the About Your Boat category where I put her skiff.

Marty, I don't want you to think I can weld like that with a hand torch and dip rod (two opposed hands). I can't- now- maybe never was very good with a free hand torch I have to lock my elbows or drag the cup freehand. I use a TIG gun that feeds wire with a motorized feed just like a small MIG 1lb. gun and is a two handed affair.

So, just like firing hand guns - get both hands on the grip and you're 10 times the shot you are with one hand only. This gun allows me to get decent quality TIG at very near MIG speeds, by steadying down my shaky old carcass's swings and jabs of the tungsten.

I built from the mid '70's to the end of the 80's building commercial salmon net boats, in Kasilof (kuh-see'-luff, or kuh-see-loff) Alaska. I did a few hundred 18-24' ers and a dozen maybe 30 over 28' ending at 40'. I've built my share of tanks and brackets so I was just showing an example since there was some current discussion of tank fabrication on the site.

Thanks for your kind words about the welds,

Cheers,

[warthog5]

I use a TIG gun that feeds wire with a motorized feed just like a small MIG 1lb. gun and is a two handed affair.

I'd like to see that. Can you post some detailed pix's?

With my welding skill's I know what needs to be done, but doing it is another matter.

A lot has to do with my eyes. My left eye is the dominate one and my right eye turns out,unless I close the left one. I've compensated for depth preseption all my life.

That tool is something that may help me?

[kmorin]

warthog5,

here is the TIG gun from several angles.



laying on the right side left side up



Laying on the left side; "back" (right hand) side up.



looking at the TIG torch (300 Amp water cooled)



Top open showing proprietary wire roll, we just re-roll our own from larger format rolls instead of buying from OTC/Dahein America.



Gun in hand showing the re-arranged controls. Originally the wire speed was on the back of the gun and was supposed to be set and left alone- I moved that pot to the handle to be under my thumb. The larger pot located on the handle with black tape is the remote (pedal) control for the power supply and the small toggle switch above my thumb is the Off/Weld switch which allows you to shut the contactor relay off to change tungsten or fiddle with adjustments.

The trigger is held with the right trigger finger for start and stop, the wire speed and heat are under the thumb. I like this arrangement but then I have always added remote speed and heat pots to my MIG guns. [Now the Python from MK has speed pot built in to the handle/torch.]

This gun is driven by a 'controller box' with a relay for the contactor in the power supply and speed control for the DC variable speed motor in the handle.

For reasons that are obscure the company that makes this gun hasn't done too much to promote it, I've this one four years and before that had one I wore out for 20+ years. Most welders think I'm making up the story when I tell them I use a TIG gun, but I do.

My first "TIG gun" was a Linde 350A water cooled TIG torch on mounted with an aluminum bracket to the side of a 1978 MK Products Cobramatic MIG torch with the welding power on the TIG torch and the wire feed in the Cobra. Worked well but then the distributor found this and I've used one since.

Hope this helps?

cheers,

[mojomizer]

I think I want to get adopted :lol:. Faithful hardworking son in search of creative talented boat builder living in Kenai Alaska.

Mark

[CTMD]

Can I suggest you move the fire extinguisher away from potential fire risks. Do you really want to reach into a fire ball to grab it?

[kmorin]

CTMD,

This extinguisher is on deck to use on the engine and the only soft fuel line in the boat that is aft the transom on the engine mount. This extinguisher isn't intended to be retrieved if there were a filter fire- just the engine and lines aft.

The SS tube valves and fittings are not exactly known as "leak prone" but since the Racor and all the surrounding areas are either aluminum or SS so the ignition potential by spark, even if the bowl were burst, is about as low as possible.

If the bowl burst AND there were an ignition event, even as unlikely as that is, the console has the other extinguisher for use in the stern area of the mount shown. Reaching into a fire for an extinguisher does seem somewhat counter intuitive and isn't intended by the location of the engine's extinguisher.

Cheers,