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Corners add strength to the structure, and also why I mentioned bead rolling, but yeah, you'd need a manly roller w/ the thickness you're looking at.
 
Greg

Have you looked at the Jaz Jeepspeed fuel cell? I'm afraid your heading down a long road with this fuel tank thing. It's pretty common knowledge that AL only tanks crack and have issues, can you make it work sure. Knowing what I know now I personally would't install any sort of fabricated tank without a bladder myself, mass produced or otherwise.

Are you reinventing the wheel in and area that could use a pretty mild compromise and make life way easier with just one click of the mouse?
 
Greg

Have you looked at the Jaz Jeepspeed fuel cell? I'm afraid your heading down a long road with this fuel tank thing. It's pretty common knowledge that AL only tanks crack and have issues, can you make it work sure. Knowing what I know now I personally would't install any sort of fabricated tank without a bladder myself, mass produced or otherwise.

Are you reinventing the wheel in and area that could use a pretty mild compromise and make life way easier with just one click of the mouse?


Brandon,

Thanks for checking in (again). :waytogo:

Please indulge me for a few questions:

It seems pretty clear from this discussion that Aluminum is not going to be a good material for this size tank. I've resigned myself to using a thick stainless (11GA) or I suppose even mild-steel. If there's going to be a bladder inside anyway, I don't think there's much concern about corrosion even with mild-steel. It could be cheaper to build and could help offset some of the costs of having a custom bladder made. :thinking:

  • Are you equally dubious about stainless steel for this project? I very quickly looked at the JAZ tanks which appear to be 20GA powedercoated steel (I saw flanged wraparound corners too)
  • Does the bladder offer any kind of slosh protection, or it is purely a safety item to prevent spills if the tank DOES rupture somehow?
  • If I get a bladder custom-made, do I even bother trying to build baffles internally? It seems like the bladder is just going to expect a large, undisturbed volume of space to lay into?

I always like the idea of "one click and done"....I'm a bought not built kinda guy! :wink1: But seriously, I may end up reworking the rear framerails outward to fit a tank with enough capacity (say 32 gallons or more) that is still a reasonably shallow depth so I don't bash it...


-G
 
How often to you anticipate needing 30+ gallons of fuel? You've already said that for any cross-country type trips you are going to have it hauled. How often do you plan on going 200+ miles without stopping?
 
Fuel safe will make you whatever you want as far as bladders go, they build huge 45+ gallons for the desert racing community.

That is money very well spent, certainly save you from the stress of welding together a 38 gallon bomb for the first fuel tank you ever built. You can still build the steel take it sits in, flange and bolt the lid down.
 
How often to you anticipate needing 30+ gallons of fuel? You've already said that for any cross-country type trips you are going to have it hauled. How often do you plan on going 200+ miles without stopping?


Think of it in terms of a 100% electric car.... a lot of would-be buyers have "range anxiety" about a car that can't be assured of making it to work-and-back every time.

Sure, in a perfect world 20 gallons is probably fine. But I don't want to feel like whenever I want to drive somewhere, the first stop is always the gas station.... or that at the end of a day's wheeling I absolutely HAVE to stop for fuel again so that I'm ready for the next day's outing. It's just a crummy feeling..... maybe it's OCD, or whatever but if I end up always thinking about fuel....using fuel.....planning for fuel....getting fuel... it's really going to ruin the enjoyment of this truck, and eventually I'm just NOT going to want to take it out and have fun with it.

With 30+ gallons..... I'm good for long highway jaunts. I'm also good for some around-town driving mixed with a spontaneous trip to Boston to visit my buddy there (without stopping first to top-off)... or I can just drive it around town for fun for a couple weeks straight without pulling into a gas station. I know, I know.... it's going to cost a fortune when I finally DO pull up to the pump, but somehow it feels like less of a reminder of my bad fuel economy if I stop less-frequently (albeit at a higher cost per visit) for fuel.

Don't underestimate the value of NOT having to hear crap like this from tree-huggers / environmentalists at a fuel stop:

"Hey, back again? Wow, you should really get something more efficient.... you know that truck is causing global warming right??"


A big fuel tank gives them fewer opportunities to act supercilious.... and makes it less likely that I'll have to punch them in the face. :haha:


-G
 
Gotcha. We all have OCD things that bend our opinions of what is "worth it" and what is not. It sounds like there is a bevy of reasons that, for you, make it worthwhile to build the maximum amount of fuel capacity you can.

I was trying to see if it was simply that you assumed you would need that much capacity, as it didn't seem likely to me. As usual, you've probably put way more thought into this than I gave you credit for. :)
 
Gotcha. We all have OCD things that bend our opinions of what is "worth it" and what is not. It sounds like there is a bevy of reasons that, for you, make it worthwhile to build the maximum amount of fuel capacity you can. I was trying to see if it was simply that you assumed you would need that much capacity, as it didn't seem likely to me. As usual, you've probably put way more thought into this than I gave you credit for. :)


......also, I have issues.




:haha:


-G
 
Brandon,

Thanks for checking in (again). :waytogo:

Please indulge me for a few questions:

It seems pretty clear from this discussion that Aluminum is not going to be a good material for this size tank. I've resigned myself to using a thick stainless (11GA) or I suppose even mild-steel. If there's going to be a bladder inside anyway, I don't think there's much concern about corrosion even with mild-steel. It could be cheaper to build and could help offset some of the costs of having a custom bladder made. :thinking:

  • Are you equally dubious about stainless steel for this project? I very quickly looked at the JAZ tanks which appear to be 20GA powedercoated steel (I saw flanged wraparound corners too)
  • Does the bladder offer any kind of slosh protection, or it is purely a safety item to prevent spills if the tank DOES rupture somehow?
  • If I get a bladder custom-made, do I even bother trying to build baffles internally? It seems like the bladder is just going to expect a large, undisturbed volume of space to lay into?

I always like the idea of "one click and done"....I'm a bought not built kinda guy! :wink1: But seriously, I may end up reworking the rear framerails outward to fit a tank with enough capacity (say 32 gallons or more) that is still a reasonably shallow depth so I don't bash it...


-G

Let's break this into two generalizations, Built as #1 and Bought as #2

Built tank #1

Any material you use, stainless, mild steel, AL, etc will be tough to get the seems to seal. Can it be done? Yes, it's done everyday in factories etc. For a home builder such as yourself I would say this will be a doable project that's going to take some time to get all finish welded with 0 leaks. Now you have to deal with flexing and cracking in use. With your proposed tank shape, something, somewhere will end up cracking, will it happen right away? that's the big question.
Material choices to me for a fabricated tank with no bladder are Stainless or mild steel. Both will require internal strengthening methods that your well aware of, more will be better. Overlaying the welded joints with more material will help and maybe make my concerns invalid. If you want to fix a leak you have to drain the tank, get all residual gas out of the tank, clean it as best you can and then purge all the air from the tank with an inert gas, then start welding and hoping you did the above right. I've helped weld one diesel tank and one gas tank before and it wasn't a terribly fun job because of the consequences.

If you design this, build the shell and send it to someone like ATL or Fuel safe they will build a "flexible bladder" to fit your tank profile and shape. How flexible this bladder is I'm not sure, I don't think it shrinks in volume if there is no fuel in it though. They can integrate anti slosh things (I don't know if this is foam or another method), fuel pickups, pump wiring etc. to make it a truly awesome tank. This does and will come at a pretty good cost. With this bladder in place the only thing your external tank does is offer shape and protection of the real fuel holding device. If a crack forms at a weld, well so be it. If you decide to fix said crack you can disassemble the tank, remove the bladder and weld it up without fear of blowing yourself up by welding in a gas fume environment. Thickness of the outer tank material should be I would guess thinner than 1/8" but sized to handle the size and shape your doing, also how you mount it can help with the overall thickness and design as well.

#2 bought tank

A Jaz/Summit/ATL/Fuelsafe premade fuel cell will typically have a thin sheetmetal out skin and a "rotomolded" internal bladder. Now this bladder isn't like the above custom built bladder for your tank shape, this is honestly the tank, it's hard plastic, holds it's own shape and in some cases is sold without the sheetmetal outer skin. All of those over the counter red Jaz fuel cells are this, rotomolded plastic tank within the outer shell. The shell is a UV, debris, covering that adds some protection in the event of a puncture or crash. These types of fuel cells use the Foam as the anti slosh device. I've had great luck with the foam in the tank and the pump mounted outside and below the level of the bottom of the tank with a good large prefilter, pump, post filter arrangement. I've seen guys on the side of the course changing their 5th pre filter of the race that was full of foam too. I theorize that those that overprep their fuel systems take the foam out every race and when putting it back in create lot's of small foam pieces that travel to the filter, we treat the cell as a closed system and don't mess with it once it's done the first time.

You noted the thin sheetmetal "tank" which on first glance is what you think is the whole thing, but the plastic inside is the real tank and the red shell holds it. The jeepspeed tank has some shape to it so it might just be worth looking at, plus I want to say it's a 32 gallon cell, which is the upper end of practical for offroad use IMO. 32 gallons is a lot and that size cell weighs a lot too.
 
I think if you're worried about foam, you may be able to put one of those fuel pickup mats in underneath the foam and that would help filter debris if it were to break down...
 
Mikes 555 ran 18 hours of the trifecta without running out of fuel. (MIKES TANK WAS 20 GAL) but what about the possibility of running a 25-30 gal tank and carrying extra fuel for the long adventures. I did that when I went to Moab and the extra fuel I took I ended up putting in Erics truck!
My 454 was taking about 2gal per hour of actual running time on the trails of Moab, running the dunes for actual run time of a couple hours (much more partial and WOT time) would only burn 8-10 gal. I had Kert build me a custom 31 gal tank and havent come close to using half of its capacity yet.
 
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2016.04.27 - UPDATE!!! - BRING IN THE LASER...!!!


Slight detour in the fuel tank discussion to share a few update photos from the last couple of days.

As you all know, there isn't a whole lot of rusty metal left on my Blazer.... which is to say there isn't a whole lot of Blazer left in my project! :haha: The vertical step panel is in pretty rough shape and since the part is backordered, and isn't really the final shape I want anyway, measurements were taken so that it could be replicated / modified in a fresh piece of steel.

It's a pretty simple part, just a slight taper cut on the ends...

IMG_9810.jpg




And it's pretty LOOOONG as well....

IMG_9812.jpg



At this point, it's important to capture as much information as I can from the part....and it's relationship to the rest of the remaining floor, etc. Once I cut this part out the floor is basically just a floppy, unsupported mess that won't be good for any kind of accurate measuring.... so it was important to note the seat centerlines and other critical dimensions.


Last night, UPS dropped off a small but deceptively heavy 45Lb box at my house. I'm pretty sure they hate me now.... my new best friends at A & A Manufacturing took my CAD drawing of a simple cage plate and dropped it onto their laser table in just a few short days, and made me a delicious pile o' parts!! :bow:

IMG_9834.jpg



Closeup to show the cut quality of the plates and holes:

IMG_9836.jpg



I couldn't help myself, and cleaned off my impromptu "workbench" so that I could see them laid-out in their final positions..... :)

IMG_9839.jpg



.....I asked for 48 plates total, since there's really no point in coming up a few plates short. The setup costs and minimum quantities for custom-cut parts make it a LOT cheaper to just buy more than you need than to come back later for 1 or 2 plates. I ended up with 54. I think they basically run whatever fits efficiently in the layout on a large sheet of 3/16"... so you get a few "extras" depending on how they fit the sheet. No biggie. :waytogo:

IMG_9843.jpg


The parts look awesome, and they were really easy to deal with and enthusiastic about helping me get the exact design I wanted, even though they had some "off the shelf" stuff that was pretty close.


-G
 
Just flat plates? I thought you were doing something to puzzle piece them to the floor contours?

Don't get me wrong, they look nice just not what I was expecting.
 
Just flat plates? I thought you were doing something to puzzle piece them to the floor contours?

Don't get me wrong, they look nice just not what I was expecting.


One step at a time good sir!!! :waytogo:

A & A Mfg did the flat plates on their laser table, and I've got a local machinist doing the convoluted plates on his CNC....

I got a call last night that the first "prototype" matched set should be ready today for test fitting. :saweet:

Hopefully it all checks out as expected with no programming tweaks and he can run the rest of the parts through quickly. I'd love to have all my materials by the weekend in case Mike announces another MPS Day.


-G
 
Sweet! You've always set the bar fairly high so I was a little worried. LOL looking forward to seeing the rest of the pieces. :thumb:
 
Out of curiosity, what was different about these plates from the stock stuff they had on the shelf?
 
Out of curiosity, what was different about these plates from the stock stuff they had on the shelf?


Their "generic" cage plate was 3/4" longer in one dimension than I wanted, and had 3/8" through holes instead of 1/2"...

By the time I got my plates ordered (in the bulk quantity I needed) my "custom" design was only a few pennies more per part, and I got exactly what I wanted. :waytogo:


-G
 

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