Build your own gas tank? (1 Viewer)

[chicago]

Anyone done this?
Im not loving my options on an off the shelf tank (RCI, Summit etc.)
My very best option would be to either build my own, or have one built.
The DIY route scares me a bit cuz...well...its GAS. Gas is FLAMMABLE! I BURN.
Unfortunately, I want this HOW I WANT IT. Anything else is just gonna suck IMO since I had to cut out my stock tank for my dual cases.
Does it have to be Aluminum?
Can you treat steel so it wont corrode?
Do you need baffles?
How would you test it for leaks?
What Ga. steel/ Al. should I use?
Is top or bottom fuel feed better?
Foam....needed or not/ good idea or not?

This WILL BE MOUNTED BEHIND THE SEATS! So, on an FJ40 it will run between the fender wells. The goal for me is to minimize taking up too much of the cargo area and maximizing the fuel capacity. I have one of the RCI fuel cells now in the 15 gal., but there is SOOOO MANY THINGS that I wanna change about it that Im thinking custom is the ONLY way to go. The poly tanks would be SAFEST, but the only way to run those is to eat up precious cargo space.

Gimme what you got gents!

Here are a couple of pics of the tank I have and the location that I want it for reference.

Thanks in advance!

Keith

 

[97kurt]

I've also considered making my own fuel cell, but it does scare the crap out of me. My advice would be to have DrSmash build you one, its kind of his specialty. Or if you are dead set on building your own I would pick his brains for info.

 

[Chop Shop]

A welded steel tank is far superior (providing you can weld OK) to the one you have in the pic.

The cheap rci tanks tend to crack in the corners after years of bumping around. They were never meant to be mounted by the tabs on them so they need a cage on the corners to clamp them down and have to sit on a structure to.

A steel tank can be made in any shape you desire. It is easy to build a sump on the bottom of a steel cell. About the size of a coffee can willl let you run on your side for 20 minutes.

Weld a bung in the bottom of the sump for a drain. then you can steal lawnmower gas when you dont want to go to the store too.

It wont corrode if ya keep it full. DONT coat it or paint it inside. If you do, well that will be the end of your filters. Gas is a solvent and will soften up anything coated inside.

STAY AWAY from FOAM. It is the devil. if worried about slosh just weld in a few baffles when building it. The foam will crumble into little pieces and plug up everything. Thsi is no joke, Im not speculating or telling you what I read on the interweb, FOAM SUCKS and will screw you if used. The amount of alcohol in todays fuel will eat the s***. Unless you run straight race fuel then NO FOAM.


test for leaks with air and water. fill it up with water and give it a few (like 15 or less, dont blow it up) psi of air to locate any water leaks. Once tight, drain, let dry, install and fill.

I have made several tanks from 10-12 gauge steel. They all work great and fit even better.

 

[bustanutley]

Nothing wrong with the tank pictured, but yes, do not use the tabs. Cut them off and use straps much like the factory cruiser method of fastening. Having a tank built is fairly cheep if you find the right sheet metal guy. Just make a cardboard model and take it to him. Making your own would be fairly easy also if you have access to a largish break. You can use this stuff called aircraft sealant to assist sealing the welds, just make sure you don't have any screens you don't' want sealed

 

[AirCruiser]

Don't go over 1.5 - 2 psi unless you like explosions, The aircraft tank sealant's work very well for pinhole leaks

 

[Chop Shop]

Don't go over 1.5 - 2 psi unless you like explosions, The aircraft tank sealant's work very well for pinhole leaks

I run 20 psi in a homemade water tank on the service truck (just dont tell the boiler inspector).
Once in the winter the regulator froze up and when it got to 35 psi it swelled all the seams and looked like a ziplock baggy full of air, but it didnt blow up. In fact it still gets used everyday with its new bloated look.

If you damage a tank with only 2-3 psi in it, I would never put fuel in it.

It takes more than 2-3 psi to blow dents out of old 2stroke bike exhaust pipes. They are thin like paper too.

 

[handcannon]

Chop Shop hit the nail on the head.

BE SURE you design in a sump with a drain. This will give you the "run on your side when low on fuel" ability and a way to drain the water/garbage out of the tank if that becomes a problem. A long flat bottom tank "wastes" fuel capacity. A friend built me a tank that goes across under both seats of my 40. It doesn't have a sump and I estimate that I have about 5 gallons of fuel left in the bottom that I can't use when under the best circumstances. Neither my friend or I thought about it when designong the tank. Live and learn.

The water and low pressure air does a great job of finding pin holes.

Don

 

[Kent]

Here's what I did.

No sump. Might be better to have one but I'll keep a Jerry can with me so low fuel won't be an issue. I did not line it for the reasons listed above.

https://forum.ih8mud.com/40-55-series-tech/378994-home-made-under-bed-gas-tank.html

 

[GLTHFJ60]

Do you have to have home made gas tanks certified if you want to drive the truck on road?

 

[spressomon]

Keith,

Nothing particularly tough about fabbing your own tank. Baffles strengthen a large tank and also reduce sloshing. I watched the process when Sam built my 25-gallon aux tank. I think he used .120 for the top and sides and .188 or close for the bottom that also serves as a skid (even though its mostly protected).

They TIG'd mine which is tedious but probably better suited for the job at hand than MIG (pin holes would be the downside to MIG).

He used a fuel tank specific gel/epoxy type coating (not sure of the actual make-up of the coating...but its made for this specific purpose) that makes it rust proof. It was a 2-step process: First step was to etch the interior of the steel tank with the acid component they provide. Then after that is done they poured the coating in and rotated it until all sides were thoroughly coated; poured off the excess and then let it dry outside in the sun for a couple days.

But having said that, as 97kurt mentions above, Dr. Smash works relatively cheap and does good work per Jack, et al, ...and it might just be worth your while to outsource the tank to him.

Dan

 

[locrwln1]

Keith,

Nothing particularly tough about fabbing your own tank. Baffles strengthen a large tank and also reduce sloshing. I watched the process when Sam built my 25-gallon aux tank. I think he used .120 for the top and sides and .188 or close for the bottom that also serves as a skid (even though its mostly protected).

They TIG'd mine which is tedious but probably better suited for the job at hand than MIG (pin holes would be the downside to MIG).

He used a fuel tank specific gel/epoxy type coating (not sure of the actual make-up of the coating...but its made for this specific purpose) that makes it rust proof. It was a 2-step process: First step was to etch the interior of the steel tank with the acid component they provide. Then after that is done they poured the coating in and rotated it until all sides were thoroughly coated; poured off the excess and then let it dry outside in the sun for a couple days.

But having said that, as 97kurt mentions above, Dr. Smash works relatively cheap and does good work per Jack, et al, ...and it might just be worth your while to outsource the tank to him.

Dan

As we have talked about before, if you are going to go through the process of building your own tank, I would put it under the tub. There has to be room under there somewhere. And yes you want baffles and most importantly, you need a sump. The last thing you want is to be on some difficult obstacle and have the fuel get away from the pickup and the engine stall out.

Definitely talk to Dr. Smash. He will give you a good price and does good work.

Jack

 

[D'Animal]

Go with the walbro dual fuel pickups in the bottom of the tank along with dual sumps and you will not starve your engine for fuel.

Auto Performance Engineering - Walbro fuel pick-ups

I would do a mockup in cardboard and then ask Dehondagod how much he would charge to make it. Since you are close, I would go with SamCo Fabrication (Sam Cothrun) and see if he would do it as well.

 

[Chop Shop]

Go with the walbro dual fuel pickups in the bottom of the tank along with dual sumps and you will not starve your engine for fuel.

Auto Performance Engineering - Walbro fuel pick-ups

Currious how a weed eater pickup is going to hold more fuel than a coffe can sized sump on the bottom of a tank?

Those just tumble around on the bottom of the tank hoping to follow the fuel around.

Why dual pickups? One for a spare or backup or sumthing? Cuz if both are hooked up and one is not in fuel it will pull air while the one in fuel does nothing.

Looks like a unneeded way to spend money on something with not much benifit.

Maybe using one as a prescreen sock IN a sump is all I could see.

 

[CruisinFJ60]

Currious how a weed eater pickup is going to hold more fuel than a coffe can sized sump on the bottom of a tank?

Those just tumble around on the bottom of the tank hoping to follow the fuel around.

Why dual pickups? One for a spare or backup or sumthing? Cuz if both are hooked up and one is not in fuel it will pull air while the one in fuel does nothing.

Looks like a unneeded way to spend money on something with not much benifit.

Maybe using one as a prescreen sock IN a sump is all I could see.

about the pulling air, those ones linked are designed to close off when they are no longer submersed in fuel so if one looses fuel it will close off and the other will continue to draw.

 

[megolfer]

Walbro are the way to go. Just check what they are suing for most of the KOH rigs. Most of them are running 4 pickups. The walbro are about the best out there and they do not suck air.

 

[Arya Ebrahimi]

I built the tank in my mini-truck in an afternoon. I got two c-shaped pieces made of 16ga sheetmetal from my HVAC guy (any sheetmetal shop should be able to do these pieces for very cheap) that fitted together to make a rectangular shaped tank. I cut a sump into the bottom and then welded it all together with some baffling. I'm over simplifying, but it really wasn't that hard.

I plan to make a tank for my 80 in a similar way. However for that one I think I will make the bottom and sides all out of one piece and then weld on a top(only welded seams would be the verticals up the sides and the top).

 

[chicago]

Sorry for not getting back on here gents...
I have been home in Chicago for the last 5 days with no computer access.
So any thing on the baffles and how they should be set up inside the tank?
When you say a "sump" what exactly are you referring to? I thought a sump on a tank has the fuel inlet and outlet off of it and it hangs DOWN below the tank for the purpose of easier fuel pick up. However, it sounds as if you guyz are talking about something different?
I sent Dr. Smash an e mail and will probably talk with him tomorrow about it to see what he can come up with.
Thanks for all the input.

 

[chicago]

As we have talked about before, if you are going to go through the process of building your own tank, I would put it under the tub. There has to be room under there somewhere. And yes you want baffles and most importantly, you need a sump. The last thing you want is to be on some difficult obstacle and have the fuel get away from the pickup and the engine stall out.

Definitely talk to Dr. Smash. He will give you a good price and does good work.

Jack

Jack,
There really IS no room for a tank to go under there.
Under the cargo area toward the rear of the tub is out because of the axle relocation. Pass. side of the rail is all the drive train, t cases and stuff and the DS of the the rail WILL BE exhaust...dont think I want that being close to the tank.

Ill look a little harder tomorrow at it since Im probably gonna go the custom route, but...Id love it if I could though. that would solve a TON of storage concerns Im having.

 

[chicago]

Is there a reason under the back of the tub is out?

From what I recall on the FJ40, you can do a 6" deep, 33-36" wide, and 24ish long tank.

The problem with having a custom tank made will be the price. Don't be surprised when the shop comes back with $600+ for your tank.

As for material, I think either or is fine. Stock tanks are steel that are lined(painted)

To me, the biggest issue is going to be baffling it correctly to minimize starvation during side hills especially as you get a wider tank.

Im bracing myself for the price. If its too high, Ill give it a go myself. I can be pretty handy when forced by the almighty BUCK. However, I had already paid 239 bucks for the RCI cell that I have pictured and will spend more if I can get what I WANT in the end for a good custom made tank where I want it.

 

[rusty_tlc]

Another vote for Dr Smash.
The nice thing about AL is you NEVER have to worry about corrosion.