Removeable gas storage tank for trailer

[Metal Troll]

Hello everyone,

My boss wants me to make a gas tank for his pull behind trailer. He wants it out so it can be removed when empty. He wants it to be 24" deep by 24" tall by 50" long out of aluminum so it can fit in tje front of the his pull behind trailer. My initial response was "We dont weld aluminum and I dont have any idea how to build a gas tank that is going to be safe." but the sad fact is we are very slow at are shop and any little project that keeps us working is worth a shot.

I was going to fabricate it out of 1/8" aluminum with bafflers spaced every 10" to 12" to try and keep the gas from moving around to much. When i get all the pcs cut try to weld them up but I know that welding aluminum can be tricky. All we have is a mig welder so we would have to get a spool gun for aluminum.

My question for you all is there anything that i am missing that i need to have in this or a special kind of aluminum, specific thickness? Any ideas or comments would be a ton of help.

I have attached a few pics of the trailer he wants to use. It is rated for 3500lbs. And a rough drawing of what i will be constructing.

[Loyd]

First, let me dispel the myth about needing a spool gun for aluminum. When I was a plant/operations manager at a satellite antenna factory and an aluminum treestand manufacturing plant we had 10 mig welding machines welding aluminum all day long without one spool gun in either factory. We used a pallet of 40# reels of aluminum every week. I have a hobart 170 and a miller 200 that I weld aluminum with in my shop now.....no spool gun.
1. Use a 10' lead
2. Use 5056 .035 wire
3. Use .045 tip and liner
4. Crank up the amps so that you are approaching spray mode. We used mm200's high range 5 or 6 (If I remember) @ 90 on the wire feed.
5. Move fast, don't let your lead crimp
You will be amazed, I've had so many "certified" welders tell me it couldn't be done it isn't funny. Problem is, we did this for 11 years!
Practice on scrap to get the technique down. Weave back and forth fast.
Do not use 3003 aluminum you will regret it. 6000 series will do you well.

We did not clean our aluminum, it came straight from the mill it was 6061 T6 various gauges.
You may have to clean with stainless brush and acetone.
It looks like you have a good plan. Don't forget some kind of venting.
Good luck hope this helps.
Loyd

P.S. Almost forgot....we used 95/5 argon/oxy mix. Hotter, smoother weld.

[Loyd]

That is a 125 gallon tank. Which equals 777 lbs of gasoline when full. Plus 20# or so of tongue weight. We are looking at almost 800# of tongue weight on the hitch. The max is probably 200#. Something to think about! Looking at the trailer design with the wheels so far back and what looks like 3x3 tubing (what ga.?) When that trailer hits a bump there is no telling the weight that that hitch is going to be subjected to. Some more to think about.
Loyd

[Metal Troll]

I have to look a little closer to the trailer but the tongue is 2" x 3" not sure of the thickness. I know it was a Home Depot trailer that the owner got for dirt cheap do to some small damage. I have a feeling that this one is not going to work and you have stated many of my fears. I am not a engineer but if push comes to shove I can do some "farm fixing" on some stuff. It will end up looking like Frankensteins monster when I am all said and done and costing more than a new trailer but you know how it is when the boss man has a idea in his head .

Thanks alot Loyd for your info.

[Loyd]

I know exactly what you mean. lol I was also a PM at two different utility trailer mfg plants. For a while my youngest son and I built custom color matched trailers until he got tired of that. If I can help, let me know. That hitch has got to go, get a bulldog hitch for it.
I assume no responsibility of course.
Loyd

[Metal Troll]

Well we got the trailer flipped over and finally got a real good look on how its constructed. You can already see where the frame is bent from just carring normal stuff in it. I think it would be best to take off everything and build a whole new frame, tongue and just put the sides, bottom, axel and electrical on the new frame.

Got a picture of the bottom and some drawings of actual frame layout and drawing of what I plan to construct. I think the new one should be able to hold that tank and anything else you can throw at it.

Let me know what you all think.

[jerrybarrett]

I think you need to move axle forward there will be too much tongue weight when tank is full I would set it no more than 8--10" behind C/L of trailer box. I build a lot of AG trailers with tanks and we have to allow for difference in weight in tank. (Full Half Full Empty) There is a big variance!!!! Jerry Barrett

[Loyd]

Just 2 suggestions..
1. move the axle so that it is 60% back from the front of the box
2. beef up the tongue similar to the picture, this is very important. I had a good friend of mine with a 5 yr mech eng degree "design" and build a trailer for himself.
It wound up spread all over the highway on it's maiden flight. That tongue needs to angle out to the sides of the trailer and down the sides at least 3 feet. The standard angle if I remember correctly for welded hitches is 50 degrees. If you want the straight hitch you can do yours like the picture. You just have to stabilize those sides with that much weight.
Loyd

[Loyd]

Jerry, good advice!
Loyd

[jerrybarrett]

Loyd I like the extable tongue. 2 1/2 x 3/16 outer 2x inside. Am I right Good idea. Jerry Barrett

[Loyd]

Jerry, Yes you are right! Good eye!
Loyd

[Metal Troll]

Thank you all. That information will help me tremendously. This site is the best and so are the members. Knowledge is more valueble than steel or a dxf file in my eyes. I tip my hat to you all for being so generous with yours.

Have a wonderful and safe 4th of July everyone.


And thank you again

[Loyd]

Hey MT, Make sure you give us some pictures, OK? Be nice to see what you came up with!
Thanks,
Loyd

[Metal Troll]

Well the trailer finally is complete and out the door and here are some of the finished pictures. We ended up using 1/4" 2" x 3" tube steel for the whole frame. When all said and done with the tank on empty you can grab the tongue and left with 1 hand and move it around. Let me know what you think.

[Wesley Nichols]

You did a really nice job on that trailer... I like to see guys here in America that take pride in doing a nice job.

[Eagle Mtn Metal Works]

Hey MT
I know you said that you where slow but you did not have to take it to the max, six month to build that great looking trailer That looks like a good trailer to haul a two seater. Your shop must have got real busy and the trailer got put on the back burner.

[Metal Troll]

It wasn't a rush job thats for sure and we only worked on it when there was nothing else to do in the shop. So we could take are time. Usally around here its sit around and wait for some work and then its "Hey can we get this yesterday?" ahh customers what can you do. I try to tell them if I had a magic wand and could tell the future I wouldn't be here I would be in Vegas gambling and making tigers disappear but for some reason they dont think thats funny.

[Eagle Mtn Metal Works]

MT
Yes, but with out customers the power would not stay on and we could not cut out our stuff. So keep the customers happy as you can and they will keep coming back.