Author Topic: How to make or modify a small fuel tank?  (Read 1954 times)

Offline PekkaNF

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How to make or modify a small fuel tank?
« on: December 25, 2014, 02:22:29 AM »
Hello all,

I have a small diesel generator and I thought that buying a aprximately correct size and shape fuel tank would not be a problem. I was wrong:
http://madmodder.net/index.php/topic,10272.msg116460.html#msg116460

I need a small (10-20 litre, 3-6 gal) fuel tank that has to fit on certain space, in my case ( abot 40 * 40 *15 cm , 16x16x6") and has to store diesel.

I probably will settle for a compromise now, but I would like to figure out how I could make a fuel tank if I need to. Material will dictate a lot and acessories too.

1) Because I can find thick walled HDPE or thin PE fuel containers that "almost"  fits I was trying to find if I could make them fit. I asked myt brother who went to school to learn about palstics. Turns out that: a) Rotomolded PE can't be very succesfully moulded to another shape, it tends to retain it's original shape (Darn, my first plan was to make correct shape bould of wood, heat up ready made canister and press/blow it to new shape. B) it does not glue well at all, it can be welded but weld tned to be porous....there went my another plan to buy one container that is of correct shape, but has screw top on wrong side. He has weld it with a hot air gun and they tested specimens, I don't expect to do better home.

But I remember this "How It's Made" episode where they friction welded a lid ot a camper car tank. The cap assembly was spun with a electric drill until plastics was gel and then pressed and held until it solidified. I clould not find it on this list:
http://en.wikipedia.org/wiki/List_of_How_It%27s_Made_episodes

I only found this one, Plastic Gasoline Containers

     <a href="http://www.youtube.com/watch?v=14zgE-TvI0A" target="_blank">http://www.youtube.com/watch?v=14zgE-TvI0A</a>

2) Welded sheet metal construction. My brother can weld alminium and it's not too hard to find weld unions to Al tanks, but it I haven't found anything other that "racing" filling and breather parts to them. Price and work escalates.

3) Mad modder solution, found a stainless steel kitchen sink of proper shape and size. It is very thin, just wondering that how to seal ss sheet "top" to thin "bowl". I have to ponder this a litle before going any further, it just looks temping, but welding thin stinless steel not.

Pekka

* Update, Found correct term "Spin welding":

     <a href="http://www.youtube.com/watch?v=fMdLWAYr7Ck" target="_blank">http://www.youtube.com/watch?v=fMdLWAYr7Ck</a>


     <a href="http://www.youtube.com/watch?v=KSHy6BeiVw0" target="_blank">http://www.youtube.com/watch?v=KSHy6BeiVw0</a>


And another interesting video:

     <a href="http://www.youtube.com/watch?v=r0zpqhhcmp4" target="_blank">http://www.youtube.com/watch?v=r0zpqhhcmp4</a>

« Last Edit: December 25, 2014, 11:26:58 AM by dsquire »

Offline Lew_Merrick_PE

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Re: How to make or modify a small fuel tank?
« Reply #1 on: December 25, 2014, 11:36:05 AM »
Pekka,

If a 40 cm cube is your package limitation, why not just get a piece of (say) 154 cm X 41 cm sheetsteel (call it 16 gauge or 1.5mm thick) and form up a square, flanged piece that will mate to (2) 40 cm square pieces.  You could silver solder, braze, or weld that assembly and, for the "base" part, fill in any openings using a high quality true epoxy (JB Weld is the true epoxy sold on this side of the pond) as the seal.  Assuming that the "top" only needs to be splash tight, a similar "fill" from the outside should do the trick.

Just about any sheetmetal shop that does "ducting" for buildings should be able to do the forming for you.  Assuming it as a "flange out" type of construction, you would end up with (38 * 38 * 39 =) 56.3 l of capacity.  ???  Obviously, you could reduce the size to end up with your 20 l capacity.

Offline PekkaNF

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Re: How to make or modify a small fuel tank?
« Reply #2 on: December 25, 2014, 12:13:46 PM »
Thank you Lew,

I had this big idea of using something ready made and just modify it a little bit. But if it is hard to find a almost perfect semiproduct then I might go all the way.

My brother can weld AL and stainless steel, then it comes down to where to get the sheetmetal and fittings. It might come down to that and design to minimize weld seams.

Pekka