FridgeFreezer Posted February 16, 2007 Share Posted February 16, 2007 Due to (ahem) a few light mods to the 109 the rear mounted fuel tank won't fit anymore (winch cradle in the rear X-member), now in an ideal world I would ring Allisport up and get a pukka blingy one made. However, money is tight and I've gotta get the thing wired, plumbed, and through an MOT yet Under-seat tanks are not really an option - the battery box is one side, the other may end up having the stock hydro tank bolted back in for the winch. Either way I don't especially want gallons of fuel sat under my arse, and the stock SWB/90 tanks stick down too far especially for a vehicle that has a (marginally) lower breakover angle. I have a decent MIG set and would make the tank out of slightly thicker steel than the OE ones, both for strength and to crank up the volume on the welder a bit. The only reference I can find on google is this guy who seems to have lived to tell the tale, and after sorting a couple of poor welds (TBH his welding Fu seems a bit weak ) it held fuel OK too. So, if I set about welding my own fuel tank together is it going to end up like a chocolate teapot or is it not too hard to make it hold fuel with a bit of careful welding? Secondly - assuming this isn't a suicide mission - anyone got any info/links to fuel tank and baffle/pickup design? Quote Link to comment Share on other sites More sharing options...
Lewis Posted February 16, 2007 Share Posted February 16, 2007 Didnt RogueVogue make one for the bishtail, theres a thread around here somewhere . . . here Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 16, 2007 Share Posted February 16, 2007 IMVHO Mig coiuld be a nightmare, slightest pin hole = leaky TIG is your answer, all of a sudden I am relieved I can't TIG Nige Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted February 16, 2007 Share Posted February 16, 2007 More than do-able, Ive had a few homemade/designed ones, all worked fine. In fact DD is making a mother of, as we speak. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 16, 2007 Author Share Posted February 16, 2007 IMVHO Mig coiuld be a nightmare, slightest pin hole = leaky I realise I will have to strongly align the welding Chi and employ the leak test / patch-up method but the price of an Ali one buys a lot of fab time. Also there's a voice in my head saying if LR can stick a steel tank made of tinfoil together then I should be able to do something that will hold unleaded. For persistent pinholes there's always POR15 fuel tank sealer, if their paint is anything to go by you could line a cardboard box with it and call it "job done" Quote Link to comment Share on other sites More sharing options...
Lewis Posted February 16, 2007 Share Posted February 16, 2007 In fact DD is making a mother of, as we speak. Really? Tell him to get on with the horrible yellow thing Sorry, back on topic now Quote Link to comment Share on other sites More sharing options...
Mark Posted February 16, 2007 Share Posted February 16, 2007 John, Nick (rougevogue) has made a couple of tanks recently, one for Bish, and one for Rocker. I saw Rockers one during build, and it had baffles in with 'one-way-ish' valves. Anyway, it was all made of steel, but I can almost guarantee it was TIG welded rather than MIG'd. I have also used the POR15 fuel tank liner, as sold by frosts, and it does work for porous tanks! Just my 2p Mark BTW get some bleedin pictures up og the 109 will you??? Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 16, 2007 Share Posted February 16, 2007 It's a very long time since I made a fuel tank. Mine was made for my Sunbeam rally car and it fitted in the spare wheel well. I used ordinary mild steel. I think I just soldered it. Mig wasn't an option in those days You could get then as well some tinned sheet steel that they used for repairs to fuel tanks. I wonder if it's still available. I did baffle mine. Lengths each way inside. About quarter of an inch from the bottom. Also because the filler neck was very near the filler pipe I made a baffle to rtry to stop the petrol flowing back up the filler. Yes it did work to my suprise. My fifty pence worth mike FOAK Knickers I can cause trouble in an empty house !!! Quote Link to comment Share on other sites More sharing options...
Diff Posted February 16, 2007 Share Posted February 16, 2007 I have made fuel tanks too. Very straightforward if it is a regular rectangular shape. Used mild steel and a mig no problem, though oxy on the end plates(edge welds is easier). I found the best way is to fold a sheet so that you only have one overlap weld along the length(at the top). It helps if you punch/drill a line of holes in the top part of the overlap which you can use to do a line of plug welds to hold the overlap together before you do the long overlap weld. Then I made two end plates with folded edges(this gives extra rigidity and easier welding). Pushed the end plates into the ends of the tank with the folded edges facing outwards so that the edges were flush. Then welded the edges. For baffles, I made plates the same as the end plates but with the corners cut off, and pushed them into the tank and welded them in place before I welded the end caps in. Fittings etc will depend on what you are using, but are fairly straight forward. If you use fairly thin steel you may need a reinforcing ring welded to the tank with captive nuts if necessary for fuel pump, sender or whatever. Complicated shapes are fiddlier, but try to fold as much as possible out of one sheet to minimise the amount of welding. Good luck! Regards, Diff Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 16, 2007 Author Share Posted February 16, 2007 The shape would be something like this: Although I may kick the deep end back up a bit so that the low point is roughly 2/3 of the way from the rear rather than at one end. The rear X-member has a winch cradle in it now so is less tall then the original, and the intermediate x-member was so close to the back of it I chopped it out and re-did it a bit further back out of 40x40 box (with spreader plates to the chassis) so as to allow max fuel tank space. Is there any mileage in MIGing the thing together then using one of those "Bernz" brazing kits to sort of double-seal the joins? Or even using domestic solder (or are we into 02GF74 territory there?) Quote Link to comment Share on other sites More sharing options...
landy_andy Posted February 16, 2007 Share Posted February 16, 2007 Hi, How about these.... http://www.tek-group.co.uk/acatalog/Fuel_Tanks.html If your just after a regular shaped tank then they might be a good option. Alot cheaper than a fabricated tank and very robust. Cheers, Andy Quote Link to comment Share on other sites More sharing options...
Steve Hiatt Posted February 16, 2007 Share Posted February 16, 2007 A bit of diesel in a new tank tends to show any leaks and it's easier to re weld than when petrol has been in it. Alternatively, finish potting my cut out, I'll give you some money and bend Allisport Andys arm for a discount for you. Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted February 16, 2007 Share Posted February 16, 2007 A good way of leak testing the tank is to use compressed air, and submerge the tank in water to check for leaks. I've had no trouble mig'ing fuel tanks up. Quote Link to comment Share on other sites More sharing options...
dollythelw Posted February 16, 2007 Share Posted February 16, 2007 weld spy, two cans in stores - its a 6:30 start tomorrow BTW John Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 16, 2007 Author Share Posted February 16, 2007 There's a 6:30 in the morning? Got a 4.6 in the boot (thanks Nige!) and a big trailer on the back (thanks Rich!) so all "go" for a weekend of pain hard graft. Quote Link to comment Share on other sites More sharing options...
reads90 Posted February 17, 2007 Share Posted February 17, 2007 Due to (ahem) a few light mods to the 109 the rear mounted fuel tank won't fit anymore (winch cradle in the rear X-member), now in an ideal world I would ring Allisport up and get a pukka blingy one made. However, money is tight and I've gotta get the thing wired, plumbed, and through an MOT yet Under-seat tanks are not really an option - the battery box is one side, the other may end up having the stock hydro tank bolted back in for the winch. Either way I don't especially want gallons of fuel sat under my arse, and the stock SWB/90 tanks stick down too far especially for a vehicle that has a (marginally) lower breakover angle. I have a decent MIG set and would make the tank out of slightly thicker steel than the OE ones, both for strength and to crank up the volume on the welder a bit. The only reference I can find on google is this guy who seems to have lived to tell the tale, and after sorting a couple of poor welds (TBH his welding Fu seems a bit weak ) it held fuel OK too. So, if I set about welding my own fuel tank together is it going to end up like a chocolate teapot or is it not too hard to make it hold fuel with a bit of careful welding? Secondly - assuming this isn't a suicide mission - anyone got any info/links to fuel tank and baffle/pickup design? Speak to Tonk he has made his own Quote Link to comment Share on other sites More sharing options...
steve b Posted February 17, 2007 Share Posted February 17, 2007 hi, i made both my tanks mig welded no probs clean metal n good joint alignment are key imho....and i used 2mm baffles are in the bottom and are 100mm high. leak test with air 5-10psi n washing up liquid cheers steveb Quote Link to comment Share on other sites More sharing options...
Corrode Finger Posted February 17, 2007 Share Posted February 17, 2007 stock SWB/90 tanks stick down too far especially for a vehicle that has a (marginally) lower breakover angle. But surely you have fitted portals, does this not negate the breakover angle problem? If the old tank is only just too big, have you thought about modifying the existing tank by shortening it? Ok, you have to wash and clean the tank of vapours etc, but it must be viable. Quote Link to comment Share on other sites More sharing options...
Tonk Posted February 19, 2007 Share Posted February 19, 2007 Ali or mild steel tank is best tig'd IMHO, it can be done with mig but leak test it once finished, either with pressure testing or dyepen. Quote Link to comment Share on other sites More sharing options...
Jon White Posted February 19, 2007 Share Posted February 19, 2007 There's a 6:30 in the morning? Got a 4.6 in the boot (thanks Nige!) and a big trailer on the back (thanks Rich!) so all "go" for a weekend of pain hard graft. Hard graft?? You didnt look dirty enough when i bumped into you on saturday! Jon Quote Link to comment Share on other sites More sharing options...
landybehr Posted February 19, 2007 Share Posted February 19, 2007 Hi, isn´t hot dip galvanizing an option ? There may be problems with bending of greater plane sheets of steel under the heat, and there must be any possibility for the zinc to drain. But the zinc should kind of seal every tiny holes - even small gaps. And you do not have to paint it I remember there were some arguments against, can´t recall. Think it had to do with Diesel fuel and some additives acting with the zinc. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 20, 2007 Author Share Posted February 20, 2007 Well, the Stig reckons he can glue it together with the MIG - and if that fails there's a TIG too. Quote Link to comment Share on other sites More sharing options...
Les Brock Posted February 20, 2007 Share Posted February 20, 2007 The tank I used in the Hybrid was welded by myself with a mig I had one tiny pinhole withwas cured with a quick blact from the torch......so If I can make one Stig should have no trouble Put two baffles in, fitted a internal collection pot for the V8 (much like a swirl pot) etc Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.