Well I planned on running an aluminum cell from Summit (20 gallon). It does not fit so I am sending it back. I am thinking of bending up my own out of 18ga steel, so I can have it fit perfect. Where can I buy the sending units and fuel cap kits? Should I just drop down to a 15 gallon cell and live with mor efrequent stops? The 15 gallon cells will fit fine. Actually the 20 gallon cell will fit fine if I turn it sideways, which is why I am thinking of just making my own out of steel. Any thoughts or suggestions? Are there any other companies out there to shop? I have tried RCI, Summit, Jegs, Rock Valley. I suppose I could get Rock Valley to custom fab me one out of stainless but, they are NOT cheap. I suppose I could make my own out of stainless as well.

Royce:

I've built my own fuel tanks for years and a few cells for our earlier race cars.
Check out ATL's site - http://www.atlinc.com/racing/page20.htm - for parts like filler necks and bladders.

John

ps: Sorry I missed GG's - I was gonna contact you to see when you'd be there, but ran into "issues" with the boat and cabin in Donner that took me more than a week to resolve - well almost resolve, I'll be up there again this weekend doing the follow-up stuff...
Glad to hear it was a good show and congrats on your coverage in GG's 2004 Annual. :thumbsup:

www.chassisshop.com has "easy turn fill caps" that are weld on, you can get them as large as 2-3/4 and are $32 with the cap.

I'd personally build it out of aluminum becuase it will be light, and wont rust. And aluminum looks nice.

Thanks John and Brian. Those links have the info I was looking for. I will keep searching and if I can't find a cell to my liking I will build my own.

John,
Sorry about your issues with the boat and house. While the Goodguys show was nice, the swap meet was pretty skimpy. There were a ton of cars for sale in the car corral. A lot of overpriced stuff as usual but, there was a real nice 73 Z28 (no engine) for $4,500 (it was clean, silver). I was very tempted.

Brian,
You're right aluminum would look better and be lighter. I am not worried too much about weight at this point. I think the car is going to be pretty light. If I end up bending up my own cell I will either use stainless or aluminum. I have heard of guys have problems with aluminum cells cracking. I don't see why they would if installed correctly.
Thanks!

I have heard of guys have problems with aluminum cells cracking. I don't see why they would if installed correctly.
Thanks!

I've used aluminum for several applications and it can be a real B1tch...
It is easy to form and cut but, a bear to get the welded areas to hold up under certain use, like around brackets, mounts and jointed corners.
The modulus of the metal is greatly disturbed when doing aluminum fabrication and if you don't get the metal back to a stress free state you are going to eventually get some cracking in my experience.
My Eliminator boat (the trouble-free one... :D ) has aluminum fuel cells and they have developed cracks over the years that have required repairs and finally the replacement of one of them. The pounding they take in the boat is bound to have caused some of this but, the newer models now have blow-molded tanks to get away from the cracking aluminum.

I have considered stainless for the next time I need a tank also. It fabricates well and is relatively easy to weld. I think the polished look would be a plus also if it's in a visable area.

Hey - was that 73 'Z' an RS?

John

ps: "Sorry about your issues with the boat and house." Oh - it was nothing 36 bags of concrete and a few trips to the MasterCraft dealer couldn't take care of... :clonk:
Thinking back - maybe I should have just put the 36 bags in the boat - then sat back and popped open a beer... :beers:
But then I would have just gotten a big fine for polluting the lake... :sad:
I might even get in a few ski runs this weekend :thumbsup:

John I am pretty sure the Z was an RS as well. I tried to keep my distance so I didn't end up bringing it home. The more I think about the more I wish I would have taken a real good look and made the guy an offer. If nothing else I could have made some money by re-selling it.

Good point about the aluminum cell and why/how they crack. I have talked to guys in the past that had them in their cars and most of them said they wouldn't do it again.

I might have found one that is made by JAZ, I have to call Chassisworks to make sure it's what I am looking for. I will have to add a sending unit (no biggie).

They might not have fined you for adding to the fish habitat, LOL. All the work usually is worth it in the end. You'll forget about all the hassle when you are out there skiing.

A tip: Use 2024 or 5052 alum for bending. Inside bend radii should be no less than 3X material thickness. Bend in segments, may have to apply heat.

Have you considered using fiberglass? There are a few guys at the airport here that make home built planes like the VariEze and J-3 Cubs. They use a block of styrofoam and shape it to the size they want. Then they attatch the fillers and guages to the styrofoam. When everything is ready they layer it with fiberglass to the thickness they want. After the fiberglass has set up they slowly pour gasoline in and the gas dissolves the styrofoam. They rinse them a few times with gas and put it in the plane. I have seen them do it and it really works good.

No way would i bend the aluminum, but rather weld all the joints.

Everett thanks for the tips I will keep that in mind and I'm sure it will come in handy in the future (even if I don't use it now).

Deerhunter, That is a pretty slick idea, never thought of that.

Have you considered using fiberglass? There are a few guys at the airport here that make home built planes like the VariEze and J-3 Cubs. They use a block of styrofoam and shape it to the size they want. Then they attatch the fillers and guages to the styrofoam. When everything is ready they layer it with fiberglass to the thickness they want. After the fiberglass has set up they slowly pour gasoline in and the gas dissolves the styrofoam. They rinse them a few times with gas and put it in the plane. I have seen them do it and it really works good.
most fuel cells use a blader to keep fuel spray to a mimimum in case of a rupture right?is there an air space required around the bladder for flow efficency reasons?
if not,could the glass be moulded around the bladder itsself?
if fiberglass really impact resistant enough to serve as a fuel cell in a sport that has it's share if high impacts?
nhra got anything to say about this?
if it all checks out i could see some really sweet fuel cells in the VERY near future!
(applying for patent as we speak)
Eric B

Eric,
I will check the rule book.

Brian,
The aluminum fuel cells you buy are bent and only welded where needed. I just returned one to Summit. It would not fit like I wanted. Iwas all bent (one long weld on the side) and then the ends and sump were welded on. I'm sure that makes it easier to build and gives you that much less chance of a leak. I am sure it's cheaper too.

I'd probably go stainless too . . . it is easy to weld, just have about 4 or 5 times the number of cutoff wheels handy that you would normally use when fabricating steel. For some reason stainless seems to chew them puppies up quick.

Eric, You're right stainless is tough stuff and likes to work harden. I just bought a shear so hopefully I won't have to use many cutoff wheels. Stainless is also a good way to chew up drill bits. I will run by the supply house today and see what they have for stainless sheet. The only other problem might be getting stainless bungs (NPT). I kow they make them I will just have to figure out where to get them.

The only other problem might be getting stainless bungs (NPT). I kow they make them I will just have to figure out where to get them.

Royce:

The bungs and fittings really shouldn't be a problem. "Google" the brand name 'Swagelok' - I use them everyday and they are available from all the common local suppliers, like Grainger and MacMaster-Carr as well as most industrial piping/fitting stores (there's got to be one near you - that 'Buttwiper' plant right across the freeway has to use a ton of them... :D ).
They come in all the common pipe sizes and thread fittings (NPT & ect...) with several confiqurations in each type.
I happen to like the NPT/Compression ones for fuel plumbing alot :thumbsup:
If you have problems finding them or need a couple samples of sizes let me know.

Hope this helps;
John

(edit) Here you are - http://www.swagelok.com/ - I just 'googled' it myself...
John

Cobalt drill bits and McMaster-Carr for the bungs.

John,
I didn't even think about Swageloks, I have used them before and I actually have a few out in the garage. they are VERY nice fittings. I also have access to a Grainger. Well that about covers it. No more excuses to get this thing done. If the one that Chassisworks has doesn't fit my needs I will grab some stainless sheet and go for it.

I had never heard of McMaster-Carr before. WOW they have lots of goodies. I had to bookmark that site. Thanks for the info.

Use AN fittings since that will be what the rest of the fuel system uses. I'd think that the companies making aluminum fuel cells are bending them becuase it costs significantly less then welding the corners.

I wouldnt expect a good aluminum weld to leave a chance at leaking, personally, i like aluminum, maybe everyone else is against it, and maybe for good reason. The two i deal with (not in my car as i have a stock tank) work fine, and i like them.

Stainless sheetmetal is a little tricky to weld and keep it straight, stainless moves more from hot to cold then mild steel does. Be prepaired to "back-up" any seem welds with a peice of aluminum so that the interior of the weld is nice and clean, and the weld stays straight/smooth. Tack it ALOT before you weld a seem, and keep it cool (not cold, but dont overheat it). EXCELLENT Argon coverage is a MUST have to get good color in the weld and prevent burning the nickle out of the stainless. Typically you must use a filler wire of the same grade or better, i prefer TIG welding it with .035 wire. Stainless is a very nice metal to weld, it welds cleanly with minimal or no surface prep.

However between the two options i wouldnt consider anything except Aluminum in this application, just my opinion.

Stainless sheetmetal is a little tricky to weld and keep it straight, stainless moves more from hot to cold then mild steel does. Be prepaired to "back-up" any seem welds with a peice of aluminum so that the interior of the weld is nice and clean, and the weld stays straight/smooth. Tack it ALOT before you weld a seem, and keep it cool (not cold, but dont overheat it).


I agree with this 100%

I've had good luck MIG'ing it with 20 scfm tri-mix coverage and normal mild-steel type wire speeds. I like the fine .023" wire personally for the thinner stainless sheet metal (good for detail), but like Brian said you have to keep the heat down.

Sounds like you already know what's up with welding stainless though ;)

Keep us in the loop for sure -- I'd like to see pics of your progress if you have the time to post them.

Brian,
You're right about using AN fittings and that's all I use. You have to have a place to screw in the AN fiitings. Maybe there are some stainless AN fittings out there I just haven't come accross any. This is why I would use a pipe bung and screw a pipe to
-10 (and -8) fitting into it.

There are pros and cons to every material. I have the mild steel sheet in the garage so it's paid for. Mild steel is just not as pretty (I have all the welding supplies on hand for that as well), I probably have enough aluminum sheet or close to it to make the cell but, aluminum is a little harder to weld and there chance of it cracking is going to be there. Stainless is not cheap, I don't have it on hand, would have to buy some rod to weld it (or wire if I decided to MIG it), it looks so nice when polished but, weighs more than aluminum.

I know for sure I have to make my own cell now, so that part of the process is done. Now I just have to figure out what works best for me. A nice powder coated steel tank wouldn't be bad but, you have to worry about rust. decisions, decisions. I'll keep you posted on what I decide.

I agree with this 100%

I've had good luck MIG'ing it with 20 scfm tri-mix coverage and normal mild-steel type wire speeds. I like the fine .023" wire personally for the thinner stainless sheet metal (good for detail), but like Brian said you have to keep the heat down.

Sounds like you already know what's up with welding stainless though ;)

Keep us in the loop for sure -- I'd like to see pics of your progress if you have the time to post them.

i have a little practice :D aside from working at the machine shop now only 2 days a week, I TIG weld stainless a solid 8 hours a day 3 days a week. I use .035 becuase its the smallest we have for TIG, you guys know me, i dont mig anything really.

Yup, swagelok has some awesome stuff! :)

If you make a fiberglass cell, won't you have to coat the inside of it with something so it won't corrode?

Also I wonder if there's a way to insert foam into it, so its much safer than a blader? Hmmm.

Try McMaster Carr for stainless 37* fittings. They aren't cheap, but I'm pretty sure they have them.

ps. try here

javascript:displVstrBmsNav('516427114326','2005-06-09 07:31:54.460','Main','McMMain');

Sorry the link doesn't work, but try searching for 37* and stainless at www.mcmaster.com or go to page 127 of their catalog

Try McMaster Carr or go to page 127 of their catalog
You must include catalog number as they change it every 6 months. What is on your Page 127 of your catalog # is not on mine or others' Page 127 of their catalog.

Royce, after welding tank together, regardless of material used, fill it with lacquer thinner to the top, cap it off (seal it), and set it in the sun. This will heat it up and pressurize it to show you the leaks. Lac thinner has a smaller molecule than gasoline. If checking a light colored material, sprinkle joint with talc powder or Martha White flour to look for dampness.

I don't suggest applying shop air to pressurize it as you don't know if it will explode or not, why take the chance? Unless you have a strong containment box and a long hose to fill from afar, this is why I suggested the sun.

Eric, I will search for the fittings I would not be surprised to see they had them. That place is awesome I can't believe I never heard of it.

Everett, That's another excellent suggestion (laquer thinner). Of course we both know there will be no leaks right? LOL

I have been doing a bit of research and with all the things suggested hear and what I have found by searching, it looks like 304 stainless is the way to go (as far as stainless steel goes). I believe 20ga is what is most widely used as well (pretty thin stuff).

The Triangle Engineering aluminum cells are .090 thick. I'm heading back to the supply house today to see what options I have. If I used a little thicker aluminum I would think cracking would be much less likely.

20 gallons or so of laquer thinner huh?

Just curious how much 20 gallons of laquer thinner would cost and what the heck you would do with it all when done? LOL

Maybe pressurized water would work? You know, like the good old-fashioned drop test?

Yeah that is a lot of thinnner.

I was taught to use light air pressure and then use soapy water and spray all the welds/joints. Look for bubbles, kind of like fixing a flat tire/tube.

I will have a little while before I have to worry about a leak test. I would like to get it done this weekend but, I have a softball tourney on Sunday so I know I won't have time to finish it. So I will shoot for next week. If I can decide on a material and get it cut and bent by the weekend I will be happy.

Air and water can't get into the small spaces as lacquer thinner can. Check the chart. Like I said, the smaller molecule will get into smaller places.

You can get used lac thinner from most any body shop for free, the less thet have to pay for hazmat disposal. Buy a new gallon of lac thinner from the paint store for rinsing out the old.

Try it sometime for a science project.

I am not doubting you at all that laquer thinnner will do the job. That is just a lot of thinnner. Once I'm done with it how do I get rid of it. If it was all new I always have a use for it, but 20 gallons is a lot. Why not use gas? I can always put it in another vehicle and burn it up. I understand laquer thinner may be "smaller" but, as long as it hold gas that should work right? Are you saying laquer thinner is "finer" than air? I don't know anything about this type of stuff.

One other point, what if it leaks and I need to repair where I messed up, once I put a flamable liquid in it, doesn't that become an issue for welding?

:D

Everett,

20 gallons or so of laquer thinner huh? :D

:D Well, if all your going for is a lower Kouri-Butanol/Hilderbran Number than for Water (@50) you might as well try using IPA/Alcohol (@20+) vs Tolulene/Xylene (@19), it will be much cheaper, safer and easier to clean up (water soluble) ;)
Liquid Freon* (@15) would work well also but, it's so hard to find - I only have @5gal left...
Now if you can get your hands on @20 gallons of Pentane ... :thumbsup:

I agree that with your known welding skills, and a little 'air assist', water would probably be just fine to check for leaks.
Maybe even easier would be to check just like a tire/tube as you refered to - just inflate the kiddy pool and lower your new 'cell' into it with a little air pressure inside and viola - leak test...
I use the "POR-15" 'U.S. Standard Tank Sealer' in most the tanks I've done. The stuff isn't to expensive and it would/should/did/has :confused: taken care of any pin-holes I may have left in the tanks. A Qrt. does nicely on most tanks.
I'm looking forward to seeing where this goes... :waving:

You might want to check out the "259" line of AeroQuip $$ fittings.
Something like a 259-2089-8-8 (90) or a 259-2088-8-8 (45) might give you something you could weld in and give you threads on the inside to attach a pick-up if needed. Anyway - they have quite a few choices in fittings that might work well for you.
They are sold through Eaton Distributors to the industrial/aircraft industry under the 'FluidPower' line. The automotive applications are usually just available in aluminum.
The only "local" distributor I've used is Globe-Pacific in San Jose. We used to have a corp. account there but, I think they do counter sales also.
You might also 'google' "SSP" fittings, they made some of the fittings we used in process equipment.

Can't wate to see some pictures of your efforts - this may be a new sideline for ya :waving:

Hope you have a great tournement this weekend :thumbsup:
Getting ready to head back up to the mountains - as soon as the snow/rain stops this afternoon...

John

Thanks John for the other cheaper suggestions Toulene would be good.

Royce, you looking for a smaller molecule than gasoline to find a leak. The smaller molecule, the smaller hole the gas will find. Vacuum industry uses helium-filled volumes and "sniff" with a helium leak detector to find a leak. This is when you're trying to locate a leak with leakage rate of less than 1/2 cc per 4 years. Granted, your tank won't show this leak within our life, but lac thinner, and other liquid from the same family, have a smaller molecule than gasoline.

To answer your question in how to rid of flammable vapor/liquid, pour out the liquid, then dilute the interior with exhaust gas, an old trick used to "deaden/clean out" gas tanks before working upon the same.

Maybe I'm going too extreme.

Don't get me wrong this is neat stuff. My question was is air larger than thinner? Or is air even measured that way. As you can see this is not my background at all.

The few times I have welded on fuel tanks, I didn't test to the degree you are mentioning. I am always up to learn something new. I have heard of the exhaust gas method which removes all the oxygen (no oxygen no fire). Dry ice also works well.

I might be fine with a quick, air/water check and then coating the inside of the tank with Kreme. This is what is used to seal motorcycle tanks.

At the rate my engine burns gas I will run out long before it has time to leak much, LOL.

At the rate my engine burns gas I will run out long before it has time to leak much, LOL.

:beers: Sorta like an SR-71 then... they leak alot - but, still burn more than they can leak :D

Yes, 'air', or most gasses, have much smaller structures than liquids and will "leak" well :thumbsup:
You can get a low pressure tank of He (Helium) at 'CostCo' for balloons pretty cheap - and I have a "sniffer"... or you can just go by the old 'voice change' method :waving:
We used 'He' to check for leaks on production equipment all the time - "leaks" well and, most importantly, isn't Flamable ;)

All this just proves there is more than one way to 'skin-a-cat' - finding someone/someway to hold on to it is the hard part... (JK all you animal lovers - my kitty is asleep, do they do anything else :confused: , right here next to me on the desk.)

John

Well john once I get to the point of testing for leaks I may call on you. I think I will be able to figure something out without blowing up the garage.

I went to the supply house today and decided to go with stainless steel (not cheap). Brian you are right aluminum would have been a LOT lighter. At least where the weaight is going to be placed is about as good as you can ask for. Behind the rear wheels. I still don't know how much the cell will weigh when finished. I bought way more than enough material (59lbs worth of 20 gauge). Hopefully my cell will weigh less than half of that. Even if it's heavy it will look pretty and out live me.

Time to get out the construction paper and card board and make up my templates..

Yeah, the idea is to pressurize the tank with air only and use soap and water solution on the outside to find pinholes. You aren't trying to make the soap leak through pinholes; the air is leaks through and the soapy water is just helping you find the air as it escapes.

Or you could use a radioctive isotope on the inside and X-ray film on the outside just like they do submarine hull welds . . . ;)

Well john once I get to the point of testing for leaks I may call on you. I think I will be able to figure something out without blowing up the garage.

I went to the supply house today and decided to go with stainless steel (not cheap). Brian you are right aluminum would have been a LOT lighter. At least where the weaight is going to be placed is about as good as you can ask for. Behind the rear wheels. I still don't know how much the cell will weigh when finished. I bought way more than enough material (59lbs worth of 20 gauge). Hopefully my cell will weigh less than half of that. Even if it's heavy it will look pretty and out live me.

Time to get out the construction paper and card board and make up my templates..

ethier way a cell would still be lighter then a stock tank. Whats the plan for welding the tank, will you be TIG welding it?

I will be TIG welding it. If my car was strictly a race car I would not be making the cell out of stainless nor would I be making it as big as I plan to. I will drive this car just like I did my Camaro which means long trips and no trailer. Stopping every 125 miles was getting old (16 gallon cell with foam, held about 14 gallons on a good day).

Feel free to offer tips and tricks, I only want to do this once. Also stainless is a bit expensive to make mistakes on.

What's the shape of the tank in mind and where will it mount?

Doing a construction miniature tank is a good idea. The more panels you can bend from one piece, the better.

If you could make two sheets to do half the tank, one half is two sides and the top, the half is the other two sides and the bottom. all's well. This providing your sheet metal brake is of a size for compound bends, more than two bends and deep throated.

There a number of possibities for the tank layout on a flat sheet. The flexibility of the metal working equipment available will determine the process used to construct the tank. My suggestion is at each 2-sided and especially 3-sided corner to be bent, punch/drill a hole/diamond at the corner to prevent build-up of material when bent. Min size of hole will the thickness of the sheet.

Alum, depending on the alloy weighs approx 0.44-0.46 lbs.per sq./ft. for a 0.032" thick.
Stainless steel, depending upon series, 20 ga. (.036") is 1.51 lbs./sq. ft.

Now the further away from the rear axle, the more affect this weight will have on weight transfer.

The tank will be a rectangle and will be mounted in the trunk as far back as possible and as low as possible. I still have to take final measurements to see just how far behind the axle it will be.

The tank will be about 26" wide (side to side), 18" long (front to rear), and 10" tall.

What I had/have planned is to bend the "main body" (top, sides, and bottom) out of one piece and then weld on the ends (front and back). Does that sound OK? My break is 48" wide and is a pan/box style break. I would not be able to bend a "box" that deep. After looking at the aluminum cell I returned this is how it was made (as decribed above).

Would there be a problem if I use AN style fuel cell fittings, the kind with the washers and nut? (similar to a bulkhead fitting). This would be cheaper and easier. Not that a few bucks is going to make a difference. I can order them through Summit and have them here Monday. This would prevent me from having to chase down stainless (weldable) fittings. I would just have to drill the correct size hole and install the AM fittings. This is the type of fitting used on all the "poly" fuel cells.

Personally, I'd would not use bulkhead fitting. I'd weld a bung or two on the plate. The reason being of electrolysis between the two metals, if different, and introducing another location for a leak. Weld them on and it becomes one piece.

I'm surprised McMaster-Carr didn't have what you were looking for in fittings.

You may want to rethink the rearward location of 470 lbs of your 21 gal tank. It may be too far back, meaning a big lever of weight in relation to the rear springs. I would probably put it where the trunk incline is out. Cut it out and install tank at the same level as the top of the shocks.

Food for thought.

You are asking me questions that I do not have answers to. Sorry. I do know there are a lot of planes flying around the country that have used this method.

Have you considered using fiberglass? There are a few guys at the airport here that make home built planes like the VariEze and J-3 Cubs. They use a block of styrofoam and shape it to the size they want. Then they attatch the fillers and guages to the styrofoam. When everything is ready they layer it with fiberglass to the thickness they want. After the fiberglass has set up they slowly pour gasoline in and the gas dissolves the styrofoam. They rinse them a few times with gas and put it in the plane. I have seen them do it and it really works good.
Sorry for the late response. I do not have answers to your questions as far as the NHRA goes. I do know there are a lot of planes flying all over the country that have these tanks. I would think that a person could build a mold around the bladder as well as creating a tank. If you ever get the chance to go to the annual fly-in at Oshkosh(?) you will find lots of them in the homebuilt section.

Yup, swagelok has some awesome stuff! :)

If you make a fiberglass cell, won't you have to coat the inside of it with something so it won't corrode?

Also I wonder if there's a way to insert foam into it, so its much safer than a blader? Hmmm.
Actually your first coat is gel and then you start putting on the cloth with gel to get the thickness and finish with gel. The inside turns out real smooth and the outside can be painted any color you like.

Royce, I'd get the stainless ones and weld them in. Just about all the bulkhead fittings I've seen on the plastic tanks weep a little. If you are going through the trouble to build a really trick SS tank, I'd go the extra mile and put the "right" fittings in it.

Are you going to put any kind of sump in it? Or will it just match the contour of the trunk floor?

It's a shame I don't have access to a TIG anymore. :( My dad's shop has 3 different brakes, big 'ol shears and what not. This is making me want to build a cell of my own. :D

OK I will find and buy the stainless fittings then and weld them in, not a problem.

Everett there is no way I can get my tank even with the top of the shocks. I think there is a picture or two of the area I have to work with in my photos (I'll post one if I can find it). The trunk is not very big anymore, due to the cage, frame, shocks the body sits down over the frame, hard to explain. Where did you come up with 470lbs? 470lbs/20gallons = 23.5lbs per gallon. That can't be right, can it?

Yes I will put a sump on the tank. I will "add" it after the main tank is done. I will use a hole saw to put several "baffles" in the bottom and then weld on the sump. This is how I have done it to stock tanks. It keeps the fuel from sloshing near the outlet and also helps to prevent starvation, during breaking or hard acceleration.

I will get on the McMaster-Carr site and see if they have 37* fittings, I didn't check yet. I may also be able to get them locally at a automitive plumbing/hot rod shop, I will give them a call.

Guys I found a place that has all types of stainless AN type fittings. The prices are good too. It appears to be Earls products. Anyway here is the site http://www.anplumbing.com/ I ordered the stainless fittings to weld into the tank.

Where did you come up with 470lbs? 470lbs/20gallons = 23.5lbs per gallon. That can't be right, can it?
Yes, you're right, 21 lbs for the tank, 21 gallons of fuel at 8 lbs./gal, all = 189 lbs. Fat fingers on the calculator.

Baffles are good.

I will be TIG welding it. If my car was strictly a race car I would not be making the cell out of stainless nor would I be making it as big as I plan to. I will drive this car just like I did my Camaro which means long trips and no trailer. Stopping every 125 miles was getting old (16 gallon cell with foam, held about 14 gallons on a good day).

Feel free to offer tips and tricks, I only want to do this once. Also stainless is a bit expensive to make mistakes on.

1/16 or 3/32" 2% thoriated tungsten

.035" wire, same grade or better

What torch do you have now and what nozzle?
WHat is your argon flow meter set to?

The plan should be to get perfect Color and a nice smooth bead the first time so that you dont need to clean/grind ANY welds, or polish the stainless.

Make certain you back up EVERY weld with an aluminum back-up bar.

On long welds, tack them alot, and clamp them alot.

The fit-up must be good enough that you can fuse the tacks, meaning, zero gaps, the last thing you want to do is fill a hole or a gap on a peice like this that alot of people will be focused on.

I have a Miller TIG with the diamondback torch (air cooled). I have several nozzles, different shapes and sizes. I have all sorts of tungstens including both you mentioned.

If you have a specific suggestion on which set-up I should start with feel free to post it. I will see if I have the proper combination. Before I ever lay a torch to any part of this tank I will mock up some practice joints to get the heat and speed down. I like the aluminum back-up bar idea and I will do that, how thick of a bar is needed. Would a piece of aluminum angle be good or a solid piece of bar stock?

What do you suggest the flow meter be set at for a job like this? When you say "wire" size are you suggesting I use stainless "MIG" wire as filler?

Fitting it is not a problem it will be right and tight.

You're right I don't want to grind any welds but, polishing is not a bad thing :-)

practice joints are OK, but stainless is different then steel. Aluminum angle is good where you can fit it, if you can get it into a spot, use the barstock.

1/8" thick aluminum is plenty.

the style of torch is unnesscary, i want to know what size....20? 17?

Dont use MIG wire, use TIG filler wire, just use .035. Head to your local supply and buy 2lbs of .035 to start with. Might be enough to do the whole job.

Do you have any gas lenses or just cups?

The smallest wire I could get was .045, I went to two welding shops. I do have some .030 stainless MIG wire as well.

The practice joints will be of the same material and type of joint.

I don't have a gas lense on the torch, I can get one if needed. I have all different style and size cups. I thought you said what "type" of torch do you have not what size. It is a #17

I have 3/4" bar stock, 1/4" bar stock, aluminum angle. I can get it to fit where ever needed.

.045 is too big for this project.

use the .030" MIG wire, however cut lengths of it and straighten it with your fingers before trying to use it.

A 17 is a big torch, probably becuase its an air cooled torch and a small one will overheat quickly. On this project no big deal, but if you're going to weld on the car, you should consider a #20.
I should have worded it differently earlier.

The aluminum you have will work perfect, use it everywhere you can so that the insides of the welds are all clean.

Email me and we'll speak about the gas lenses and argon flow.

Ok, I am back on the cell. All the fittings showed up late last week. I finished cutting and bending all the parts today. I made the main tank out of two pieces, top, front and back out of one piece, bottom and both sides out of another piece. While this came out very nice, it makes for a problem trying to back up the welds as Brian suggested. I liked the idea of backing up the welds but, I also like the idea of having fewer pieces.

I was able to make the sump out of one piece. I think I will tack it all up and then cut the hole for the fill cap, that will allow me to get a piece of aluminum in there to back up the welds (I just won't be able to clamp it).

The final measurements are 29" (wide) x 10" (high) x 16" (long) =4640/231 = 20gallons (not including the sump). The sump is a typical wedge shape 2" tall at the fitting end and 6" wide, 8" long.

Going on a family trip tomorrow so I probably won't get to start welding until Friday.

Will I be able to pull it off with my 2 piece design?

Oh yeah, Eric you were right this stuff is tough on griding wheels, I didn't have much grinding to do but, what little I did was a chore. It's not easy to cut either.

back them up definetly, it'll keep the material straighter. if this were a thick wall tank and wrinkling it werent a problem i would suggest and argon purge.

Cut the aluminum to fit into each spot.

BTW when finished all the welds should have a Gold color to them if the heat/speed are correct, as well it should have the right shape to the weld (slight convex) No undercutting.
Some darker colors are fine, when they turn grey you've burnt the metal.

I dont know how much TIG experience you have, so you may already know this stuff.

I have very little TIG experience. I have toyed around a bit that's about it. I have been ARC and MIG welding for a while as well as gas welding. I am fairly confident I will have no problems. Once I get my heat right I will be fine. Of course I will make up several joints out of scrap to practice on. If I have any difficulties I will post and if I can't get the hang of it I do know aa couple excellent welders. I just prefer to do all things myself even if that means less than perfect results. You just don't learn by letting other people do the work.

I appreciate all the input, I'll take more pictures and keep this thread updated until I'm done. I should be able to finish the cell this weekend.

i tig weld a solid 8 hours a day 3-4 days a week plus building my own fabrication projects in my spare time. I'm still no expert on it, however i have all the resources i need to get the important questions answered, You guys have seen my welds, and since then i've continued to improve.

However all that said, its not as simple as heat, its Heat/speed and feed. Heat soaks into the material, a slow weld with the same heat will burn what a fast weld with more heat wont.

Seriously email me, and i'll start you off with some settings on the machine and the torch/cones.
However i will say i've faught tooth and nail for some of this information and wont post it.

I understand that there is more to it than heat. That goes for all forms of welding. I have been told several times that if you can gas weld you can TIG as well. We'll see how true this is. While I haven't done much TIG, I have quite a bit of experience with the other forms of welding. I understand speed, feed, puddle, etc.. I was just saying once I get the heat right I can manage from there.

Like I said I am lucky I know two of the best welders around and if I wanted I could just have it done for free. Just not my style I like to learn, If I let others do my work over the years I wouldn't be able to weld at all not, to mention all the other things.

I will be glad to get all the pointers people have to offer. I will get out there and either make pretty welds or blow holes all over it. Either way I will make it happen, even if I have to start all over (wouldn't be the first time).

I think my e-mail address is public, feel free to offer advice. I will just warn you I don't keep secrets well. So if you don't want everyone else to learn with me don't share with me. I don't believe in keeping info from fellow hot rodders. I have no secrets and will give every detail of my combination to just about anyone.

Fair enough i'll keep it to myself. No hard feelings.

greedy are we?

no just tired of debating, so i dont need to introduce a new topic :D I dont mind offering help via email, but i dont want to debate the TIG topic as well as everything else i'm involved in.
You see my work, and i can offer more pictures of more welds, however i dont need or want to debate my procedures.

Thanks for the update Royce . . . :D just keep us in the loop.

I like your attitude about doing and learning to do things on your own . . . I'm the same way. I'd rather screw something up myself than pay someone else to screw it up . . . LOL

. . . one of these days I'm going to have to get a used TIG and start playing :D Sounds like fun