Building a new oval gas tank for mid 20's Buick

[Oregon Desert model 45]

I have been watching the efforts of other Buick owners to repair original gas tanks, and since I don't have a tank, building a new one  seemed like a good plan.  
First step is to build a slip roller machine.  There are lots of videos on u-tube showing how to build one. I decided to use bolt on flange bearings because I don't have a mill to bore a nice clean hole needed for press fit bearings.  My old SB lathe is just long enough to hold 30" roller pipe to true up. It took a lot of time to cut and machine all the fabricated parts, plus rounding up all the purchased parts and materials needed.  The steel yard closest to me has bins of cut off discarded steel chunks from local fabricators, including assorted sizes of round water jet cut outs that are very handy for making roller ends. 

With outside tank dimensions of 11-1/2" x 17", I figured the large radius must be 16" and small radius 5-1/4".  The calculated circumference is 46-1/2" which is perfect for shearing from 48" wide stock plus leaves an overlap of 1-1/2" after forming the oval. 
On my last trip to the steelyard I found some 20GA sheetmetal sheared to 12" x 48" and 9" x 48" which is perfect for a trial run.  I cut out a wood template for checking the 16" radius plus a pair of oval templates for checking and welding the finished oval shape.  Another pair of oval templates slightly undersized are needed to hammer form the ends and inside baffles. The actual rolling of the test oval took less than 5 minutes.  One improvement the sliproller needs is to fasten the threaded pusher to the adjustable roller slide mechanism so it will retract. I had to lift up the adjustable roller to feed in the sheetmetal.  
What gauge sheetmetal are the original tanks made from ?  Most of the body parts I have welded are close to 20 gauge (.036). 
Next step of the trial run will be hammer forming the oval. The 12" wide stock is a little too narrow for the edge flange, so I welded another 1" to one edge which will be a little troublesome when I start hammering over the weld seam. 
New filler necks are available from multiple sources.  I will have to figure out how to form a flange where it fastens to the tank. 
The drain fitting and fuel outlet fittings will be relatively simple to fabricate from round & flat stock. The fuel outlet should have a 11/16-16 internal thread for the fuel pickup tube bolt. The drain is probably threaded 1/8" NPT.  
The gas gauge fitting looks like it has a bell shape at the base and threaded on top for my Model 45. The top of this fitting is different for models with inside fuel gauge.  I will need base dimensions from an original tank to fabricate this fitting.  One of the inner baffles has a cutout to clear the float with dimensions which will have to be worked out after placement of the gauge fitting. 
The gas gauge will need to be fabricated, (thanks Larry D for making this drawing) and I have a stamping die to produce the gauge faceplate dome.  Gauge retaining ring and glass to be procured from Myersearlydodge.
Exact locations for filler neck, gauge, and fuel outlet will be determined by installing a blank oval under the frame and marking hole locations from the frame rear cross member holes. 
I think the end result will be worth all the effort, and for once I won't have to deal with welding old sheetmetal. 
Kevin 

[Oregon Desert model 45]

I measured the vacuum fuel pump inlet bolt and it is .675-20 which is an oddball size.  I was expecting 11/16 (.6875).  Typically when a manufacturer intentionally makes a part an odd size it is to force the mechanic to buy the correct part instead of substituting something else.  Also called idiot proofing.  This probably means the fuel tank outlet pipe bolt was originally the same odd size.   Since I will be making both the pipe bolt and tank outlet fitting, I will be making it 11/16-20 for which tap & die sizes are available. 

Kevin

[Robert Engle]

Great job!! You can  start a side business making gas tanks.  Did you consider making the tank out of stainless?

 

 

Bob Engle

[Oldtech]

Amazing !

[Oregon Desert model 45]

Stainless fabrication is more of a specialty that requires argon gas and stainless wire for the welder plus some experience which I don't have at this point. 

I started hammer forming the end cap / baffle over the plywood oval form and found the plywood to be a little too soft which led to a crinkly looking edge that resembled a cheap tin pie plate.  Additional hammering with metal dolly  helped smooth out the wrinkles.  This is compressing and shrinking the sheetmetal.  I can also use the torch to heat the wrinkles and make them easier to hammer out.   A hammer form made from hardwood would probably work better than plywood.  Its still a work in progress and I am figuring out the process as I go.

Kevin  

[dibarlaw]

Kevin:

Very timely! I was going to spend the day reinstalling the gas tank I had sent out to be cleaned and re-coated more than a year ago. It is about time I get to finishing it as on Tuesday I installed the axles, hubs, the repainted and striped wheels also the rims and tires. I was able to set up the brakes.

 

I just had to button up the rear axle. On Wednesday I finished filling the rear axle. Much easier with the tank out and the spare tire off.

 

. 

Not sure if Meyers has a bezel for the 2 1/8" dia. gage face.

The photo below shows the comparison between the Standard (copper colored) above and the larger Master size gage below. After a year or so in the tank my nice white "Fuel Proof " finish is stained and pretty shabby. The photo you posted of the silver faced gage is that of my Standard. After a couple of years that "Fuel Proof" silver paint has blistered andf discolored also. The photo of the Meyers Dodge Bezel was for the Standard size with the 1 3/4" gage face dia. Hugh had them make up the same size as for the Dodge but for 20 tpi. 

 I can get you the dimensions of the gage tower. Anything else before I install the tank?

[Oregon Desert model 45]

Larry

Can you also measure height of fuel outlet fitting and inlet neck ? 

I will have to keep looking for a larger Master bezel or figure out how to make one. 

Kevin 

[dibarlaw]

Kevin:

  I can get to the inlet and outlet in the next post. In the meantime here is what I measured for the gage tower.

 I still have to work on the sheet metal stage that the gage nests on as it is a bit bent up.

The bezel for my Standard I made a new one out of aluminum. The tower on that tank was pretty mangled from the previous owner using a pipe wrench. It took quite a bit of inginuity to get things trued up.  I made the new bezel a bit heavier since I could turn, knurl and thread it on my South Bend 10". That was before we found Meyers Dodge. My Master tank is much better but is still a bit distorted. The dimensions on the sketches reflect that.

An extra 1/8" in diameter would give enough body to machine in aluminum or brass. You would have to make the tower and thread it to a given size then fit the bezel. The tower could be heavier on the I.D. if machining from heavier stock.

 

 

 

[dibarlaw]

Kevin: 

The inlet on mine is 1" high.

 The filler neck is of course canted out to the right and rear.

Shortest length is 3 3/16". Longest is 3 3/4".

 My thoughts as to how to locate would be to install the fabricated tank before ends are permanent. Use the tank cover to scribe for layout of all 3 holes then mock up the pieces to be inserted.  So everything will sit at their proper angle. 

 

 

[Oregon Desert model 45]

Does anyone know of a source for original size (11/16") solder on fuel line banjo fittings ?  

Searching for fuel line banjo fittings turns up lots of metric sizes, most of which are smaller than original.   The closest I found that could work has a 18mm ID but has a hose barb instead of solder joint. 

Is there any argument against using a modern style neoprene fuel line instead of copper tubing ?  Its not going to be a show car. 

Kevin

 

[Oldtech]

You can get these off Amazon. You may have to look a bit for the size you need. They are metric but work great on the banjo fittings.  I got 18 x 25 mm for gas tank and vacuum tank. Made by Autohaux.

Edited December 4, 2023 by Oldtech (see edit history)

[dibarlaw]

Kevin:

 I thought I had an extra from the Oregon stuff I got. No. With several of the scrapper chassis we have found recently there should be someone who has one to sell.

[Hubert_25-25]

Kevin, 

    Are you looking for just the Banjo?  I respectfully submit to no rubber hoses in the fuel line.  If rubber is used, it should be no more than 6", but best is no rubber in the fuel system.  I bought this copper tubing off amazon, soldered it onto the original ends.  It is much better quality copper than original.   SU fuel ends would get you where you want to be.  Attached is some digging into them that I did at one time as old parts can get scarce.          Hugh

 

Edited December 5, 2023 by Hubert_25-25 (see edit history)

[Oregon Desert model 45]

Hugh

Where did you find dimensions for AUC2695 ?  I found that same fitting on multiple British parts supplier websites but they only listed car makes that it would fit and did not include dimensions beyond tube diameter which was identified as "bore".   Searching for fuel line banjo and hydraulic banjo leads to an entire universe of parts I was not aware of.  

I made another oval hammer form from hardwood and wrapped it with a band of sheetmetal to resist denting which the plywood form suffered from. 

I tried making a gauge faceplate using galvanized steel flashing and stamping the markings.  I made about every mistake possible in the process, but that's how I figure out how not to make it.   The only way I can think of to cut the slot for the gauge pointer is to lay out the location and punch a line of holes, then  hand file the slot until it cleans up.   Easier said than done.  Also need to find fractional stamps for 1/4, 1/2 & 3/4. 

Kevin 

[Hubert_25-25]

Kevin, 

  I have an SU fuel pump in my Jaguar.  I have it set up with an SU fuel pump (diaphragm style) and a cheap electric pump.  They are connected in series and either one will work if the other fails.  I was going to change the cheap electric for another SU pump at one time.  I bought several fittings that I still have.  I took the dimensions off the fittings.  What I hate is that there are so many parts out there, but no one knows how to put a dimension on them for us retrofitters.    

 

Your gauge is looking good.  Since you drilled the 2 holes on each end of the slot and you are cutting a domed surface, you could hold that to a piece of wood and use a band saw to cut the slot instead of drilling all the holes in a row.  

 

Do you just need the single banjo, or are you going to order new?

Hugh

[Oregon Desert model 45]

Hugh

I need 2 banjos total. Either new or old if its not mashed out of shape.

The 11/16-20 tap arrived today so I set up the outlet tower (with welded on flange) in the lathe and tapped it through. The lathe holds the workpiece and tap aligned perfectly during tapping.  The chuck is locked using the back gear and tap driver handle is turned by hand about 10 or 15 degrees at a time which makes this a tedious process.  

Next I prepared a 3/4 bolt to be machined into a banjo bolt by machining down the head and drilling through.   I hit a minor roadblock when I discovered the dog was too wide to fit over the already machined down head.  The solution was to cut a notch in a short piece of tube leaving 2 tabs which fit over opposing flats on the head, then clamping the dog over the pipe.  Its now "between centers" and ready to machine down and thread.  I didn't want to make the bolt until there was a tapped hole to check the fit of the threads.  

Kevin

[Oregon Desert model 45]

Finished turning and threading the new banjo bolt.  I left extra length at the tail end where the pickup tube will be soldered or brazed on.  The vacuum pump banjo bolt has a 1/8 npt plug which I don't see any need for at the fuel pick up end, so was thinking of welding closed the hole through the head. Kevin 

[bradsan]

Kevin

 

Great work on the tank.

 

Our fuel tank fitting bolt had no plug, I think it is only on the vacuum tank fitting to allow you to prime the tank

 

If I'm not mistaken, the lettering on the fuel gauge face was etched as opposed to stamped .

 

Crazyfamily on this forum did some postings about how to do this.

Or you could contact Nostalgic Reflections if you have a bunch of spare cash!

https://www.nostalgicreflections.com/auto5.html

 

I might have a spare fuel line banjo , I'll have Cousin Jim take a look.

Should be the same as Master and Standard ( but you know how accurate I am with that kind of information!)

 

Brad

[Oregon Desert model 45]

I went to the steel yard today and had them shear a piece of 18 ga sheetmetal 30" x 48", which cost $42.50.  I decided on using 18 ga after making 2 more oval end plates from 18 ga that I picked out of the "used" bin at the steel yard.  It wasn't much more effort to hammer 18 ga vs 20 ga.  Both sizes still required heating with the torch and further hammering with a dolly to iron out the wrinkles - note the blueing around the perimeter where they have been heated.  The bonus is the finished tank will be more durable made from 18ga (.047) than 20ga (.0359). 

The slip roller performed like a professional machine and it took little effort to roll 30" wide material.  Assembling the oval end plates into the rolled sheet is a bit tricky since they keep popping out.  A ratcheting strap clamp is needed to pull the rolled sheet tight over the oval end plate, leaving some minor gaps that will be easy to close with a C clamp.   I will use the ovals made from 20 ga for the internal baffles.  

I was looking at the 2.5 dia pipe at the steel yard, which is needed for the fuel gauge tower, and all of them measured a maximum of 2.40" dia.  I don't understand why they are undersize by .100" or more.  I found a piece of 18ga x 2.5 dia pipe in my own junk pile which is too thin to thread, but could still work if I machine the threaded end from a solid round slug and leave a short length that will slip into the 2.5 pipe and be soldered or brazed in place.  

Brad - if you can find me a banjo that would be great ! 

Kevin

Edited December 8, 2023 by Oregon Desert model 45
edit (see edit history)

[Oldtech]

On 12/6/2023 at 4:14 PM, Oregon Desert model 45 said:

Finished turning and threading the new banjo bolt.  I left extra length at the tail end where the pickup tube will be soldered or brazed on.  The vacuum pump banjo bolt has a 1/8 npt plug which I don't see any need for at the fuel pick up end, so was thinking of welding closed the hole through the head. Kevin 

That plug is to allow you to put gas in the vacuum tank to prime the system when you run out along the road.  Oldtimers carried a small can of gas and a small funnel for such occasions.  

[Oregon Desert model 45]

Almost finished making the fuel gauge tower.   Machining the 2.5-20 male fitting for the top end was pretty straightforward.  I left a shallow counterbore for the gauge to seat, which might have to be modified slightly to add a notched ring to position and better support the gauge.  This fitting will sit in a 2.5 dom tube which will attach to the gas tank. 

Making the bezel ring was a multiple step process due to limitations in my skill level and equipment.    I don't like to do blind internal threading due to high risk of crashing the threading tool, and trying to maintain a grip on a thin walled part always fails.  I began by welding the rough machined ring to a larger sacrificial disk to space it away from the chuck jaws to bore & cut internal threads to fit the already completed tower fitting.  Next I made a threaded spud to hold and support the ring for the remainder of the machining work without damaging the ring or threads. Welds were machined away, sacrificial disk separated, and ring outside thickness turned down to about 1/4" thick.   Next a cap was welded on one end, outside diameter cleaned up and knurled, then a 2.0 bore through the cap.   An oil filter wrench  was needed to loosen the ring from the threaded spud as it was jammed on pretty tight.   In all, it was a lot of hours cranking handles on cold winter afternoons.  

Kevin 

Edited December 25, 2023 by Oregon Desert model 45
edit (see edit history)

[Oregon Desert model 45]

The tank was finally ready to fit up under the frame to locate holes for filler neck, gauge, and fuel outlet fitting.  The long seam is welded but both end caps are just pushed in snugly, and will come back out to fit up interior baffles and allow access for clamping copper heat sinks behind fitting flange welds.   The upper cradles originally had a strip of cushioning felt attached with rivets.  I used strips of vinyl flooring about .060 thick instead, which might be preventing the tank from seating into the cradle correctly.   The gap between the frame rear crossmember and tank seems to be a little excessive.   

 Fuel filler neck is a repro for 1960-1966 Chevrolet / GMC pickups which was the only filler neck I could find that was long enough.  Fuel cap is NOS AC GT-1 from about 1959 which, according to the table on the box, is supposed to fit Buick 1926-1956.  Cap fits filler neck perfectly. 

Kevin 

[apolo1100]

Excellent job Kevin.!

 

Cheers Apolo.

[dibarlaw]

Kevin:

 When I installed my tank to my 1925-45 I cut up one of my old leather belts. I punched holes and riveted.

 Now I guess I need suspenders.

[Oregon Desert model 45]

I made 2 baffles to go inside the tank and added air hammer raised beading similar to original. 

Another oval end plate made from scrap pieces has a window so I have access to the inside while fitting up the fuel feed tower and gauge tower.  This is obviously temporary.   The fuel pickup tube should be aimed at the bottom center which should be the lowest point where gas will pool as it gets empty.  A 5/16 rod pushed through the banjo bolt screwed into the feed tower indicates where it is aimed.  I am wondering if it would help to add a raised bump to provide a low spot where the pickup tube will be. 

I used the rear frame crossmember holes to locate the center for tank penetrations. 

It is difficult enough to install the tank when I have easy access to the strap bolts that go through the frame, but this must be a big pain when the body is covering those bolts and they have to be accessed from underneath.  It takes a stack of wood blocks under the tank to hold it in place while the bolts are pushed through the frame and cradle strap.  The cradles have a short hook on the end which catches in a slot through the rear crossmember, and will fall out if a small wood wedge is not shoved in that slot ; these are visible in the 3rd photo below.   Has anyone tried using a transmission jack with a wood cradle to lift up a tank ?  

Kevin 

[EmTee]

20 hours ago, Oregon Desert model 45 said:

Has anyone tried using a transmission jack with a wood cradle to lift up a tank ?  

I've done it with a block of wood (or scrap of plywood) and a hydraulic floor jack.  I don't see why a transmission jack wouldn't also work.

[dibarlaw]

What worked for me was my mechanics rolling seat. It has a height adjustment. I just positioned it and pressed the height release lock and up it went!

 Update on my 1925 Master's fuel issue. I thought all was solved as far as leaks.  It seem as thought the brass line cracked at the bend going up to the vacuum tank. It did not show up untill the car was parked on a bit of a side slant. It looked as though I lost at least a quart of fuel.  Even though the engine was shut down fuel was bubling out of the crack from residual vacuum. No rest for the wicked!

[BuickTom87]

That is some pure talent,  i love the progress pics 

[Oregon Desert model 45]

Since I didn't previously explain "air hammer raised beading", the first photo below pretty much explains it.  A wooden upper form slotted in the bead pattern, a lower form, and air hammer with cut off chisel bit ground down to a radius.  Its noisy and makes a lumpy bead.  Wear earplugs if you try this.  I thought it worth experimenting with this process because the long side splash aprons for the Buick have a bead, which my father made with an air hammer, and it fades out in the center area and needs some more work.

I worked on the filler neck installation by making a flange and tacking the GM pickup neck in place using Larry's dimensions.  The black powder coating had to be heated and wire brushed off first.  As it turned out, that neck was just the right length, only needing trimming to the short dimension to make it lean to the right and back.  

When I first began this project, I thought it would be waste if I only used the slip roller machine one time, and how easy it was to roll out an oval hoop to make a tank.  This was before I knew how many hours it took to make all the pieces and weld up a tank.  I got more sheetmetal from the steel yard and started working on 2 more tanks standing up  in speedster configuration and sitting on a cradle.  I learned a lot building these 2 tanks, like how time intensive it is to weld  all the joints, (approx 12' of lineal weld)  and how thin wall DOM tube can warp so much that the cap will not thread on after welding.  The 2 filler necks pictured below were made from 1/8" wall x 3" tube and both warped when welded to the flange, which was a big disappointment.  The successful 3" filler neck on the finished tank was machined from 1" x 3" dia solid slug of steel, which took hours to make.  I used copper or brass heat sinks behind every weld to make sure it didn't blow through, and with C clamps positioned about 1-1/2" apart, it is a lot of time hunched over clamping, welding, and grinding. 

Kevin 

 

 

 

 

[dibarlaw]

22 hours ago, dibarlaw said:

What worked for me was my mechanics rolling seat. It has a height adjustment. I just positioned it and pressed the height release lock and up it went!

 Update on my 1925 Master's fuel issue. I thought all was solved as far as leaks.  It seem as thought the brass line cracked at the bend going up to the vacuum tank. It did not show up untill the car was parked on a bit of a side slant. It looked as though I lost at least a quart of fuel.  Even though the engine was shut down fuel was bubling out of the crack from residual vacuum. No rest for the wicked!

Got some photos of the split on the fuel line. I have 6' of new 5/16" copper tubing and will see where I would have to cut and splice with a compression union. 

If too problematic I may have to bite the bullet and make the entire 10' section.

 

Edited February 26 by dibarlaw
spelling (see edit history)

[Oregon Desert model 45]

Larry

That would have been dripping on the exhaust if you hadn't caught it.  Do you trust a compression fitting to hold ?  

[Larry Schramm]

Being the other Larry, I would not trust compression fittings.

[Hubert_25-25]

That old copper fuel tubing is some brittle stuff.  Fred Rawling and I think you should replace it.  What you want is CNC-525.  Nice stuff to work with.  Be careful as many sellers are selling copper plated.  Kevin got the other half of my 25' coil.  The price has almost doubled compared to this snapshot of what I bought it for 4 years ago.  Perhaps you can find a remnant on Ebay or find someone who wants the other half.  

 

[EmTee]

If you have a double flare brake tool, that can be used to make a secure joint if you decide not to use a compression union.  FWIW, I have used compression unions in fuel lines without any issues.

[dibarlaw]

The original lines are brass, not copper. The other fuel lines from the vacuum tank to the carb were/are compression fittings. Previously what I thought as the leaking from the hose fittings from the stone element, glass and metal filter did a good job of washing grease and crud from the frame and dripping on the muffler.

Edited February 27 by dibarlaw (see edit history)