Fuel Tanks
My EAA advisor gave me the name of a good man to do aircraft welding, so I went out to look at John Murray's operation. He does lots of aviation work, including engine mounts (a nontrivial thing to weld up!) and many different parts - he showed me a scrap book of all the aviation fuel tanks he's done. The picture below is in his shop, and he's making a 60 gallon header tank for a Waco.
Another picture of his well-equipped shop:
And another showing him restoring a Waco airframe
He tests the tanks for leaks to 10g's. (If I do 10g's in an 801, it won't be the tanks I'm worried about!) I think he may be a handy guy to know on other things besides the fuel tanks, so if the economics are there, I will have him weld them. After talking to him, since he has the large brake, shear, and beading equipment to make the job easy, I will just supply him the materials and let him cut, bend, and weld the metal. Welding and testing will take most of the time.
Aircraft Spruce recommends 5052-H32 aluminum (this is .032) for fuel tanks, which is not what ZAC is using (.025) and this is what the welder recommended as well. I think the thicker aluminum will not be that much heavier, but will certainly do less oil canning. I had a hard time finding the caps and necks for the tanks ZAC supplies, but lo and behold, they are Piper vented caps, and I finally found them at Wag-Aero. After doing some arithmetic on catalog entries I found that the cost for both tanks will be:
| Item | Quantity | Source | Each | Cost |
| 5052-H32 4x4 sheet aluminum | 1 | Wicks | $26.54 | $26.54 |
| Extra aluminum needed | 1 | John Murray | $13.00 | $13.00 |
| CAV110 drain valve | 2 | Wicks | $9.52 | $19.04 |
| 3/8" Aluminum flange AN867-3 | 2 | Wicks | $7.06 | $14.12 |
| 1/8" Aluminum flange AN867-1 | 2 | Wicks | $6.20 | $12.40 |
| Piper flange vented gas cap | 2 | Wag-Aero | $9.75 | $19.50 |
| Filler neck | 2 | Wag-Aero | $9.45 | $18.90 |
| Finger Strainers 3/8" | 2 | Wicks | $7.27 | $14.54 |
| Gauge Senders VDO 20-200 ohm | 2 | Wicks | $37.14 | $74.28 |
| Cork and adhesive | 1 | Art supply for cork | $18 | $18.00 |
| Labor | 4.5 hours | John Murray | $40 / hr (est) | $180.00 |
| Total | $410.32 |
I am not including any hose and hose fittings here because I am not going to use the hose, so if you are, you should include that for your costs in order to compare it to the ZAC kit cost. The aux tanks from ZAC are exactly the same dimensions as the main tanks, but they do not include the return line fitting, since there is already one on the main tanks. I believe this says you must use the main tanks before the aux tanks, at least for a while. Also, I will have to make some U channel for the tank mounts, but I can make that out of scrap.
June 15, 2001
Here are the finished the tanks:
In the picture, John is standing in front of 3 tanks - I loaned one of the ZAC main tanks to John for him to use as a guide in making the others. I am delighted with them! John is a fair guy, and a great craftsman. His number is 636-398-4640 and his shop is a couple miles from the Foristell VOR, about 35 miles west of the St. Louis arch. The 4x4 sheet was a bit short, as he needed another piece to make up two tank sides. He charged me 4 1/2 hours labor, and added $13 for the extra aluminum.
A main tank from ZAC weighs 67.5 oz without the cap, finger strainer, gauge sender, or hose fittings. The aux tank weighs 78.7 oz without the cap, etc, a difference of 11.2 oz, or just 16% more. This difference is because the ZAC tank includes a return fitting flange, which the aux tank does not, and the aux tank is using .032 instead of .025 aluminum.
Maybe I should be using grams, in deference to the designer - ok, each main tank is 1.914 kg, and each aux tank is 2.231 kg.
Images on this website are either Copyright Zenith Aircraft Company and used by permission or are copyright Gary Liming