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Outsourcing fuel tank construction

didja

Active Member
Debating on whether or not I want to build my own fuel tank or have it outsourced. Anyone have a recommendation for a shop that will build fuel tanks in the Arizona area?

Trying to get a figure on costs and experiences with anyone that may have outsourced the fuel tank build.
 
You could always ask a repeat builder to do it for you. Better yet, ask the repeat builder to be your supervisor and do it with his help. I offer that once you get into it the vail of mystery will be lifted and you will see it is similar to the repetitive work you did for the rest of the wing.

If you really hate the thought of building your tanks, I think you can just buy the tanks from Van's - but I'm guessing they might be pricey.

Carl
 
Carls right

The only thing that people are intimidated with is application if sealant and riveting it together.
My recommendation would be to do all the metal work and fitting it all together. Find a local builder to supervise and help with the final assembly and sealing it up.

What I did was bring in a experienced tank builder to help and advertise to local builders that we were going to have a tank assembly workshop. Three or four showed up to help and learn. Cost was approxamately $20 to $30 for beverages and snacks. Be sure not put beverages and snacks out till tank is assembled. (Too messy to eat and work with Proseal)

There was a professional tank builder in Calif (no longer in business). You provided the parts. He charged $1600 to 2100 for a set depending on the RV model.

Steve
 
Just tested a set of tanks today (not Van's) and they use pop rivets rather than solid rivets. With pop rivets you can hold onto the mandrel and not get your fingers full of Proseal, but I don't think it pulls the two parts as tights together. I also like to proseal over the bucked ends (inside the tank) and with pop style rivets the end is much longer making it more difficult.
Had three leaks today so I will have to work tomorrow to seal them up. On my previous two sets (Van's) I think I only had two small leaks out of four tanks. Could be just a short memory, it's been a while.
All in all , sealing up tanks is not as bad as some make it. Think out your steps. Don't do more than you can in one session. And take your time and keep things clean.
 
What I hated about doing the tanks was the time pressure, the need to accept a not so good rivet and just get on with completing the session.

If I build a new plane, building the tanks will be the top priority to have outsourced. I rather paint the next plane myself than do another sets on tanks.

This is what I hear quite a bit, and exactly why I am considering having them outsourced. I'm still on the fence. I think I will try to find some folks nearby and get some advice. Maybe it really is just the "sense of impending doom" feel and not as bad as it seems! (especially if its a few thousand to have it outsourced!)

I appreciate everyone's response. I also appreciate the link to the detailed write up thread regarding fuel tank construction!
 
There are 3 main types of sealant that I used:

1. Van's type B sealant.

2. Access panel sealant for the hatches.

3. The thinner, lower-viscosity type A sealant to overlay the rivet heads and edges.

Skygeek had the last two.

These pictures show how to do it:

Tank_Sealing_1.jpg


and

Tank_Sealing_2.jpg


One mill is .001 inches, so 60 mills is .060 inches and 250 are .250 inches.

I used Popsicle sticks and the small cut squares of paper towel and a digital kitchen scale, reading in grams and tenths (just grams are probably good enough) for measuring. I let it cure before riveting it, and that left some clecos needing clean-up, no biggie.

It's not hard and if you liked playing in the mud when you were a child, you'll enjoy it. I kind of did.

Dave
 
I think the thing that most new builders fear on the tanks is working with the sealant and the possibility of a leaking tank when the work is finished. I counted myself in that group until a few weeks ago. We had one of our AOG teams (aircraft on ground) spend a couple of weeks with us dumb engineers to show us the reality of aircraft repairs on large aircraft. We did a variety of typical repairs under their supervision on a 737 we had in our boneyard and I picked up a bunch of useful information for my RV build.

They showed me how they dealt with sealant. Now I've read dozens of builder logs and many of the post on this site and nowhere was ever mentioned the tools and methods used by the professionals. I think we can adopt some, if not all, of these methods and tools to building the tanks for our RV's.

First, get a pneumatic sealant gun. If you buy a new one, it'll run you several hundred dollars. That's too expensive, but if you go to Brown Tool you can pick up a used Semco gun for $60. Once you get this tool the possibilities open up. You can use a bunch of different attachments that will make the job of sealing easier, with less mess and higher quality. You might even find it enjoyable.

Instead of using popsicle sticks to butter up a rib flange, use a roller. I used a roller to apply sealant to my rudder trailing edge wedge. The advantage to a roller is the sealant goes only where you want to and it doesn't get into the holes. It's far superior to a popsicle stick. You can get a continuous flow roller attachment ($47) for the Semco gun and replacement rollers at SkyGeek. I'd get the 2 in. roller attachment only because for some strange reason the replacement rollers are cheap (less than $3 each) and the 1 in. rollers are expensive ($17 each).

For fillet sealing there are a wide variety of dispensing nozzles you can choose from for the specific task required. If you're fillet sealing on the non-flange side you can use a standard round opening nozzle. If you're fillet sealing over a flange there's a specialty nozzle for that. Nozzles are inexpensive. They range from $1.50 each for standard nozzles to about $6 each for specialty nozzles. They are reusable if you solvent clean them after use.

Finally, sealing each and every rivet tail is another messy job usually done with a popsicle stick. There are premolded cap seals that you fill with sealant and press and twist into place. Very clean and high quality. It looks like my RV-14A tanks need about 1500 cap seals. I'm still trying to get a quote from PPG on the price of such a small quantity, so I'm not sure if this one will be economically feasible. If I can get them for 10 cents each or less then I'd do it. Any more than that and it gets too expensive for me. I'll let you know about the price when I get the quote. The seal cap video below shows cap sealing of HiLoks, but they make caps for rivet tails too. The concept is the same.

Roller sealing video: PPG Aerospace - Semco Ribbon & Roller Nozzles
Fillet nozzle video: PPG Aerospace - Semco Fillet Nozzles
Seal cap video: PPG Seal Caps

When I get my wing kit I'm going to build the fuel tanks first. I'm now really looking forward to it.
 
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I've done 6/7/8/12 tanks, over a dozen-not one leak. It's one of those areas where being all setup with the correct tools and knowledge makes the job fairly easy. I understand the fear of leaks, but if your meticulous it will go fine.
I'm in East Tennessee for the summer and will happily build anyone a tank or assist if needed.

Mike S
Glasair III
Rv-8
 
Even easier than the seal caps, mix up some of the Type A sealant (I bought mine from www.skygeek.com) and put it into a plastic syringe. Dot the rivet heads with that. Takes seconds, it's easy and your hands stay clean (except for the mixing part, maybe).

Gooey_Stiffeners_2.jpg


Dave
 
I'm probably about 1 or two shop-sessions out from finally being done with the gorilla snot and building my tanks. Frankly, for me this has been hands down the worst part of the build to date. I'm now 3 months into building the tanks but still have the fuel senders and rear baffle left to install. For me, working with sealant has been miserable. It transfers to everything (despite shucking and changing gloves frequently) and for every hour of riveting it has taken about 1.5 hours of cleanup just to get it off of parts where you don't want it, your clecos, and your tools. If I were to build another Van's model I would seriously consider buying the quick-build wings just so I wouldn't have to deal with the tanks again. Imagine hot mozzarella cheese and superglue having a love child and you are getting close to what this stuff is like.
Having said all that, I admit that after I got my technique down it has gone faster with less stress, but that doesn't mean it has been fun. I was dreading the fuel tanks, and their reputation as being difficult and miserable is well deserved in my opinion. Now the only thing I'm dreading is the canopy.
I'm 18 months into my build and I'm still amazed at how much labor is required, but I view it mostly as a zen-like experience. It gives me something to do with my time, and I find it highly satisfying to see my project (slooooooowwwwly) coming together. I haven't felt that way about the tanks; only relief that I'm almost done with them.
 
Imagine hot mozzarella cheese and superglue having a love child and you are getting close to what this stuff is like.

Hahahaha!!! That's exactly what I remember from the foam rib experience! I am still on the fence. After hearing some of the responses here, I am actually leaning back towards doing my own. When I took this project on, I had told myself I would build the entire project myself...... I think I might just have to hold true to that!

I appreciate all the responses.
 
I didn't think sealing the tanks was that bad. One build session (probably 4 hours) for each tank with a helper. Yeah, you get messy, but it isn't that big of a deal.
 
Many years ago, I also dreaded doing the tanks on my -8 and wound up subcontracting them to Evan. With my -14 tail kit on its way and the wing kit due in July, I've been reading everything available on tank construction and I'm actually looking forward to it.

I'll be ordering a Semco gun and plan to utilize the fay sealing method. I may be back here eating crow on the subject in a couple of months, but I'm really not worried about it at all.
 
The problem -

as I see it isnt in having an outside source building the tanks, its SHIPPING them to the owner UNDAMAGED. You guys in the shipping business know what I'm talking about. Would be a great side business for some of you airframe guys, but the wooden crate shipping costs might equal the cost of the tank.

Oh and the forklift holes in the crate--that would be a bummer.

Tom
 
I didn't think sealing the tanks was that bad. One build session (probably 4 hours) for each tank with a helper. Yeah, you get messy, but it isn't that big of a deal.

Are you kidding me? 4 hours per tank? Are we building the same thing? I have about a hundred hours in my tanks at this point. We must be building in very different ways.
 
Are you kidding me? 4 hours per tank? Are we building the same thing? I have about a hundred hours in my tanks at this point. We must be building in very different ways.

You're probably counting different things. I suspect Kyle is counting only riveting time, not drill/debur/dimple/clean/etc.

I remember staying up late helping my dad rivet his tanks in high school. Jumped right into it on my plane and had fun (with 4 tanks).

Were I to do it again I'd mask off the inside of the tank to cut down on the mess, but overall it wasn't bad. Just wear crappy clothes, buy lots of gloves (Sam's!), and wear a respirator when you're using MEK. Take your time and do one rib at a time; add sealant to holes with a toothpick instead of dipping the rivet. Don't try to be stingy with sealant.
 
There are obviously many ways to get it done. A multi-offender taught me to use quart ziplock bags instead of caulk guns. Turn one inside out, weigh out a roughly golf ball size mix on the bag. Turn it right side out, squeeze out the air, and mix with a short piece of dowel or PVC pipe used like a roller. Roll the mix to one corner then push it back slightly. snip off about a 1/8" to 1/4" diagonal. Now you have a baker's cake decorator bag. Very easy to get into tight spots. On interior ribs, a donut around each rivet and the drop in each rivet hole (and over the shop head, for insurance) does all the sealing. Any additional sealant on the rest of the faying surface and/or edges is just lost payload.

On quantity vs leaks:
I built 2 ea -7 tanks, and 2 ea 3-bay leading edge aux tanks, with *one* can of sealant from Van. On the two main tanks, I had exactly one leaking rivet (probably near the end of a session on a bad day). The auxes had some back baffle leaks but those were purely my fault due to running the trailing edge beads too far forward on the skins (spar has a bigger radius than the tank back baffle).

Not the most fun part of the build, but orders of magnitude better than the massive quantity of wasted time searching for parts using that pick list who's order was created by a random number generator.

Charlie
 
Are you kidding me? 4 hours per tank? Are we building the same thing? I have about a hundred hours in my tanks at this point. We must be building in very different ways.

I'm an average builder from a speed perspective. Some things go fast for me, some go slow. The 4 hours/tank was the time to seal the tank, which in my case was to rivet and proseal the 6 or 7 baffles per tank.

But from start to finish, a non-PP tank took about a week (as I recall from 20 years ago) working bachelor length evenings (5+ hours). Drill everything one evening, maybe deburr a bit. Finish deburring the second evening and dimple. Make the stiffeners the third evening, dimple and deburr them. Also make that PITA front bracket and drill it on. Proseal and rivet the stiffeners the fourth evening, maybe do the end ribs with the squeezer too. The fifth evening (or on a weekend) bring a helper onboard to buck the rivets on the baffle ribs. After that, install the aft baffle, and you're done. Throw in an extra day somewhere for fitting/installing the filler neck and the plumbing and you're at about a week per tank.

Tear something up, run out of proseal, get called away on family duty? Those things create a huge time drag.
 
Call Paul at weep-no-more

Debating on whether or not I want to build my own fuel tank or have it outsourced. Anyone have a recommendation for a shop that will build fuel tanks in the Arizona area?

Trying to get a figure on costs and experiences with anyone that may have outsourced the fuel tank build.

You should give Paul at ?weep no more? a call. http://www.weepnomorellc.com
He specializes more in repairing leaky fuel tanks but I think he can do anything that you want to a fuel tank. I think the thing to do would be to build the tanks but leave the back bulkhead off. This would allow him to get into the tank and get everything sealed up using his special process. He would then install the rear bulkhead as part of his final assembly. I?m actually going to send my quick build tanks to him as part of a preemptive strike and let him do his thing. He told me that he?ll actually remove the rear bulkhead, completely strip everything out of tanks, and re-seal the tanks using his process and then re-installing the rear bulkheads. It?s not a cheap process, but once it?s done; it?s done!! Paul is a nice guy and and I think it?d be worth a call just to chat with him and then decide what you want to do from there.

Mark
 
if you get completely plastic syringes (norm ject), then they are fine for "everything". Well, I have yet to find something that they are not compatible with. On the other had if you use them with solvents, then the body can swell overnight and not be good the next day.

It is the ones with the black rubber gasket on the plunger that are horrible. They swell like crazy and the black rubber is probably coated with silicone grease.
 
Clip a corner out of a freezer bag and use that as a proseal applicator. A box of 20 of 'em costs <$5 at the local grocery and they are easy to fill.
 
You should give Paul at ?weep no more? a call. http://www.weepnomorellc.com
He specializes more in repairing leaky fuel tanks but I think he can do anything that you want to a fuel tank. I think the thing to do would be to build the tanks but leave the back bulkhead off. This would allow him to get into the tank and get everything sealed up using his special process. He would then install the rear bulkhead as part of his final assembly. I?m actually going to send my quick build tanks to him as part of a preemptive strike and let him do his thing.

Mark

I spoke with Paul about repairing my QB tanks. I think he quoted me in the neighborhood of $1200/per tank. That's a chunk of change to "repair" tanks that should have been shipped ready to hold fuel. What about sending them to Van's? Someone else posted that they did that for repair.

~Marc
 
I spoke with Paul about repairing my QB tanks. I think he quoted me in the neighborhood of $1200/per tank. That's a chunk of change to "repair" tanks that should have been shipped ready to hold fuel. What about sending them to Van's? Someone else posted that they did that for repair.

~Marc

Yeah, you?re right, that?s a chunk of change for a ?repair?. I could just try them as they are and chances are they?ll work just fine, but I?ve been down that road before with leaky tanks and I think I?m just going to bite the bullet and have them re-done and and sealed up properly from the beginning. I?ve seen the inside of the tanks that come with the quick build kit and it ain?t pretty. I?m really surprised that more people don?t complain about leaky tanks and the lack of quality of the job that?s done in building those things. On top of that, while Paul has them opened up I?m going to have him take out the filler neck and re-seal that as well. I?m also going to have him drill the vent holes larger so that the tanks don?t have to burp air while filling them up with fuel. One other thing I?m going to get him to do while he?s in there, and that?s to installed the fuel level floats/senders. With the back baffles off it?ll be easy to tweak the bends in those things and get them perfectly dialed in. I feel confident that once Paul is finished with them I?ll be able to bolt the tanks on and never have to think about them again. Regarding Vans, and I don?t know first hand, but I don?t think there?s any warranty against leaking tanks. If someone knows any different please correct me.

Mark
 
Mindset

No one mentioned this.
Make up your mind that evey part of the building process will be fun. Be happy as you walk into the factory. Tanks were fun. Sometimes I even open a fuel cap to take a sniff of Proseal.
Yea, sick, but ever since I changed my attitude it's been a lot more fun.
I used the "Fay seal" method. 100% Clekos. Every one had a 4-40 nut for extra tension.
Sealant was applied by popsicle stick and syringe. The huge syringes fit in a caulking gun.
Tanks were pressured to 27 inches and stayed there for two weeks. I called them good at that point.
 
Testing tank

I also did a pressure test and squirted soapy water and found no leaks until they where mounted on my plane and full of fuel. My recommendation in testing the tank is to put a 1/2- 1 gallon of fuel in them and lay them on the floor rear baffle side down. If they are going to leak, it will be a high percentage chance coming from the rear baffle area. If you see stains on the floor you will know. Also, I used the thinner viscosity proseal to repair leaks. It will flow better into small areas.
 
So, I decided to go ahead and try to do one myself and see how it goes! I'm just about to start pro sealing. I've got everything prepped and deburred and in place to be ready to be put in when I need them, trying to minimize the time of assembly before the pro seal dries up!

I'll post pics of the final product. Thanks for all the input!
 
So, I have constructed my left tank to the point where I just finished my second attempt at the water test before placing the back baffle in place. My first attempt saw two holes that I had not gooped enough pro-seal over on the inner rib. I drained the tank and commenced to gooping all that I could.

A day and a half after applying the pro-seal, I tried my second attempt. I now have a small leak from one of the same join locations but instead of a steady stream, it is not only about 60 drops a minute, so I will apply more goop and that should fix that.

The other issue that I had, was the gas cap. I had a pretty solid stream coming from the seal of the gas cap. I drained the water back down below the cap level and replaced the gas cap with the cap that would have gone onto my right fuel tank. I now seem to have a *very* slight leak where after about a minute or two, a small dew drop size water drop forms at the fuel cap, but doesn't run immediately.

Has anyone had experience with the rv-14 supplied gas caps from van's being an issue in sealing? Also, being as this would only leak if I stayed inverted for a very long time, is this of concern? I'm assuming that I want zero leaks as I am not sure that it would pass the pressure test or not (depending on if the pressure test actually forced the gas cap seal to close up and therefore hold pressure)?.. I just am not sure if there is an acceptable amount of leakage from the gas cap or not.

I will try to figure out how to post pictures again to show what I am speaking to....
 
This was after about 20 minutes of sitting. its just a very small bead that has formed but has not gone anywhere. I'm not sure if this is suitable, or if I should be looking to correct it somehow? It is definitely coming from the gas cap seal, and not the gas cap frame that is sealed and riveted in place. When I pressed on the first gas cap that was leaking a solid stream, the stream would stop, and then when I replaced the gas cap with the other gas cap that was supplied by vans, this was the end result, so I am very confident that it is just the o-ring seal on the cap itself.
 
Well, never mind, I?m an idiot! After looking at the cap some more, I realized it had a spring tension nut and simply tightened the nut a couple turns. Problem solved and no leak at the cap....
 
Well, never mind, I?m an idiot! After looking at the cap some more, I realized it had a spring tension nut and simply tightened the nut a couple turns. Problem solved and no leak at the cap....

Here's that nut.

 
As it turned out, the tanks were no big deal. Lots of fuss and dread over nothing. I used a Semco gun and a combination of wooden tongue depressors & acid brushes.

Aft baffle rivets were dimpled and all shop heads were encapsulated in sealant. The insides of each tank may not be gorgeous, but nobody will ever (hopefully!) see them. The first tank had two tiny leaks by the attach bracket and the second tank was leak-free.

FWIW, I have 37.25 in the left tank from fluting the ribs through final installation on the wing. Right tank is at 23.0 and ready to install on the wing. Guess I learned something along the way! :cool:

Naturally, I won't be completely out of the proverbial woods until they've proven to hold fuel, but I feel much better about the whole thing now.
 
build your tanks...

This thread makes no sense!

Building tanks is really not a big deal and working with pro seal is pretty fun.

Like anything new, there are learning steps and some frustration but it is worth it.
 
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