Metal Tank Care

[PatRobinson]

Hi Guys,
Well I needed to revive some tanks fron planes that have been setting up and unflown for several years so I followed the process that has worked for me over the years that I use with all new tanks and tanks that need reviving.
1. Pressurize tank, put in water and check for air leaks- fix if needed.

2. a. fill tank with rubbing alcohol or denatured alcohol ( i just want to help
       clean out any oil holding bits of crud.) I have tried a lot of solvents but
       the alcohols don't smell as bad as others and seems to work fine.
    b. seal the overflow tube.
    c. I hold the tank on it's side with the pickup tube down. I then shake the
        tank vigorously and then rock back of the tank down and the rock
        forward gently squeezing the top and bottom of the tank as I move
        forward. The alcohol will squirt out onto a clean paper towel I have in
        my other hand.  You will see the crud that comes out of your tank.
        Shake the tank and repeat the process rotating the paper towel to a
        clean place so you can measure the crud coming out. I do this with
        several tank fulls and you should see a great reduction in crud.
     d. When there is nothing else coming out of the tank I fill the empty tank
         with any "old fuel" (fuel I am unsure I want to use flying) as long as it
         has nitro in it and I cap all the tubes on the tank. I have found that
         nitro seems to work as a a good solvent to break down tank crud.
         Let the tank sit from 2 days to a week.
     e.  Use the same process of shake , rock and squeeze on the fuel and
          check how much stuff comes out. If necessary refill with alcohol for
          several times and repeat process till nothing comes out.
     f.  If after 4 tankfuls you still have crud you will probably have to pop the
         back off the tank and clean or toss the tank.

This process evolved after trying I don't how many other techniques but I have found if I do it this way I just fly and clean the filter at the end of the session but if I don't do it this way I waste flying time with bad motor runs and repeatedly cleaning filters for 2-3 flying sessions till the tank gets cleaned out. Guess what I do now?

This is just one of those things we all work out for ourselves and probably don't give much thought to but it might be of benefit to some of our newbie
members and I am sure you guys have your techniques for tank care you could share.   
 
                                                                 Till next time,
                                                                  Pat Robinson

[Ralph Wenzel (d)]

One possible addition:  Eric Rule (RSM Distribution) suggests using turpentine for "removal of tank crud", and says it will even get rid of minor rust! To be followed with the "any old fuel" treatment you suggest, Pat.

[Garf]

Interesting. I happen to have a can of turpentine I bought by mistake. I might try that on one of my oldies.

[Rudy Taube]

One possible addition:  Eric Rule (RSM Distribution) suggests using turpentine for "removal of tank crud", and says it will even get rid of minor rust! To be followed with the "any old fuel" treatment you suggest, Pat.

Hi Ralph,

You may have misunderstood Eric? I think he said: "..... AFTER you buy a new tank from him for your airplane, then you can clean up the old one with turpentine before you mount it on your wall in the OLD tank collection section."   

IMHO: "..... for the want of a nail, the war was lost....." I think this holds true for aircraft as well. I would not risk the loss of a plane on an old, questionable, most likely rusty, inexpensive tank. No matter how much fluid I ran through it. FWIW: I replace the 32 oz. tanks in my "other type" planes every year, just as preventive maintenance.

My lack of skill is tough enough on my planes, I don't need outside help from Murphy's Law! 

Regards, 

 

[PatRobinson]

Hi Guys,
Ralph, thanks for the info on turpentine because that may be one of the few solvents I haven't tried.  By the way guys, I use a fan to blow the fumes from any solvent out an open door of the shop when I do this process.

When I used to mix my own fuel I used pure nitro methane I had on hand as a cleaner but I found I didn't need it to be that concentrated to give good results which was good because the price of nitro jumped dramatically.

Hey Rudy, I agree about tossing rusted tanks but my purpose for doing this process is specifically to use on "new" tanks or to refresh tanks sitting up over the winter not for tanks that should be tossed. I would never run a new tank on any plane without doing this process first because I don't want to deal with the pontential hassle that I have experienced. Mr. Murphy and his Law intrude enough in our flying endeavors without me helping him out so I spend a 1/2 hour or so cleaning the tank.
Like I said in the original post, everyone works these things out for themselves based on their own experience and we usually don't give it a second thought. We just do things a certain way because they work for us.  As I was cleaning some tanks it dawned on me that this is the kind of thing that could be useful to newbies. Many times I have been in a friends shop and I see them do something that to me is clever and new but to them it is just how they figured out how to do something.

Guys, thanks for all your input.

                                                                       Pat Robinson 
   

 

[GEOFFREY]

 good idea Pat.  I might trust a tank that  is from a retired plane  that had no  known problems , than some of the new stuff on the market . took the ends off a couple of new tanks this week that were full of grud , plus  pickup not tacked in right spot. good idea i have just hocked up a electric  fuel pump with filter on  both in and out and run a gallon jug for a hour.Geoffrey out.

[Rudy Taube]

Hi Pat,

Sorry, I misunderstood. You make some very good points about new tanks. I can imagine that it must be very difficult to mass produce metal tanks at a low price point and have them perfectly clean inside. I have given up on them. As a retread to CL I tried them with my 1st plane with poor results. I quickly reverted to using plastic RC tanks. I like the fact that I can see what is going on inside, and that I can make adjustments and changes as needed.

After doing violent 3D flying with them in RC, my guess is that the pickup follows the fuel at least as good as the typical CL metal tank. They are also at least 1 oz lighter in weight than the metal CL tanks.  A side benefit is that they are 1/3 the cost of a metal tank. I know how important tradition is in CL, but in this case I think breaking with tradition may be worth it?

In my experience, Hayes tanks are the best, no leaks and well made. The Great Planes tanks (Hayes copies) and Kavan tanks, are the next best. I stay away from any "No name" tanks like the ones that come with ARFs (I throw these away to be recycled into something usefull ;-). 

I now find myself using fewer fuel tanks, as I am becoming almost all electric in RC and CL flying. But I do really miss the smell of burning Castor Oil. Like many of us baby boomers, this smell brings back fond memories of flying CL when we were smaller kids. 

Again, I'm sorry for my misunderstanding, and my "lame" attempt at humor about old tanks.

Regards, 

[PatRobinson]

Hi Rudy,
I freely admit metal tanks need more care than plastic tanks but the main 2 reasons I am using them is they fit the planes I have and I have never taken the time to work with plastic tanks to find out how to get the results I want.
Maybe you can start a thread about setting up plastic tanks and teach me and the whole gang something. Like how to adapt a fuselage front end to accomodate a plastic tank.

Rudy, I appreciate all your data on plastic tank brand selections. Just out of curosity how do DuBro and Sullivan plastic tanks rank with you?

I seem to remember a thread where someone was using a Tettra plastic tank with an inner fuel bladder where muffler pressure goes into the tank outside the bladder. I think R/C pylon racers use this kind of tank so I am not sure how it worked in a stunt plane. Just curious? 

Rudy, there's nothing for you to apologize for - "WE BE COOL"   

                                                                        Pat Robinson

[Rudy Taube]

Hi Pat,

I feel guilty for hijacking your informative thread on cleaning metal tanks. I was a CL combat flyer before leaving CL decades ago to practice the "dark arts". I have a lot of experience with combat fuel systems but very little with CLPA wet systems. I don't think I am enough of an expert in CLPA wet fuel systems to start a thread on plastic tanks? But I will try to address some of your questions here.

RE: FIT FOR OUR CL PLANES. The narrow classic planes are more of a challenge than our modern planes, but there are many size configurations available in plastic tanks. As a start, you may want to try the link below for the Hayes tanks:

http://www2.towerhobbies.com/cgi-bin/WTI0091P?&C=QCA&V=HAY

Click on the oz. size tank you need and see the dimensions down under "Tech notes". There are several different shapes for Hayes tanks (and other brands as well), square, slim, tall, etc. There are also many different shapes made for boats, cars, and Helies. A little research should turn up a tank that will perfectly fit your CL plane. I have a Hayes in my wet powered Nobler, Flight "Doodle" Streak, and one in my wet Cardinal.

RE: SULLIVAN AND DUBRO TANKS: I have not had good luck with the Sullivan and DuBro fuel tanks. They are both fine companies, and I use many of their other products, just not their tanks. Many of them use the old fashion "stopper" method. They are the only type that I have had leaks with. If you buy the aftermarket metal covers/washer for the stopper, they seem to work better, but I find it easier and more reliable to just use the brands I mentioned.

RE: TETRA TANKS: Yes we used them in our pylon racers. They do a very good job of feeding the fuel and using the last drop available. I think they might work well in our CL planes, but I have no experience with them in this application.

Cool. ..... Now if you have any questions on ECL fuel tanks, I may be able to have some better answers for you? 

Regards,

[Ralph Wenzel (d)]

Rudy,
The Tettra tank is absolutely fabulous for CLPA! It's my preferred tank when I can fit it in, or on, the plane.

[PatRobinson]

Ralph and Rudy, thanks guys for the additional info. Interesting posts from both of you I learned something - Well Done!
 
Ralph, will the Tettra tank let the engine  produce a 4-2  type of motor run or does it work better by providing a steady fuel supply for a modern "pipe" type of run. Is it just hooked up to muffler pressure. I bet, not many guys are running this tank, so I bet  a lot of folks would like to hear more details on how you set it all up- I know I would.

                                                                  Pat Robinson

[Rudy Taube]

Thanks Ralph,

That is good to know. I always wondered why more CLPA flyers did not use these excellent tanks. I am putting my AT in a Nobler and I may try one with it.

[Bill Little]

I know that Mr. Werwage was using plastic tanks years ago.  Along with his, and Bob Hunt's help, I have used clunk tanks on uniflow using the system that was later in one of Bob's "Robin's View" videos.  Any container can basically be used for the tank.