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General control line discussion => Open Forum => Topic started by: Bootlegger on January 21, 2012, 06:02:16 AM
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Guy's I made a tank of some .007 sheet metal and yesterday when I got ready to use it I pressure checked it again and found a leak, I repaired the leak and checked it again, and found where it has rusted thru in several places.
Any one else had this problem??
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What did you use for metal and solder? Nick
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Got the metal from Mc=C and used rosin core solder, the metal is where it is leaking, not in the joints.
I had pressure checked it, then the tank set up for about 6 months.
Using stock (brodak & veco) tanks I didn't have this problem.
Looking at some of the other sheets that came in the same pkg, I see some rust spots on them also.
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Try sheet brass next time.
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You still didn't say what sort of sheet metal. Plain steel? Tinned steel? Gold? Silver?
I've been making up tanks from Dole pineapple cans, which is tinned steel. I've only been doing so for a couple of years, so I don't know if they'll last a lifetime but they're certainly lasting more than six months!! I've been using acid flux, and haven't seen a problem with corrosion yet.
One thing that I do that's certainly different from your practice is that I've been putting the tanks into service almost immediately. Fuel has oil in it, and oil inhibits corrosion -- so maybe that's why I haven't had a problem.
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Empty fuel gallon cans work great, or acetone/solvent quart cans from hardware store
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Use the K&S sheet tin stock, it is .008 thou, a bit thicker, also use copper tubing. I have never had a problem with this material. Did the leaks occur at a bend? Was the metal rusted before you made the tank? Did you use Non Corrosive solder paste and rosin core solder??
Don
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Yes, it is tinned steel as far as I know, also using copper tubing, flushed the tank with fuel to see if if had trash in it, then I stored it, when I got it down, I pressure checked it, then found the leaks, no they weren't in the soldered seams.
All the leaks were either in the bends, or the flat sections.
I used non corrosive flux, and rosin core solder that I have used many times before with good results...
After repairing a couple leaks, I pressure checked it again, and it showed leaks in the flats AGAIN!! That get's frustrating to say the least.
I've built tanks before, but not with this metal, will go to tin can stock on the next ones..
Sure do thank you fellow's for your help/suggestions
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I've always used evaporated milk cans. thiner than hobby shop stuff. Brass works ok , buuttt, it turns green. HB~> don't want that %^ jim
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use the evaporated milk cans, easy to work, light, and solders easy. make sure the cans are soldered togeather like carnation brand wiill be.
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Food cans often have a lacquer coating on the inside. Not good for tanks. Brass? Also not good. Brass "work hardens" where it is bent, and failure is common at the bends.
I've used empty Brodak Thinner cans for tanks. The BEST material is K&S tin-plate. The normal size is 4"wide, but larger sizes are available if your tank is over 4".
Floyd
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Use the K&S sheet tin stock, it is .008 thou, a bit thicker, also use copper tubing. I have never had a problem with this material. Did the leaks occur at a bend? Was the metal rusted before you made the tank? Did you use Non Corrosive solder paste and rosin core solder??
Don
Second the motion to use K&S "tin" stock, I have built many tanks with it and no issues at all.
Brett
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Yepp, always build my tanks from K and S tin,,
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXUTU8&P=7
I hate having to deal with straightening something of unknown origins to make something,, just give me a nice new sheet of metal to work with,,
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Mark & Brett, I sure do thank you for your input's, Floyd what is the part # and or description to get the K & S Sheet in larger sheets?
Do you also have a place to buy the larger sheets?
Again thanks for the help...
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Bootlegger, the link in my post will show you one place you can buy it
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Mark & Brett, I sure do thank you for your input's, Floyd what is the part # and or description to get the K & S Sheet in larger sheets?
Do you also have a place to buy the larger sheets?
Again thanks for the help...
I don't know about bigger sheets. I prefer making the tank body in two pieces anyway, so i just use the regular kind straight from the hobby shop.
I would never suggest tin cans or anything like that, it takes too much work to get it flat again.
Brett
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Thought I'd share the most useful bit of equipment I have for bending up tanks. Around 18 months back, an "old student" I had back in the 90s (now well into his 70s) contacted me about joining the Hobby Classes again for a project he had. As I'd retired and only do part time I had no say in the matter but the new boss had no issues with it "as long as it met the guidelines"!! The bonus was that as long as I did the welding on the frame, he'd make me one as well. A few months later he presented me with the nicest sheet metal folder you'd ever want. By using a strip around 3/8" square the tank body can be folded with no interference as would be with the standard clamp fingers.
The little combination brake press/rollers/guillotine is also great for cutting the tank metal to size.
And yes Brett, if flat material can be used it's much better than flattening coffee tins etc.
HH