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Building Tips and technical articles. => 1/2 A building. => Topic started by: Larry Renger on February 27, 2009, 10:28:03 PM
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I love how the tanks perform, but they seem to spring leaks with alarming frequency. I will hold onto your envelopes (and money, in one case, if that is OK) until I find the source of the problem. I suspect that 1-mil film is just too flimsy, it was intended to hold lightweight stuff, not fuel in a high vibration environment. I think that 2-mil film might just solve the problem. Balloons are good, but vinyl has got to be better once we find the magic combination.
There are a couple of suspects, first is overpressure when filling and popping a seam. The other is some roughness inside the tank holding box. The latest failure is exactly at a seam...... >:(
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Larry, I for one appreciate your integrity, readiness to admit a problem, and determination to solve it before passing these along.
My wife has some "snack bags" from the grocery store, 6.5" x 3.25", with a "strip seal" down one side that is claimed to be leakproof...I wonder how they would work. A Little big but you wouldn't have to fill it all the way. The box doesn't mention the thickness (or material, for that matter).
Also, inserting the fuel line through a corner would seem to give almost that "neck" with which to seal, that you mentioned in the other post.
Following with interest.
--Ray
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I think the problem is the stress riser caused by the heat sealing of the bag. No way to get around it. If you widen the heat sealed portion the EDGE of the seam is still there. theregy lays the problem.
Would be nice if the baggies were formed from something other than a tube.
Balloons don't have any seams!
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But unfortunately, they're not entirely inert to fuel...maybe a month, 6 weeks of use, and they begin to get sticky and leaky...I just live with that fact and replace them monthly--balloons are cheap, simple to make up into tanks, not a big problem.
But a long-lasting reliable substitute would make it an ideal world!I'm still watching with interest, and will probably do some of my own experimenting as well. I appreciate Larry bringing the vinyl baggies into consideration.
--Ray
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One other thing occurred to me about balloons. You may have seen my posting about my plugs going bad with a whitish coating on the element. Well, I have been using white balloons....... ??? '' HB~>
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Try another color ballon and see if they coating matches ?
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Maybe if you use orange balloons the plugs will light up brighter???
Seriously, I've use balloons for years and never had a glow plug issue.
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Larry, i use the Playtex standard baby bottle disposable liners, 4 oz. and seal them with my monocote iron. Maybe waste one or two trying to cut the hose connection correctly but i can't seem to bust them when i try them out. The box i bought includes 100 of the bags. Thru trial and error the same heat setting for sealing Monocote seems to work for sealing (cutting) these bags. For my purposes the balloons just seem to fit better but this may better in some planes and may last longer. More trials with this to come! As a note!!! I borrowed this idea from Heman Lee @ Aeromaniacs.
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Can you measure the thickness of the plastic for us? It would provide a good starting point for further research.
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Larry ,, i wouldn't feel good about my accuracy measuring with my old tools. I will put some in the mail to you tommorrow.
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I use condoms FOR FUEL TANKS. They must be non-latex types. SLEEPY
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That would seem a little pricey, relative to balloons or plastic bags.
"Safe", though...
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Bill, where did you get these condoms?
I use them for fuel tanks honey.
Yeah, right! mw~
Sorry, couldn't resist. LL~