#$%^%$@#$ fuel tank bung

Not familiar with the exact tank you are using, but you might want to run a knife blade or file around the inside lip of the fuel tank to develope a slight bevel on the opening of the tank. Sometimes the hole is too small because of the flashing remaining when the tank is molded.

Good luck.

OS

Well...

*I* use a small (1/8") screwdriver blade to push it in one small part at a time being careful not to cut it since I will be depending on it to seal the tank.

I think that water just makes it stick all that much more. Try using a shot of spray silicone. That always works for me.

MJC

The slip easy stuff is a silicone spray - but it didn't help - but thanks for the reply

David

Looks like I might have to try this - thanks mate

David

Six_O'Clock_High wrote:

I will give one of the other (hopefully less destructive) suggestions a go first, and if no luck will try this - thanks for the reply

David

Old Sailor wrote:

I guessing this is a rubber stooper dip it in rubbing alcohol should make it slippery as the dickens. save the good stuff for drinking.

tomb

Sounds like a good idea - can I use scotch if I haven't any raw alcohol handy?

David

tomb046 wrote:

Hi David.

When I read your term of endearment, I just knew you were an Oz. :)

Mate, unless WM have changed their fuel tank or bung design or sourced same elsewhere (Vietnam?) for the cheapie Sky Raider, you simply shouldn't be having a problem unless induced by the proverbial "finger trouble". ie: Don't take offence, but that you're putting together a Sky Raider implies you might just be a newbie?

Can you fit just the bung alone without any of without the plates and screw in place? If so, you just need to loosen the screw some more.

If not, on balance of probability there might just be a minor defect in manufacture of the tank neck or a bit of flash obstructing the bung. Have a look. You might have to remove the flash with the blade of a hobby knife, of if the neck itself has a minor deformation, attack it with a Dremel or round file. A lot quicker and more practical than sourcing an exchange replacement unless the LHS has another Sky Raider box in stock. If it's seriously deformed, just return it to your LHS. WM offer a replacement parts warranty, and the Oz distributor of WM, HobbyHQ are much more supportive of LHS customer complaint than that opposition crew in Melbourne.

My recommended World Models bung insertion and testing technique.

1. Have the expansion screw as loose as possible, but still inserted sufficiently as to just retain the inner plate.

1. Preferably using *rubber* grease, apply an ultra thin coat both to the bung and to the tank neck.

2. Insert bung and tighten screw. Don't overtighten and distort bung.

NB: IME you have to finesse the tension a little better with WM bungs due to the lack of a secondary fitted cap over the neck a la DuBro or Sullivan units. However, *provided you tension the bung right*, the std WM unit proves itself just a reliable in practical service IME.

1. Seal vents with silicon fuel tube and test tank in water filled sink for leaks. If bubbles are seen, tighten bung screw some more with incremental finesse until air stops leaking from tank.

If that doesn't work for you, then either the unit IS porked OOTB or you should find another hobby.

Good luck. WM are the best ARFs in the marketplace today and their hardware including tanks stands up to the in-service reliability test. I appreciate the Sky Raiders are their budget priced offering, but I couldn't see WM allowing their reputation to slip on what is essentially a intro to the hobby model targeted at newbies.

Thanks for all the good advice K - much appreciated - and yep and Aussie thru and thru

While you are right that I am a newbie, this is the 4th World Models plane I have assembled (2 x Superstunts, 1x WorldStar 40) and a 60 model Tiger trainer) so have put a couple of bungs in before without too much hassle.

Anyway, after a few replies I decided too ream out the neck of the tank

- no sweat except (of course) I may have overdone it a bit. Got the bung in and tested it underwater - nice bubbles. Tightened the screw a bit more and no more bubbles, but then saw some fluid in the tank. Have removed the bung and washed out the tank, and am now waiting for it to dry.

I thought it might be a good idea to seal the tank with some sort of 'goo' - but am wondering what will stick to that sort of plastic - seems similar to what I use to mix epoxy on (bottom of milk bottles) and I know the epoxy doesn't stick too well on that.

Of course if all else fails I'll make the trip and buy a new tank.

Incidentally, one poster suggested I fuel proof the fuel tank compartment - how the hell do you do that? You can't get at most of the bugger from either the front or rear!

And I agree with you about World Models - those Superstunts are the best trainers around I reckon - just got a 60 size I am dying to try. If you are wondering why "so many planes with so little experience" - its simple - I hate fixing em when they get bent - rather get a new one.

Cheers

David

K wrote:

Hi David

This is a nonsense which deserves no more accord than the rest of R/C folklore belonging to a bygone age. Forget it.

If the bung comes out and the tank contents leak into the fuse, it'll penetrate into the joints everywhere whether you've "fuel proofed" or not. Fact. Weakest link and all that. Fuel oil spreads like blood and oil over a floor into every nook and cranny. OTOH if you've pranged badly enough to split the tank with the same result, the fuselage will likely be going into the bin with the rest of the splinters.

Concur. I also have a well flogged WM Superstunts 40. Magic piece of kit. A very versatile 'trainer'. Not used as such, but as you say, stick her on low rates, and it's docile enough to be used as one.

I'm a builder from way back, but I agree entirely with your perspective. Seven years ago I wouldn't. Today, ARF quality has lifted so much and the price is so amenable that it's simply an egoistical nonsense to build not to mention economic stupidity.

Good luck with the tank. PS: BTW, the 'secret' is sealing and lubricating the bungs/stoppers with rubber grease which doesn't deteriorate the rubber, helps with the seal as a bit of lubricant on a gasket always does. You can buy rubber grease from any decent auto shop.

As you, I've not had a problem with WM tanks yet, so given your experience based comparison, your current one certainly sounds flawed beyond modification or repair OOTB.

Not nonsense at all. I always fuel-proof the tank compartment and the firewall. I use 15-minute epoxy thinned with fuel quality alky. Fuel tanks leak sometimes. Fuel-proofing keeps the oil out of the balsa. Strengthens the wood and joints in a critical area too.

CR

K wrote: