Kevin1963

I was flying my 4*60 yesterday and brought her in for a landing ... not perfect, but far from a hard landing. The gear folded under and ripped out a chunk with them. Wierd, I thought, but no big deal. I'll epoxy the square back in and get it in there nice and solid.

Well, I carry the plane back to the pits and notice its all soaked in fuel. The tank is slimey, the foam around the batteries is soaked and the wood on the bottom of the plane under the tank ( where it broke) is soaked. Obviously, I have a leak, a good one. Its easy to see how it came apart.

I haven't taken it apart yet, just put it away while a ripped around my WM T-34 .... I fugured I would just get a new tank new lines and replace everything while I had her apart. My question is, the tank I have now (12.8 oz ... 380cc) is a rectagle with the opening slightly higher than center. It squares right up to the hold in the firewall and everything fits perfect. When I look online, I don't see the perfect match. What if I wanted a bigger tank? What if it doesn't fit in that firewall hole perfectly? What the story here? Do you trim the wood in the fuselage to fit a bigger tank and not worry about matching up to the firewall hole? Should I cover that hole and make smaller holes for the lines? And most of the tanks I see have a part of the tank sticking out on the bottom so they won't butt up against the firewall anyway. I'm lost ...

What to do? What to do? Share your knowelegde with me please!

opjose

If you can't get the tank in the hole perfectly, don't sweat it.

I placed a larger tank in one of my planes last week, and things did not align.

I recessed the stopper, ran the tubing, and used a bit of expanding foam to seal up the hole.

Silicon sealant is probably an even better option.

Ideally you want something that can ultimately be removed.

carrellh

You can order a replacement tank from SIG, and it should be an exact fit.

http://www.sigmfg.com
Aircraft
> Aircraft Parts - R/C
>> Sig R/C Aircraft ARF Parts
Scroll until you find the 4*60
Click the photo to see the list of parts with description.

SIGRPFT273ARF - Fuel Tank Assy Four Star 60 - $7.49

JohnBuckner

My Feedback: (1)

I would highly suggest not replacing with an exact replacement. Fitting a stopper bung tightly into a firewall hole will only make all the foam padding a moot point. That type setup is just asking for problems as well as foaming.

One of the best tanks type you can get is the Hayes but careful there are some rip offs included with some ARF's and these are not hayes and they do fail with a great deal of regularity. The true hayes tank if far less failure prone than any other type.

John

bruce88123

Why don't you see what's wrong with it first? May be a minor problem like a cut line or a loose stopper.

Kevin1963

So I took the tank out. Looked it over and didn't see anything obvious. So I left the two lines on, submerged it in water and pinched one hose, and blew into the other ... no bubbles and the pressure built up like normal ... I don't see anything wrong!?!?!?!?!?

JohnBuckner

My Feedback: (1)

With the tank out fill it completely with fuel or rubbing alcohol. Now using the original fuel line the one that went from the tank to the carb and loop this from the tanks feed line outlet to the the vent outlet.

Dry the tank completely on the exterior especially around the plug. pointing the plug away from your face flex the sides strongly with you fingers. This will put more pressure than just blowing. Watch for dampness around the plug cap or cover and also around the outlet tubes in the cap. Sometimes if the weeping is slight and the plug is not very old you can just retighten screw and it will be OK. If the rubber plug is old or has been removed too many times then no amount of tightening will help.

This method will also detect hairline splits in the feed line itself close to where it slips onto the outlet tube on the tank, This is a pretty common occurence and can be prevented by deburring the harsh edge on the bronze or aluminum tube. On a new tank especially if I have cut the tubes just sand the outside corner of the tubes lightly with some fine paper. Clean the tube in some alcohol of course after deburring.

John

Wild Foamy

i had the same problem with my trainer on its maiden, luckily i had sealed the tank bay and engine firewall when i first got it, with Wood Glue, nothing special just regular white wood glue and it works a treat at very low cost

also, put your battery in a baloon and put a zip-tie and a bit of hot melt glue around the opening to keep it waterproof (ok so your not going to take your 4* swimming, but its just a bit of extra moisture and damp protection)