Wing/fuselage joint has oil

I finally got a little time to take a look at the wing/fusealge joint on the Mustang. I could tell from the bubbling in the paint that something had let go in the joint between the balsa fillet and the fuselage side so that seemed like a good place to start. I first removed a small piece about 2 inches long and discovered that it was slightly soggy. Not a good sign. I then proceeded to pull more of the fillet off to see how far along the joint was the damage. As it turned out, it is the entire length of the fillet. What this means is that the entire fillet will need to be replaced. However, first I need to clean out the joint with the K2R. I will apply this a couple of times, remove in between with a disposable brush and then after the last coat tonight, I will let it sit for a couple of days to see if any wet spots appear. If any appear, then this would mean that the oil is still soaking through slowly. I will reapply as necessary until I am satisfied that the joint is as dry as I can make it. I will then put a layer of epoxy and fiberglass cloth at the joint to reinforce it then replace the balsa fillet, shape, sand and refinish that area.

If anyone is interested, I can post on the process of fixing this thing, from now until how I blend in the paint.

Since I epoxied/fiberglassed the center section of the wing, it should be fuel resistant. This is a big plus right now.

Although not intending to ever make such a large repair, especially so soon, I am glad I painted the plane grey because it is going to be a whole lot easier to blend in so knowone will ever know what it has been through.

How long until next flight? It will be ready when it is ready is all I can say.

For those who wonder, I am posting this as just some advice to those who may have a problem but do not want to fix it. It is better to cut into a plane and then try and fix it right, than to hope it goes away only to come back and bite you. If this joint lets go, I would undoubtably lose the whole plane. This way, I will have it back up in a shorter amount of time and not have wasted all the time making it in the first place. It is alway a shame to lose an airplane but really a shame to lose one so young and to stupidity just because you may not want to cut into the new finish. Especially one this complicated and time consuming.

Please....definitely post pics and progress.
Thanks,
Lou

Matt,
And I thought I was the only one that has problems. That is heart breaking. Did you find where the leak came from, gas tank or just normal flying etc. Will the tank compartment get recoated etc. I feel the pain such a beautiful ship.

Yes , please Matt, keep us posted. I honestly commiserate with you.

I had myself a Sirotkin Spacehound once that got soaked within one day of flying. The oil came out of the tank compartment wich opened to the front. It was very difficult to see what was happening. Talking about it now makes me wonder if I did not simply have exhaust fumes entering the tank space. The wise words of Al Rabe now ring in my ears about an opening up front. The trouble is, there is so much stiffness to be gained by constructing the fuse like an open cylinder in stead of an open box !
I admire your spirit !

I did not post pictures of the bubble because even under super high resolution and blown up to 10" x 20" would still not show up. It was something that you have to see with the naked eye and even there would almost have to feel it. It is only from experience and knowing the plane did I detect it.

It was not really a suprise that there was oil there since I saw the oil on the inside of the canopy.

I am quite confident that I can put it back together just as good as it was before. It was caught early before any real major damage was done. The main glue joint is still quite intact so that is very good.

Right now it is the height of flying season for me. With it being light out until 8:15 now, I don't get home until almost 8:45 then eat. By that time I am ready to just plop on the couch and be a couch potato and go to bed. I am also in the process of fixing the dings and dents in the Stuka getting it ready for the contests. It is now a year old, 1000 flights but fortunately it only looks like it only has 900.

The Mustang will fly again, that I am sure.

Matt.
Tell me is it fuel leak or oil from exhaust? And where is is coming in at?

is K2R still available? i have one tube of dye-b-gone left, which is a similar product but i'd like to find the original K2R somewhere.

"i ain't got it! really, i ain't got it!!!"

LAST EDITED ON Jun-13-06 AT 06:54 PM (CST)
 
Richard Oliver sells K2-R

Matt,

It is hard (nearly impossible) to diagnose problems without examining first hand the problematic structure. I offer some opinions which may lack validity due to my distance from your airplane.

Still, It seems that fuel has gotten to to inside of the fuselage. By what other route could it get to the inside of the canopy? It also seems that oil is soaking through the fuselage to the wing fillet. If the fillet is externally fuel proofed by the paint job, where else could it have come from? The fuselage may appear to be internally dry, but it must be soaked. The wing is probably OK because the center section is glassed. In time, fuel might migrate into the wing through the flap pushrod slot in the wing.

It seems to me that you must first stop the leak. Considering the amount of fuel getting into the fuselage in such a short time, I'm wondering about the possibility of a leaking tank as well as an imperfectly sealed tank box. There might also be a pin hole in one of your fuel lines.

Maybe you can get by with just fixing the source and repairing obvious damage but a fuel soaked fuselage is heavy and migrating oil is fairly sure to cause problems with blistering paint in other areas. This may be cause enough for the airplane to fail to meet your expectations for competitive performance.

I hate to have to cut on a nearly new airplane, but I'd probably open the fuselage enough to get K2-R to every inside surface to remove the oil which deteriorates, and weight which saps performance. Personally, I would be more concerned with making the airplane fly well than restoring a pristine appearance.

Matt, here is a wild idea. What is the possibility that fuel is getting into the fuselage from your semi-scale radiator? The exhaust stack sends the engine exhaust toward that general area. Also in that area is the flap horn exit from the fuselage. I worry about any opening in the fuselage structure.

I think that the only way fuel could have gotten inside the canopy is gravity, either starting, transporting, or storing the airplane inverted.

First, You must find and fix the source of contamination. Then remove all the contamination which inhibits performance.

One possibility for cleaning the inside of the fuselage would be to try this. Work through the removable tail wheel opening. Use a long extension on a spray can of K2-R which can reach beyond the flap pushrod opening into the fuselage interior. Repeatedly fill the entire fuselage with a cloud of K2-R. Use a compressed air spray gun to try to agitate and remove the K2-R, possibly with vacuum assist to pull loose K2-R out of the fuselage. I would repeat this procedure, using possibly more than one complete can of K2-R until I was sure the inside of the fuselage was completely dry. When the wood is completely dry, it should be possible to remove all of the dry K2-R with compressed air agitation.

If you have to cut, I'd consider the bottom of the semi-scale air scoop to gain better access to the interior. It would be difficult, but not impossible, to block most of the flap pushrod slot. It would be a little like building a ship in a bottle, but possible, to keep as much K2-R out of the wing as possible.

This procedure, any procedure, to remove oil from the interior will also remove lubrication from your controls. so what? I have never been convinced that lubricating controls did much more than satisfy a desire to not overlook any possibility of making freer controls. Practically, I don't think it matters either for smoothness or longevity, but, yes, I do it too.

I wouldn't worry about the oil in the cockpit unless K2-R winds up there too. then you would have to remove and replace the canopy. this would also offer an excellent access to the fuselage interior.

>is K2R still available? i have one tube of dye-b-gone left,
>which is a similar product but i'd like to find the original
>K2R somewhere.

I bought a can of K2r from my somewhat nearby Ace Hardware today, Scott. It is a regular inventory item and is usually available. If your Ace Hardware doesn't have it on hand, they will probably be happy to order it for you.

Bill

Scooterjay and others...

If efforts to find K2R fail or are too complicated, remember corn starch and rubbing alcohol are EPA-friendly and work almost as well, but they cost a lot less than K2R.

70% isopropyl rubbing alcohol works well, as it dries a bit more slowly than the higher priced 95%+ isopropyls.

Mix to a 'heavy cream' consistency and work it on with an acid brush. (Haven't tried spraying it.) It's a bit more effort to get it all off the treated area. When most of it is off, repeated wiping with the same alcohol used to mix up the paste gets it done.

The corn starch powder seems to pull oil up for quite a while after it looks and feels dry. The alcohol helps dissolve into the oil to bring it up to the absorbent corn starch.