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Kitfox 3 Bushplane Project.

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Posted (edited)

Vinegar and baking powder/soda  mixed together in a clump and rub it in, then wash good with soap and water, Just my thought

Edited by TJay

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Posted (edited)

Baking soda is a base and vinegar is an acid. Add them together and you will get a reaction. They will neutralize each other.

To remove/convert the corrosion you need an acid.

Like with steel, rust is iron oxide. Add phosphoric acid to it and it becomes iron phosphate. The same with aluminum.

I used to love organic chemistry lab in college. We were always blowing up or burning stuff!

Edited by Fly-n-Low

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Posted (edited)

I missed out on chemistry both in high school and in college.  About all I know is that if you cook Ice cubes you get water!

Oh yes, and I read that if you mix ammonia (pee) and Clorox bleach, you get chlorine gas, which can kill you!  I think that is why the Army gave us gas masks?

EDMO

Edited by EDMO

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Posted (edited)

Doug I hear ya, will grab a gallon of that tomorrow when I am running errands and soak everything in the wings tomorrow afternoon. wont be covering for a few weeks so can probably do it a couple times. 

Spent yesterday afternoon finishing removing the old glue from the airframe. thats just a whole bunch of fun, but luckilly I suckered a buddy of mine into helping me rub MEK all over the plane, so we had someone else there to drag whoever passed out first into the fresh air :). Then spent today cleaning the powder coat off of the tubing where the gussets will be going in along the seat truss and above the gear mounts, that took a lot longer than anticipated. Also wasted an hour and a half stripping the dash cover of whatever material was glued onto it thirty years ago, which took much longer than anticipated as well. Im starting to sense that I under-anticipate the time it takes to do everything….. Wondering if my goal of ready to fly by June is too optimistic?

Anyhow should be spending tomorrow getting the gussets cut and fit so the welder can just go along and stitch them in nice. Also waiting on the Murle Williams wide body kit so I can mock that up and prep things so its just a matter of welding on. 

On another note, I took measurements today and the tail cannot get taller, I measured a total of 87" currently from the ground to the top of the rudder when the plane is siting on the trailer (which it will be every single time I come back from flying and put it away) Measurement of my barn door, 89". So will just extending the chord of it be enough?

One last thing, will be ordering all of the covering supplys/ paint from Wicks tomorrow and am still torn on the color I want to paint it. I would still like to do a sport green and black scheme, but am worried about the red tubing clashing. My Mkiv avid was white and red and I did like that color scheme so wondering if I should just go white and red with this as well. Oh decisions

 

Oh mek fumes. Note the slightly confused/ distant look on my buddies face….

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My kitfox can play dead. Easier to clean off the bottom sides of the tubing when they arent the bottom sides

96CB1150-3D3C-4DD8-B335-AFDEDB9FBA0C_zps

Edited by Neloner

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Posted

Ha I wanted to be finished with mine 2 years ago:)

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Posted

I used square tubing in the opening for my trim tab - looked like it would be easier to attach the piano hinge to that.  EDMO

Great tip will keep that in mind for that piece. 

Ha I wanted to be finished with mine 2 years ago:)

Oh boy I hope it doesnt take that long!! Just sold my ready to fly Avid today thinking I could make it a couple months without flying, but a couple years, no chance

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Posted (edited)

I started building mine from scratch in 1997 - had it ready to fly in 2001 except for painting.  Had to move from Alaska "temporarily" until 2004 and wife decided to go back to Alaska without me.  Bought a derelict HUD house in Missouri and got a divorce.  Rebuilt house and built shop for plane and another for storage.  Went to Alaska in 2007 and sold house and machine shop there and moved plane and 12000 lbs of stuff to Missouri.   Hit a limb on construction detour of Alaska highway, knocking plane off of trailer and causing major damage.  Made another trip to Alaska in 2008 and brought back 5000 lbs of stuff.  Got married again in 2009.  Started to modify and fix plane in 2010 and still making parts.  Now getting verrry old!  Shit Happens!  Ha!  EDMO

Edited by EDMO

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Posted

Hey Paul - No chemist here but I'm beginning to think it all depends on what the meaning or context of "neutralize" is. What I've read suggests that simply attempting to neutralize the alkaline salts with an acid is not enough to prevent corrosion. Here's what I found:

When urine is deposited it has a pH between 5 and 6 (slightly acidic due to Uric Acid). As it dries, the urea is broken down by the bacteria (that decomposition is what makes it smell like ammonia) and it turns into an alkaline salt with a pH between 10 and 12 (strong alkaline). Urine is the only product in nature that changes from an acid state to an alkaline state. Who knew?

Urine is composed of things that REQUIRE enzymes to break down the chemical bonds. Soap, vinegar, baking soda, ammonia, chlorine, and hydrogen peroxide are not chemically capable of breaking down the uric acid. Home-made mixtures or typical household cleaners made from these simply do not contain the required ingredients to remove all the components of urine. Urine is composed of:

• Urea
• Urobilin/Urobilinogin
• Uric Acid
• Sodium
• Other electrolytes
• Creatinine
• Pheromones
• Bacteria – typically 5 different strains.

The urea and urobilin/urobilinogin are not hard to clean. Urea, urobilin/urobilinogin, creatinine and the pheromones are water soluble (urobilin is the pigment that causes the color). Traditional household or carpet cleaners will deal with these and this is why some appear (initially) to be effective at eliminating the problem. But the problem has not been solved! Uric acid and its salts have been left behind. Uric acid is not water soluble and bonds tightly to whatever surface it touches.

The only thing that will break down the uric acid to permanently remove the smell and stop corrosion is an enzyme cleaner. The enzymes penetrate, consume and break down uric acid molecules into carbon dioxide and ammonia, both gasses that then easily evaporate. This is why it is also essential to allow the enzyme cleaner to air dry. It needs the “natural” drying time to break down the uric acid salts, allowing the resulting gases to evaporate. Protease is the enzyme that breaks down protein stains like urine best, although amylase, which breaks down starch, may also help.

Again, maybe my initial use of 'neutralize' was a poor choice of word?

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Posted

Doug you make my head hurt…… I worry about getting too knowledgeable hanging around with you

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Posted (edited)

@JimT - yeah, my head hurts now too!

Nice progress. If you're having a hard time with the powdercoat, read THIS. Or go pick up some Jasco brand 15min. "Premium Paint and Epoxy Remover" at Lowe's. It is a semi-paste that you can brush on, cover with Saran Wrap and let work for 15 minutes. Then hit it with a brass wire brush on your drill, should take the powdercoat right off.

I would lower the winch post on your trailer before throwing out the taller rudder. Is this gonna be a 'Gentleman's Bush Plane" or the real deal? Everything you can do to improve elevator and rudder authority at slow speed is going to be well worth it. There was a reason KF increased these tail surfaces, no?

I've attached pics of the rear spar carry thru tube gussets and the trim tab from my Avid. I should have the drawing somewhere.

Pics of my KF 4-1200 rudder pedal reinforcements HERE

gusset.jpg

 

CIMG5173 (Medium).JPG

CIMG5198 (Medium) (2).JPG

CIMG5200.JPG

Edited by dholly
post drawing

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Posted

 Is this gonna be a 'Gentleman's Bush Plane" or the real deal? Everything you can do to improve elevator and rudder authority at slow speed is going to be well worth it. There was a reason KF increased these tail surfaces, no?

I will take more measurements tomorrow regarding rudder height, don't want anyone thinking I'm a gentleman!!!

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Posted

Jim T.  you mentioned buying your covering materials from Wicks tomorrow.  Here is a way to save a bit of money on fabric.  It's uncertified and very rarely has a flaw in it, but it's really the same stuff they put a stamp on and charge 3 times as much for.  JImChuk  http://www.aircraftspruce.com/menus/cs/dacron.html

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Posted (edited)

Jim T.  you mentioned buying your covering materials from Wicks tomorrow.  Here is a way to save a bit of money on fabric.  It's uncertified and very rarely has a flaw in it, but it's really the same stuff they put a stamp on and charge 3 times as much for.  JImChuk  http://www.aircraftspruce.com/menus/cs/dacron.html

Jim Chuk, Which fabric of the 3 listed do you use?  EDMO

Edited by EDMO

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Posted

I used the medium grade and the lightest one as well.   Actually, a lot of the kits were sold with uncertified ultralight fabric, so probably a lot of people have used the lightest weight.  JImChuk

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Posted

I used the medium grade and the lightest one as well.   Actually, a lot of the kits were sold with uncertified ultralight fabric, so probably a lot of people have used the lightest weight.  JImChuk

Is the medium the 2.7oz? I think thats what I will order. Didnt get that done today, on the list tomorrow. Also decided to stick with the light green and black color scheme I originally wanted. 

Spent today doing more prep for the welders, removed more powdercoat, and cut and fit all the gussets for the frame. Also started test fitting the Murle Williams widebody. Not super impressed at what $250 bought me but we will see how it goes together when its time to weld. 

Oh, and I also bought a couple bottles of an enzymatic Urine cleaner. Although I think I need a couple more. Tomorrow is supposed to be a cloudy rainy day so going to soak them and let them sit in the barn and slowly dry. 

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Posted

Nice fabrication work!  Are you planning to cut some lightening holes in the gear truss gussets?  

Remember you do not want to weld these directly in the center of the tubes.  Off to one side makes it stronger.  In the middle they can actually collapse the tube if under stress.

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Posted

Nice fabrication work!  Are you planning to cut some lightening holes in the gear truss gussets?  

Remember you do not want to weld these directly in the center of the tubes.  Off to one side makes it stronger.  In the middle they can actually collapse the tube if under stress.

Really?!?! Cut these all to fit in the center, and used up most of my material doing so, and actually would have been much easier to do it your way. Worth redoing it all over again? 

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Posted

NO!!  

My buddy, Dave, who helped build my plane (a certified welder) always said, "If I can step across the gap I can weld it."  They don't need to be tangential to the tubes, just off center.

Just hold the piece in position off center of the tube and weld it there.  Mine are positioned such that the welds would be off center, but the fabric on the outside would not show the welds.

 

The theory on this is:  Think of your gussets as a knife.  If it is aligned perfectly on center of the tube it can cut into the tube.  If it's off center, even slightly, the tube will try to push the knife to the side, but the welds will hold it together.  IMO this makes the welded assembly stronger.

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Posted

Remember they only need to be stitch welded, too.

post-36-13595152030056.jpg

I chose to not go completely into the corners, either.

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Posted

The 2.7 weight fabric is the medium fabric.  I actually might go with lightweight fabric on the wings, and just use the heavier fabric on the belly.  Up to you though.  Just a bit more weight if you use all medium.  My fuselage widening has about $50 worth of tubing in it.  ( 1/2" X 15')  ((sorry if that hurt))  Probably a bit more work then Murle's  though.  JImChuk

 

 

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Posted (edited)

As I understand, placing a single triangular gusset on the centerline of a 90* degree joint will transfer most force to the tangential end points, creating very large stress concentrations at the furthest corners of the gusset. Therefore the primary failure potential is those ends acting like a can opener cutting into the tube when under compression. It would be even worse with a rectangular, rather than round, tube but it is not an issue in tension.

Placing the gusset tangent of a singular triangular gusset to the tube outer diameters puts the welds in shear, aids in spreading the stresses along the gusseted length of the tube and does not place the tube in bending by presenting a force in the center. Which normally on a 90* 'T-type' joint with 2 of 3 legs welded to the base structure would be preferable.

However, I really doubt choosing the centerline location is a significant concern issue in this application because: 1.) there is only one 90* degree gusset joint in the side truss base tube structure geometry 2.) all three gusset legs are welded in the truss openings 3.) gusseting multiple adjoining truss openings with different leg lengths effectively spreads out and minimizes (eliminates?) the concentrated 'can-opener' forces 4.)  the gusset end points are removed to facilitate welding.

That said, I also see no reason to offset from center if it makes you feel better. Definitely need some lightening holes. :)

Edited by dholly

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Posted

I agree with the holes,  a good sharp hole saw in the drill press on the slowest speed possible with a little cutting oil cuts right thru them,

 

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Posted

Spent this morning thoroughly spraying down the wings with enzymatic cleaner, and put a bunch in the spars and slowly spun the wing around to coat the entire inside, my wife was nice enough to help with this. the unfortunate incident that transpired while doing this is my thigh caught a rib tail and snapped it off. guess this is the best time to have that happen though as I will be installing all of the tail strengtheners and will reattach it at that point. Anything else I should do when reattaching it? was going to use Hysol to glue the butt ends together, then hysol on both sides sandwiched between the aluminum strengtheners, then rivet the strengtheners. 

Also put in my full order for coverings through Wicks and got their 10% off, but ordered the uncertified medium fabric from Spruce, along with the whelen microburst wingtip lights, and a bunch of other smaller things (fuel line/ filters/cotterpins/ body filler etc etc….

One more question. I am going to go with a similar paint scheme as posted on page one, with light green being the main color and black being the scallops, I ordered 2 gallons of green and one gallon of black, in anyones experience is 3 gallons enough to do the whole plane?

 

DOH!! my wife heard some bad words slip out when I pulled this bonehead

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My go to color scheme that Im trying to match

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Posted (edited)

I would not just butt-glue the rib tail.  I have replaced several of them, and it is so easy to cut a slot in the rib and put in about 12" of new tail and glue it all around then glue, rivet and sandwich the braces on each side of it.  That is a much stronger repair.  I beveled the edges of the insert and the cutout in the rib so I would have a stronger glue joint.

Edited by EDMO

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