Strip it the rest of the way down?


27 posts in this topic

Posted (edited)

Okay guys ever since I bought the plane I've been trying to convince myself that the rust I could see on the fuselage wasn't a big deal. With all the work I'm doing to this plane it's getting harder and harder to convince myself not to just bite the bullet and have a plane that I don't have to worry about for a long time. 20190911_194635.thumb.jpg.9def4c728db1f320190911_194610.thumb.jpg.627b3262db385120190911_194554.thumb.jpg.98ae405b1a97e3perhaps the idler is the piece that's doing the most to convince me. It just looks really rusty and it's just bothering me really bad. So pretty much committed to doing a full tear down and recover.

I'm also wondering about the fabric. I have the floorboards out and was just test fitting the rudder pedal back in and it fell forward and the rudder cable attach tab went right through the fabric on belly. It shouldn't be able to do that right? 

Ok so here's where the questions start. 

What's the best way to strip the paint and rust? Ive been looking at the sand blaster from Harbor Freight. Any reason not to go that route?

What's a good paint to use? It looks like it's got zinc phosphate on it now, and I'm thinking that didn't work so well.  So what's a better option? Hopefully it's something that i don't have to spend a lot of money buying application equipment. 

Edited by Willja67

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Posted

For me there are only two choices for fuselage,  Epoxy or powder coating.  Either way it maybe something to farm out.  Some of the prices for powder coating that folks have been getting would be hard to beat.  The downside to pc is that it is hard to get it off if you need to do repairs and rust can grow out of sight under the coat.  Painting there is a lot of waste, time consuming and a fair amount of specialized equipment to do a good job safely. Think outside air source for breathing.

Sandblasting takes a lot of air so the bigger the betters far as compressors go.  I've used some of the small pot blasters and was less than impressed, ok for small projects only.

So all that said I would probably tackle the job myself using Epoxy but I do own all of the painting equipment.  Sandblasting I would farm out because it is a nasty job requiring big compressor, a big sand pot and lots of heavy media.

The above is just my thought and worth about what you paid for it.

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Posted

May want to check out this thread on how I did the rebuild on a Kitfox 4 which included sandblasting and painting the fuselage.  JImChuk

www.avidfoxflyers.com/index.php?/topic/5381-kitfox-4-rebuild/
 

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Posted

Maybe Ive just missed this but Ive never seen plywood over the top of the wing tank before in any pics. I admit since I wasn't looking for it I may not have seen it.

I just started stripping the fabric off the wings and found this:

20190919_195635.thumb.jpg.2d2054a6748c43Is this normal? Looks like a lb of weight that could be lost to me. 

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Posted

Dont know if normal, but my tanks in the set of wings i just did for KF #0038 had the same plywood over the top of tank. 

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Posted

If it's structural definitely don't want to get rid of it but if it's just for looks then, I'll take the weight savings

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Posted

Aluminum tanks??

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Posted

Aluminum tanks??

yes

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Posted

I would venture that its structural and would not remove unless you like popped seams and leaky tanks.  There was a reason that KF stopped using aluminum tanks, I would not take away anything that adds stiffness in that area.

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Posted (edited)

Had the same hesitation some years ago, the more I striped it down the more rust I found. Had all metal sand basted and powder coated. Covered with Oratex UL600.

Take a look at my blog, this link is pre-selecting the rebuild posts

http://avidsimonini.blogspot.com/search/label/Rebuilding the Avid Flyer 

This is from the covered parts of the tail plane while free tubes didn't look any worse than yours. A critical area, difficult to inspect, is the tail. Whatever you do, uncover it to find out...

IMG_2947.thumb.JPG.bfc074d8d8f43b17ad1d5

Edited by FredStork

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Posted

I was pleasantly surprised to find all the tail structure to be almost completely free of rust. 

The upper portion of the fuselage frame is also mostly free of rust. Not sure why that is.  There are drain hole grommets or there were and it looked like they were correctly placed. But that doesn't explain the rust on the elevator idler. And other locations where moisture couldn't pool. 

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Posted

I would venture that its structural and would not remove unless you like popped seams and leaky tanks.  There was a reason that KF stopped using aluminum tanks, I would not take away anything that adds stiffness in that area.

I guess it stays. 

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Posted

I've seen many that the fabric was great and rust was on  the tubing. Moisture will form inside the fabric in certain conditions just like taking a glass out of the freezer. If there is a scratch in the primer or defect, the rust will start.  From the looks of the elevator bell crank, it appears it wasn't properly cleaned prior to priming.

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Posted

Ok next question, we all know the KF1 could use some more yaw stability. So what if I raised the stringer going down the spine to add a strake kinda like the P-51D?20190921_215740.thumb.jpg.5e63ff97e8c1c8

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Posted

It may interfer with folding the wings,.  JImChuk

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Posted

If i don't go above the tube the h-stab bolts to i think i should be fine.20180831_163509.thumb.jpg.a8df6085b23e02any structural considerations?  Would probably want some support under it so the fabric dosen't buckle it. 

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Posted

I added a bit of height to my Mk-4, more for looks really. This was all I could get before interference with the flaperon counter balance weights when folding wings.

image.jpeg

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Posted (edited)

I added a bit of height to my Mk-4, more for looks really. This was all I could get before interference with the flaperon counter balance weights when folding wings.

image.jpeg

totally missed the counterbalance weights when looking at that pic, but on mine they're aft of the rudder when folded so no issue there.

How did you raise it? Metal or wood?

Edited by Willja67

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Posted

I chose to Hysol in a piece of metal tubing.

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Posted

Ok next question, we all know the KF1 could use some more yaw stability. So what if I raised the stringer going down the spine to add a strake kinda like the P-51D?20190921_215740.thumb.jpg.5e63ff97e8c1c8

Proof positive that there are very few original ideas:

61283551_358507364802413_304182101243384Scott Palmer's model 4 Kitfox has this exact mod. Would be nice to see inside how it was done. 

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Posted

Ok next question on a possible part to leave out when I put it all back together and that is the skylight support, specifically the rib profile. I just noticed none of the newer foxes (5-7) have the support. I'm not concerned so much with how much weight that will save as I am with the extra inch of head clearance. The polycarbonate seems pretty stiff when supported on all 4 sides especially with the airfoil curve in it. Thoughts?20190926_213227.thumb.jpg.d06ac23ba5b555

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Posted

I would keep it, but I'm short. ;)

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Posted

Am I going to be listening to it oil can right above my head if I take it out? I can imagine that would be disconcerting and highly irritating. If so that's a good reason for leaving it but with my plan to sit in the middle i can only just put a finger between my head and that brace and that's without a headset. 

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Posted

I was hoping  a few would chime in on this one as I have wondered the same! My 1.5 mm screen is due for replacement,the support won't be going in unless there is a flutter issue.

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Posted

I think it's there for good reason. I had to add a T-deck support post to stop the rattle.

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