Skin repair using an English Wheel

[featherbedder]

I severely damaged left front corner banana wrap dented and bad crease. A shop wheeled it no stretch of aluminum, no prep before nothing after can not even tell was damaged but this shop is a pro shop that spec. in fab. work, mostly custom cars but will do any type of metal work. Little exp. but less cost than plastic wraps plus keeps vintage intact. Bill

[Keyair]

Can someone refresh my memory on what Aluminum to buy to replace a panel?
And thickness?
I have to make this rear RH mid, and lower, that some PO dented.
The upper was made worse by repairing with a slide hammer and screws...

[shinytincans]

Keyair I use 2024t3 you can get it from aircraft spruce ..I would use 0.040 for that panel... good luck..

[mimiandrews]

2024T3 works great on flat panels and those with a simple curve (one direction only), but it is pretty stiff and easy to crack. I'm not sure you'd be able to work it into the compound curve I see on that upper panel. I'd recommend researching other alloys (that's the 2024 part) and other heat-treat levels (that's what T3 indicates) before you buy.

[Keyair]

I found this info which says:
1983 Alcoa 3003‐H18 .032 Controlled mill finish

https://www.airstream.com/wp-content...92c0a731f5.pdf

[sgschwend]

I would just fix that panel, if you have extra holes from the PO I would make a single patch or try rivets in those holes.

I all case you are going to pull that skin, so why not clean the inside and English Wheel it? Anneal that area if need be, just make sure you work the part directly after annealing.
steve

[Keyair]

Good point and advice.
Also, 3003 is very weldable, so might take a shot at filling those holes then wheeling it a little...
What is the worst that could happen!

[DavidsonOverlander]

Originally Posted by sgschwend

As to creases, if you had the skin off and you annealed it then the crease would likely repair to a point that would be better than acceptable. I annealed most of those 5 skins. Annealing really does give the metal a chance to release the dent caused stresses and also softens the aluminum so that it moves easy.

What is the procedure for annealing?

[Isuzusweet]

During the annealing process, the metal is heated to a specific temperature where recrystallization can occur. At this stage, any defects caused by deformation of the metal are repaired. The metal is held at that temperature for a fixed period, then cooled down to room temperature.

You might want to remove any interior structure and insulation before attempting this.

Cheers
Tony

[Buck Rabbit]

Originally Posted by Isuzusweet

During the annealing process, the metal is heated to a specific temperature where recrystallization can occur. At this stage, any defects caused by deformation of the metal are repaired. The metal is held at that temperature for a fixed period, then cooled down to room temperature.

You might want to remove any interior structure and insulation before attempting this.

Cheers
Tony

Is the heating something that can be done with a propane torch? How can you obtain a specific temperature? What temp for this type of material? How do you hold it at that temp? I was going to replace 3 panels with new but now am looking for a wheel to try that.

[sgschwend]

I use a large rosebud, but a weed burner would work. You want a big round flame not a focused one. Keep the flame moving. Anneal temp is around 650F.

The skin has built in stress, as the skin is heated to the proper temperature the skin will move, you can see it easily. That seemed to work well enough for me.

[Buck Rabbit]

I found several English Wheels within an hour or two of my house, for a reasonable price. As the weather improves, I am preparing to take the plunge on this project. Vintage Trailer Supply has a pretty comprehensive Buck Rivet kit that I will be ordering before I start drilling. What should I use to seal between the panels when I reassemble?

[Mollysdad]

Originally Posted by Buck Rabbit

I found several English Wheels within an hour or two of my house, for a reasonable price.

I remember bike builder Jesse James saying getting your thumb caught in an English wheel was like hitting yourself with a hammer, except the hammer didn't let go.

[Aerowood]

He is correct, it will leave a real pretty blood blister, been there, done that.

[Lumatic]

I have a nice dent on the front corner of my 71. The area is a bit of a compound curve but not as pronounced as the endocarps. I would like to make a "rock guard" primarily to cover the dent that is already there. The rock guard should be about 18 to 24 inches high and wrap around the front corners of the AS. Anyway to do this without an english wheel? Can an english wheel be used on aluminum diamond plate?

[Aerowood]

An English wheel will not work on diamond plate. If I was you I would just use a piece of .063 and wrap it around the corner with some stand-off’s. The compound is slight. I replaced the forward corners using flat sheet. I’m sure you have seen it and just didn’t notice that it is flat sheet.

[Keyair]

There are grease pencils available that melt when the correct temp is reached.

[Keyair]

I think this thread is very interesting from the standpoint of panel repair...


http://www.airforums.com/forums/f311...ed-186935.html

[sgschwend]

As to indicator, you can use a pine paint stir stick. The sap will flow at the full soft temp. I used a my torches rosebud and that way I could cover the skin without hot spots. I did not need an indicator stick because the skin shifts under the heat, the shifting shows the skin has been "relaxed".

As to repair: I started this thread after repairing all of the five rear end cap panels. The machine can do it all: creases, dents, and distortion inward or outward.

Recently I met a aluminum airplane skin repair expert. He could even make new skins by using a planishing hammer to rough out the part then an English wheel to complete the skin to a smooth finish. He said what I was doing to fix a damaged skin was easy and I agree it is easy to fix a damaged panel. Even if you have a tear in the skin a patch can be riveted on to cover that hole, I prefer round patches; there is a thread on this forum showing more decorative patches. The round ones are just easy to fit and install.

[Keyair]

Yes, I've noticed the "Shifting", but wasn't sure if that was expansion or relaxing.

Bought the correct wax pen but have not used it yet.

Built out my E-Wheel, with a P-Hammer attachment, as well as Bead Roller and have been getting some practice in...