Breaking edges of Tailcone Skins

So on page 10-2 it talks about breaking the edges of the tailbone skins. I bypassed that and prepped the skins, deburred the holes and edges and just last night I installed one of the bottom corner skins (1282) non-broken and one broken with the avery tool (I have the cleaveland tool on order) - these are cleco'd only at this point.

iMHO, the non-broken skin edge overlap looks just fine, but keep in mind, I haven't actually riveted yet. On the aft stab skins, I just gently used a seamer to bend the skins in slightly and they turned out fine.

It strikes me that perhaps because we are using pulled rivets and the quality of the kits indicate that perhaps the traditional edge breaking techniques are not fully required?

Any feedback is appreciated. I see from previous archives on the site that perhaps the top skins require more breaking? Thanks in advance for any feedback.

I came to the same conclusion from the same mistake. After riveting there was no indication of the results you are supposed to have from the rivets on an unbroken edge.
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DonFromTX said:

I came to the same conclusion from the same mistake. After riveting there was no indication of the results you are supposed to have from the rivets on an unbroken edge.
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So you think it is ok to rivet UNbroken skins provided they lie flush with the underlying skin while cleco'd?

The one I did break looks like ****. I mean it is on the bottom, and I guess it lies a little flatter - I really didn't break it that much and paint will fix all....but I really don't want to do any more edge breaking if I can help it.

Wait for the Cleveland tool to arrive. Get a scrap piece of aluminum, doesn't have to be 8' long.... Practice for 10 minutes then break the skins. You will get a much better look on the tailcone. It's not a difficult skill to learn and will pay off when finished.

I would never recommend anything different than the plans, but my experience showed it seemed to make no difference really.
Breaking the skins was a real learning process for me, did not seem like I could get the hang of it quickly. I was using the "vise grips with rollers" model. As previously stated, practice on some scrap a bit to get the hang of it. Once I got the hang of it there seemed to be less unsightly breaks. When done well, the effect seems to be slightly advantageous, not sure what it will look like after paint. The rivets do tend to pull the surfaces together and thereby lessen the break line.
Others will chime in I am sure, but I think it would not be a big deal if someone did not do any skin breaking on pop rivet construction.

I bought the Cleaveland tool. It was easy to use and did a fine job. The break is surprisingly slight, except for the top rear skins where the plans have you form a more definite angle. Just run the tool along the edge, WITHOUT applying any extra downward pressure to force an angle. The correct break angle is formed by the rollers. As to whether the break is necessary or not, if the lap is between two flat sheets, I think you could probably get a good result without it. If the lap occurs where the sheets are curved, the break would be a good idea IMO. As you already have the Cleaveland tool on order, why not use it?

Almost to this step...

rgmwa said:

...except for the top rear skins where the plans have you form a more definite angle.

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G'Day rgmwa: Also have the Cleaveland tool and will very soon be doing this step. Could you please clarify just a bit...were you able to gradually increase the break angle on the top skin with this tool, according to the plans (seems maybe not possible)? Or, did you disregard that part and simply made the break uniform over its full length?

Thanks in advance,

I just laid the skins on my work bench with the skin overlaying the edge and worked a wood block back and forth until I got a curve with the tangent line running through the center of the rivet holes. Quick, easy, cheap and it works!

I used the Avery tool with GREAT success!

Not trying to downplay the folks that had trouble with this step, but 'breaking the skins' is quite easy! I used the tool from Avery. It looks like a black anodized, thin hockey puck, with two nylon rollers. Lay the skin on the workbench with just about 3/4" - 1" hanging over the edge. Gently apply outward and downward pressure on the top of the tool and work the tool in a fluid steady motion down the edge of the skin, pulling toward you. Not much pressure is required, and the actual 'bend is very very subtle. The rollers do all the work, based on your slight downward/outward pressure while pulling the tool toward you. It is NOT a radical / extreme bend. Once you've worked the tool down the edge, bend down and look down the edge of the skin. You can easily tell is there is an area you've not applied as much of a bend..if so, just work the tool back through that area. As I mentioned, I used the Avery tool with great success. Long after I used the Avery tool, I found a set of the vice-grip versions of edge breakers, that I forgot I had. I tried them on a piece of scrap, and it looked horrible! I suppose it is just whichever tool you feel the most comfortable with. I found it to be a quick and easy task. I can't stress enough though, that when breaking the edges, it is a VERY VERY subtle bend. Nothing major.

The plans call for doing this process again before you rivet on the fuselage (cockpit) side skins. It took all of about 45-seconds to 'break' the edge of each skin. Once rivets are installed, the skins can lay different than when just held on by clecos. I understand some folks didn't break the edges and their skins look fine. But I followed the plans to the letter, and all of my fuselage skins look fantastic. If someone is using the Avery style 'puck shaped' tool and is having problems, please send me a message and I will call you. I'd bet I could verbally walk you through just how simple it is. I'll be glad to help if I can.

XOverZero said:

G'Day rgmwa: Also have the Cleaveland tool and will very soon be doing this step. Could you please clarify just a bit...were you able to gradually increase the break angle on the top skin with this tool, according to the plans (seems maybe not possible)? Or, did you disregard that part and simply made the break uniform over its full length?

Thanks in advance,

Click to expand...

I used the Avery 'puck-shaped' tool, so I'm not sure if it is similar to the Cleveland version? But yes, you simply apply more pressure to the area where you are required to put in more of a bend. I somewhat dreaded this step before I did it (not wanting to screw up a fuselage skin) just like the longeron bending. But both breaking the edges and the longeron bends both ended up being a non-stressful event, and turned out great. Breaking the skin edges is a very quick process.

txaviator said:

I can't stress enough though, that when breaking the edges, it is a VERY VERY subtle bend. Nothing major.

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I'm the guilty party here. So when you broke your edges, did you see an actual slight line in the skin? Or am I doing too much pressure? I should say that both Avery and Cleaveland make excellent tools and I am happy (sort of) to give them my money for the quality I receive...that said....I watched the EAA video, and they show a line and then talk about how that can be buffed out later.

I haven't gone far with this process yet. And this is the first thing that I have found rather intimidating in the build process. I get the concept, the idea and the process. It's just the result that has me wondering if I am doing to much breaking, or if it is really required at all?

The Cleaveland tool should arrive shortly and I will scrap my scrap....some more!

cactuspilot said:

I'm the guilty party here. So when you broke your edges, did you see an actual slight line in the skin? Or am I doing too much pressure? I should say that both Avery and Cleaveland make excellent tools and I am happy (sort of) to give them my money for the quality I receive...that said....I watched the EAA video, and they show a line and then talk about how that can be buffed out later.

I haven't gone far with this process yet. And this is the first thing that I have found rather intimidating in the build process. I get the concept, the idea and the process. It's just the result that has me wondering if I am doing to much breaking, or if it is really required at all?

The Cleaveland tool should arrive shortly and I will scrap my scrap....some more!

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Yes! You will see a slight line, most definitely. Part of this is the slight bend/break of the skin, and some of what you see will be a line formed by nylon roller residue (if using the Avery style tool I used).. But yes, you WILL see a faint line, which should be perfectly straight down the edge where you 'broke' the skin.

This part is tough to explain, but it takes a pretty decent amount of tool pressure to create the SUBTLE bend. Just be sure that when pulling the tool toward you, that you keep the face of the tool flush against the outer edge of the skin. Again, this is using the hand-held 'puck' style tool. The vice-grip version is a completely different animal, in terms of describing its use. I loved the results from the puck style tool.

I was very happy with the vice-grip style tool. For ME (then a first time builder), the key to that was NOT to "pull" it towards me. Instead, one hand held the tool and the other hand turned the roller part manually. VERY precise control resulted from that method, compared to "pulling" and "running off the edge." It is just a small amount slower. Either tool works with the right technique though.

I never got beyond the "pulling" phase, should have tried the push system. My problem was learning to control it in such a way that it did not run off the edge constantly. Unlike the nylon rollers, the vise grip type tool takes very little pressure to get the right bend, in the beginning I was using too much pressure on the rollers. Also don't try to "force a bend" with this tool, let the rollers do all the work and do not try to twist the tool to make a bend.
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Bill_H said:

I was very happy with the vice-grip style tool. For ME (then a first time builder), the key to that was NOT to "pull" it towards me. Instead, one hand held the tool and the other hand turned the roller part manually. VERY precise control resulted from that method, compared to "pulling" and "running off the edge." It is just a small amount slower. Either tool works with the right technique though.

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XOverZero said:

G'Day rgmwa: Also have the Cleaveland tool and will very soon be doing this step. Could you please clarify just a bit...were you able to gradually increase the break angle on the top skin with this tool, according to the plans (seems maybe not possible)? Or, did you disregard that part and simply made the break uniform over its full length?

Thanks in advance,

Click to expand...

XOZ: I used the tool as normal to put a uniform break on both sides of the top skin. Then to increase the break over the rear portion as shown in Fig 1, Page 10.02, I did what I said not to do in the previous post - applied more downward/rotational force to progressively increase the break toward the end of the skin. You could also use the normal wide-mouthed pliers type of tool to do this if you have one.
The main trick with using the Cleaveland tool is to adjust the gap betwen the rollers so that it is not so tight that it becomes difficult to drag along the edge, nor so loose that it doesn't form the break properly. Then make sure you hold it firmly against the edge so that it doesn't slip off.

UPDATE -

I received the vice-grip rollers from CT and tried those today using the instructions provided and they did a much better job for me. I am pretty happy with the bottom skins now. The trick does seem to be to get the right clamping force and it does leave a very slight, but consistent line and the overlap seam is very tight. I would post pics but I don't have the pic posting process down just yet.

Thanks to all for your advice and counsel.

Breaking Edges of Skins

Regarding edge breaking of skins, I'm building RV number three and have found the Cleveland tool the best one, by far, for this job. A neater joint will be formed if the edges are so formed.

XOverZero said:

G'Day rgmwa: Also have the Cleaveland tool and will very soon be doing this step. Could you please clarify just a bit...were you able to gradually increase the break angle on the top skin with this tool, according to the plans (seems maybe not possible)? Or, did you disregard that part and simply made the break uniform over its full length?

Thanks in advance,

Click to expand...

Always practice on scrap first, but I would recommend doing it all uniform first, then sequentially tightening up the tool and re-rolling the parts that you want more of a bend. Keep in mind that on most surfaces the bend should be so slight that it's barely noticeable. This is often overdone. Use a razor blade to see when the skin edge is just leaving the blade edge, and that is all you need. The object is only to keep the skin tight against the other skin in between the set rivets, not to create a crease.

-Mike

The Cleaveland tool if used correctly beautifully breaks the edge on the skins. There will be NO line or crease. The break is almost imperceptible. Using a flat surface, as suggested by Mike, such as a razor blade shows your progress.

From my blog.....

"To use this tool, open up the set screw and close the jaws. Then put the tool on the edge of the piece to be broken with about 20% of the roller engaging the skin. Then tighten the set screw just enough to get the rollers to touch the metal. Then open the jaws and close them with edge guide (roller collar) against the edge of the material. Then just pull the tool along the edge without twisting it down. The tool does the work and only bends about 3/16ths inch of the edge down. If the tool does not pull along easily, you have it too tight. Remember, you are not putting a large bend in the edge, but a slight bend (2 degree) on the very edge. The tool does that without having to twist the tool. If you twist the tool down while pulling on it, you will put a crease about 5/8ths inch in from the edge where the inner edge of the tool is. That is not where the break is supposed to be."

And I add......If you make three passes with the tool, with it slightly loose to start and then tightening it ever so slightly between passes, you will have more control of the tool. And always ensure the collar on the tool remains against the skin edge.

straigten

cactuspilot said:

The one I did break looks like ****. I mean it is on the bottom, and I guess it lies a little flatter - I really didn't break it that much and paint will fix all....but I really don't want to do any more edge breaking if I can help it.

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My F-1282R looks exactly the same. Like ****
The edge has become wavy over a length of about 23" and the more I try to fix it the worse it gets. I consider to re-order that part, although it's gonna be very pricy, above all to properly crate and to ship it safely to Europe.
Unless there is a way to get the edge straight again. I was using the Avery "hockey puck" tool which I am not blaming. It was me, learning that technique on a precious A/C part. If only I had ....
I still have hope that somebody can point me to a less expensive solution rather than re-ordering.
Thank you !!!!!

Builders are usually more critical of their own work than others are. Have others look at it and ask if you should live with it, try to fix it, or replace it. There is a tool called a stretcher\shrinker that might be able to take waviness out. But I have no experience using a shrinker. And you might make it worse.
One builder was sick looking at his finished tailcone with oilcan effects. He asked his wife what he should do about the dents. His wife looked at it and asked, "What dents?" And so, what looks bad to you might not be noticeable to others. Sheet metal is not going to be perfectly flat.
Joe Gores

I too have the hockey puck tool and fortunately tried it on another project. I too had a wave edge that looked terrible. I switched to the vice grip pliers type of edge tool and had much better success.

The key to either tool is light pressure and just a small break. Practice on something else first! If it is wavy, you're probably trying to hard. On the hockey puck type tool (at least the one I have - over 10 years old) the amount of break you put on is really determined by the angle that the tool is applied to the metal as well as the amount of pull on the tool along the edge. To me looking back it seemed that I did neither consistently well and ended up with strong waves. Some people use this tool without issue and have great success. For me, as a beginner, it probably should have never been in my toolkit.

The vice grip type is smoother to operate (for me) and since its adjustable, in terms of how much edge you put on, is easier to get a smooth break on. It really doesn't take much. Like both tools - pull slowly.

In the end I didn't use the piece of metal I had waves on. I didn't think I could ever straighten it out and make it look good. Eventually, The Hummel project ended up on the shelf and forgotten about so the break didn't matter.
If I ever drag it out again, that skin will be replaced.

Bob

The vise grip roller edition is the way to go. If you can see a crease you went way TOO far. Practice on scrap.

What Marty said.

MartySantic said:

The vise grip roller edition is the way to go. If you can see a crease you went way TOO far. Practice on scrap.

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Start with very light pressure, go slow. Multiple light pressure passes worked best for me.

Have been using the puck since the tail cone. The leading edge of the rudder (before I bought the tool) could have used it. I did the wings (building EAB) at the leading edge. I'd say the joints are water tight. I also did every skin on the tail cone. Pretty easy once you get started. I also only hit it once with enough pressure to get the break. The pucks directions say that too much rolling will stretch the skin. Haven't seen that but I do like the way everything has come together.