'71 Globetrotter Full Monte

[Bauxter]

Originally Posted by Aerowood

I was finally able to get some work done on The GT. What I did was to rivet a small clip attaching the new stringers to the frames. The work was slow and it took me a couple of days to do. Next on the list is to open clean and install stringers on the two upper skin lap joints. I will also be installing a flush lap joint repair to repair a vent hole in the lap joint. Why the engineers at Airstream did this is beyond me.

Aerowood, Did you buy or build the stringers? If you built them, what aluminum grade and thickness did you use?

[Aerowood]

I bent them up at work. They are made of .063 2024-T3 Bare (no Alclad)

[Bauxter]

Originally Posted by Aerowood

I bent them up at work. They are made of .063 2024-T3 Bare (no Alclad)

Kip, I see that airparts has 3003 H14 .063 for a lot less. Would it work OK?

[Zeppelinium]

Originally Posted by Bauxter

Kip, I see that airparts has 3003 H14 .063 for a lot less. Would it work OK?

Let's see if I've learned anything from Kip.

Use 5052-H32, it's also cheaper than 2024. The 3003 is soft, you don't want it for structure. You can also use 6061-T6, which has great corrosion resistance.

Let's see if the Master agrees...

Zep

[Aerowood]

Here is a answer from best to worst

7075-T6 overkill
2024-T3 best
6061-T6 better
5052 H34 good
3003 worst

[Bauxter]

Kip, I have heard from others that 2024T3 cracks when bent to a 90. Has that happened to you?

thanks

[Aerowood]

2024-T3 cannot be bent with a knife edge top die on the break, it requires a radiused bend. For .063 a 1/4" radius is best, 3/16" will work but breaking against the grain is a must, along with polishing the edges at the bend. 6061-T6 will require a smaller radius of at least 1/8". 5052 and 3003 can be broke with a knife edge.

[gnmostream]

Kip,

I noticed a small leak last summer in the area of the water tank panel that is lowered on the bottom of G T. I removed the front angle iron and bellie pan sheet metal covering the plywood that supports the water tank but the plywood will not slide out of the angle iron channel even with the help of a rachet strap and a com-along. I pryed and beat on the plywood and angle iron but to no luck it would not budge. There are no apparent fastners from the plywood to the angle iron. I have a couple photos attached. Any suggestions on removing the plywood that appears to be in good shape with no apparent rot?

Thanks,

Guiseppe Margiotta
Pagosa Springs

[Aerowood]

Mine had a few screws that went through the bottom channel into the ply that had rotted off leaving the shank still in the iron. I punched these into the ply. I also had the devil of a time getting mine out. you might try screwing a strap or something to the ply to get a good hold of with the come-a-long. It took me the better part of a day and a six pack to get it out.

[Breadbug]

Originally Posted by gnmostream

Kip,

I noticed a small leak last summer in the area of the water tank panel that is lowered on the bottom of G T. I removed the front angle iron and bellie pan sheet metal covering the plywood that supports the water tank but the plywood will not slide out of the angle iron channel even with the help of a rachet strap and a com-along. I pryed and beat on the plywood and angle iron but to no luck it would not budge. There are no apparent fastners from the plywood to the angle iron. I have a couple photos attached. Any suggestions on removing the plywood that appears to be in good shape with no apparent rot?

Thanks,

Guiseppe Margiotta
Pagosa Springs

<img src="http://www.airforums.com/forums/attachment.php?attachmentid=124942"/>

<img src="http://www.airforums.com/forums/attachment.php?attachmentid=124943"/>

<img src="http://www.airforums.com/forums/attachment.php?attachmentid=124944"/>

Mine was stuck in there too. Tons of gunk! I used my TV. I attached a chain to the front center of the plywood. The other end of the chain was hooked to my TV. I made sure the trailer was secure and then very slowly pulled. It came out like sliding on butter. Once out I could see that the rust and debris along with swelling from dampness had it wedged in so tight that I would never have gotten it out without such measures.

It took all of 15 minutes to do. What a relief it was.

Ed

Ed/Breadbug

[Prickly Pear]

Mine was a fairly heavy piece of plywood. A thin pry bar between the back edge and rail moved the board a few inches. That gave enough space at the front to drill a hole. The come-along attached to a loop in the hole got it out along with some hammer blows and expletives. A jack was used to control the tank drop. There are four plywood strips around that might drop also.

Jim

[constructor]

The constructor took off the front angle iron after removing a few screws and rigged a come along to the tow chain and screwed a hook into the end of the plywood with long screws to the attach to the come along. The 1st 1 inch was tough and stuck then released and pulled out once moving.

[gnmostream]

Thanks for all the suggestions. I forgot the six pack and explitives!! If I had to wreck the plywood out is it imperitve to replace it with the 1"-8 ply treated plywood that appears to hold the tank in? Or will the 3/4" variety treated work with some shims?

Thanks,

Guiseppe

[Aerowood]

I would laminate to the removed thickness.

[gnmostream]

My thought was to use 2 1/2" pieces and glue them together for the 1" thickness. I will send you some more photos when I get to that point.

Thanks,

G

[filterman]

Could you elaborate on this a little better and how to make the tool please. Thanks

Originally Posted by Aerowood

I'm hesitant to bring up this procedure due to the beating I'll probably get by some members stating it's not possible, but here it goes anyway. Most people think that the end caps are made of 2024-T3. I've been working aircraft sheet metal for so long that I can identify alloys and heat treatment just by how the metal works. When I first started working on the skin replacement on my Globetrotter I noticed that the end cap aluminum was quite abit softer then the flat sheets. They are 2024 but I know they are not T3. The skins are most likely stretch formed 2024-0 and any hardening was by cold working as the sheet formed over the die, so the temper is most likely some where in the neighborhood of T1. Knowing this I fabricated the tool below to try and roll out some gouges and dents. On the larger ones I (here comes the naysayers) I heated up the area to semi anneal the aluminum. I then rolled out the dents and gouges with my "new" tool with some areas backed up with a lead shot bag. The aluminum was stretched in some areas and I proceded to shrink the aluminum back using heat and cold water. It worked better then I expected. The End

Kip

[vinstream]

SO... I too have been doing some "homework" regarding the alloys of the end caps and have determined that the end caps are not 2024-T3, And further research has brought out even more questions! The end cap aluminum in 58-63 (seven panel) and my guess but still researching 64-69 (Five panel) are not Alclad at all! I have through further research found that 58-63 (seven panel) it is a aluminum alloy that is no longer used. It was used in the aero space industry in the 50's and early 60's. The 2024 Alclad even with no temper was not used in the "stretch forming" process. Based on common aircraft production of the time. If you look at any 58 to 63 trailer with the interior completely out you will even see a visual difference in luster of the un-weathered aluminum color. It appears to be a tad duller. After even more research I believe that the Aluminum seven panel end caps are made with 5005 aluminum very uncommonly used in todays market place or in forming of today! So... this raises the real question if you can not or should not use 2024-T3, 3003, 5052, or 6061 then what should you use and what can you use? I have discovered 6013! it is 10-13% higher yield than alclad and it the choice of Boeing in all stretch forming! It also has the highest amount of Magnesium than non Alclad aluminum making it shine or polish up just as good as Alclad...

As per the mill spec!!!

"6013 Aluminum Sheet

6013 is a new medium strength aerospace alloy that provides improved corrosion resistance and formability for use in aerospace applications including primary aircraft structures. Alloy 6013 is an aluminum-magnesium-silicon-copper alloy that has yield strengths 12% higher than alclad 2024-T3 and is virtually immune to exfoliation and stress corrosion cracking. Industry use has demonstrated that 6013 in the T4 condition has better stretch forming characteristics than other aerospace aluminum alloys. Parts can be formed in the T4 condition and aged to the T6 condition without costly heat-treating or annealing operations. Heat treatable.

Applications
Uses for 6013 include primary structural applications including fuselage panels, leading and trailing edges and engine cowlings. Lockheed has chosen 6013-T6 for the fuselage of the Navy's P-7A aircraft. Canadair has specified 6013-T6 for the leading edges of the Regional Jet.

Questair has been producing the Questair kit aircraft since 1986 entirely from 6013. Major jet aircraft builders are considering 6013 for applications on large commercial aircraft.

Alloy 6013 is receiving consideration in most new programs taking advantage of the improved formability, lower density and corrosion resistance."


Todd

[Aerowood]

Originally Posted by filterman

Could you elaborate on this a little better and how to make the tool please. Thanks

I just did it by eyeball. I drilled a 1/4" hole through the middle of some 1.5" Al. bar stock and then turned a slight radius on the it. I did this all by eye no dimensions. I bent the "'U" bracket up out of .125 6061-T6 aluminum. I used a piece of 1/4" all thread for the shaft. The handle is also 6061-T6 .75 Dia with a Keensert threaded into one end to bolt the bracket to.

[Aerowood]

I don't quit understand Airstream engineers, why in the world would one cut a huge hole in the upper lap seam to install a waste vent. Being I am changing the location and style of vents I had one to patch. I decided to do a flush type lap seam repair only because I can. I also decided to install stringers on the upper lap seams. I also removed the fridge vent to roll out some dents and install a screen over the opening. I ran into another can of worms. The fridge vent was only riveted on with a few randomly spaced rivets. It also had a 1/8" cork gasket that was rotted out. I couldn't let this go so I removed the whole nine yards cleaned up the corrosion and the rest of the mess, and reinstalled with a few extra rivets. I still need to install nutplates for the vent cover. The lap seam itself was shot together dry and there was minor corrosion there as well. I cleaned this up also and shot the whole mess together with sealant. I am slowly working myself to the top.

[wasagachris]

Hi Kip I've got a question for you. What are the cleco's with the wing nuts on them? If you don't mind can you explain their function and uses.