Aerowood and Boatdoc are my hero's! You are doing some great work.
I recently bought a '67 Tradewind 24' which I thought just needed a "little sprucing up". As I started to remove parts I found a great deal of rust on the frame.
Just aft of the axle mount flange the top and bottom beam of the main frame C-channel is rusted completely through! Arrrrgh! Boatdoc's observation in another post is painfully true, the engineering at the Airstream plant was painfully lacking.
I was hopinign to just slip a little new plywood under the wall and be using it in a few weeks. Now I am at the point where it looks like I need either major frame repair or to build a new frame.
I have extensive experience as a mechanic and moderate experience as a fabricator (although not much in sheet metal) so I believe I have the skills to effect a first class repair.
I do have a few questions:
1 - I have no experience with bucked rivets and would like to use those as able in this restoration. Can you give me a good reference for a book or preferably a website which details the process of bucking rivets?
2 - Can you tell me the specific tools I need to buy to buck the appropriate rivets? I am assuming a bit for my air hammer and some type of hand held anvil. I checked with my local Snap-On dealer and he had a bit but could not tell me what size rivets it fit.
The process is pretty basic in theory and simple to do after some practice. Put the rivet set, which is in the rivet gun, on the rivet head, and the bucking bar on the tail, pull the trigger and push the bar and after the head swells up to form the bucktail let go of the trigger on the rivet gun, simple . There are some really good aircraft S/M books out there and I will post the names when I find one off my old ones. As far as tools are concerned you will need a 3X rivet gun, 5/32 universal head set, bucking bars, good air drill 2500-2800rpm, cleco's and cleco pliers. That's the basics. I like using these people: Brown Aviation Tool Supply Co. Your air hammer will not work properly for shooting rivets, the piston stroke is not fast enough and will cause damage on thin skin. Snap On tools owns ATS (aircraft tools) and your dealer can get the tools you need but there's quite a markup on price. Alot of tools are available on ebay using aircraft tools on the search engine. I hope this helps.
Thanks for the info. I'm already through the web page and working on an order from Brown.
I thought it was relatively simple. I imagine it will take a few practice tries to perfect (or at least or at least not completely screw up) the technique.
So do I need to buy 5/16 rivets? Or is that the size of the head and the rivet is smaller? Also, is there a partiuclar alloy of rivet which is best to use? Are there various size bucked rivets used on the AS or just one?
The size of the rivet is determined by the diameter of the shank. The stock rivets in your Airstream was a 1/8" diameter with a larger brazier style head. These rivets are no longer available, but a 5/32" dia. universal head is very close. If there is a dimple in the head, that is a rivet with the aluminum alloy of 2117-T4. If there is no dimple then it is 1100 aluminum and very soft. the P/N for the 2117 is MS20470AD5-X and the P/N for the 1100 is MS20470A5-X. X equals the length if the rivets in 16ths with half sizes available. The length of the rivets is determined by the combined total thickness of the pieces being shot together and the diameter of the rivet installed. D always means Diameter. So to find the length needed add the materials thicknesses together such as in airstream skin .032 + .032 = .064 which is almost dead on 1/16 and then add 1.5D for the bucktail. Add it all up .032+.032+.156+.078=.298. .298 divided by .062 equals 4.806 so the rivet length will be a -5
The rivet part number MS20470AD5-X brakes down as follows
MS20- Rivet
470- Rivet head style, Universal protruding head
AD- Rivet alloy, 2117-T4
5-Diameter in 1/32's, 5/32
-X length in 16's with 1/2size longer being .5
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
Bananna wrap: I just finished pulling the wood putty and 25 sheetmetal screws some joe had repaired curbside front corner with - will be interested to see how painlessly your battle goes! Seeing the clecos in like that makes my interior rehab minor in comparison, thanks
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
This was the technique that came to my mind after seeing one of these custom Harley shows. They were forming a new fuel tank using aluminum after annealing it with a rosebud torch. The technique he used was to use acyteline only, no oxygen in the flame. I found that a cool idea (no pun intended) after some bad experiences as a young man with aluminum puddles while trying to heat some aluminum. I'm still "goosey" about heating aluminum after all these years...
Did you use this or some other tecnique?
Dave
I just used a propane torch, It gets hot enough to soften it up, but I didn't linger with the torch. I experminated with one of the lower removed skins before I commited to the upper skins. The big gouge I worked out is not perfect but you will have to look for it to find where was.
I straightened the corner bannana wraps and have made repaires on both. I am installing them under the side skins. I drilled them all up, and I am now ready to prime all the new skins and misc. parts. I would like to have everything ready to shoot by this weekend weather permitting. I may have to wait due to my bucker may have to go to Japan this weekend.