Shaping aluminum sheet

[SJorgensen]

I want to do some modeling with aluminum sheet. I haven't done much of this and there will be a lot of compound curves. I will probably buy some sheet material of about 14 or 16 gauges and do my best at stretching and shrinking it to suit. While thinking about this, my mind asks why I can't lay up sheets of foil into the shape that I want, and why can't I do this with superior structural properties. How best to bond thin aluminum sheets into a solid material. Should I use a spot-welding process? Should I use a pressure bonding or cold weld method? Should I use an adhesive? Would it be an advantage to use hard adhesives in some areas and maybe flexible glue like silicone cement in other areas?

I guess I need to do some experiments.

[Evan]

Yikes. Lots of easy to ask questions with hard answers. First, hand hammering compound curves in aluminum is a fine art. For an example see here:

http://www.honeyshotrods.com/projects_cobra.html

Laying up foils to make a composite sheet is possible but not at the home shop level. The Airbus 380 uses a new material called Glare made from multiple sheets of very thin aluminum interlaid with fiberglass.

Spot welding is possible for most alloys but will leave a pattern of marks. Cold bonding is also possible but the aircraft industry normally uses vacuum bonding in an autoclave.

The best semi-flexible adhesive for aluminum is polysulfide adhesive/sealant and is used on pressurized aircraft to seal the hull. It is totally compatible with aluminum alloys and has very strong adhesive properties. It's also a freekin pain to work with, has a limited pot life and stinks.



[This message has been edited by Evan (edited 02-21-2006).]

[CCWKen]

Man, that's why I like working with steel. I can make it move just about anyway I want without any anealing steps. I guess it's what I'm used to but someday I might try AL.

It's basically learning to read the metal and how working an area affects the overall shape. Knowing when to stretch and when to shrink for a given shape may seem easy but getting it there takes a while to master.

[timz1999]

<font face="Verdana, Arial" size="2">Originally posted by Evan:
Yikes. Lots of easy to ask questions with hard answers. First, hand hammering compound curves in aluminum is a fine art. For an example see here:

http://www.honeyshotrods.com/projects_cobra.html

Laying up foils to make a composite sheet is possible but not at the home shop level. The Airbus 380 uses a new material called Glare made from multiple sheets of very thin aluminum interlaid with fiberglass.

Spot welding is possible for most alloys but will leave a pattern of marks. Cold bonding is also possible but the aircraft industry normally uses vacuum bonding in an autoclave.

The best semi-flexible adhesive for aluminum is polysulfide adhesive/sealant and is used on pressurized aircraft to seal the hull. It is totally compatible with aluminum alloys and has very strong adhesive properties. It's also a freekin pain to work with, has a limited pot life and stinks.

[This message has been edited by Evan (edited 02-21-2006).]</font>

Evan
Did you work in aircraft maintenance?
You are right about that polysulfide When I was young and stupid I got some of that stuff on me and my coveralls. It took a week to get that stuff off my skin and i don't think it ever came off of my coveralls! i finally threw the coveralls out after 5 years (i say they shrank in the wash my wife say I gained a few extra pounds!)

[Rustybolt]

The best semi-flexible adhesive for aluminum is polysulfide adhesive/sealant and is used on pressurized aircraft to seal the hull. It is totally compatible with aluminum alloys and has very strong adhesive properties. It's also a freekin pain to work with, has a limited pot life and stinks.

Most people would freak our if they realized that a lot of the structures in modern passenger planes are glued together.

[Evan]

" Did you work in aircraft maintenance? "

Other than changing a few wing spars on C-130s and related tasks, not much.

I was a tin basher for a number of years but also did much more than that except engine work. I've worked on everything from fabric covered aircraft to helicopters to homebuilts to transports. I also worked as a heavy steel fitter/welder for a little while.