PointMagu

My Feedback: (11)

I need a little input.
I've read that aluminum cannot be welded but I know I've seen it done, (bicycle frames, etc). The plans for the Corben Baby Ace show square aluminum tubing for the fuselage, fin/rudder and horizontal stab/elevator.
I originally thought to simply replace with balsa and spruce woods. However, at 61, I would really like a new modeling challenge and this airframe looks to be that ticket.
Does anyone have any "small-scale" experience with something akin to K & S products as far as joining other than flattening and bolting together????

GREG DOE

Aluminum can be Tig welded. There is also a "brazing" system that uses special aluminum rods with a propane torch. Some people have mastered the skill of aluminum brazing , and some, like myself could only burn holes! Tig welding involves a tungsten welding tip that creates an arc, and then you feed a flux coated rod into the joint. Good tig welders are artists too. Do an internet search on both processes, and you should be able to find loads of information. Ask in your local clubs, or hobby shops who repairs broken mufflers, or engine crankcases. Good luck, Greg

Flypaper 2

http://www.messerwelding.com/Product...t/MG%20460.pdf
Give this stuff a go. You have to play with it for a while to be satisfied with it.

PointMagu

My Feedback: (11)

TY!

FlyWheel

I have never heard of aluminum not being able to be welded. I believe what you heard is that it cannot be soldered (that's what I've heard).

GREG DOE

PointMagu, Mac Hodges has a full scale Super Ace. It's a two place with a 90 horse Continental. You might consider building your Ace to replicate his. Some years ago Jerry Nelson offered all the items necessary to build riveted aluminum models. Jerry shut his business down a few years ago, but there might be modelers still around who built airplanes from his process. Jerry's company was the source for the Nelson paints.

sensei

6061-T6 aluminum is weldable, 2024-T3 or 7075-T6 are not, or should not be.

Bob

combatpigg

My Feedback: (3)

Ron Fournier has a book in the HP Books crafts series about metal working. He devotes quite a lot of room to cover aluminum gas welding. He uses hydrogen instead of acetylene and so you need to adapt it into a standard ox-acet torch. The other hurdle is to obtain blue lenses to shield your eyes. The blue lenses can see through the yellow flux cloud as the puddle is forming. Gas welding is superior to TIG for many projects where stress cracks are a concern. Lots of Formula One tanks, brackets, etc. are done with gas.
I use aluminum solder and MAPP gas for general work around here. It is a little bit tricky to use, so you just need to be stubborn about not giving up until you "get it". I repaired a deep crack in a friend's outboard engine case with this stuff.
It will also hold together a header pipe to the flange up to .15 size. Larger engines will soften it to the point of fail [I've learned]. I'm not sure what process MAC's uses [they wont tell me], but they admit that they did not have a 1.000 batting average when they first got geared up to produce the fine products that they sell now.

NazAir

You may also look into gluing aluminum. I have a 1980's Vitus Bicycle whose tubes are glued, they are holding very well. I know that glue is also used in commercial airplanes.

flybyjohn

My Feedback: (2)

Epoxies will work with aluminum quite well, however there is a trick to using epoxy on aluminum. As you are probably aware, aluminum oxidizes quite fast, as a mater of fact it will start oxidizing immediately as soon as it is exposed to the air. Because of this reason, it is hard to solder, paint, or epoxy. The trick I learned from a boating repair place is to mix up the epoxy, and put a thin layer on the aluminum. With fine sandpaper, you sand the aluminum while the epoxy is coating it. The sandpaper will scrub away the oxidation and the epoxy covers it immediately. Using the right epoxy, you will have a forever bond, unless you heat it above the epoxy melting temp. Solders also work with any aluminum with some zinc content. You just have to scratch the surface of the aluminum as you are applying the solder to break through the oxidation layer. I have used alumaflux or some other types of aluminum solder and once you get used to using it, it works great. You need to heat the metal and then while keeping the metal hot, rub the solder stick on the aluminum to scratch the surface and it will start to flow onto the surface. It also helps to tin both parts of aluminum before trying to weld together.

Be aware that some aluminum will soften quite a bit by adding heat to them. I had a piece of aluminum welded by a friend with a oxy/acetylene torch and the aluminum became very soft and flexible.