rossmans

Anybody used aluminum (aluminium) for a thrust tube and what were the results?. A test was done a few years ago in Radio Controlled Jet International by the now - editor that seemed to result in an ally tube being ok as far as heat was concerned. If you made your own you had to roll it and fold the joint. Be cheaper if it was possible to use an ally thrust tube. as opposed to a thin titanium job.
Any constructive thoughts?

Miniflyer

Aluminum is great, but very very difficult to weld. A "bend the joint" seems a little "dangerous" for my taste....
The easiest, quickest and most reliable method remains thin stainless steel sheeting....can be spot welded easily, bends nicely, is easy to work with, and the weight saving is only marginal when using other materials....
My opinion....

A10FLYR

My Feedback: (1)

Ross, I'm afraid not. Miniflyer is right. I have done a few outer tubes from thin alli sheet for others but have not heard anything negative, (or positive!) from them. used the same spot welder that I use on SS tubes but it was very hard to get every spot right. I had to sand the area to be welded and keep it very clean or it would either burn thru or not even weld the spot. I feel it was not worth the trouble and have stayed with SS.

Here is a pic of one that saved the day when the inner T/SS tube burned from a hot start! The dark spot by my foot to the left of the plane is a piece of the T/SS pipe still burning! You can't see the flame in this pic but can in the original!

rossmans

Just wonder if the sanding and welding weakened the ally. Maybe rivets would do the job. On the other hand it may be better to spend money..be safer! Thanks anyway for the info.,

rossmans

Just wonder if the sanding and welding weakened the ally. Maybe rivets would do the job. On the other hand it may be better to spend money..be safer! Thanks anyway for the info.,

freestyln

I used to TIG as a job both stainless and alloy and still do a lot of work from home, and we used to TIG 1mm sheet a few times for various things, it takes a good amount of practic but its doable.. but the difference in weight between 1mm alloy and 1mm stainless wouldn't be worth the worry i don't think. The added extra heat ability of stainless definately makes it more promiseing. It doesn't take much heat with an oxy to bend alloy sheeting even at 10mm, so 1mm wouldn't take the heat associated at the exit of the turbine i wouldn't think to a point where you could say its 'safe'.

EddieWeeks

Sounds like a bad idea to me... I often melt the Aluminum foil on the outside of my 0.008" SS pipe...

Eddie Weeks...

rossmans

Found the original article about ally tubes. Apparently it was 0.25mm thick ally LITHO plate from a printers!. Test revealed the exhaust from a St St pipe on the end of Wrenn 54 was about 260 degs C whilst the litho melts around 500 to 650c. Still..a lot of work for a bit of cheapness (well relatively cheap as the brazing material used costs about $75 for 2.5kgs! (about 6 lbs) Need a big interested club for that lot to be justified. The article was in the Radio Controlled Jet International for Aug/Sept 2001.Ah well..as I said..back to the drawing board! Thanks fellas!.