Maybe wrap the whole thing in fiber reinforced plastic (fiberglass,
carbon fiber, kevlar)?
Wicks Aircraft Supply www.wicksaircraft.com sells graphite carbon fiber
"tape" that's 5" wide and compatible with all major resin types:
http://www.wicksaircraft.com/gotopage.php?page=20
They also have kevlar cloth (which is difficult to cut) and epoxy tapes
(cheap).
As I believe someone else already mentioned, you would want to determine
whether the tube is bending or twisting before you decided how to apply a
uni-directional tape, or use a bi-directional cloth. Possibly wrap the
uni-directional carbon fiber tape in a "barber-pole" pattern from top to
bottom... once in each direction?
If you scrub the thing down with a scotch-brite pad soaked in an
acetone/resin mixture... it will "prime" the aluminum and prevent oxides
from forming on the surface, so you get a better bond.
David




"qedude" wrote in message
...
I'm hoping someone can help me with a problem I am having. I have a
telescope
mounted on a 54 inch tall, 3/16 inch wall, 8x8 square aluminum tube with
1.25
inch plates welded to the top and bottom and bolted to 2/3 of a yard of
concrete. The problem is I am getting a little too much movement out of
the
tube and I need to increase the stiffness of the tube. The ideal situation
would be to replace the tube with something larger but that's just not
possible
at this point in time. I don't need a radical increase in stiffness either
so I
think there is something I could do to for a slight increase in stiffness.
I
need to kill low frequency vibrations so please don't suggest sand or
concrete,
beside concrete and alumimun don't get along with each other. Any ideas ?
Would
putting the tube under tension help ?


Scott Hogsten