Question about aluminum handrail fabrication

[winchman]

A friend wants to build some sections of hand rail using 3/8" x 2" aluminum flat bar and 1/2" round bar spindles.

That's easy enough to weld together, but I'd like to have some way to space the spindles evenly side-to-side and along the rail. We can punch holes in the bottom rail, but we don't want to punch the top rail. Jig are almost always a PITA.

Could I dimple the underside of the top rail by putting a piece of steel under the aluminum, and setting the punch to go part way through? That would give me a recess to position the spindle for welding. How deep could I go without distorting the top side?

Roger

[tattoomike68]

trying to punch part way would warp the top plate bad, you might think of using a drill press and flat bottom drill to locate the spindles.

even on the bottom plate where you punch through holes you might want to punch every other hole on one side and the others from the other side. Or just flip the bar for each hole as you punch along.

[Jim Caudill]

1/2" center cutting endmill used to create a pocket. 1/8" depth would be plenty; try even .060 -.080" pocket. Make a little jig and feed thru the vise on the mill.

http://i72.photobucket.com/albums/i183/Ferrofab/Hurcocouterbore.jpg

http://i72.photobucket.com/albums/i183/Ferrofab/Hurcotoprail.jpg

[wierdscience]

How about a seperate tack rail? Maybe a piece of 1x3/8 flat bar with the holes punched through and the spindles welded in.Then weld that rail to the bottom of the top rail.That's the way commercial rail is done,the top piece is just the cap rail that covers up all the ugly.

The other way is to just go ahead and punch through,then countersink the top side and weld the spindles in from the top and grind off the excess weld.