Cutting Aluminum Columns

[Dunc]

I purchased several of these (http://www.imperialgroup.ca/railingcolumnsfencing.cfm) to do a front porch makeover. They will be used decoratively, not structurally. Each square column is fabricated from two "U"shaped pieces of aluminum that are 9 feet long and about 1/8 inch thick; these pieces snap together using a tongue & groove joint. Two of my existing columns abut the brick; hence, I only require one "U"section to cover them.

My problem: the tongue side of the half-column is longer than the groove side. I need to trim (a rip cut) the tongue from the material so that the column will be oriented correctly. I have an assortment of saws & blades that are capable of doing the job (hand-held jigsaw, reciprocating saw) but I expect that the cut would be too wavy - even on one of my best days. Could this material be cut using a 10 inch woodworking table saw with a carbide tipped blade? It would have to be at full speed (~5300 rpm) since I have no way to slow it down to imitate a cold-cut saw. Number of teeth? If a high tooth number is required (40-60) I could purchase a blade for a portable saw (7-1/4 inch diameter).

Any/all ideas appreciated. Thanks!

[Cuttings]

I cut aluminum with a carbide tipped blade on the table saw quite a bit. It cuts well at speed. You just have to make sure you cover up well - face shield, gloves etc. there will be a lot of aluminum chips flying around.

[Toolguy]

And earmnuffs - it's very loud. The table saw is the best way to go. You want either a high count tooth blade or a lower count that only lets each tooth cut a small depth of cut. Move the material through at a speed that lets the blade cut well, without crowding it.

[Weston Bye]

+3 on the table saw. Be prepared: It seems terrifying when you do it.

[john hobdeclipe]

Yeah, table saw.

See if you can find a nonferrous metal cutting blade that has zero to slight negative hook.

And be sure to have some kind of solid support for the outfeed end.

[Duffy]

I guess that I am the only partial dissenter. DEFINITELY use the table saw. Chip protection is a must; the little devils are light but may be hot! Blade choice does not matter a bit, as long as it is sharp. High tooth count, low tooth count, carbide, or plain steel; they have ALL worked for me just fine. I have cut thin flashing, downspout, cast section, plate and strip, thickness up to 2 1/2 inches, with no problems. A bit of common sense DOES help. Oh yes, and ear protection IS a must!
By the way, a chop saw is handier than a pocket in a shirt for cutting aluminum stock-much faster and more accurate than a band saw. BUT adjust your feed rate to the cross-section of your material. A 12 inch, 40 tooth carbide blade DOES NOT WIN when fed too fast to a 1/2 inch diameter rod! (Dont ask how I know.)

[mikem]

You could use a router to trim it with a carbide bit and cut along a straight edge--just make sure that the straight edge limits the depth that the router can cut in case it starts climbing away from you!

[sansbury]

+1 on the table saw with a fine-tooth carbide blade. I've put 1/4" plate through with very little fuss. A face shield and safety glasses are highly recommended as the chips fly everywhere but other than the noise it's easy going. Aluminum is a much more homogeneous material than wood so as long as you don't try to feed it too hard it won't surprise you.

[fjk]

If each piece is made from 1/8" AL, and is half of a 6"sq column, you've basically got a 9' x1' x1/8" sheet of aluminum, or 1.125 cubic feet of al --- at 178#/cu ft, that's about 200# of aluminum per column.

Instead of wrestling 200lb of aluminum on the table saw, why not clamp a guide to the column and use your hand-held jig saw? (some come with adjustable/attachable fences too)

frank

[ezduzit]

I use a Skilsaw with carbide blade on long stuff like that, cutting through one wall thickness at a time .

[SteveF]

If each piece is made from 1/8" AL, and is half of a 6"sq column, you've basically got a 9' x1' x1/8" sheet of aluminum, or 1.125 cubic feet of al --- at 178#/cu ft, that's about 200# of aluminum per column.

....................

Not quite.

9' x 1' x (.125/12) is .09375 cu ft. Times 178 #/cu ft is 16.7 lbs.

I put in two columns like this last year and was trying to figure out where you got 200 lbs.

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I cut my round columns (3 sections) by making a pencil line all the way around and cutting them on my metal bandsaw.

Steve

[lbhsbz]

If each piece is made from 1/8" AL, and is half of a 6"sq column, you've basically got a 9' x1' x1/8" sheet of aluminum, or 1.125 cubic feet of al --- at 178#/cu ft, that's about 200# of aluminum per column.

Instead of wrestling 200lb of aluminum on the table saw, why not clamp a guide to the column and use your hand-held jig saw? (some come with adjustable/attachable fences too)

frank

Check your math.. 1/8" = .0104'

The volume is closer to .09 cubic feet, so 16lbs.

Table saw will work the best. I'd use whatever blade is in it already...carbide tip seem to work good. Just give the cut line a shot of WD40 before you get started. I generally wear my welding gloves and a faceshield. It's loud but cuts better than wood.

[lbhsbz]

He forgot to convert inches to feet on the thickness.

[darryl]

You can put together a simple plywood jig to guide a skil type saw. Just three sides, basically a saddle that will fit over the columns. You would first use it to put guide marks on opposite sides of the column, then turn the column 1/4 turn and align the jig with one of the marks, cut one side, roll it 1/4 turn, cut the next side. Then reposition the jig with the opposite mark, then make another two cuts. That will give you about the closest thing to a square end that you can get using a portable saw. The worst case scenario is if the saw you're using has too much slop in the arbor bearings- if you can't make a straight cut in plywood using the base of the saw against a guide, then don't even bother trying it in aluminum. Other than that, use a carbide blade with lots of teeth. It will be loud, there will be lots of hot and sharp chips. In spite of this, just use a slow, smooth push and the cut will end up nice.

Whatever thickness material you use to make the guide jig, cut some extra pieces that can be used to support the column on both sides of the jig, and lay the column across those (on a flat floor) to prevent jamming.

[CCWKen]

I would just grind it off. Too much setup and hassle to make a fixture to feed it to a table saw, skill saw, etc. And at nine feet long, you'll need something. Use a body grinder/polisher with a 30 or 60 grit sanding disk. It'll be gone in no time. (Wear appropriate safety gear.)