Tool/bit for finishing aluminum plate edges

[matemike]

I will be working with an aluminum structured boat next week installing new windows.

The existing window cut-outs are in 3/8" aluminum plate and they are very rough and ugly and I want to smooth them out and make them prettier before going back in with frameless windows. I have a die grinder and can get aluminum specific bits for smoothing out the rough cuts. What bit should I be looking for?

I know the hand held die grinder may be a little difficult to work straight and smoothly and, yes, I have considered a router. But these edges are already in place and do not have a flat straight edge with enough flat area to rest the router face. I cannot foresee anything but a dremel or die grinder getting in there to work the rough cut edges smooth.

Any suggestions?

 

[kazlx]

I'd probably just use a sanding block and then a finer sponge.

 

[matemike]

I'd probably just use a sanding block and then a finer sponge.

Oh I should have clarified. These are not just rough cuts, they are very rough. As in the lines are not even straight. There are hills and valleys. I want to straighten those out. When I used the term smooth them out I was misleading.

 

[metaleltr]

Would it be feasible to make a wooden template. Adhere the template to the substrate with two sided tape. The a router with a flush cutting bit would follow the template.

 

[theoldwizard1]

Would it be feasible to make a wooden template. Adhere the template to the substrate with two sided tape. The a router with a flush cutting bit would follow the template.

Good suggestion ! You can use standard carbide wood bits, including bevel and round-over, just go slow.

If you are going to use a die grinder by hand, make sure you have burrs for working on aluminum. The one for steel will clog up quickly.

 

[kazlx]

A band file might work well.

 

[bimmer1980]

How many linear inches of window opening do you have to do? pending how much material you have to remove, I would use a hand held belt sander.... a 3x21 or similar...Bosch, etc. I would start with some 60 grit and work up from there.

At that thickness, the material removal will not be that fast. The belt sander has a wide enough platen that you should be able to end up with fairly smooth lines.....

For the record--I did use this method on sanding down some large extrusion for a work project. I had to get within about 0.020" for alignment. It worked well for what it was....

Just be aware of the heat that is going to accumulate in the aluminum....

I think a die grinder is going to be tough to control to get smooth lines. A small band file will be marginally better, but very slow. Die grinder or band filer will be better in the corners.....

 

[cvairwerks]

Single cut vixen file. Properly used, one can remove a huge amount of material at a rapid pace. I can smooth a foot of aluminum edge faster with the file than you can with a power tool.... From a rough edge to a mirror finish is not hard, and is quite fast.

https://www.yardstore.com/14-flex-vixen-file-single-cut

 

[matemike]

I have about 2400 linear inches (200ft) of window opening to do.
23 windows x 4 = 92 rounded corners.

 

[kazlx]

How many of the windows are the same size? You could make quick wood templates and then use a flush cut router.

 

[Jacko264]

Jig saw with a metal cutting blade to do the bad bits and a ******* file
Graham

 

[iajonesy]

I'll second the vixen file method. You take your time at first to find out how much material will be removed and slowly file faster. A vixen file can give a beautiful smooth and shiny finish if used properly.

Mike

 

[matemike]

How many of the windows are the same size? You could make quick wood templates and then use a flush cut router.

23 windows and about 13 different shapes/sizes. We have paper templates, but making templates out of plywood will be costly and timely cumbersome.

Jig saw with a metal cutting blade to do the bad bits and a ******* file
Graham

I have a gang of files, I will have those handy

I'll second the vixen file method. You take your time at first to find out how much material will be removed and slowly file faster. A vixen file can give a beautiful smooth and shiny finish if used properly.

Mike

I need to get a vixen file.

I do have a Ken Onion worksharp knife and tool sharpener and just got 10 coarse belts for it. It should be useful.

 

[ttpete]

Sanding drums. Ones with 1/4" shanks. I have a set that goes up to about 3". The drum is rubber and you slide abrasive tubes on and expand the rubber drums. You could use either a drill motor or a drill press.

https://www.amazon.com/dp/B01BUSM7YW/?tag=atomicindus08-20

 

[gearhead1]

A pic would be helpful, but you can use the same wood cutting carbide tipped circular saw blade to cut aluminum.

Aluminum is gummy. For example, a 4 flute or more end mill will plug up. I use a 2 flute end mill for aluminum. So the deburring bits that have many edges will probably gum up pretty fast.

 

[no704]

I’d get a couple hunks or 3/8 steel flat and big c clamps. Set up as a guide , run over it with a 4 1/4 flap sander on angle grinder.

 

[ttpete]

Another way would be to dog it down to a mill table and use a boring head to clean the holes up.

 

[joe49]

Vixen file also, and aluminum die grinder bits and die grinder if you have to do radiused corners.

 

[racer-john]

"Another way would be to dog it down to a mill table and use a boring head to clean the holes up."
When the window openings are attached to the boat, don't think so!

 

[AZ Pete]

Draw file with a Vixen file! Then scotch bright pad to dull the sharp edges

 

[Doms]

Circular saw with a demo blade depending on access.

 

[steel 35]

How many linear inches of window opening do you have to do? pending how much material you have to remove, I would use a hand held belt sander.... a 3x21 or similar...Bosch, etc. I would start with some 60 grit and work up from there.

At that thickness, the material removal will not be that fast. The belt sander has a wide enough platen that you should be able to end up with fairly smooth lines.....

For the record--I did use this method on sanding down some large extrusion for a work project. I had to get within about 0.020" for alignment. It worked well for what it was....

Just be aware of the heat that is going to accumulate in the aluminum....

I think a die grinder is going to be tough to control to get smooth lines. A small band file will be marginally better, but very slow. Die grinder or band filer will be better in the corners.....

Belt sander and don't pass on the 40 or even 36; I would pass them another template!

 

[hawkeye2]

Belt sander and angle grinder with flap disk

 

[FSrepair&fabrication]

If you could figure out a way to attach said file to a sawzall you could really save some time and your wrists lol

 

[dogdog]

if all the windows are the same size, templates and router bit with the guide bearing and double side tape would be the best. The template would be reused multiple times unless you damaged it.

** didn't realized router was already suggested.

 

[Bsmb62519]

If you could take a pic of exactly what youre dealing with you might get better answers.

 

[ez-duzit]

Circular saw with a demo blade depending on access.

Circular saw with carbide aluminum-cutting blade.