Deburring aluminum?

[Michael.52]

Hi, I was fortunate enough to get a free custom made aluminum STA, based on the OMS model.
I was told that is is made from an aviation grade of aluminum. From a web search I quickly understood that there are many different grades of aluminum within the aviation title.

My two questions are:
1) Is there any simple way to determine the specific grade? and could it have any critical importance regarding question 2 or generally just diving?
2) Some of the corners are a bit sharp still, how would I go about deburring them, so they won't damage any of my gear and so that it will be nicer to handle?

Sorry for the webcam quality photos, but they may be of some assistance, or you may just be curious.

 

[Tortuga68]

Does it have any sort of surface treatment, and are you intending to use it in fresh or salt water (or both)?

 

[Michael.52]

Salt water, by default.
But fresh water wouldn't demand anything beyond what salt water specifications would supply though, correct?

May I emphasize that I have little DIY experience, so you would have to help me with some signs that would tell me if it's treated or not.
At a close glance it has a fine matte grainy/crystal like texture, and appears to have been deburred or sanded on certain edges, which leads me to assume it's not been treated.

 

[RickyF]

It's almost impossible to determine the grade without a chemical test. The pictures indicate it has not been treated. You can use sandpaper or a fine file to debur any sharp edges. Even aviation grade ( I believe it is 6061) will oxidize in salt water. Just take care to rinse it well and you should be fine for many years.

 

[RVBldr]

Using sandpaper can do the trick, just make sure you're using aluminum oxide paper. You can deburr with a Vixen file followed up with 400 - 600 grain sand paper, or follow-up with a de-burr wheel on a Dremal. If you have a compressor with a die-grinder, you can get 1" and 2" 3M de-burr wheels for that tool, and those would work great. I've used a 6" 3M deburr wheel on a lot of aluminum parts, but I suspect you don't have one of those around. Whatever you use, dont' use anything that has been used on steel prior to using on the aluminum, with the exception of a clean file. You don't want steel particles in the aluminum.

 

[spectrum]

For your needs the alloy won't matter. The part looks like mill finish, free knock-offs don't usually make it to the finishers and that is fine since you will be rinsing your gear well after each dive day. If it did get anodized you still need to complete the project with some hand finishing.

I would begin easing edges and rounding corners with a hand file. You don't want anything that can slice or poke. From the file go to some sandpaper and finally a Scotchbrite finishing pad green or gray). The pads are in most paint departments. In the end it should be as smooth as a a baby's behind.

Pete

 

[Michael.52]

Using sandpaper can do the trick, just make sure you're using aluminum oxide paper. You can deburr with a Vixen file followed up with 400 - 600 grain sand paper, or follow-up with a de-burr wheel on a Dremal. If you have a compressor with a die-grinder, you can get 1" and 2" 3M de-burr wheels for that tool, and those would work great. I've used a 6" 3M deburr wheel on a lot of aluminum parts, but I suspect you don't have one of those around. Whatever you use, dont' use anything that has been used on steel prior to using on the aluminum, with the exception of a clean file. You don't want steel particles in the aluminum.

Thank you for going into such detail, I had to looking up half the terms you used, and would like to confirm a thing or two:
The sand paper must be composed of very fine grains, relatively, correct?
How can I tell if the sand paper is/not aluminum oxide? (and out of curiosity, what would be wrong with that type?)
"With the exception of a clean file", meaning if I already own a file that has probably been used on steel, I can clean it off and it will be OK to use?

For your needs the alloy won't matter. The part looks like mill finish, free knock-offs don't usually make it to the finishers and that is fine since you will be rinsing your gear well after each dive day. If it did get anodized you still need to complete the project with some hand finishing.

I would begin easing edges and rounding corners with a hand file. You don't want anything that can slice or poke. From the file go to some sandpaper and finally a Scotchbrite finishing pad green or gray). The pads are in most paint departments. In the end it should be as smooth as a a baby's behind.

Scotchbrite, just like the kind we probably have under the sink in the kitchen, I assume?
That should do for the final finishes, correct?

 

[spectrum]

Scotchbrite, just like the kind we probably have under the sink in the kitchen, I assume?
That should do for the final finishes, correct?

Like the kitchen pads minus the soap. If you have the soapy pads handy it should just work as a cutting lubricant so give it a shot.

Pete

 

[mddolson]

For the Die-Hard DIYers you can also annodize aluminum yourself.

Here's how: Bryan's Site | Anodizing

regards

Mike D

 

[victorzamora]

You can also get a deburring tool. Something like this if it's bad. Once you figure it out, you can create the sexiest bevels across EVERY edge. If that's not good enough, then you can go to scotchbrite pads. However, I would totally start with a deburring tool. It'll also give it a SUPER professional look if you do it right.