Page 1 of 1

Finishing aluminum.

Posted: Mon Jan 25, 2016 9:21 pm
by Brennan Clark
Hello, I'm currently a high school student enrolled in an Ag mechanics/welding course. This is my 3rd consecutive year in our fantastic program. I have a partial AWS certification, and am only a few tests away from receiving my level one AWS certification through our program. Right now we are in the middle of a project build to take to an Ag mechanics/welding competition. Our project is an aluminum livestock truck box made from a 5056 Al rectangular tubing frame, wrapped in 4043 1/8 inch aluminum sheet. The build is coming along nicely, however we aren't sure how we should finish the aluminum. The entries in the competition we will be entering is almost almost %100 mig welded carbon steel. We're hoping that our tig/aluminum will set us apart. This being said, we really want a finish that will stand out from the steel and draw attention. It was recommended to us to use red scotch Brite pads and wet sand in one direction. We have experimented on some scraps and it's definitely better than the mill finish, however its still rather dull and the grain is visible. I think a higher polish finish would really look nice. Would wet sanding with the scotch brite, then hand rubbing a polish such as "mothers aluminum and mag polish" produce good results? The competition is only 3 weeks away, so we kind of need to figure something out fairly quick, we'd also prefer to not have to order an expensive complete system if possible. Things that can be bought locally are definitely a plus! The finish just really needs to look good for a week or two for the purposes of the competition, however if we can create a lasting finish that looks good, it'd be better. Sorry for the long first post, but I really look forward to any advice yall can give on this topic, and hopefully many more in the future.

Re: Finishing aluminum.

Posted: Mon Jan 25, 2016 9:45 pm
by LtBadd
Brennan Clark wrote:Hello, I'm currently a high school student enrolled in an Ag mechanics/welding course. This is my 3rd consecutive year in our fantastic program. I have a partial AWS certification, and am only a few tests away from receiving my level one AWS certification through our program. Right now we are in the middle of a project build to take to an Ag mechanics/welding competition. Our project is an aluminum livestock truck box made from a 5056 Al rectangular tubing frame, wrapped in 4043 1/8 inch aluminum sheet. The build is coming along nicely, however we aren't sure how we should finish the aluminum. The entries in the competition we will be entering is almost almost %100 mig welded carbon steel. We're hoping that our tig/aluminum will set us apart. This being said, we really want a finish that will stand out from the steel and draw attention. It was recommended to us to use red scotch Brite pads and wet sand in one direction. We have experimented on some scraps and it's definitely better than the mill finish, however its still rather dull and the grain is visible. I think a higher polish finish would really look nice. Would wet sanding with the scotch brite, then hand rubbing a polish such as "mothers aluminum and mag polish" produce good results? The competition is only 3 weeks away, so we kind of need to figure something out fairly quick, we'd also prefer to not have to order an expensive complete system if possible. Things that can be bought locally are definitely a plus! The finish just really needs to look good for a week or two for the purposes of the competition, however if we can create a lasting finish that looks good, it'd be better. Sorry for the long first post, but I really look forward to any advice yall can give on this topic, and hopefully many more in the future.
Hi Brennan
Welcome to the forums
Do you have a DA sander or orbital sander available? This would provide a random finish and tend to hide any imperfections in the sheet.
Of course diamond plate would look great, but that would be expensive.
Post back with some photos if you can would like to see your progress

Re: Finishing aluminum.

Posted: Mon Jan 25, 2016 9:50 pm
by Oscar
MAAS metal polish works good and is cheap. get a white buffing wheel on a low-speed drill and go to town on it.

Re: Finishing aluminum.

Posted: Tue Jan 26, 2016 3:54 am
by Arno
Brennan Clark wrote: The finish just really needs to look good for a week or two for the purposes of the competition, however if we can create a lasting finish that looks good, it'd be better.
Then after polishing it all to a shine put a nice coat of (car)wax on the metal or have the metal clear-coated for a longer-lasting protection.

Even without treating it, as long as it's kept somewhat out of the weather then it should stay looking good for some time. Once it's exposed to weather the ali will quickly develop it's somewhat milky oxide layer. Any contact with water and salts will accelerate this.

Bye, Arno.

Re: Finishing aluminum.

Posted: Tue Jan 26, 2016 9:06 am
by kiwi2wheels
These also work well on aluminum with a Scotchbrite pad if you aren't going for a mirror finish.

http://www.ebay.com/bhp/jitterbug-sander

Play around with different pad grades and used wet or dry depending on what you want.

Overlapping the base with the pad allows you to get into corners.

Re: Finishing aluminum.

Posted: Tue Jan 26, 2016 2:39 pm
by BFTrout
If I was a part of this build, I would like to have my school name on the side of that sheet. . . i.e. "Ag mechanics/welding course" or whatever it is.
To achieve this, polish the center of the sheet to a mirror shine. get a large sticker of "said" school and stick it on the super shiny part of the sheeting. break out the sand blaster and rough up everything on the sheet. once that's done, clean the sheet and remove the sticker. everything will be a matte finish except the metal hidden by the school sticker. . . which should be shiny as a new dime.
Good luck.
BFT

Re: Finishing aluminum.

Posted: Tue Jan 26, 2016 3:14 pm
by Tokoroa_Welder
Have a look at your local hard ware/renovation store. You should be able to get different grades of 3M scotch brite. I used to work for an anodising company and to get the Ali parts to shine we would go over them good with three grits in order. Red, green, white. Of course your colours may vary.

Re: Finishing aluminum.

Posted: Wed Jan 27, 2016 3:11 am
by Brennan Clark
BFTrout wrote:If I was a part of this build, I would like to have my school name on the side of that sheet. . . i.e. "Ag mechanics/welding course" or whatever it is.
To achieve this, polish the center of the sheet to a mirror shine. get a large sticker of "said" school and stick it on the super shiny part of the sheeting. break out the sand blaster and rough up everything on the sheet. once that's done, clean the sheet and remove the sticker. everything will be a matte finish except the metal hidden by the school sticker. . . which should be shiny as a new dime.
Good luck.
BFT
That's a great idea, howe've we are going about it a different route. We cut out our school logo on the cnc plasma, and we are planning on welding it to the side of the box. After polishing, we're going to tape off everything but the logo, and paint it orange(our school color) I brought a piece of scrap alum home, and I'm gonna try several different methods and see which one works best