Recommended vibratory media for Aluminum

[SRT Mike]

I just picked up a burr king vibratory bowl. Nice unit.

I have pieces of 6061 AL that are are anywhere from the size of a pack of cigarettes with some pockets on the back and a window cut in front, down to the size of a large stamp with a pocket in the back.

They will ultimately get anodized or chrome plated. I want to take them from machined finish to "pretty bright finish" (not mirror - I doubt that's feasible).

Can anyone recommend media, size and time? I figure I will need to do it in 2 steps, so I'll get another bowl so I can change out the media easily. But I don't know where to start.

Step 1 -> off the machine with toolmarks take off the toolmarks

Step 2 -> from step 1 to as bright a finish as possible.

Any suggestions?

[Runner4404spd]

i just started doing this so take it with a grain a salt, but i use the triangular media from harbor frieght to break the machine marks. once the part has a matt finish then i use the walnut shell media that i added polishing compound to. it takes a while but it saves a ton of time compared to doing it by hand.

[Sparky John]

Most of my customers are using a plastic media to get a pre-andozing finish. It will still deburr your parts, but will not cause the impingement that ceramic will give you. A strarter kit for the 200SX Burr King includes 50 lbs. of 1/2" cone / medium grade, 1 quart of BKS 60 soap and 1 qt. of AR-60 anti-rust. Stock number SK200P and it sells for $151.00. The plastic tends to be a bit messy, so you will have to clean your system more often, especially when you break the media in.

Harbor Freight is good for buying gloves, but that is about it.

For more help, call Burr King at 1-800-621-2748 and they will be glad to assist or e-mail me back.

[Sparky John]

I forgot to mention, for polishing my customers use a walnut shell treated with Chrom. Oxide. Burr King stocks that as well and it sells for $4.35 per pound at th 25 pound level or $$4.10 at the 50 pound level. Not cheap, but it is the best stuff I've seen so far.

[SRT Mike]

John,

Thanks for your insight. I have three followups if you dont mind

First, its a Burr King 200 series vibratory bowl. They sell the media by weight not volume... so how much media should I put in the bowl? You said the starter kit has 50lbs - is that a bowl full or is there extra leftover?

Second, the plastic to take off the machine marks... does that take the parts to the point where you can then put them in walnut shells for polishing? Or is there an intermediate media that you'd use?

Third, the anti-rust and polish - do you just dump them in full strength with the media or is it watered down? When you say "clean the machine" you mean wash out the media? (which I'd assume means you then lose your anti-rust and polish and need to re-apply, right?)

Thanks - if I should email Burr King about this, I'll do that.

Thanks also to the first respondent, I have some ceramic media in there now I got with the bowl and it's real harsh on Aluminum. Sounds like walnut shells are the way to go for the polishing step.

[Sparky John]

Did you purchase your 200SX thorugh a Burr King distributor? If so, they are doing a really rotten job in supporting you and you should contact your local Burr King Manufacturer's Representative (I am the one for Illinois). Burr King can give you his phone number. If you picked it up used or over the internet, then I can understand your predicament.

However you got it, you are in luck because you have a machine that is American made and fully supported.

Contact Burr King directly (1-800-621-2748) and tell them what you are trying to do. Ask for technical support on vibratorly and tell them that I refered you (John Park, not Sparky John). You will probably end up sending them some parts that they will run them for you in the proper media and then send them back to you for your review before you purchase the media. They have all types there and can normally determine the right combination for your application. Once they find your solution, make sure that you buy the media from them and not some other guy who has done nothing to help you but simply has a "cheaper" product.

That being said:

1 - 50# is how the media is packaged and you will have some left over after filling the bowl. You will lose about 3% to 5% of media each 24 hours of run time, so you will use the ballance to compensate.

2 - Steps are typically 1 -debur with plastic media then directly to anodizing or 2 -then to walnut shell with Chrom Ox. for brighteneing.

3 - You will not need the anti-rust for aluminum, just the soap. Normally a couple of ounces per gallon of water. I don't know the set-up you have, but at the least you should have a 5 gallon bucket with a pump to recirculate - - - at best the Burr King 4000 filtration system.

4 - By cleaning, I mean to clean out the bucket or check the filter in the filtration system.

Good luck with yorr system!

John