Vibatory Tumbler vs. Bead Blasting

[apeman88]

In the past, I have tolerated tool marks and if I really want a nice shine, I put the part on the buffing wheel. I'm now more critical and like to find an easy solution to a nice finish after machining.

Been looking into vibratory bowl tumblers but it seems you would need one tumblers to remove tool marks/deburr and another one or two tumbler to polish and buff the part. The worst, IMO, is the time it takes... been reading 1~4 hours for deburr/toolmark removal and 8 to 36 hours for final finish.

My question is... can a bead blaster be used in place of a tumbler? I assume it is much faster than tumbling? What type of media is need in a blaster for deburr/tool removal and what type is need for polish and buff?

Which will yield the best quality? Which is more popular?

I attached a most recent part I cut for a friend... while the flat side and side walls looks great (about 15sec on the lathe with a sanding block)... I can't get into the holes on the other side with any conventional polishing tool. I need something that can get into small holes and etc.

Thanks!

Ken

[JimPAC]

ApeMan you have a lot of holes in those parts!

The trouble with bead blasting tapped holes they will need to be plugged.

Is your customer acceptable to design change, such as a grove instead of holes?

If so that would reduce the machine time dramatically, while improving the part and finish quality.

Also are turning and then milling? You can get a better finish turning then milling!
sI have machined several parts out of various material types for gas turbine engines. I had to find ways to eliminate tool marks
and for the most part was pretty successful. Tumbling should be considered as the last finishing step after debur and hand finish.

Hope this helped !

JimPAC

[apeman88]

JimPAC,

The entire piece was milled... the center hole and the taped holes were drilled on the mill as well. After milling, I placed the piece on the lathe to chamfer the edges and about 15sec with a sanding block.

I can lathe some of the operation but the main holes still have to be milled becuase it is exactly 0.505. A 0.5" pellet fits inside so dimension of the holes have to be exact.

I can tap after finish so no need to cover the tapped holes. So if I bead blast... will it be able to remove tool marks inside the holes as well? What type of media should I use to remove tool marks?

Ken

[Med-Pac]

I've used a dremel tool before to work the tight areas that conventional tools can't get to. This works great if the quanities are small, or if you have a lot of spare time on your hands. Not sure if that would work for you on this, might be worth a try.

Mike

[destroyer125]

Beadblasting isnt going to remove machine lines. It will simply put a rough pattern over it. The first is beadblasted, the second is deburr and polished with a tumbler to a nice finish.

[High Seas]

Destroyer125 -- Nice looking Knuckle-Dusters --Or are those "wire" looms?
Cheers - Jim

[destroyer125]

Originally Posted by High Seas Destroyer125 -- Nice looking Knuckle-Dusters --Or are those "wire" looms? Cheers - Jim

Heh, These things are only an inch and a half long, so no need for an alternative name.

[apeman88]

Originally Posted by destroyer125 Beadblasting isnt going to remove machine lines. It will simply put a rough pattern over it. The first is beadblasted, the second is deburr and polished with a tumbler to a nice finish.

Nice Brass knuckles! Thanks for the feedback! I guess I'll have to get both a bead blaster and tumbler now.

Ken

[High Seas]

destroyer125 - I am following with great interest. We have got 25-30 mast steps - I'll send pickie later - that are in need of refinishing.
Uggh at an hour each and a single polishing wheel each and rouge - I could do them to a very high sheen. BUT so much labor and so little time.....
BUT - I just picked up a spot abrasive (sand) blaster - thought I'd give it a BLAST - but first gotta source some media.

Am I on a reasonable path - or will this also be a 1 hour job to get them cleaned up?
The parts were anodized - an now covered with sea salts and associated "gunk".

Jim

[destroyer125]

Originally Posted by High Seas destroyer125 - I am following with great interest. We have got 25-30 mast steps - I'll send pickie later - that are in need of refinishing. Uggh at an hour each and a single polishing wheel each and rouge - I could do them to a very high sheen. BUT so much labor and so little time..... BUT - I just picked up a spot abrasive (sand) blaster - thought I'd give it a BLAST - but first gotta source some media. Am I on a reasonable path - or will this also be a 1 hour job to get them cleaned up? The parts were anodized - an now covered with sea salts and associated "gunk". Jim

Shoot me a PM or email if your wanting to have them refinished and reanodized.
You will want to chemically strip the anodized aluminum with a sodium hydroxide/water mix (use crystaline drano in a pinch). You will not want to physically remove the anodizing or you will foul up the aluminum underneath. The seasalts and other gunk will be removed by the lye mix, but I would suggest give them a good dishwashing before you try to strip them. Salt water will corrode raw aluminum very quickly, hence the reason they were anodized in the first place.

[High Seas]

destroyer125 - pm sent - couldn't attach the pic - so as promised:

[destroyer125]

Those arent as big as I had suspected. You can try focusers anodizing guide, Im sure you will turn some good results.