Small Parts Tumbler

[wment]

I have been using a rotating tumbler I got at a yard sale. It has a Sears label on it. Using some aluminiun oxide blasting media and a drop of dishwashing liquid it works great. Dont over do the dishwashing liquid. It is hexagonal inside, about 4" deep and about 8" in diameter so it wont hold carb bodies but small parts like nuts and bolts is ideal.

 

[Cottontop]

Today, I bought a dual drum tumbler from Harbor freight. The dual drum was on sale ($35) and only $5 more than the single drum ($30).

https://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=90979

I passed on the a fairly expensive $10 for 8 ounces of Harbor brass polishing media.

I am using play sand from Home Depot = $3 for 50#.

I think that I will achieve the same results, however.

I am now an hour into the tumbling and I can already see good things happening.

Now, I'm off looking at available and cheep plating materials.

 

[GregW]

[ QUOTE ]
Now, I'm off looking at available and cheep plating materials.

[/ QUOTE ]
Hi Cottontop,
I don’t know if you read the threads about plating earlier this year. Caswell ( Advertises here) sells some pretty cool plating kits. John Loftus bought the Copy Cad kit and I have the nickel plating kit. Check out the before and after shots in both threads. They’re on page 2 of the tool forum.

 

[Cottontop]

Greg,

Thanks for the tip on Caswell. Their Nickel kits provide a MUCH less porous surface than I really want
(I want to paint the bolt heads) and are MUCH too pricey for my budget for plating nuts & bolts.

I have a lifelong friend who sells plating materials and chemicals here in the D-FW area.
When I last did this hardware clean-up thing, he gave me a bottle of zinc phosphate plating solution.

The plating is done on a hot plate or stovetop at ~188F. It worked out very well.

I think that I'll try that route again.

I talked to him last night and I have another bottle coming.

While I am getting satisfactory results with the tumbler and sand, the sand has large particles that will
not pass through my blast nozzle.

Since I am going to buy a bag of Aluminum Oxide anyway, I am going to try it in the tumbler.

I'll post the results.

Thanks again,

Tim

 

[Cottontop]

Here are the before & after results of 24 hours of tumbling with play sand. Mix = 1 cup of hardware, 1 cup of sand, 1 cup of water.

Not as clean as media blasting, but much better and paintable after plating.

The cleaned hardware has already started to rust as I was blow-drying them. The next batch will do directly into the zinc-phosphate plating vat will still wet.

I can live with these... There is still some paint in the recesses of the bolt heads, but if the old stuff didn't come off, it ain't coming off.

The whole process is much less labor intensive than blasting (labor intensive = standing at a blasting cabinet doing one piece at a time).

Will post again after I get'em plated.

Tim

 

[Banjo]

Looks good. I'm definatly thinking about getting me a tumbler.
A trick for blasting hardware is to punch several holes in a coffee can (or find some sort of perforated container), throw in a handfull of hardware and shake them around as you blast. It works well.

 

[Cottontop]

When I had a blast cabinet, I took a foot long piece of 2x8 and drill 1/2" holes on a 2"x2" grid.
Then I'd stand the bolts up in the block and blast them from each 90 degrees.

I'd stack up the nuts and washers on a thin screwdriver or ice pick and let them spin as they were blasted.

On the bolt heads above, I've found that a quick 360 with a sharp awl point flakes out that paint residue in a jiffy.

I've got another double batch running now. I've got a whole tub of hardware to do and this clean-up method is as good as free.

Tim

 

[mcguijo]

OK. .I too went to Harbor Freight and bought a rock tumbler. The wife has burned up the batteries on digital camera taking pictures of the baby. .as such, for the time being I'll describe my results. These were grade 5 (I think) bolts/nuts/washers off of a 1959 TR3A. I first soaked stuff overnight in a gallon paint bucket of carb cleaner. Next I put some parts in the tumbler with brass polishing powder from harbor freight and tumbled for 24 hours. Worked well on nuts, mixed success on bolts, not very successful on washers. Areas of the threads that had rust were clean but metal was lost. Moral of the story, 46 year old bolts probably ought to be replaced with new ones.

Next I tried the brass polishing on some aluminum (front piece of thermostat housing). This endenvour was largely unsuccessful.

I'd experiment some more but only after less then 48 hours of use, the motor of my Harbor Freight rock tumbler has burned out.

 

[Cottontop]

Golly....

Sorry to hear that I walked you into a minefield.

Of course, take the tumbler back and get another or your money back.

If you decide to try again, I'd switch to either play sand (cheep, but mixed particle size)
or a specific grit size of clean silica sand or Aluminum Oxide.

Direct from the tumbler & washed, here are the results of my second batch after 15 hours of tumbling.

I'm going to put in some new sand and give it another 12 or so.

I'm going to get a different tumbling media. I don't care for this play sand.
It seems to get pounded to dust quickly. When mixed with water, the dust creates a sludge
that probably inhibits the tumbling/cleaning action.

Tim

 

[mcguijo]

OK. .I'm back in action with a new (cheap) tumbler from harbor freight. I have some sand am trying as we speak. I'll compare with just brass media and sand followed by brass media. I have some glass media, I may try it for giggles as well.

One thing I've noticed with this cheap tumbler is that if the black tumbling barrel gets too warm (such as from direct sunlight) it expands and gets hung up on the tumbling arms (and hence burning out a motor).

 

[mcguijo]

Attached is an image of some of the bolt heads that were tumbled solely using carb cleaner and brass polishing media. A few I went over quickly with a brass wire wheel.

 

[GregW]

I replaced all the old nuts and bolts on my car that would cause me grief if they failed. This is a trans to bell house bolt that couldn’t take the torque. Not only did it fail, but it ruined the thread in the tranny. Forcing me to drill and re-tap for a helicoil.