Adding chemicals to tumbling media

MongoMike

MongoMike

New member
I am a corn cob guy. I have tried adding both Nu-Finish and Frankford Arsenal polish, and both work pretty well, but I still don't seem to get the shiny finish that some guys seems to get. I also realize shiny brass does not equate to accurate brass, but the really shiny brass makes me feel better about my reloaded ammo.

I read a post here the other day from a guy who said he added "a splash of mineral spirits" as well as Nu-Finish to his media and his brass came out really shiny. He think he may have even posted a photo.

Can anyone tell me what the mineral spirits do for the tumbling process, and if there are pros or cons with using other chems like lacquer thinner, acetone, or denatured alcohol? It seems like the chems would have a negative effect on the polish, and possibly dilute it. On the flip side, the chems would probably evaporate pretty quickly.
 
The guys using NuFinish and getting the shiny like-new brass are probably letting the unit run for a lot longer than you are. I also use cob & NuFinish and after about 6 hours I have lovely brass.
 
I use walnut, NuFinish and mineral spirits. Usually run about three to four bours in the big Dillon. Brass comes out presentation bright.

The spirits seem to accelerate the process. I also use a couple dryer sheets in the mix.

Greg
 
I use walnut bird bedding with a couple splashes of nufinish. Tried dryer sheets and they helped with dust but nufinish is more effective IMO. Never tried the spirits but I have some and some brass to tumble so may give it a shot. Usually takes about 4hrs to get super shiny range pickup but after that initial cleaning its about 2 hrs or so
 
I'm the guy that you're referring to. The mineral spirits is to cut the NuFinish (so it's not a chunky mess) and to keep the dust down. That it. I only tumble my brass for two hours and even that is probably a lot more than it needs.

This is 2x fired brass after 2 hours of tumbling:
IMAG0628_zps753b0d7f.jpg


The procedure is as follows:

Put walnut media into tumbler (no brass)

add a cap full or so of NuFinish and then pour some mineral spirits on that (not a whole bunch though)

then run the tumbler for 10 to 20 minutes so that all the media is saturated

Empty the tumbler (and check to see there aren't smears of Nu-Finish stuck on the bottom occasionally this happens) and then fill 1/2 full of brass and dump the media on top of that. I then run the tumbler for a minute or shake the tumbler and keep adding media until it is full. Thats it. Turn it on and come back in two hours to shiny brass.


This isn't MY invented recipe. I got it on another forum and have been using it ever since because it works so great.
 
Denatured alcohol works well.
I use it in the treated corn cob stuff.
I've only done 3450 pieces of brass on this batch so I can't say how it will hold up on the long term.
 
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Just got done prepping some brass last night. While looking around I found a bottle of Flitz tumbler and media additive that I had forgotten about. I added some just to try and was very happy with the results. Only tumbled for about and hour and they came out looking great! The cases weren't that bad to start with but it cut the tumbling time in about half. I took a picture but I cannot figure out how to post it on here.
 
Originally Posted By: fw707Denatured alcohol works well.
I use it in the treated corn cob stuff.


Just denatured alcohol? Or are you adding it along with something else?
 
Originally Posted By: HidalgoOriginally Posted By: fw707Denatured alcohol works well.
I use it in the treated corn cob stuff.


Just denatured alcohol? Or are you adding it along with something else?

Go back and read my post:

Originally Posted By: fw707Denatured alcohol works well.
I use it in the treated corn cob stuff.
I've only done 3450 pieces of brass on this batch so I can't say how it will hold up on the long term.

I went out to the shop and checked, and it's the cheap gallon container of Frankford Arsenal treated corn cob media. I run it in a plain old cheap Lyman Turbo tumbler, or whatever they call it.
I've been running the first half of the jug for 2 years, and I have the other half left.
The "3450 pieces of brass" was just a guess. It might have been more, or it might have been less.
I haven't added anything to the media since I dumped it into the tumbler (early 2013) except the denatured alcohol. I do that to cut the Imperial sizing wax I use in my sizing dies.
 
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I do run a batch longer than most folks probably run it.
I've got 100 pieces in the tumbler right now that have been running over 8 hours.
 
Corn cob comes in various grits. It is used as blasting media. Find a media vendor and score a bag of 80 grit corn cob. It will cost less than a jug of cleaning media. I used it for years with Nu-Finish added and got good results, but ran it for extended periods.

Before I tumbled in corn, I would wet tumble in ceramic beads which really helped the brass to finish nicely in the corn. Now days, I run SS pin media in the wet tumbler with Dawn and Lemi-shine, and no longer need to tumble in corn cob. I get better result is ss media in a couple hours than I used to get with the two stage process which took a couple of days.
 
Originally Posted By: fw707I do run a batch longer than most folks probably run it.
I've got 100 pieces in the tumbler right now that have been running over 8 hours.

i do that too. my tumbler is in my shop plugged into a lamp timer that shuts off a 2 am. some of my brass might run 10-12 hours. comes out nice and shiny.
 
I've only reloaded for a couple of years and have used Brasso with my corn cob media - it really shines up the brass, The Nu Finish looks like something else (better?) to try.
 
Brasso does indeed have ammonia in it so you may want to stay away from it. I've had some tell me they have used it for 30 years with no problems. I had problems.

About 15 years ago I started using mineral spirits with walnut media. This does an excellent job in my opinion. Never needed to run the tumbler longer than 2 hours.

The trick is not adding to much mineral spirits. However, if you do just let it sit for an hour and it evaporates.
 
Will lacquer thinner work the same as mineral spirits. I happen to have plenty of that on hand. I am not chemist, but something tells me it is stronger than mineral spirits.
 
Originally Posted By: MongoMikeWill lacquer thinner work the same as mineral spirits. I happen to have plenty of that on hand. I am not chemist, but something tells me it is stronger than mineral spirits.

Yes, they are the same thing. If one is stronger than the other I can't see it. You'll have to experiment with the right amount. To much and the media will just sit there. But, let it sit for awhile and it will evaporate till you're back in business.

I was told about using this 15 years ago. Haven't thought of using anything else since. I rarely have to run my tumbler over 2 hours.
 
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