How do you polish the insides of your sizing dies?

[RegionRat]

If we assume that the OP means just a normal cleaning, then I just use a chamber brush or bore mop with CLP or Hoppes.

That is often easier said than done since good chamber brushes are hard to find in my life.
To make them is easier than finding them.

I start with an over sized brush, and cut it to size and shape against a counter rotating wheel. I do this often enough that it is normal for me to have several ready due to AR usage. I make these in nylon and bronze.

If I have to get more aggressive, then I apply a thin layer of Scotchbrite to the brush and saturated with JB or Iosso. This can get into removing material and affecting the surface of the die, so be careful. The maroon Scotchbrite is basically aluminum oxide and the grey is silicon carbide.

I have salvaged dies this way for friends that had floods and fires, but you have to watch what you are doing under magnification and while using a borescope so you don't over do it. Scotchbrite can be as aggressive as sandpaper so caveat emptor.

 

[Kracken McGraw]

The neck sizing portion of a die became abraded producing longitudinal scratches on the neck portion of the case.

I’m convinced that Imperial dry neck lube will cause these scratches. Lately I have been wiping it off the outside of the case before sizing and it has stopped. I can’t help believe that it’s not a little abrasive on the expander balls that I use in the Forster FL dies too. I have some moly lube coming from 21st Century to try as a replacement.

 

[Fast14riot]

I use a small strip of maroon scorch brite pad in the end of a brass rod chucked in a drill. I do not like a mirror finish in my dies, need a very fine finish to hold some lube. Same concept as an engine cylinder.

 

[bobaloo22]

I use the white scotch brite for my wood projects it’s supposed to be equal to 0000 steel wool.

 

[RegionRat]

I found this handy.

 

[Fast14riot]

To be clear in my above post, I use 7447 scotch brite pads for dies.

 

[Kracken McGraw]

This is a interesting thread, but you would think that the major die makers are putting out a quality product that’s good to go. One of those if it’s not broken, put your tools away.

 

[DRK]

To be clear in my above post, I use 7447 scotch brite pads for dies.

Same thing, scotchbrite and diamond lap if needed. Mcmaster Carr has various grits of diamond lap.

 

[Shooter13]

Am I the only one in the whole shooting world that does not have a lathe?

No, but there may just be 2 of us!

 

[gunsandgunsmithing]

Smoother sounds great but is not always better. Too smooth can cause problems like galling, which leads to scratches, etc.
Other than spot on size, a sizing die is a very simple tool with an incredibly easy job to do. Lots of money gets spent for looks when the old saying, pretty is, as pretty does, holds very true in this case.

 

[JFrank]

Last time I checked the Wilson website my sizing die is case hardened and heat treated beyond a grade 8, I’m wondering if this is even a thing.

 

[K22]

I’m convinced that Imperial dry neck lube will cause these scratches. Lately I have been wiping it off the outside of the case before sizing and it has stopped. I can’t help believe that it’s not a little abrasive on the expander balls that I use in the Forster FL dies too. I have some moly lube coming from 21st Century to try as a replacement.

You may have something there. I've been using Imperial Sizing Wax ever since I abandon neck sizing many years ago but when I did neck size, I use Imperial Dry neck lube so that could have been the source of scratching the necks.

Ever since RCBS repolished the neck portion of the FL die, I have not had any problems. But as I stated, I use Imperial Sizing Wax for FL sizing.

 

[RegionRat]

Last time I checked the Wilson website my sizing die is case hardened and heat treated beyond a grade 8, I’m wondering if this is even a thing.

Hey SPJ, Grade 8 bolts have a specific set of processes and specs. Typically, the focus is on tensile strength so I am not sure why Wilson draws that hardness comparison of their die to a bolt grade but it doesn't matter. There is no mention of "case hardening" but they do say "heat treated".

A low grade bolt is typically near the annealed strength of the material but may pick up some strength from work hardening while having the threads die rolled instead of cut. Better grade bolts use both better materials and heat treatment to get their tensile strength up. Roughly speaking we are talking about double the tensile strength.

Mother nature is cruel... rust will typically attack the higher energy surfaces first, so hardness isn't always in your favor in terms of rust or stains. Some treatments like nitriding can harden the surface and help a little with corrosion resistance, but even those are not perfect.

In other words, how to clean them is still a valid question regardless of the strength or hardness.

 

[NZ_Fclass]

My wife operating the die polishing machine.

 

[JFrank]

Hey SPJ, Grade 8 bolts have a specific set of processes and specs. Typically, the focus is on tensile strength so I am not sure why Wilson draws that hardness comparison of their die to a bolt grade but it doesn't matter. There is no mention of "case hardening" but they do say "heat treated".

A low grade bolt is typically near the annealed strength of the material but may pick up some strength from work hardening while having the threads die rolled instead of cut. Better grade bolts use both better materials and heat treatment to get their tensile strength up. Roughly speaking we are talking about double the tensile strength.

Mother nature is cruel... rust will typically attack the higher energy surfaces first, so hardness isn't always in your favor in terms of rust or stains. Some treatments like nitriding can harden the surface and help a little with corrosion resistance, but even those are not perfect.

In other words, how to clean them is still a valid question regardless of the strength or hardness.

Are you removing material from a hardened die with a scotch brite or just cleaning off surface rust ?

 

[AlNyhus]

Just looking for information from those that do.

Boyd, while I have 'polished' quite a few, it's not something I routinely do before using one.

As a matter of fact, the 'polishing' I’ve done has been more to put some texture into the die....knocking the mirror finish down a bit. A slight deglazing of the internals can make a noticeable difference in reducing sizing effort.

For what it's worth. -Al

 

[RegionRat]

Are you removing material from a hardened die with a scotch brite or just cleaning off surface rust ?

When there is surface rust, like when someone accidentally gets their dies polluted in a fire or flood, or just by leaving them out in a humid dusty shop... the surface rust and stains can go deep enough to cause damage to the dimensions when they are removed.

Most of the time, if it is a die that is caught in time, the surface rust isn't very deep and you can scrub it off without taking off enough material to notice.

You always have to assume there can be damage done when using any abrasives on dies, so you have to be careful. Most of the time, it works out fine.

There are more instances of needing to clean off polymerized lubricants that have nearly turned into glue where that stain accumulates dirt that starts scratching the brass. There are also times when brass galls and sticks to the die surface and starts scratching up brass. These are probably just as common of a reason to scrub a die clean and may require some of the elbow grease that polishing cloth, Scotch-Brite, steel wool, etc., can provide. But...

You only use as much scrubbing and pressure as it takes to remove the stains. Pushing long enough and hard enough to do dimensional damage is possible, but you have to be ham handed for that to happen.

If the bore mop or chamber brush don't get it done, these are the next steps.

 

[BoydAllen]

Boyd, while I have 'polished' quite a few, it's not something I routinely do before using one.

As a matter of fact, the 'polishing' I’ve done has been more to put some texture into the die....knocking the mirror finish down a bit. A slight deglazing of the internals can make a noticeable difference in reducing sizing effort.

For what it's worth. -Al

So how do you deglaze?

 

[Cecil S.]

Jewlers Rouge is pretty nonaggressive.

 

[AlNyhus]

So how do you deglaze?

Boyd, it's not real scientific. I load up a bore mop screwed into a short extension on a cordless drill and do half a dozen in-and-outs. Then clean the beejeezus out of the die and size a case with it. They'll often start working better even when there's no apparent new crosshatch. I use Permatex valve lapping compound. Before you think my cheese has slid off my cracker for using something so 'gritty' ...it breaks down really fast and has a very good oil based carrier.

A real dirt clod way of doing it. -Al