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Posted By: SKB metal prep - 08/08/20 03:23 PM
I had a PM asking some questions about preparing barrels for bluing and thought I would start a thread on how I go about it. There is more than one way to do good work, these are my techniques. Input from on others on the way they approach things is always welcome.


Before I begin polish I measure things up on my barrel wall gauge to determine the condition of the tubes.

Here is a picture of some of the tools I use.



Learning to polish metal requires a bit of patience, it is not a really hard task, just laborious but you do need to develop some skills. You want to avoid rounding your edges and washing out any engraving, sharp contours or lettering. Pitting has to be approached over much larger area than the pit itself, if you just polish the pit out you end up with a low spot that looks terrible. This is where striking or re-striking comes in.

When I re-finish a set of barrels I begin by removing the blue with paper on a backer like the concave rubber one pictured. I like this method as any dents, dings, pits, rivels, bulges etc. stand out and this is the time you want to address them.

High spots I address first, pounding them down around a mandrel as needed. Large bulges can be a real problem but smaller ones are often simple to repair.

Once I have most of the finished removed I start looking at any imperfections then decide my course of action. Very lighting pitting can often be removed with 240 grit on a rubber backer and be ready to move on. On areas with deeper pitting, dents have been worked in the past, deep scratches etc. I begin with a file. I use a 8" mill bastard with the edges broken on a belt and a smooth cut half round file. When I start work on one of these areas I work the radius well to each side of the problem so not to get a flat spot on the curve. I also start my file stroke several inches before and continue it on several inches after the problem in order to not get a low area. The idea is that you feather out any work you do over a long distance.

Once the file work is complete I progress on using paper on a backer and the mold maker stones pictured above. The stones are a semi-soft aluminum oxides which breaks down as you use it and can conform to the shape your are polishing. I try to start with as high of a grit of paper or stone as I can get away with. It is a trade off, more course grit cuts faster but leaves deeper scratches you have to remove later. I use more 240 grit than anything else to remove pits and file marks.

How high of a polish is dependent upon the type of rust blue you do and the finish you are trying to obtain. Some people rust very aggressively and if that is the case you do not need to polish much past 320 grit in my opinion. On the majority of the work I do I polish to at least 400 grit and then bland out with a fine .003" wire wheel and oil.

The small wire wheel picture above fits my Foredom tool, basically a fancy dremmel. It works very well for removing bluing on matted ribs.

The hobby sticks polishing boards are handy and come in numerous grits.

For lettering and engraving I polish "up to and around" it, then just a very light blending pass of my final grit of paper. If the engraving or lettering is damaged or pitted then I polish below the damage and have an engraver re-cut the area.

Steve
Posted By: Der Ami Re: metal prep - 08/08/20 05:38 PM
I find a barrett file very handy for "backing up" abrasive cloth next to the ribs, they can get a little closer than half round.
Mike
Posted By: Woodreaux Re: metal prep - 08/08/20 08:35 PM
Thanks for the great rundown. I appreciate your willingness to share your methods as always.
Posted By: BrentD, Prof Re: metal prep - 08/08/20 11:52 PM
These questions is getting a little ahead of the conversation, but, Steve, what do you use for rust bluing solution? I've used a fair number of them now, but find I want to cut them by about 50% to slow them down to my pace and for my final expectations. Most are too strong, esp. Laurel Mt. Forge.

And, have you ever done any post-rust bluing polishing or buffing? Another thing that I want to try someday.
Posted By: SKB Re: metal prep - 08/09/20 12:29 AM
I like Pilkington's for rust blue myself. I put on light coat after ridding a foam applicator brush of the excess fluid, leave it to hang in my garage and boil 10 hours or so later. Two coats a day this way and done in about a week. I use it full strength and find it to be not overly strong.

I have fiddled with making my own rust blue solution but have not found one I like as much as Pilkington's. I do make my own browning solution from a recipe in Angier's which I modified. The Angier's solution I use gets cut at least 50% to start and then reduced even more as I progress on my brown finish.

I have never really messed with post blue polish or buffing but it would be interesting.
Posted By: BrentD, Prof Re: metal prep - 08/09/20 12:34 AM
Sounds a lot like what I do. 2x a day, 12 hrs between coats. I use a barely damp cotton pad or cloth t-shirt. Never thought about the foam brush approach.

I've used Pilkington's, and I still cut it a little bit at least.

My favorite was WinRest, but they are long gone now. I'm not even sure if Pilkington's is still with us.

The only difference I've seen in different solutions is strength. They all produce the same color. I think simply because rust blue is all the same chemically. But others seem to think that different solutions give different hues. Not been my experience.
Posted By: SKB Re: metal prep - 08/09/20 12:48 AM
The different hue thing exists, as to why I can not say. It may be combination of factors. Have you ever noticed the high proportion of Scottish guns which have plum tone to the blue?

We are pretty dry here in CO and humidity is certainly one factor that effects how aggressively the rusting agent reacts to the steel.

I had a completely different process I used at my old shop. I would turn on the tanks and close the door on my bluing room after coating the barrels with solution. It would get up to about as hot as I could stand it in there with 100% humidity. Within 10 minutes the barrels were ready to boil. Lots of short passes resulted in a very high luster blue.


I am happy with my current method but I am always tweaking things. I recently starting playing around with steam conversion. It has a place in my shop for sure.
Posted By: BrentD, Prof Re: metal prep - 08/09/20 01:05 AM
I blue summer and winter in my shop. Humidity can be all over the place. I use milder solution if I think it will get away from me. I too prefer lots of applications of very mild solution to get a smooth luster, however, I have to adjust my solution to the rest of my life. I can't do a bunch of coats quickly.

I think all rust blues and all brownings tend toward plumb eventually. There is a slow conversion to some sort of equilibrium of Fe2O3 and Fe3O4 (or whatever the correct compositions are) or at least that is wha II think happens over long periods of time.

Different steel alloy has different colors. Some of the welds I have had done can be seen no matter how much I try to blend them. My favorite welder for Winchesters, however, gets it just right every time. I don't know how he does it, but legend has it that he collects coat hangers.

Posted By: Recoil Rob Re: metal prep - 08/09/20 02:32 AM
Steve,

Steam conversion? Please elaborate?


thanks,

Rob
Posted By: SKB Re: metal prep - 08/09/20 03:13 AM
Rob,
instead of placing the barrels in boiling water they are subjected to a steam bath in a pvc tube. It works well and consumes less water.

Steve
Posted By: Der Ami Re: metal prep - 08/09/20 02:23 PM
Alabama is pretty humid and the German solution I use is aggressive enough that I don't need to polish past worn 320 grit. I apply it with de-oiled 0000 steel wool. I watch the color instead of applying a certain number of coats. Different parts of the same gun may take color differently. Highly polished, hardened, steel doesn't want to "bite" so stopping at 320 grit doesn't hurt.
Mike
Posted By: Recoil Rob Re: metal prep - 08/09/20 03:13 PM
Originally Posted By: SKB
Rob,
instead of placing the barrels in boiling water they are subjected to a steam bath in a pvc tube. It works well and consumes less water.

Steve


Hmmm. I repair small steam generators for work.

How long must you generate steam for?
Posted By: SKB Re: metal prep - 08/09/20 03:29 PM
It takes a little time for the steam generator I use to come up to full steam production. Once that thing is cranking pretty good I put it in the tube for 12-15 minutes. I drilled a hole cross ways in the pipe at the top and insert the barrels which are suspended on a dowel placed through the hole. Place a cap on the top and excess pressure vents out through the hole drill for the dowel.


Steve
Posted By: Mark II Re: metal prep - 08/09/20 04:35 PM
I have found the speed of my carding wheel makes quite a bit of difference in the outcome. It seems I run faster than most people. It seems to burnish along with carding. It does make it harder to blend the kind of flaws you can get with more of a mat finish.
Posted By: SKB Re: metal prep - 08/09/20 04:55 PM
Carding wheel....on my never ending to do list. I still card by hand using mostly steel wool but at times carding brushes as well.

Most time when I blend rust blue out I darken the area where I did my work to close the same color as the barrels then put solution on everything a time or two until I get the desired result.
Steve
Posted By: BrentD, Prof Re: metal prep - 08/09/20 05:03 PM
For a while, a friend was rust bluing with ammonia fumes. It was definitely but subtly different.
Posted By: hereford Re: metal prep - 08/12/20 01:40 AM
What type of sand paper are you using and the brand, where you get it, etc? I have been buying the cheap on the roll paper from harbor freight which wears out quick but easily replaced since on a roll. I use similar backers such as yours. They seem to work great. As for solutions I've used brownells, Mark's Express blue, and just bought a bottle of the laurel mtn. To date I like marks express blue best.
Posted By: SKB Re: metal prep - 08/12/20 10:39 AM
I use Norton paper and like Pilkington's solution. I buy my paper in from several suppliers as it is easy to find. I like the free shipping from these guys:

https://www.zoro.com/
Posted By: mc Re: metal prep - 08/12/20 10:41 PM
I have a steam cabinate for rust bluing.it has a water tank boiler in the bottom with a tube that feeds steam to the area where the barrels hang there is a heater to adjust the humidity a temp and humidity gage water is fed to the boiler through a garden hose it has valves for controlling steam water heat.
Posted By: mc Re: metal prep - 08/12/20 10:43 PM
I have used Pilkington, brownells and laurel mountain forge solutions I cut the laurel MT.forge down by half
Posted By: Run With The Fox Re: metal prep - 08/27/20 08:03 PM
If your "favorite welder" is using coat hangers for his TIG filler rod, he must have learned his craft from the same type of "old timer" I apprenticed with-- coat hanger wire, coated, will flow at a slightly lower input arc temp. I'll also venture a guess that instead of 100% Argon for his shielding gas, he might have a split system regulator, he has a tank of helium and variable mixing regulators to give him a percentage flow mix of 2 inert gases at the torch cup. Check it out with him. I use a Miller 250 amp with Linde water cooled torches, foot pedal rheostat and 2% thorium tungstens. RWTF
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