Author Topic: Filing and Polishing Brass  (Read 6548 times)

agaboric

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Filing and Polishing Brass
« on: March 25, 2010, 07:51:15 PM »
Is there a tutorial on how to take, say a sand cast trigger guard and go from that to a finished smooth shinny piece of brass or iron or german silver for that matter. See I have a trigger guard that was sand cast and after A LOT of filing now I am down to where I need something finer and bring it to a nice smooth shinny finish. Anyway I was wondering if anyone has done a tutorial on this subject.
Thanks,
Andy
« Last Edit: February 26, 2013, 10:13:41 PM by rich pierce »

northmn

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Re: Filing and Polishing Brass
« Reply #1 on: March 26, 2010, 04:39:36 PM »
I tuned in hoping to pick up any hints someone else may have. I do  not have a pictorial but can give some pointers. Sand cast brass is the most authentic of the products offered as compared to the investment cast stuff now as it also matches the alloy closer.
Getting it down to be ready for final finishing takes a collection of files, ideally some coarse and some finer to get it ready for sanding.   Again it is a lot like sanding wood in that you start with coaser paper and work down to fine.  400-600 grit will give a very fine finish which is really all that is needed.  One thing is to use a backing to maintain edges and flats.  I have a large buffing wheel that really can put on a shine, but may not be authentic. 
Its work requiring elbow grease. Pure and simple.

DP

holzwurm

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Re: Filing and Polishing Brass
« Reply #2 on: March 30, 2010, 01:33:23 AM »
Except, probably the rear entry pipe, the trigger guard is my least enjoyable piece of furniture to finis and inlet. I discovered that doing it in two steps is, for me, the mose efficient.

First I bed the TG in a piece of 1/2" thick wood long enough to be able to cut the approximate shape of the TG. I slather on a batch of Bondo along the wood pattern profile and bed the TG in the bondo. Try not to have any Bondo smooshing up and over the TG. Some will - it's hard not to.  I've learned to use as thin a piece of wood as possible so I can work the convex complex curves inside the shape of the guard. Set it aside overnight.

Now you can hold the wood piece in the vise and go at the inside of the TG with files, scrapers, and sand paper till it's as finished as you want. When you are finished heat the TG with a heat gun or propane torch and it will drop right off the bondo. It stay's hot for a few minutes unless you drop it in water.

I repeat the process using another piece of wood and bondo the front and rear fineals onto the wood. If you are working too hard friction will heat the metal enough that it will part from the Bondo, so take it easy.

That's how I do it  ;D

agaboric

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Re: Filing and Polishing Brass
« Reply #3 on: April 02, 2010, 05:12:17 PM »
I think that I kind of see what you are saying. Do you have any pictures of this process? I think that would help me out a lot.
Thanks,
Andy

Offline Dphariss

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Re: Filing and Polishing Brass
« Reply #4 on: April 06, 2010, 04:37:21 PM »
Is there a tutorial on how to take, say a sand cast trigger guard and go from that to a finished smooth shinny piece of brass or iron or german silver for that matter. See I have a trigger guard that was sand cast and after A LOT of filing now I am down to where I need something finer and bring it to a nice smooth shinny finish. Anyway I was wondering if anyone has done a tutorial on this subject.
Thanks,
Andy

Buy some fine cut needle files and some fine or smooth cut mill/flat/pillar/round files. The Swiss pattern round about 12" in the finer cuts is very useful for contours.
Get a piece of 1/4" plexiglass, 6" x 12" or a scrap about that size is big enough.
Cut into strips to the width you want to use then using double stick carpet tape stick wet or dry paper too it. If your filing is pretty rough start with 180 grit or so. Otherwise 220 is a good place to start. Use this just like a flat file.
For contours use various diameters of wooden dowels and/or pieces of rubber tubing, fuel line and heater hose as backing. Rubber can be bent or flexed to match a contour.
Rod pipes I usually hold with the rod I form them on.
Dan
No, sir, I don't give 'em $#*!, I just tell the truth and they think it's $#*!. Harry S Truman