How to polish?

M

mellow_c

New member
I'm wanting to do some polishing on some internal parts of my Sigma SW9VE. I'm looking to smooth out the trigger a little. I'm not about to start messing with or removing springs. I'm wondering what to use. People talk about using dremmels but I'm not going to go that route. I was thinking about using 1000 grit sand papper or something like that.

Should I use a polishing compound? if so what should I use and how do I use it?
 
Disassemble it and inspect it first. My Sigma's parts were cleanly stamped and did not require polishing. I did remove the pigtail spring and replaced the outer sear spring with one from a BIC ink pen. That plus a dab of grease lowered the trigger pull to 9 pounds from 16+ pounds.
 
You are correct about not choosing the Dremel.
You do not want to change the size or shape of the part.You do not want to worry about low spots.If you have a high spot like a parting line from casting or a burr or some very rough tool finish,and it has friction with another part,there may be something to gain.Sandpaper often is a poor choice because it lacks shape so it rounds out a defined part.It can sometimes be used on a flat plate.I generally use stones.A few silversmith's stones in fine india and hard arkansas can be good.See the MSC site.Norton is good.Usually,just a floating is good,flat stone over flat functional surfaces just to knock the high spots off.Eliminate teeth and hair sticking up,thats all.In many,but not all cases,a light,.003 or so corner break on sharp edges is good.Don't do that to edges designed to be sharp,like sears,hammer hooks,disconnectors generally,unless you have skill and understanding,professional know how,and the right tools,leave sears and such alone.Hand stoning changes angles,rounds things,and takes them out of square.Same for safety surfaces.
If a spring,like a leaf or hammer spring,rubs on a receiver at a bearing point,a little smoothing there might be good.
They can be slicked up and improved a bit,but think of it like drilling holes in the hull of a boat.Enthusiasm is best avoided.
 
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Well, this post is a bit late. But I hope you guys can help... I'll try my best to describe what I need to polish....

There is a block type thing that rides inside of a 2 prong fork type thing which is pinned inside a plastic thing that holds it all together. So the block thing is metal, and it has a lobe on it that rubs against an area on the plastic housing thing. And the lobe on the metal block has horizontal lines on it, so that when I pull the trigger, I can feel them rubbing on the plastic, almost like when you rub your thumb over a clean apple, (squeaky clean)

The horizontal lines are what I want to smooth out, but they are not on a flat surface, so I dont see how I can use a stone, and so far, the best idea I have is to get some really fine sandpaper and maybe wrap it around a wooden dowel and use that to polish off the lines the best I can... I wish I could just show you guys some pics, or at least use the right terminology. I'm hoping someone will be familiar with the sigma and have some good advice for me...

Thanks for the posts so far
 
Gosh.I'm a little conflicted here.i MAY HAVE A Woody Allen anxiety attack.
You see,on the one hand,if this is simply a parting line on a cast part,and you have the ability to see that it is causing a friction problem....Well,it may be the perfect oportunity for a little stonework,using it like a file,to smooth things up.Gun parts are sometimes harder than a file,I;m just a stone using guy.I was a moldmaker.I really want to respect and support your efforts.
A + point for your vision and seeing and feeling what is going on.I sincerely believe you have potential.
Here is the flipside.The thingamajig and doohickey description tell me you really do not quite know what you are doing.
The problem with that,is we have 3 possible outcomes.outcome one,you are successful.Beautiful!! Applause!!Outcome 2,you screw up your gun.Bummer.Its out of action,you have to buy parts,and tell a gunsmith how you screwed it up,and would he please fix it.This is how gunsmiths get crotchety.
Unfortunately,we must discuss outcome 3.You are modifying trigger parts.You could create an unsafe condition that injures/kills someone.
Suggestion:Look in Brownells/Midway for some DVD armorers course,like an AGI,on your handgun.Buy it,view it,and see how your understanding and confidence work out.
Or,offer tour local smith some cash for his time to look at what you want to do and bless or discourage you.
Good luck,and I meant the positive things.
 
Heh, Thanks

Well,,, it's not a line from casting in a mold. Here, this should help

http://www.youtube.com/watch?v=3OhO5-SvbDs

Watch the whole vid if you like. The part that I'm talking about smoothing out is at 5 min and 25 seconds...

So I'm wondering what would be the best way to remove those groves/lines. They are horizontal, running on the face of that surface from side to side.

Thanks for all your help so far HiBC
 
OK,well,in truth,I have never even held a Sigma,and so I am not a Sigma tech.IMO,this guy is not the mentor to choose to teach you how to work on yours.Some clues,using a jewelers screwdriver for a drift punch to knock out pins.We use a drift punch.The claw hammer to hit the screwdriver.Its a PR thing,if you are gouing to make a gunsmith video...
Then ,grabbing the pin to pull it out with the needlenose,the serrations in the pliers jaws are likely to bugger up any pin softer than the pliers.Then there is the re-springing with a ballpoint pen spring,I tried something like that on an FN FAL once.Not recomendable.There are outfits like Wolfe who sell spring kits through Brownells/Midway.
His wife's manicure emery board.I have used those on plastic and such,but NO for what he is doing.We do not hold a part in one hand and an emery board in the other and wave our hands back and forth.No.We use a vise.Holding a part in your hand rounds everything.You have no control.
His motion was stroking side to side,in the same direction as the lines,No.We stroke perpendicular to the lines,We are cutting the high spots off the lines as we cross them,and we watch the low spots uniformly disappear(I understudied a Master mold and die polish man)
Did you notice his shiny spots on the edges and his darker unpolished center? He is rounding everything out.His Polished" surfaces are now lower,and ineffective.Ony the part he did not touch,in the center,now works.
I would use a Gesswein mold polishing stone,maybe 600 grit,maybe 900,an EDM or some medium hardness that would break down a bit to conform.I would grind a little shape on the stone to get started,and stroke the length of the profile of the part,across the grind or wire EDM lines you see,and in the directiion of function of the mating part,I would watch the low spots of the tool finish and keep my progres uniform.And,I would not take all the tool finish off.As soon as I thought the mating part would smoothly bridge the low spots,Id stop,They hold lube and trap grit.
You may try another post asking"Who is a good,reliable smith to do an action job on a Sigma?" and see what you find out.

FWIW,I consider myself an amateur,hobby smith. I don't take in work,I have no FFL.
 
:D
Fortunately I had noticed all the things you said about the video. I on the other hand did use punches to dissasemble my gun as opposed to screwdrivers and pliers. And if I do get around to pollishing this thing, I'll be sure to wrap the part I'm going to polish in something soft and then clamp it in the vice before I do any work.

as far as you explenation on what I should try, well, it took me a couple times to read it before I fully understood. But I understand exactly what you're sugesting now, and it sounds good.

However, I just did a search, and I cant find any stones like you sugested, especially at 600-900 grit. This is where I'm wondering how bad would it really be for me to use a wooden dowel wraped in a fine grit wetsand paper. Maybe start with 600, then go to 900, or 1000? I figure if I do that, I will have a round solid tool to work with, that should be easy to use with the part in a vice. But now that I think about it.... I should check to see if I can really wrap a piece of sandpaper around a small enough dowel or even a pen, to get where I need to go. without the sandpaper creasing and cracking I mean. Or maybe I should wrap the paper around something flat, Like a small square metal bar... Oh, I dont know.

I'm getting close... the gun has ben sitting there with that hammer stuff out of it for a couple weeks now. I completely disasembled and reasembled the gun for a good cleaning (well beyond field stripping) and I'm happy to have the gun looking a feeling like new again... I'm really looking forward to a little improvment in the trigger. I've gone through an easy 2000 rounds with this gun, never a failiure of any type. I have nicer handguns that I "like" more. But I sure am getting to know my sigma, and I'm really starting to love it.
 
Go to mscdirect.com
Great outfit.Ask them,they will send you a catalogue tha weighs about 8 lbs.
They are online,look for "polishing and sharpening stones,files,and sticksMost of the time you will have what you need in 2 days,delivered.
Now,something that might get you started,they make a little diamond fish hook sharpening tool your local fishing shop might have,Looks like a pen,Round,with a groove.Hold it sideways,perpendicular to the part. and stroke.Its a bit coarse,dont push down real hard.Then,remember the old crock stick ceramic knife sharpening rod? do the same with it.That will give the smoothness.






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