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How to make your 20% look 100%.

Contribution from Racer 88

I’m just a noob when it comes to building guns. But, I’ve been working with my hands in some fashion for my whole life (coming up on 58 trips around the sun). And, I rather enjoy teaching and demonstrating techniques I have found helpful in my professional and other endeavors. So, it wouldn't be long before I did the same in this facet of the firearms experience! 😎

How I got here.

After shooting a friend’s P80 build at the range, I bought my first P80 frame about 2 years ago with the idea that MAYBE some day I’ll build a gun. And, there it sat in my closet. The recent political saber-rattling about “ghost guns” compelled me to get my ass in gear. The President, himself, said that anyone can, “just order a kit through the mail, and in 30 MINUTES have a working gun!” Well, hell… I can surely spare a half hour to have my very own “ghost gun!” 😉

So, I dove into the P80 pool… DEEP. When I decide to pursue an interest, I jump in with both feet. I gotsta know EVERYTHING. And soon!

Luckily, I stumbled across an MGB video on Youtube. At first, I thought “Damn, this guy is long-winded.” But, wait… who ELSE do I know like that? 😉 Then, I realized he’s a perfectionist, even when perfection is not required. Who else do I know like that?? It takes one to know one! He’s speakin’ my language! From there, I found this MGB forum and a truly fine group of helpful and friendly people.

OK… let’s get on with the subject at hand: How to finish a frame that doesn’t look like you turned a rabid rat loose on it after binging on bath salts.

Be kind to the plastic!

One thing I’ve learned about working on plastic, or POLYMER if we are feeling sophisticated, is that it’s not like working on hard materials such as metal or even wood. It’s SOFT. So, abrasive and cutting instruments will remove material very quickly. Furthermore, plastic is “grabby.” It will grab that rotary instrument and PULL it in. Cue Homer Simpson’s, “D’OH!”

Another property of plastic is that frictional heat will MELT it. Electric motor-powered tools have a lot of torque. They don’t stall if you press hard. They keep going, and the friction will QUICKLY generate heat. A lot of heat. And, plastic no likey heat. Ask me how I know!

I was polishing the shelf with a felt spear point like in MGB's video.

Whoops! Too much pressure! Had to trash the housing. (You can skip polishing the housing altogether, IMO.)

Another challenge of using rotary tools on small movable items is chatter. Chatter can happen when the tool AND the material or item being worked on are not being held steady in relationship to each other. It makes for a choppy, boogered up surface.

The Dremel tool is ironically quite unwieldly for something that is designed to do fine intricate work. It’s heavy. It’s fat and cannot be gripped like a pencil or paintbrush. It’s like trying to conduct an orchestra with a baseball bat instead of a proper baton.

Using a much narrower and lighter flex-shaft handpiece attachment for more delicate procedures helps with that issue. However, both the Dremel and flex-shaft have the additional burden of an electrical cord or cable shaft, which add weight and torque while holding and using the respective tools. This causes hand fatigue (yeah, it’s a thing), which makes for shaky work.

So, you’ve got a rather vulnerable piece of plastic in one shaky hand being subjected to a heavy high-speed high-torque rotary cutting instrument in the other shaky hand. This piece of plastic is destined to become a device intended to contain an explosion that hurls a piece of deadly metal downrange with PRECISION. If you fuck it up, at BEST it won’t work. At worst, someone could get hurt, including you.

Take control !

How do we avoid all that? With CONTROL. You’ve got to have control over the tool and the material you’re working on. Similarly, in precision rifle shooting (another passion of mine)… The more points of contact you have between the firearm, your body, and the ground (or other structural foundation), the steadier everything in the “system” will be.

Where to start? First we need to lock down the frame. For obvious reasons (I hope!), clamping it directly in a vise is a no-go. I picked up a nifty and rather simple device called the “Ergo Mast.” It’s a $15 piece of plastic molded to fit into the mag well of your frame. It also has a notch to lock into the magazine catch. But, even without the mag catch installed on your frame, the Ergo Mast will steady the frame very nicely. The Ergo Mast can be secured to your bench top via their own optional base, which is bolted to the bench.

It can also be clamped into your bench vise, which I prefer since my vise can be moved and positioned as needed on my bench.

With the frame secured, you now have BOTH hands available to control the tool being used, whether it be a Dremel, flex-shaft, sanding block, Exacto blade, pin vise drill, etc. Having both hands available allows better control of the tool via multiple contact points between your hands, the tool, AND the immovable frame. This allows for very fine and controlled manipulation of the tool on the frame.

Your dominant hand, naturally, is mostly involved in controlling the tool. Though, it may also have some contact with the frame. Your non-dominant, or support, hand is used to steady the tool and provide contact with the frame via “finger rests” or “fulcrums.”

As I mentioned earlier, plastic can be vulnerable to damage with heavy pressure and poorly controlled tools (shakes, grabbing, chatter). When you have control of everything, you get First Time Quality results!

In this photo, you can also see how I looped the flex-shaft cable over my task light to reduce torque and weight, allowing much finer control of the handpiece in this vertical orientation.

Slow your roll and 'channel' your inner craftsman.

My advice to other noobs (and even build veterans!): Watch MGB's videos. Then watch them again. Go SLOW. Use LIGHT pressure. It’s easier to remove a tiny bit of material at a time. It’s easy to “take a little more.” It’s much harder (and sometimes impossible) to add material back. With polishing, it’s the same thing. Tread LIGHTLY. It’s far better to make many light strokes with the polishing instrument than to be in a hurry go hot and heavy. Don’t rush it! Woo that plastic into a factory-looking sharp and smooth finish and high shine.

I believe that a First Time Quality home built pistol begins and ends with the frame finishing. On the forum, we’ve talked about “Tolerance Stacking” as it pertains to the internal components of the gun. I believe that “stacking” starts from the very beginning… before you even start throwing in the parts. If the frame is crap, the problems START "stacking" there.

I understand the excitement of a first build. Woohooo! I’m building a gun! I want to show it off. And, I want to shoot this bad boy as soon as possible! Slow down and hold your fire, Sparky! It will save you so much trouble, AND it will create a FTQ result you can be proud of.

My first build!

My friend who got me into precision rifle shooting said something that applies to most things in life: “A lot of little things add up to a big thing.”

A parting shot.

Lastly… Mr. President. You, sir, are full of shit. I estimate I’ve spent at LEAST 20 - 30 HOURS, not minutes, DIRECTLY on my first build. That doesn’t include the countless hours of watching videos and time spent on forums researching and learning from others. To get things working right, I had to source parts and tools from dozens of sources. And, this gun cost FAR more than the same model gun purchased retail. Actual criminals aren’t passionate hobbyists. They’re just going to buy a gun much faster and much cheaper from their thug cohorts on the street. Leave us Freedom Protectors alone, you leftist tyrant!

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