FINAL FITTING
IT IS ALWAYS THE DEVIL IN THE DETAILS THAT GETS YOU. IT WILL BE A SMALL SENTENCE INCLUDED WITH THE PARTS YOU BOUGHT FOR THAT OLD GUN THAT SAYS “SOME FITTING REQUIRED” THAT RELEASES THE SELLER FROM ANY RESPONSIBILITY FOR HAVING THE PART THE CORRECT SIZE OR SHAPE. MAYBE THEY WILL USE THE PHRASE “TO BE INSTALLED BY A COMPETENT GUNSMITH” OR SOMETHING ELSE BUT IT COMES DOWN TO THE BOTTOM LINE IF YOU READ LONG ENOUGH, IT WILL BE THE WORK OF THE GUNSMITH THAT WILL EITHER MAKE THAT GUN WORK BETTER THAN NEW OR SOMETHING LESS. WHEN IT GETS DOWN TO THE LAST FEW THOUSANDTHS IT IS THE WORK OF THE OLD MASTER GUNSMITHS THAT WE WANT TO COPY. TO DO THIS WE NEED TO KNOW HOW THEY DID IT WAY BACK WHEN. EVEN THOUGH WE CAN APPRECIATE THE BEAUTY OF THEIR WORK THERE IS NO NEED TO ABANDON MODERN CONVENIENCE WHEN IT WILL PRODUCE A SAVINGS OR ENHANCE WORK. THOSE OLD GUYS WERE ALSO ALWAYS LOOKING FOR A BETTER, FASTER AND EASIER WAY BUT THEY WOULD NEVER USE ANY METHOD THAT RESULTED IN LOWER QUALITY WORK. THIS IS WHY WE MARVEL AT THEIR WORK.
THE HAND SCRAPER IS A MAGIC TOOL FOR FINAL FITTING. NOT MANY PEOPLE REALIZE HOW VERSATILE AND BENEFICIAL THIS TOOL CAN BE. THINK OF THE SCRAPER AS A ONE TOOTH FILE. IT CAN REMOVE THE FINEST SHAVING OF METAL AND CAN BE CUSTOM GROUND TO ANY SHAPE AND REGROUND AS MANY TIMES AS THE STEEL WILL ALLOW. STOCK MAKERS ARE ALL ABOUT SCRAPERS FOR REMOVING THAT FINAL BIT OF WOOD TO ACHIEVE THE PERFECT FIT BUT SCRAPERS ARE JUST AS VERSATILE WHEN IT COMES TO REMOVING METAL. AS LONG AS THE SCRAPER IS HARDER THAN THE METAL IT WILL REMOVE METAL. MY FAVORITE IS A THREE SIDED SCRAPER GROUND FROM AN OLD THREE SIDED FILE. I LIKE THE FLATS AROUND 1/4 INCH WIDE AND MINE TAPERS TO A POINT AFTER ABOUT 1 INCH. IT IS SET IN A SMOOTH HARDWOOD HANDLE. I HAVE SEVERAL OTHERS BUT THIS IS MY FAVORITE.
SMOKE IS THE MACHINIST INK OF OLD. A LIGHT COAT OF SOOT FROM A KEROSENE LAMP WILL MAKE A FLAT BLACK COATING THAT WILL BE DISTURBED BY THE LIGHTEST TOUCH. IN USE THE PART IS SMOKED AND THEN WORKED TO REVEAL WHERE THE HIGH SPOTS ARE LOCATED. THESE SPOTS ARE LIGHTLY SCRAPED OR POLISHED TO ACHIEVE A BETTER FIT. IT WON’T MAKE MOTHER HAPPY WHEN SHE SEES YOUR HANDS BUT IT HAS WORKED FOR CENTURIES. OF COURSE ANYTIME YOU WILL BE USING AN OPEN FLAME AT THE WORKBENCH OR EVEN INSIDE THE SHOP STOP AND REVIEW YOUR SAFETY.
ABRASIVE BLASTING WITH GLASS BEADS CAN BE OF USE LIKE THE SMOKE POT. WHEN THE PARTS ARE EVENLY FROSTED FROM THE BEAD BLASTER THEY CAN BE ASSEMBLED AND WORKED TO REVEAL HIGH SPOTS AND AREAS OF DRAG. THIS MIGHT BE EASIER THAN SMOKE IN SOME APPLICATIONS BUT BE CAREFUL WITH GETTING GLASS BEADS IN SENSITIVE AREAS.
LAPPING PLATES HAVE BEEN USED TO ACHIEVE PERFECTLY FLAT POLISHED SURFACES ON PARTS SINCE BEFORE JOHN BROWNING’S GRANDPA PICKED UP HIS FIRST FILE. LAPPING PLATES ARE PERFECTLY FLAT PLATES THAT ARE SCORED AT REGULAR INTERVALS FOR ABRASIVE COMPOUND. AS THE PART IS MOVED ACROSS THE SURFACE OF THE PLATE HIGH POINTS ARE GROUND DOWN UNTIL THE PART BECOMES PERFECTLY FLAT. IT IS LIKE A MANUALLY POWERED SURFACE GRINDER! PARTS LIKE THE SIDES OF HAMMERS AND TRIGGERS REALLY GET SLICK WHEN THE SIDES ARE POLISHED ON A LAPPING PLATE.
OTHER LAPS CAN BE FASHIONED INTO ANY REQUIRED SHAPE AND USED TO POLISH ALMOST ANYTHING. JUST LIKE BUFFING WHEELS THEY SHOULD ONLY BE USED WITH ONE SIZE ABRASIVE. LAPS CAN BE MADE OF LEAD, BRASS OR EVEN WOOD. IN USE THE ABRASIVE STICKS INTO THE SOFT SURFACE AND CUTS THE HARDER METAL. WHILE NOT EXACTLY LAPPING, A WOODEN STICK WITH BROWNELL’S 555 POLISH WILL TAKE STEEL TO AN OPTICAL FINISH AND PUT AN EDGE ON A KNIFE THAT IS SCARY SHARP.
POLISHING STICKS CAN BE MADE UP WITH FINE SANDPAPER FOR A FEW BUCKS THAT WILL DO AWESOME POLISHING. SIMPLY PUT THE PAPER ON A FLAT SURFACE AND SPRAY WITH ADHESIVE. THEN WRAP TIGHTLY ON THE STICK AND TRIM EXCESS WITH A RAZOR KNIFE. A POOR BOY’S VERSION OF A LAPPING PLATE CAN BE MADE BY USING THE FINE SANDPAPER GLUED TO A FLAT SURFACE. WOOD WILL WORK BUT SOMETIMES A TRIP TO THE LOCAL GLASS SHOP WILL RESULT IN A PIECE OF FLAT GLASS THAT WILL SERVE AS PERFECTLY FLAT BACKING JUST FOR THE PRICE OF ASKING!
ONE OF THE CLOSELY GUARDED SECRETS OF MASTER GUNSMITHS WAS TO MATCH WORKING PARTS AS TO HARDNESS. THIS REQUIRES A ROCKWELL TESTER BUT THE RESULTS WILL BE YOUR WORK HOLDING UP BETTER TO WEAR. IT ONLY MAKES SENSE THAT WHEN A HARD AND NOT SO HARD PART RUB TOGETHER FOR YEARS THAT THE SOFTER PART WILL WEAR OUT, HOWEVER IF BOTH PARTS ARE EQUALLY MATCHED THE WEAR LOAD WILL SHARED AND THE PARTS WILL GO THROUGH MANY MORE CYCLES BEFORE THEY NEED REFITTING. THE FAMOUS PISTOLSMITH JOHN VIDECKI WAS ENVIED FOR 1911 TRIGGER JOBS THAT SEEMED TO OUTLAST EVERYBODY ELSE’S WORK. HE TOLD ME HE SORTED AND MATCHED UP HAMMERS AND SEARS TO THE SAME ROCKWELL HARDNESS BEFORE HAND AND THAT MADE THE DIFFERENCE. HE ALSO MADE SURE OF CORRECT PART GEOMETRY. WE SHOT TOGETHER FOR MANY YEARS AND HAD A LOT OF GOOD TIMES.
TIMOTHY P. WHEALTON