hello all. i was approched with the question about the possibility of doing a french gray on a reciver for a friend. i done lots of hot caustic bluing from the blue- black to matte. i need some imput on how to do and or achieve the french gray look. thanks for any advice

keenan

French gray is performed a few ways and I'm shooting from the hip right now but one way is a phosphoric acid dip. another way I know of is light bead blasting of a polished surface. or lightly bead blasting a nickel plated surface.

Either way it is essentially a raw steel surface and must be protected with oil

It's not a real metal surface treatment in the sense of Black oxide, blueing, parkerizing etc.

It's just a polish if you will to achieve a grayish finish on a otherwise in the white pice of steel.

Brownells has a little sheet on a few ways it's done and it is basically what I said above.

Here's a cut and paste

"FRENCH GRAY METHOD" BY JOHN K. BARRACLOUGH.

THE BASIC PRODUCT THAT I USE IS REFERED TO IN THE AUTOMOBILE
REFINISHING TRADE AS "BODY PREP" OR "STEEL PREP". THE SPECIFIC
PRODUCT THAT I PURCHASE IS MADE BY DU PONT COMPANY AND IS LABELED
"STEEL REFINISHING SYSTEM", "STEP B"*5718-S ÒCONVERSION COATING" +
THERE ARE OTHER BRANDS BUT I KNOW THAT THIS. ONE DOES THE JOB FOR ME.
THE PRODUCT IS OBTAINED FROM AN AUTOMOTIVE PAINT SUPPLY STORE IN A
PLASTIC BOTTLE, .946 LITER SIZE FOR ABOUT $20.00-$25.00.
NORMAL CARE SHOULD BE EXERSIZED IN THE USE OF THIS PRODUCT. READ
THE LABEL. FOR OUR PURPOSE THE PRODUCT CAN BE REUSED MANY TIMES
SO POUR IT BACK INTO THE ORIGINAL CONTAINER CAREFULLY AFTER USE.
POUR ENOUGH MATERIAL TO COVER THE PARTS TO BE GRAYED INTO A NON-
METALLIC CONTAINER, I USE A LARGE PYREX MEASURING CUP WITH A
POURING LIP AS IT IS EASY TO REPOUR THE PRODUCT INTO THE BOTTLE.
FIX A STEEL WIRE TO EACH PART SO THAT IT DOES NOT HAVE TO BE
HANDLED DIRECTLY. CLEAN EACH PART BY DIPPING IT INTO LACQUER THINNER AND ALLOW
IT TO AIR DRY.
NEXT, DIP EACH PART INTO THE BODY PREP AND LET IT SIT UNDER THE
SURFACE OF THE FLUID FOR ABOUT ONE OR TWO MINUTES.
RAISE PART BY THE WIRE AND CHECK ITÕS COLOR. CHECK IT AGAINST A
PIECE OF UNTREATED METAL
WHEN IT TURNS A NICE LIGHT GRAY, STOP THE ACTION BY IMMERSING
IT IN CLEAN COOL WATER
TAKE THE PART OUT OF THE WATER BATH, HOLDING IT BY THE ATTACHED WIRE.
DRY IT WITH A WARM AIR HAIR DRYER. MAKE SURE YOUR PART
IS GRAY ALL OVER AND AS DARK AS YOU WANT IT. DO NOT BE CON-
CEREND ABOUT A SLIGHTY CLOUDY FINISH, IT WILL CLEAR UP WITH
THE FOLLOWING STEPS.
AT THIS STAGE, WHILE THE PART IS STILL WARM, IT SHOULD BE
DIPPED INTO A SEALANT TO PROTECT THE FINISH.
THE SEALANT SHOULD BE MIXED, TESTED AND CONTAINED IN AIR TIGHT JAR,
AND BE ON HAND EEFORE STARTING THE FINISHING PROCESS.
MIX THIS IN A SCREW TOP JAR, SHAKE AND TEST BEFORE EACH
USE, KEEP IT THINNED DOWN AS NEEDED.
TO MAKE THE SEALANT SOLUTION, HALF FILL THE JAR WITH CLEAN
ACETONE AND ADD ABOUT A TABLESPOON OF SPAR VARNISH.
DO NOT USE PLASTIC VARNISH; USE THE OLD FASHONED ROSEN TYPE.
SHAKE TO MIX, TEST AS FOLLOWS.
TO TEST THE SEALANT MIX.
HOLD THE BACK OF YOUR HAND OUT IN GOOD LIGHT AND NOTICE THE TEXTURE AND LIGHT THAT
REFLECTS FROM IT. DIP A FINGER INTO THE MIX AND MAKE A QUICK
SWIPE ON THE BACK OF THE OUTSTRECHED HAND. THE WARMTH OF YOUR
HAND WILL IMMEDIATLY FLASH OFF THE ACETONE AND LEAVE A VERY
LIGHT DEPOSIT OF VARNISH WHICH YOU WILL SEE AS A SLIGHT SHINY
STRIPE ON THE BACK OF YOUR HAND. IF YOU DONT HAVE A STRIPE MIX A
LITTLE MORE VARNISH IN AND TEST ON A DIFFERENT PART OF YOUR SKIN.

AFTER GRAYING AND WITH THE PART STILL WARM FROM THE DRYER AND BEING HANDLED ONLY
BY THE WIRE, DIP IT INTO THE SEALANT MIX. REMOVE AND REDRY THE PART IN THE AIR.
HANG BY THE WIRE UNTIL FULLY DRY, 24 HOURS IF TIME PERMITS.
APPLY INK TO THE ENGRAVING TO BRING OUT THE DETAIL. REMOVE
THE EXCESS INK FROM THE FLAT AREAS WITH CLOTH DAMPENED WITH ALCOHOL.
AVOID FLOODING THE SURFACE, WIPE SEVERAL TIME WITH A JUST DAMP CLOTH.
LIGHTLY POLISH ANY DIMENSIONAL GOLD OR SILVER INLAYS WITH A SOFT ERASER,
STAY STRICTLY ON THE INLAY.
SIT BACK AND ENJOY YOUR HANDWORK.

thanks for the info and i found the cut and paste on a knife form doing a serch on the subject.

I was under the impression that French Gray or coin finish as I used to call it was case hardening with the color polished off. It can be very attractive.

Jerry Liles

That work as well.