12 August 2010, 20:56
Hal HWhat grit valve grinding compound?
I would like to slick up a MK V action before I rebarrel it .
What grits of valve grinding compound I need to get ??
Thanks
Hal
12 August 2010, 21:10
jeffeossonone - Use "mother's billet polish" or any other "nano" polish. Mother's can be bought at autozone.
even fine valve grinding is too coarse.
don't get on the lugs, unless you KNOW what you are doign.. in other words, DO NOT get on the lugs.
12 August 2010, 22:11
J.D.SteeleTo lap an already-polished surface such as the moving parts of a bolt rifle, I always start with 600-grit OR FINER first. Mix into a loose slurry with your lubricant of choice and lap a few strokes, checking for reduced binding. When the binding feeling is reduced(not necessarily gone but noticably reduced), I clean THOROUGHLY and go to the next-finer grit to lap some more. Repeat until reaching 1200 grit or maybe even 1800 if you're so inclined, at which point I always lubricate with MoS2 (Moly-D, molybdenum disulphide, black slickum) grease and call it good.
NO LAPPING ON THE LUGS, EVER! Leave that to the pros and make sure that your particular 'pro' ISN'T using one of those spring-loaded abortions to apply pressure to the bolt!
I don't lap underneath the extractor collar either, it's hard to remove all the lapping compound. I remove the collar and stone its groove smooth, then use special pliers to apply pressure on the re-installed collar to burnish it in.
Brownell's sells lapping compounds in grits up to at least 1200 and I believe at one time they offered up to 2400 grit. I personally rarely use grits coarser than 600, the coarser stuff is used mainly on things like upcock conversions where the rough surface is a compound curve or spiral and therefore difficult to polish with stones alone. Most of my lapping of bolt rifles is done with 600, 800, 1000 and 1200 grits in garnet compounds.
When the cocking cam is lapped properly, the shooter can lift the bolt knob almost to the cocked position, then release the knob and it will SLAM down into battery. The bolt body should glide back-&-forth with no discernible hitches or rough spots, regardless of any off-center pressure from the shooter's hand.
Regards, Joe
13 August 2010, 01:50
Boss Hossquote:
Originally posted by jeffeosso:
none - Use "mother's billet polish" or any other "nano" polish. Mother's can be bought at autozone.
even fine valve grinding is too coarse.
don't get on the lugs, unless you KNOW what you are doign.. in other words, DO NOT get on the lugs.
Jeff is correct about Billet---I have used over 10 jars of the stuff over the last 8 years since it came out. Below are pics of metal that was polished with Billet. No mechanical tools used only old baby diapers. Not the covers on the back of the swing arm---those are raw aluminum and after Billet they always look like chrome. In short Billet is the best polish there is and I have used them all on the Beast---yes that is a Scott Shafiroff Race Engine 540 built for the bike.
14 August 2010, 07:35
lawndartHow does Simichrome stack up?
I just ordered a kilogram sized can. I use it to clean up really nasty looking, but intact and valuable brass cases. I also use it for final polishing on the inside of loading dies.
LD
14 August 2010, 07:36
lawndartPS That is one sick looking bike. Sick as in way to cool for any school that I have ever attended.

16 August 2010, 05:29
Big EarlI have always favored Clover compound. Either 1000 or 1200 grit. One can will last several life times.
quote:
Originally posted by lawndart:
How does Simichrome stack up?
I just ordered a kilogram sized can. I use it to clean up really nasty looking, but intact and valuable brass cases. I also use it for final polishing on the inside of loading dies.
LD
Simichrome is what I use for a polish on knives after buffing them, for a mirror finish. I then go to Flitz. Simichrome has an abbrasive in it, but I don't know what the grit size is, but it is very fine. Flitz has little, if any abbrasive in it, and it just peaks up the finish.
Fred Barker, in Precision Shooting about 10 years ago, had an article on the relative grits betweem all of the polishes like Simichrome. He tested polishes like JB Bore Polish, JB Bore Bright, Simichrome, Flitz, and others that I've forgotten. Fred is a class guy with a Phd from MIT.
Don
16 August 2010, 22:06
Boss Hossquote:
Originally posted by DMB:
quote:
Originally posted by lawndart:
How does Simichrome stack up?
I just ordered a kilogram sized can. I use it to clean up really nasty looking, but intact and valuable brass cases. I also use it for final polishing on the inside of loading dies.
LD
Simichrome is what I use for a polish on knives after buffing them, for a mirror finish. I then go to Flitz. Simichrome has an abbrasive in it, but I don't know what the grit size is, but it is very fine. Flitz has little, if any abbrasive in it, and it just peaks up the finish.
Fred Barker, in Precision Shooting about 10 years ago, had an article on the relative grits betweem all of the polishes like Simichrome. He tested polishes like JB Bore Polish, JB Bore Bright, Simichrome, Flitz, and others that I've forgotten. Fred is a class guy with a Phd from MIT.
Don
Billet makes Flitz seem like sand paper---been there done that..