View Full Version : plating the rails?
November 2, 2005, 06:00 PM
i posed this question at another forum and so far no takers.
i trying to find out if anyone has ever plated their frame rails to take out the slop.....like hard chrome or nickel. i know that the frame rails can be peened and the slide squeezed. i am just looking for another way.
November 2, 2005, 07:25 PM
Never heard anyone plating though you could I suppose build up the rail with hard chrome. Another method which I have used is to weld the rails.A fine weld bead is put on the rails with MIG then the rails are filed and lapped to fit.
November 2, 2005, 10:14 PM
Most plated finishes are way too thin to help slide to frame fit if it is bad enough to warrant some sort of repair.
November 2, 2005, 10:22 PM
I asked the same question years ago. I spoke to a plater years ago and he wondered why that couldn't be done on a gun, since it's an accepted procedure for building up worn gear teeth. Electroless nickel is commonly used for repairing worn gear teeth. Also, selective plating is easy to do. The parts you do not want plated are masked off with a laquer that's simply peeled off after plating the unmasked areas.
If it works for gears, why not on the mating surfaces of a firearm?
November 2, 2005, 10:52 PM
I have seen small amounts of free play taken up by using plating and they are still wroking fine. I would suggest plating the entire gun when doing this though unless it is a stainless gun. When I say small amounts, I mean just that, only a thou or so.
November 2, 2005, 10:58 PM
that was exactly what i was thinking.....having designed special machinery for 30+ years your example of the worn gears was right where i was coming from. also saw the main shaft for an o.d. grinder hard chromed as opposed to replacing it...saved the company save a bunch of bucks.......i am currently investigating the various forms of nickle plating that are available.
the 1911 i am thinking of only has a small bit of play but i figured why not take care of it now when the amount of plating required is small.
thank you all for the input....any leads or product names would be appreciated.
November 3, 2005, 03:51 AM
If my memory serves me right, there is a company called Texas Plating that sells plating kits for the DIY'er. See if you can google them. I feel pretty sure that their kits could help you with what you are wanting to do. Once you get it plated, then I would use 800 grit to fit the slide to the rails.
November 3, 2005, 10:04 AM
Many years ago, Russ Carniak told me he had a plater that would build up hard chrome for him on worn 1911's and he would use a surface grinder to bring them back to size. I know decorative chromium plating baths destroy steel, so a nickel plate is laid down first. I presume the same is true of hard chrome plating. The main difference is the plating rate is higher and tougher for hard chrome and it is often much thicker than a decorative plate. So it can be done. You'd have to ask a plater what the thickness limits are? Techmetal's web site puts around 15 mils as a limit for one of their electroless nickel processes. Another site with comments by platers put 12 mils as an upper limit for hard chrome. The caution with electroplating is the very thick coatings become non-uniform in thickness and must be ground to a uniform thickness post bath. The electroless processes are more uniform. There is considerable difference in corrosion resistance and lubricity among them, so I would investigate carefully.
November 3, 2005, 06:50 PM
Just do a "slide to frame" job and forget the plating.
November 3, 2005, 06:56 PM
Consider Accurails for "another" way.
Assuming the sights are mounted on the slide rather than the frame you may find the pistol quite satisfactorily accurate with the existing play and something like Slideglide from Enos may delay much more play for longer than you'll be shooting the gun.
November 3, 2005, 09:39 PM
can you explain what a "what is a slide to frame job" is ?
November 3, 2005, 10:23 PM
It varies with the gun and the amount of play. The old method worked on soft-slide government issue pistols from the WWII era involved first squeezing the frame ways inward using a special set of vice jaws. You would tighten the jaws then strike the vice with a deadblow hammer to stress relive the slide and help it take a set in the new position. Then check the slide and frame fit for horizontal play. Repeat until it is difficult to get the slide on. This can still be done on modern slides, but their heat treatment is different and harder, so this approach takes more effort if you try to use it.
Having taken the side-to-side play out by narrowing the slide ways, the next step is to remove vertical play. This is done by hammering the rails on the frame down until they squeeze down against the ways in the slide. Special tools are made for this purpose. Principle among them are a set of flat ground anvils. You determine how much vertical play has to be removed by seeing how thick a feeler gauge you can jamb inbtween the bottom edge of the slide and the frame. You remove the slide and measure the height of the channel under the rails and select the anvil that is less by the amount of vertical play you need to elimenate. You then hammer the rail down against this anvil to achieve the desired dimension. Final fit is by lapping the slide and rail together.
Other tools and variations occur. Some people peen down the whole rail length on the frame, while some just peen down the rails fore and aft of the magazine well. This is because the metal is thin around the mag well, and it is easy to hammer it narrow by mistake. A mag well solid insert is available to prevent this if you want to peen rails their whole length. A special punch to make the peening more uniform and to avoid hammer or small punch marks is likewise available.
In most instances the peening of the rails spreads them enough that they will take up both vertical and horizontal play. This makes the first step of narrowing the slide ways unessessary. You peen, then file the rail width back to fit the slide width using a flat file that spans the whole length of the rail. Use a micrometer to check width and parallelism. Then you lap.
For detailed descriptions of the procedures read Hallock's and Kuhnhausen's books.
November 4, 2005, 03:14 AM
"You would tighten the jaws then strike the vice with a deadblow hammer to stress relive the slide and help it take a set in the new position."
This is definitely a first in the engineering world, stress relieving with a hammer is new science. Lol
The only way to relieve stress in metal is heat treatment, the wacking the vice with a hammer would just take up the thread clearance and introduce slightly greater set on the slide, swinging the vice handle slightly would do exactly the same!
November 4, 2005, 04:27 AM
Unclenick, hard chrome can be plated directly on steel. ...Foxman there are some interesting new ways to stress relieve steel other than heat treat.
November 5, 2005, 11:46 AM
I am behind the times on plating. Back when I tried chromium plating in college, the basic solution was chromium trioxide dissolved in sulphuric acid. Any piece of steel put in began to etch and make hydrogen so fast that plating was impossible without an acid-resistant nickel layer being put down first. A look at Techmetals (http://www.techmetals.com/EngineeredFinishes.asp) tells me an awful lot has happened with steel plating in the thrty-five years since I was in school.
If heat were required for stress relief in steel, springs at room temperature would never take a set. But they do; and a set is exactly what the hammer on the vice encourages. There are even some systems that use ultrasonics and magnetic impulses to promote stress relief. Both a kind of hammering in their own way, though I have no idea how well they work?
November 6, 2005, 10:02 AM
I'm sorry but UNKLENICK is absolutely on target! It is done on a daily basis in the best 1911 shops - every day. I frown badly on this "re-heat treat" business. It is dangerous, we do not know the analysis of the steels used and until you know that you're guessing and "guessing" in firearms is irresponsible and dangerous.
At the "decalsecence point" the carbon steel (or alloy) becomes non-magnetic; or with a pyrometer when the needle stays still and the heat increases - at that point the decalescance temp is reached (the point at which there is a chemical change in the carbon --------- see!
November 6, 2005, 04:33 PM
Yes, there are other ways of stress relief for metals and putting set into springs is as you say done at room temperature I have no problem with that, it was the stress relief with hammer that left me wondering. I also take Harry Bonars point that the steels used are of varying carbon content / quality in older guns. In fact heating them could well promote cracking of the metal. However I did not advocate heating them, I just questiond the stress relief by hammering the vise, which as I said is a new method in engineering terms.:) There is as has been metioned elsewhere in these forums, work going on with cryogenic treatment which is claimed to produce an inverted form of stress relief and very well may do so. Plating of heat treated steels causes hydrogen embrittlement without heat treatment afterwards, raising the same problem as raised by Harry Bonar again. Metal spraying has come along way in the last few years an can reclaim worn parts with no risk of base metal cracking and good machineability too. If squeezing does the job, and it obviously does, why not.
November 7, 2005, 06:13 PM
maybe my idea of what is wrong is flawed....what should i measure across the frame rails.....maybe its the slide ....
November 9, 2005, 09:20 AM
When one does the math in a 1911 style pistol they will find there's a very small accuracy gain when tightening the slide to frame fit.
Unless your gun is exceptionally loose I would not worry about the slide to frame fit.
If you do feel you need to tighten the gun, the best way is to weld the rails on the frame and machine them to the specs you want them to be.
November 9, 2005, 12:06 PM
you maybe right...maybe i am being a bit too picky....i am finishing the gun and have added a new barrel bushing and barrel link and pin and adjustable sites. while this has been going on i looked around and thought...."what would you do if you could" and that was the only place that i found that was mildly lacking. maybe after i finish these ongoing projects i will take another look at the situation.
by the way ...a very nice web site.
November 23, 2005, 11:08 PM
for anyone who is interested plated the rails on my 1911-a1.
as suggested i found a source for the nickle plating kit.
it was the texas plating company out of texas.....however i got the kits from an outfit in tempe arizona....that sells them for restoring old radios and the like. my stepson is in the air force in tuscon and i had him pick me up 1 kit and 2 refills of the chemical. it is a gel rather than liquid. the kit is designed for doing small parts at 3 volts....i had to play with the voltage and ended up at 4.5 volts d.c. i added .002" to the overall width of the frame rails and .002' overall in the slisde ways..so total i picked up .004". I also padded my hand by picking up some slide guide and started using it. i hand sanded the frame rails with some 1000 grit wet/dry just enough to smooth them out.
so far i have about 200 rounds and i have not noticed any break down. only time and lots of rounds will tell if this is going to be durable and permanent fix.
my thanks to all who provided input.
November 25, 2005, 06:45 PM
Hunter's right about the slide and frame fit. The rule of thumb I was taught was that barrel lock-up was 70% of accuracy work, the bushing gave you another 20% of what was possible, while frame-to-slide fit, barrel extension fit, and other little tweaks all combined only provided the last 10%. The two main reasons for slide and frame fit are to overcome excessive lock-up height (as when you get a gun that even the longest standard link is too short for after cutting the link lugs) and to improve operating cycle consistancy in a gun that, for example, tends to rub the outside of the recoil spring tunnel against the edge of the dust cover.
In other words, slide and frame fit are not an accuracy essential, but they can promote functional consitancy and help get the last little bit out of the gun. With Russ Carniak's generous advice, back in the mid 80's I learned to fit up 1911's the old fashioned way, with TIG weld-ups on the barrel and a lot of pounding and lapping. The target below is what it shot with jacketed SWC's. The barrel was the original Colt, about half a thousandth out of round at the muzzle (0.451 on one 45° axis and 0.4515 on the perpendicular to that), but with a clean crown. From a Hoppe's pistol rest with sandbags, using an Aimpoint sight on a frame mount it shot 0.37 inches C-T-C with Hornady 200 gr. SWC's. I'm just sorry I hadn't put a fresh center and backer up when I shot the group. It is ragged because the backer was shot out behind it. However, on the original you can see the marks from the bullet perimeters and measure across them with calipers. It was witnessed by two people. I don't think it would have been quite this tight without the slide and frame fitting.
November 27, 2005, 12:45 PM
unclenick and hunter....thanks to the both of you for the information...i have saved both the text and the web site for future use. as i mentioned earlier....i did manage to get the frame rails nickle plated....not that much overall ....maybe .004" if i recall correctly....maybe it wont make a difference....in time we will see....i was able to after some research find the dimensions across the framerails and was only out a couple of thou....so i must assume that any extra play comes from the slide.....if that is the case i will either have to get the slide squeezed or get a diiferent slide....and of the 2 i would probably go for the slide. as far as the frame goes the tig or even mig approach does seem to have more merit...but i would think that the frame would have to be out by more than a couple of thous to make it worth it.
right now i am going to go out and put some more rounds thru it (my wife is) i will use the mill spec. as this progresses i will add to the thread.
thanks again and to all ...Merry Christmas.
November 28, 2005, 08:00 PM
You are certainly welcome for any help or info that I gave you.
Thanks for the compliment on the web site, I hope to update it some day.
If Russ was helping you I can assure you that you had a very good Mentor. I'm sure you already know this but for those that don't Russ was one hell of a good smith and a damm fine person.
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