Preventing rust

[Parallax]

Today I noticed that the screws on my Ultimak were rusty. I removed it from the rifle, but in the process one of the screws snapped in half while I was unscrewing it, and is now stuck in the clamp. I also noticed a small amount of rust on the clamps and on the barrel in the spaces where the clamps connect to it.

I soaked the screws and clamps in rust remover and that worked, and the rust on the barrel wiped right off. I also noticed a very light amount of rust on the top cover, but it wiped right off.

I'm not sure why this happened because the area I store my weapons is dry, I've never had a problem with rust with any other weapons, and there was no rust anywhere else on my rifle. Just the top cover, Ultimak screws/clamps, and the barrel under the clamps. I also don't understand why that screw snapped, there was no rust on the threads, just on the head of the screw. Also, one of the other screws seems to be messed up, it won't screw all the way into the clamp.

I lubed up the rifle with a ****load of CLP, but I want to know why this happened and the best way to prevent it from happening again. Also, does anyone know how I can get the broken screw out from the Ultimak clamp, and where I can get another set of screws and maybe a clamp if I can't get the screw out of this one?

 

[Cop Bob]

I'm going to take a shot at this.
Looking up the Ultimak clamp website, I see that they are machined from 6061 Alum.. The screws are steel.. With the corrosion, however minor, it may have set up a dry condition that would put undue stress on the screws when they are removed.. This is not at all uncommon when dissimilar metals are joined, or mated.. This is especially bad with Stainless Steel, as it is really bad about "galling" With SS screws, they are pretty much stuck forevermore, only heat, pressure, tapping may work them loose.. I have had situations with custom bike parts where we just had to have them burned out with an EDM and re-welded, re-tapped, and refinished.. Such Fun... and not cheap.. It is the same with carbon steel, and 6061, just not as bad..

As far as removal, MAYBE a smaller dia, left handed drill bit in a mill, if you can get it to center up, and bite, it will unscrew.. but good luck... It looks just small enough to be dang near impossible.. Like a #4 or 6 screw, maybe a #8.. finding an endmill and drill to dress it down under the minor tread diameter.. oh boy...

If it is drilled and tapped all the way through, MAYBE you could get a small enough Rt hand (standard) drill bit to start and thread it all they way through.. But really, it looks too small to be a viable option.. it would take a good machinist awhile to set it up.. It is the kind of stuff that drives me nuts...

I hate to me pessimistic, but once you find out what machine time cost for one off repairs like this, it may be cheaper to buy another piece.. They have a website, I found it pretty quickly..

As far as finding the proper replacement screw, from looking at their website, it looks to me to be pretty much standard Allen Head Screws...If you have a fastener company close by, take a good one over to them and they can size it, and match it..

As far as preventing it from re-occuring, I generally put things like this (dissimilar metals) with a touch of Anti-Seize compound, if none is available to you, a touch of blue loctite.. but I prefer the anti-seize, and torque it to the proper spec.. your manufacturer or the fastener company can tell you what that is..

You did not mention how or where the corrosion occured, in storage, I use drying rods in the safe, Never put a gun up wet, compressed air and good oils and water displacement products are your friend. There actually IS a good use for WD-40, (Water Displacement formula #40). I love Hoppe's#9.. Ballistol for cleaning and wipe down before storage.. To take em apart, PB Blaster for penetrating those threads, a touch, and a few light taps on the tool before I start to disassemble.. I cannot tell you the # of times I have sprayed down my work pistols, shotguns, and carbines with WD-40 and then blew them out with compressed air.. JUST to get all the rainwater off of them.. Then a proper cleaning and lube later..

One cheap thing I was taught a few (cough) years back was a cheap homemade desiccant (sp?) pack.. place a few charcoal briquettes on a baking sheet in the oven, heat them on low heat for a 45 mins or so to draw all the moisture out of them (just making sure they are dry), and when they have cooled to the touch, place them in the foot of an old sock or pantyhose, and drop them in your safe or storage area, they will take up moisture before anything else will... Replace or reheat to dry them every few months..

There are smarter men than me on this board, if someone knows a better option, maybe I will learn something..
Bob

 

[Black Butte]

Agreed. Galvanic corrosion can result when dissimilar metals are in direct contact. The metal with the stronger affinity for electrons will oxidize the other.

 

[BrocLuno]

I can recommend BoeShield T09 (Boeing Aircraft) as a good rust preventative. It's a spray on film that was developed for aircraft landing gear that must work in icy, snowy and slushy conditions with who knows what chemicals in the environment. It drys to a film and works very well. Not greasy or slick, just there. Not easy to find, but can be ordered on-line

 

[zhyla]

Agreed. Galvanic corrosion can result when dissimilar metals are in direct contact. The metal with the stronger affinity for electrons will oxidize the other.

Except the Ultimak products are all hard anodized aluminum. The anodized layer is a fantastic dielectric (insulator). No galvanic corrosion is possible here.

I would just chock this up to cheap screws. They rusted, and probably one bound in the threads because of a burr on one side or the other. Remove it somehow and replace all the screws with some decent stainless screws from the hardware store.

 

[Miked7762]

Not easy to find, but can be ordered on-line

Actually, any full line Sears store carries it, though you might have to convince a salesman that they really do have it in the stock room.

 

[35 Whelen]

Several years ago Gun Tests magazine did some really grueling, extensive testing of rust preventatives. The hands-down winner by a lrage margin was Hoppe's Gun Grease. I bought a tube and I'm a son-of-a-gun if the stuff didn't look and feel like petroleum jelly. Ironically, they tested petroleum jelly in the same article and it did almost as well as the Hoppe's.

FWIW a local gunsmith was quoted as "hating" Break Free CLP because it's almost impossible (according to him) for him to get it off of firearms prior to bluing them.

35W

 

[george d dennis]

the old timers including myself, use rig

 

[hawkeye10]

Plus one on the Rig. I have had a can for years and is still over half full. Don

 

[valnar]

I'd recommend dumping CLP for Weapon Shield, personally.

 

[wep45]

i use weapon shield exclusively on all my S&W revolvers

 

[ballistol]

Keep your gun lubed up brother.