Cosmetic repair of brass

[Obi-Wan Cannoli]

The previous post I saw on this topic was dealing with a structural repair of brass, so I am taking a shot in the dark that my question is different.

I have a sand cast brass butt plate of good quality. I finished the rough file work, inlet it to the stock, and drilled the holes. I countersunk the top screw nicely, but went a little over board countersinking the bottom screw and removed about a 2-3mm finger nail clipping sized bit of brass from the surface area just below the counter sink. The butt plate locks up tightly with flush screw head to brass and brass to wood contact. I do not want to get a new butt plate since the mistake is marginal, cosmetic in nature, and I do not believe my current skill level would justify it. Additionally, I am leery about blending it in too much with the final file work as I think it would just exacerbate the problem area.

Is there any way of permanently attaching a finger nail clipping sized piece of brass or similar metal/compound to that area? solder or (cringe) jb weld it on? Or even use a filler or putty of some kind that will eventually blend in to a brass patina and not chip out from coming in contact with the ground from loading?

Sorry, I do not own a digital camera, so I can not provide any pictures.

Thank you.

 

[TNGhost]

Without seeing a picture its hard to say. A shot in the dark would be building back up by brazing, then reshaping. :idunno:

 

[Len Graves]

Perhaps you could use a larger diameter head screw, and recountersink to that size.

 

[frogwalking]

What Len said. If you don't like that idea. how about finding a very large brass flat head screw or bolt, preferably for a Philips screwdriver. Cut the head off and solder it into the hole, redrill, smooth up and polish. If home depot or Lowes does not have what you need in stock, they have much more on-line.

 

[Obi-Wan Cannoli]

Would the solder alone hold the repair in place, or is it dependent on the screw behind it compressing the repair to the butt plate? My concern is that I have been reading that it is near impossible to bond brass to brass.

 

[Artificer]

Would the solder alone hold the repair in place, or is it dependent on the screw behind it compressing the repair to the butt plate? My concern is that I have been reading that it is near impossible to bond brass to br,
,ass.

Not sure what they were talking about in your past reading.

When one uses silver solder aka silver brazing, it would not require the screw to hold the repair in place. You need the medium high to high temperature silver solder so you get the correct "brass" colored solder, though.

Back in the early 1980's when I made up a M1850 Foot Officer's Sword and scabbard from an original blade and dug brass parts, the brass "drag" or tip of the bottom of the scabbard had a cut off section in the thick portion of the brass, about 1/8 inch thick or a little more, but I don't remember what it actually measured. (I think the cut off section came as a result of it having been sheared off by a modern farm/tractor cultivator when it was still in the ground.) Well, the good news was because of the cut off section, the original/dug brass drag was cheap, so I bought it with the intention of repairing it.

We did not have the correct thickness of brass in the shop, so I sawed a piece off a thicker piece of brass we had and filed it to shape. Then I silver soldered the repair piece onto the original drag. The important thing is I did not know what exact type of brass either the original dug part was made from, nor did I know the exact type of brass we had in the shop. After I soldered the two pieces together and filed the excess off, I put the new portion of the drag into a vise and tried to bend/break it off. I put more pressure on it than it EVER would have had to stand and it did not crack or break. When I finished filing/sanding/polishing, the repair was virtually invisible.

Gus

 

[Obi-Wan Cannoli]

Would you recommend the silver solder over a resin core lead solder? I have both. The previous post was "how to fix cast brass" from 10-23-15. The almost impossible part of my comment was a combination of me never soldering brass to brass and then reading every bonding brass to brass horror story on google.

 

[Len Graves]

The part can be braised or brass welded. Get a good welder to do this. However, this takes a lot of heat, can warp the part, will certainly anneal the part and when all done the brass rod used for fill might not match in color to the original part. I would recommend unless you can't do anything else use this as a last resort. sometimes it's easier to start with a new part and time wise might be cheaper.

 

[Pete G]

Most cast parts are oversized to begin with to allow for shrinkage and final shaping. You say that you have rough filed the part so perhaps you should look to see what will happen if you file it enough to reduce the size of the counter sink. Incidentally, most buttplates should only have an edge thickness of about 1/16" at the lower edges.

OTOH once you put the rifle into service and get a little wear and/or patina on this area it will probably not even be noticeable. Remember that we are dealing with hand made items that often are less than perfect cosmetically, but are perfectly serviceable. Sometimes "good enough" really can be good enough. :wink:

 

[Artificer]

Would you recommend the silver solder over a resin core lead solder?

Absolutely and just make sure you buy silver solder that has a "brass" or "yellow" color after soldering. The intent is that after you polish the trigger guard, it should be darn hard to see the solder line. You can use the lowest temperature silver solder with yellow color to solder what would be a brass plug (from a brass screw head) in your oversize hole. You should also try to shape the brass screw head as close as possible to the chamfer angle of the oversize hole, so the solder does not have to "fill in" any more open space than needed. You can chuck the brass screw into a drill press or even a hand drill to turn it and file it to more closely match the angle of the chamfer in your trigger guard.

BTW, I got a real kick out of your Avatar name.

Gus

 

[Obi-Wan Cannoli]

Me and some friends go fishing/camping off the Juniata river every year where the beverage of choice is yingling. Our motto we use for yingling is "when good enough is all you need", maybe this is one of those situations. I will have some things to consider from all the good advice I received. Thank you. :hmm:

 

[Obi-Wan Cannoli]

glad you like it! also, both my spools of solder turns out are 60/40, lost the silver solder to the sands of time. would 60/40 create a strong brass to brass bond on a Bplate if I am not concerned about the silver seem or any other discoloration?

 

[Gustavo Hoefs]

I fix these type of situations on a weekly basis, brass can be tough to work with and it can be simple depending different factors. Brass tends to reach critical temperature over a larger area than say steel and like sterling silver it does not retain strength so it can slump in a large lump or a larger area than you intended and will lose its shape an become distorted. That being said the mistake could still be filled and finished if you use a brazing rod ( brass) with a lower melting temperature than the casting. This could be determined if you used some of the sprue remnants to practice on try a bare brass rod ( with borax flux 20 mule team & water, ) If I was making this repair I would use an oxy acetelyne torch with a # 1 or #2 tip get the flame some where in the middle coat area with a slurry of 20 mule team borax and water. Now it is time to warm up the area dry the borax, as you increase the heat the borax will fluff & crust then as it gets hot melt into a glass and then you are very close. Zero in on the spot use a bare brazing rod and slump a small lump of rod on one side of the divet then repeat across the length of the area. The mistakes during this process will result from the following nervous tension, overheating, the flux will turn black and retard flow, too much flame and an oxidizing flame rather than a normal range double cone reducing flame.

 

[jerrywh]

I would have to see this to be sure but I routinely fix small defects in brass and even steel castings with inlays. It is possible to put a brass inlay in that spot. I have doubts if you could learn to do this without personal instruction.
Basically you just cut a cavity in the area, undercut the cavity, pound a small piece of brass into the cavity and then flush it off. you can cut the cavity with a chisel or a rotary burr.

 

[Obi-Wan Cannoli]

I would have to see this to be sure but I routinely fix small defects in brass and even steel castings with inlays. It is possible to put a brass inlay in that spot. I have doubts if you could learn to do this without personal instruction.
Basically you just cut a cavity in the area, undercut the cavity, pound a small piece of brass into the cavity and then flush it off. you can cut the cavity with a chisel or a rotary burr.

do you need to anneal the buttplate prior to soften it up, and then re harden it after the inlay is in? thank you for the advice, probably experiment on some scrap before I try it. Flehto was talking about some solder paste in a different post that I may incorporate. I think I will combine a bit of everyones advice: get a small brass screw, file the threads off, anneal the shaft, drill a small hole just below the mistake, counter sink it, flux it, insert the makeshift brass rivet, peen it down, solder it, swiss file to match the curve of the original counter sink?

 

[jerrywh]

Sand cast brass comes annealed. It is annealed by the process of casting to a large degree. Brass does not harden like steel by the same process.
With a brass inlay you do not solder it in. The hole is not countersunk it is undercut.
Done correctly there is no visual evidence that it exists. Cut the hole undercut the hole puond in the inlay. tha;s it.

 

[Obi-Wan Cannoli]

Sand cast brass comes annealed. It is annealed by the process of casting to a large degree. Brass does not harden like steel by the same process.
With a brass inlay you do not solder it in. The hole is not countersunk it is undercut.
Done correctly there is no visual evidence that it exists. Cut the hole undercut the hole puond in the inlay. tha;s it.

could I cut off about an inch or two off of an old hacksaw blade, file it down to about 3mm wide, and then put a knife edge on one side to make a tool for the undercut? also , will filing a knife edge on the side of the inlet that will be inserted into the undercut help when pounding it in, or will putting that edge on it just cause it to buckle?

do you recommend annealing sheet brass (like what you buy from a ml supply or hobby shop)when you are making dramatic bends in it, ie trigger guard scratch build?

also, I may just go with silver soldering a small piece of sheet brass to the area, would a soldering gun heat up the area sufficiently enough to make a good joint, I would like to avoid my propane torch bc of brass low melting point. unless you recommend different. thank you again for your time.

 

[jerrywh]

Sheet brass needs to be annealed because it work hardens when it is rolled out. A piece of brass wire will do. Hardware stores have that. Almost any sharp pointed punch that fits down in the cut will work for an underctting tool. The undercuts do not need to be contious but it is better if they are. I just fixed a silver casting yesterday and I just undercut both ends of the small channel and put a silver wire in it. The flaw was only .020 wide and about .100 long.
How big is your cavity? This is just like a dentist fill a tooth.

 

[Obi-Wan Cannoli]

How big is your cavity? This is just like a dentist fill a tooth.

Thank you for your help

2.35mm by 5.25mm. basically, I found out a little too late that the angle at which I drilled was not going to work, and had to come in at a different angle. it is this size of a finger nail clipping shape just below the final counter sink. I can not file it out because it bottoms out too close to where my final counter sink ended up bottoming out.

 

[jerrywh]

I doubt if you can do this without some one on one instruction.