Angel on one shoulder, devil on t'other

[Cooter]

I've been lurking here for a while, enjoying the conversations!  I've also been building a Kibler SMR, and despite contrarian advice from the man himself, decided to make a nosecap for it.  I'm pretty happy with it and learned some lessons along the way.  The bending went pretty well once I made the jig.  I'm not very experienced with metal work, and have a question:  I'm fixing to attach the front to the cap and was planning to silver solder it.  But, when I was filing it to fit, it occurred to me that the little horns near the top might overheat and ruin the whole thing.  Then the devil popped up on my shoulder and said "just JB Weld it".  Any of you have any wisdom to offer?  Am I doomed to eternal damnation with the JB Weld?  OK, that was two questions.  In advance, I very much appreciate any advice.

Thanks! 
Steve

[Stoner creek]

JB Weld is a good product but it won’t hold up in the long run in your particular application.

[Bill Raby]

Go with solder.

[oldtravler61]

  Some of the originals were filled with lead on the end of the cap....

[Dennis Glazener]

I do not use an inside fit. I use an oversize end piece hold it with a pin vise, set the curved cap upside down on the flat piece, then silver solder from the inside, playvtorch from underside which will suck solder into joint.  Let cool slip cap onto, the stock use an awl to scribe the octagon shape on backside of the soldered on nose cap, cut out with a jeweler's saw the grind the outside edge as close to cap as you can then finish with fine file. Done right you will not see the solder seam.
Dennis

[J. Talbert]

I’ve made a number of nose caps with an inside fit attached with Soft Solder, all without problem.
No need for silver solder, especially with the inside fit of the end piece.

Jeff

[bama]

As others have said, JB weld is a good product but not for this application. Follow Dennis’s directions and you will be much happier. The hardest part of learning to solder is not over heating the parts and using a good flux. You do not need to use silver solder for this application, soft solder will work. Bring the heat up slowly use flux and you will get a good joint.

[JBJ]

I follow essentially the same path that Dennis laid out. To minimize the chance for overheating and burning the flux, I take a piece of sheet stock (usually a piece of sheet steel) and clamp it in the vice. I then place the end piece on top of the sheet steel and rest the nosecap body vertically on top of the end piece. Flux is applied to the inside of the body and end piece assembly together with 4 or 5 small bits of low temp silver solder. Make sure that the bits of solder are placed at the seam of end piece and body. Heat is applied from beneath the steel. The heat transfer is slower than heating the pieces directly and you are much less likely to overheat the flux. As soon as the bits of silver solder melt, you will see a tiny bright line appear at the joint between the end piece and the body. Turn off the torch and allow everything to cool slowly. Finish up as Dennis described. Have also done the same thing using an electric stove eye as the heat source. As soon as the solder joint appears, turn of the stove eye and let things cool.

J.B.

[flehto]

I've always fitted a 1/8" thick brass piece inside the the formed sleeve. .....aids inshaping the sheet metal and used high temp silver solder that duplicated the brass color so the end insert isn't obvious.....Fred

[t.caster]

If you do it like Flehto described you can put a nice radius around the front edge like you would have on a cast nosecap.

[davec2]

Here is an excerpt from my post on building a miniature rifle for my grandson.  One method of doing a two piece nose cap.....

The heat went down from 113 yesterday to 101 today.  The shop is a cool 97.....so I went out and decided to make one of the miniature muzzle caps I need for the little rifles.  Here goes......

First step, cut out a piece of 0.032" thick brass sheet and anneal



Second, do an initial form around a piece of EMT tubing





Next, refine the curvature as the cap rolls in to contact the barrel sides.  This is done with a nylon hammer and a steel mandrel.....



The lips of the cap were left intentionally a little long, so here they are trimmed to proper height



The height is checked on the barrel (upside down from where it will be installed, but a good place to check at this stage in the fabrication process)



After cutting a small piece of brass for the front of the cap, both pieces are cleaned of oxide and surface dirt, fluxed, and set up for silver brazing



Here I have cut a couple of small pieces of silver braze alloy and will melt them into a ball and pick them up while still molten on my soldering point



The parts are heated to brazing temperature from the outside and then I have placed the solder on the inside of the joint.  It runs immediately and the second piece of solder insures that the entire joint is complete.



After brazing, a quick pickle in dilute hydrochloric acid to remove scale and flux residue



A quick inspection of the joint shows it to be tight and completely brazed





Most of the excess brass on the face piece is clipped of with tin snips



A few file strokes and the face piece is brought to near final contour



Now I smoked the end of the barrel and put the cap in place so I can tap on the face piece with the nylon hammer





The result is a smoke print of the muzzle on the inside of the cap.  The barrel flats are beveled slightly at the muzzle so the print is a little undersized but it will allow me to get very close before the final fitting.



Most of the face piece brass is cut away with files and some back and forth check to get a tight final fit



Final check on fit and the completed tiny cap

[Cooter]

Wow!   Thanks for the excellent advice.  Dave, awesome tutorial, especially the part about blacking the end of the barrel.  I made mine out of 1/32 steel, and ended up continuing with the "inside" application.  I tried to silver solder it, but must have been heating it wrong (mapp torch).  When that didn't work out, I went to town and got some soft solder which worked well for me.  I' happy with it, even though it's a hair sigoggly.  Thanks again for the assist, boys!  Pipes, including an entry pipe, are next.  Then I need to decide if I want a side plate or not.

One more question:  is the procedure to brown/black the nosecap, pin/epoxy it in, and then finish the stock?

[bluenoser]

davec2
What is that insulating block you have the parts sitting on when soldering?  It looks to be a thoroughly charred piece of hardwood.

[B.Barker]

Mapp gas doesn't get hot enough for high temp silver solder at least for me.

[davec2]

Bluenoser - the block is solid charcoal.  Made primarily for jewelry work, it helps to consume local excess oxygen while you are heating the work and keep the joint from oxidizing.  They are available in various sizes and hardness from jewelry supply houses like Rio Grande.

https://www.riogrande.com/search-page/?q=charcoal+block&tab=products

https://www.amazon.com/EuroTool-NA-Charcoal-Block-SOL-482-00/dp/B012C5ZFN2/ref=sr_1_5?crid=5QKZLX3XTPLO&keywords=charcoal+block&qid=1672366267&sprefix=charcoal+block%2Caps%2C200&sr=8-5

B.Barker - what you say might be true for very large parts but I can silver braze (with the highest temperature alloys) even with propane.  I have sliver brazed trigger guards, butt plates, knife guards, etc., and a lot of plumbing fixtures.  If you can get the parts to a dull red temperature, you should be good to go.  Mapp gas should work even better.

[Daryl]

Mapp gas doesn't get hot enough for high temp silver solder at least for me.

If you use fire-bricks, it sure does, even propane, however if clamped in a vice, no dice.

[Jakob]

I've soldered high temp silver with this & propane:
Precision LP Gas Torch 44

I used it a lot when I doing jewelry.

Unfortunately it's nearly impossible to source now.

[alacran]

Much easier to make a one-piece nose cap. Acer Saccharum has a great tutorial on how to do it. No soldering at all.

[sdilts]

davec2
What's that little torch you are using?

[Jakob]

davec2
What's that little torch you are using?

Fairly certain it’s a Smiths little torch. Uses oxygen and propane.

[davec2]

sdilts,

I have and use several torches from a large Victor oxy / acetylene rig for welding and cutting large steel sections down to very small butane torches that I use to anneal gold wire for inlay work.  The torch in the pictures I show is indeed a Smith "Little torch" that I use for a lot of jewelry work as well....but it uses oxygen and acetylene rather than propane.  You can find them on Amazon and at jewelry supply houses. 

https://www.amazon.com/Smith-Little-Torch-Soldering-Welding/dp/B000T43L30/ref=asc_df_B000T43L30?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80745502881004&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584345029461618&psc=1

For a lot of larger casting work and larger brazing, I use a Prestolite torch that burns acetylene and air.  I'm not sure if these are made any longer but they are GREAT and there are many of them on the used market at very reasonable prices.....like this....   

https://troutunderground.com/Oxy-Acetylene-Welding-Prest-O-Lite-Acetylene-Torch/

With the little torch, you will need two small regulators as well to control the gas pressure supplied to the torch.  For the Prestolite torch, you will only need one to control the acetylene pressure.  The air is drawn from the surrounding atmosphere and, hence, no regulator is needed for the oxidizer side.