Made an underlug

[HighUintas]

I decided to make an underlug (my first one) because I screwed up thinning the dovetail base on my purchased lug. I got too excited with the file and took it down to 0.020!

I purchased some 22 gauge sheet from Lowes to make one and unfortunately didn't take my calipers. I thought that it would be 0.030 like it's supposed to be, but apparently everyone is cutting costs wherever they can. It is actually 0.026, more like 23 gauge.

So I used some sheet I had bought from MBS awhile back which is 0.045 thick.

The lug turned out pretty well. I used some Oatey brand instant solder paste to test it out. It seemed to work just fine. The appearance is not bright silver like silver bearing soft solders. See my thread asking about flux and solder types for a picture and more info on the Oatey solder paste.

Making the lug took much longer than I thought it would and doesn't actually seem to be worthwhile unless I need something I can't buy, or don't want to pay for shipping for just a single lug or small amount. Maybe I'll be able to make them faster in the future. My vise is sub par and I used the bare minimum amount of sheet needed for my finished lug dimensions, which slowed the process down. I think if I just cut the piece a bit oversized and then file to dimensions it would go faster.

Either way, I like the sense of accomplishment in making one. I'll have to try making some rod pipes on my next rifle build.

https://ibb.co/G4Z8FQQy
https://ibb.co/jk0XQPP8
https://ibb.co/HpdYkgwT

[rich pierce]

[Jim Kibler]

That looks like some nice clean work.  You might want to experiment a bit more with the soldering.  Ideally, it ought to flow out to a smooth surface.

[Bill in Md]

With a hacksaw, a few good files, a vise, and some elbow grease, you can take solid bar stock and craft your lugs also.

[B.Habermehl]

Looks like the part might have been a bit overheated due to the porosity. Although I have not had any experience with solder flux combos. BJH

[Daniel Coats]

I can make a strip of 3 in just a few minutes by folding up sheet metal. Cut them off at an angle with a hacksaw and the dovetail is done at the same time. I've even used brass and copper.

[smylee grouch]

You might also consider " T " iron. Already shaped and only needing to be cut to length.   

[HighUintas]

Those are great ideas. Thanks!

I'll keep experimenting with soldering and different methods of making lugs.

[Pukka Bundook]

What Bill in MD says up the page.
I was shocked that they could be made any other way!

 

[HighUintas]

What Bill in MD says up the page.
I was shocked that they could be made any other way!

 

I assume you prefer making them from solid bar stock?

[Daryl]

So very much simpler with folded and soldered sheet.

[J.D.]

Clay Smith video on the easy way to make folded sheet metal underlugs.

[Daryl]

I would not use a solder paste. Tried it once and threw it in the garbage. I used wire  50/50, 30/70(or whatever) and silver bearing or real silver solder - no paste ever again.
I didn't like the bubbly result as shown in the photo. No excess heat was used.imho

[HighUintas]

Thanks for the video link, JD.

Daryl, I will experiment with this paste a little more. I was primarily interested in it because it should darken a little more than silver solder and not be as bright where there is a solder line visible. I also have never gotten that ugly bubbly surface when using the Solder-It paste. I think it maybe has to do with the amount of solder vs flux in the mix.

[Daryl]

Excess flux/solder ratio was my feeling as well.

[HighUintas]

I tried the Oatey solder paste again, this time with much better results. I shook it up really well, but I also did before and don't think it looked any thicker this time. So I don't know if excess flux was the issue.

This time, it was looking bubbly just like before but I kept heating gently. Then the flux started turning brown but the solder also started looking like it was flowing like it's supposed to so I kept going until it was all an even amber brown.

Washed off the brown flux with water and this is the result. Much better.





I'll continue to use this and experiment.

I have a question on key and lug clearance. Does anyone know how much width clearance is needed for keys and lugs? My key is about 0.415 and my lug width is about 0.590-0.600. would 0.075 or so be enough clearance? That would give me at least 0.050 width for the lug thickness on each side of the key. That should be plenty strong

[Bob Roller]

A 2 piece under lug? I might get a piece of 3/8" square 1018 and make a strip of them that can be cut to any length needed.Your approach to the problem is a good one.If I ever do any more shop work I may take a shot at this idea and see if it works out.I hope to see some of you at the CLA Show soon but leaving my wife alone may not be a good idea.I am concerned about her falling and not being able to get up and she says some of the doofus looking men that now walk past the house make her uneasy.She is now 82.
Bob Roller

[Pukka Bundook]

HighUnitas,

Apologies for slow reply.
Yes, made of solid anything is my way.
No need for bar stock, just a good chunk of solid scrap iron or steel. 
I first saw folded ones made when I went on a gunmaking course held at WKU in 2003, , and was rather disgusted.  Never saw any originals made of folded tin!

Best,
R.

[HighUintas]

See reply #15 with updated testing of the oatey solder paste flux