Do you mean that you are trying to Silver Solder the blind pin?

If so, it doesn't meet "The Letter of The Law".

BATF clearly states Pin & WELD!

yeah, that's what i am doing. just worded it wrong.

Back in the ban era I silver soldered on several brakes and flash hiders.

I initially used the brownells product silver solder but later bought it cheaper from a jewelry supply place.

All you need is the right solder and a MAPP torch from hardware store (fullsize).

Clean the threads coat with solder then time your brake/flashider - you don't have to use a crush washer as the solder will hold the device in place.

Heat the area on the brake/flashider until it gets cherry red and keep it there to ensure the barrel is also getting to same state.

I never bothered with heat stop as the barrel can handle the heat.

Used cold blue to match up the finish - still looks fine years later.

Let me ask this!
Why wouldn’t i drill the FH, and barrel and then top
Off the pin with silver solder paste to make it the required
“Blind Pin” ?
Why am i heating the entire muzzle area rather than
A spot where the silver solder needs to melt in the hole...

Funny how I had to remove that FH.  It was easy to drill out the pin, since I left enough weld to see the location.  I saved the FH and then sent the barrel off to Adco to have it made shorter with a re-thread.  All things change.

I like the solder method better myself.  I have drilled and welded and I don't like the weld spot.  I use the Brownells solder paste and a oxygen acetylene torch and heat the base of the hider quickly and evenly so you don't draw a lot of heat into the barrel.  You would be surprised how well the parkerizing holds up to it and there is no ugly weld spot. Oil it up and you cant even tell its soldered on.

Hey, this is an old thread, but I have a question directly relevant to this. I have this Colt barrel with a permanently attached flash hider. It was attached to using the brazing method with 1100+ degree silver solder.
There is notable discoloration and what seems to be paint used to refinish it. I'm okay if it's just ugly, but noticing the gaps around the flash hider and the discoloration makes me worried about potential damage to the barrel or not meeting the legal standard.

To test, I tried to remove the flash hider, and it seemed pretty secure. Is there any risk to my barrel, the heat treat, or anything else? Or if it's just ugly, is it pretty much good to go? What do you guys think?

Note: I will be using this with a suppressor, and without.

As long as there isn't any obstruction, send it.  I'd check with a rod after threading on the suppressor.

I've got a couple of flash cans i need to solder on pistols.  Can some tell me what I need to order from Brownells?  I can't find the solder paste that guys mention here on B's website.  I find silver solder and paste.  I have a MAPP torch for the heat.

Thanks!

It appears Brownells no longer carries it.  It was 322120650 STL-1260-650 SILVER BRAZE, 1 OZ.  The paste they carry now doesn't meet the BATF temperature requirement.
I believe this is the same stuff:  https://www.sra-solder.com/stk-1260-650-brazing-paste-1-ounce

Agreed.   Discoloration will happen unless you use the Heat Stop paste, that really is your best control for this.

not sure how I missed this.  Thanks!

Ordering it now.

My question is will high temp solder discolor an anodized titanium muzzle device? I'm afraid getting the comp red hot will ruin the anodizing, and its kinda hard to re anodize the comp if its permanently attached to a rifle

Years ago me and a buddy soldered a few muzzle devices and none of them held.  We followed the directions, used the cooling paste etc. and all of them eventually came loose.  We both ran ours suppressed which might be the reason the soldering didn't hold.  I've gone with a pin-weld ever since.

Cheers

The link to the soldering method at [email protected] (remember that place?) is broken but I hopped in the wayback machine and snagged a copy of the text.

How to Permanently attach a Muzzle Break to a Post-Ban Rifle

(assuming the barrel is threaded)

By: Scott A. Jimenez of AR15-L

One of the BATF recommended ways to perm attach a muzzle device is by 1100+ degree F silver solder.

Over in FAL land, this practice is very common with the 'smiffs.'  Recommended stuff is a MAPP gas torch ($59 bucks for a spiffy trigger start unit from Home Depot) and Fusion Silver Solder (silver solder
and flux pre-mixed in a syringe):

www.silversupplies.com
Item #56
1 oz syringe $7.95
1145 deg melt, 1205 deg flow.

Clean and degrease threads and muzzle device, apply solder paste, index device if necessary, heat device until cherry red for 3-4 minutes, Voila!  Permanently attached.

MAPP gas will slightly discolor the park so refinishing may be necessary if you're fussy.  my particular barrel is for a beater posty 16" LW so I just hit it with CLP to make it dark again and I'm good to go.

Notes:

1) Sometimes, the threads can be such a close fit that all the solder paste gets pushed back when you thread the attachment on.  The solder won't really have much place to go so you need to create an interrupted thread in the attachment.  a Dremel with a long, round grinding stone will be fastest/easiest.  Create a few thin troughs
perpendicular to the threading inside the attachment.  This will give the solder somewhere to flow and hold if the threads are tight.

2) A way to check if you need to do this is to apply a good bit of the paste to the barrel threads, thread the attachment on, then back it off.  Is all the paste backed up on the barrel shelf where it meets the threading?  If yes, see above (#1).

3) The more you apply the MAPP torch, the more discoloration you will get.  It's gonna discolor a bit anyway.  i

4) The heat should be concentrated on the base of the attachment that is covering the threads.  Some flame will spill over onto the barrel edge but if you keep that to a minimum by adjusting and aiming your flame, you should be able to minimize discoloring on the barrel's park job.  You can do a home park job on the end of the barrel and
attachment in a cup in the kitchen, but that's a whole 'nuther DIY project.

5) The 1oz tube of paste should be good for ~10 attachments.  Use that to estimate how much paste you should be using.

Nice stuff for the DIY'er who doesn't have the requisite tools to pin and weld muzzle devices and do extensive refinishing.  there are also arguments that even heating to only ~1200F is kinder to your barrel
than drilling, pinning, then unevenly heating to welding temps (2x the above temp??).  Whichever.

Submitted for your approval and chock full of AR content.  Get yourself a dremel (to remove the offending bayonet lug) and you can make post-ban compliant barrels all day with this method; or attach your favorite FH to that less-than;16" barrel.

Just a side note on this process:  It's always good to keep a brass welding rod of appropriate diameter
around so that you can knock out a bead of silver if it protrudes into the bore or inside the diameter of the brake's obturator.  A quick bronze brushing with a non-plastic rod before the silver has cooled will also do the trick.

Also, a wet patch can be used to wipe molten flux mess off the barrel or brake before it burns too much or before it cools and hardens into a mess. Not using too much flux/solder mix on the threads will avoid any need for the above, but best to be prepared, eh?

Note from Rex of AR15-L: It shouldn't be necessary to heat it to cherry-red, nor to heat it so long (from Machinery's Handbook):

    Temperature  Color
    Fahrenheit
         752             Red heat, visible in the dark
         885             Red heat, visible in the twilight
         975             Red heat, visible in the daylight
       1077             Red heat, visible in the daylight
       1292             Dark red
       1472             Dull cherry-red
       1652             Cherry-red

New Member here, first time posting. Joined because of the all the rules that keep coming down. Thank you all for this information. I am going to be trying the SS paste method on my 13in pistol and a 3.25in flash can once I get everything ordered. This thread is EXACTLY what I was looking for. I could not find instructions that made much sense to me. I'm tech nerd through and through! Most exciting things I do is some carpentry and changing the oil in my car.