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Posted: 9/10/2004 7:29:26 AM EDT
I have a 14.5" Bushy Barrell. I have a Vortex on the way from Brownells. I also have some 1100 degree silver solder and some flux on the way.

Can anyone step me through the process of attaching and soldering it? I am assuming that I need to coat the threads with flux, then thread the FH on. I guess I then heat it up and try to flow the solder into the threads from the outside?

Is a MAPP gas torch hot enough to reach 1100 degrees? (I already have one) If not, what will work? Do I need an Oxygen/ Acetylene torch? (I have always wanted one)

Thanks in Advance.
Link Posted: 9/10/2004 7:34:54 AM EDT
Get some paste 1100 deg. silver solder. Also heat stop paste is a good idea but not necessary. Apply solder paste to threads. Screw on flash suppressor. Heat flash suppressor until red/orange , only on the area where it is threaded. Let cool. Spray with Alumihyde II or whatever.
Link Posted: 9/10/2004 7:35:41 AM EDT
MAPP is hot enough. You need to clean the threads on the barrel and FH, removing as much park as possible. Bare metal will take to the solder much better than coated metal. Some people slot the threads on the barrel so that the silver solder has a place to flow but I don't really know if that is necessary. Liberally apply the silver solder and install the FH. Heat the FH till red and maintain heat for a few minutes to ensure proper solder flow.

It is advisable that you devise some means of keeping the bore cool during this heating process. Welders where I work at apply a continuous flow of compressed air through pipes that have heat sensitive parts in them when they weld on piping systems. Some have filled the barrel with sand - I don't like this idea too much, but I guess it works.
Link Posted: 9/10/2004 8:08:43 AM EDT
Thanks guys. I already ordered the stick-type silver solder. Is it possible to use that or should I just suck it up and order the paste?
Link Posted: 9/10/2004 8:20:12 AM EDT
Full directions can be found in the How-To Do It section at www.MD-AR15.com
Link Posted: 10/4/2004 3:16:31 PM EDT
Do you think putting the barrel in a tall bucket of water, where the water level was just under the FH would do a good job keeping the barrel cool? Is it even necessary to take such a precaution?

Link Posted: 10/4/2004 4:48:02 PM EDT
I would not advise getting water anywhere near the barrel during this process. I was successful using the following procedure.

Coat the threads with silver solder paste from Brownells
Screw on the FH
Remove the handguards and bolt/bolt carrier
Chuck the bbl up in a vice
generously apply heat-stop paste (also from Brownells) to the outside of the bbl just past the FH
Heat the Fh with a MAPP gas torch until is is cherry red (I think this tool about 5 minutes)
Let it cool (this took quite a while)

Even when the fh was glowing, the end of the bbl where it threads into the upper wasn't too hot to the touch.

I zeroed the rifle and it shoots great.
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