Bronze Brazing Nuts to Plaque

[Gordon Gould]

I have a neighbor friend who is an artist that works in bronze. Every once in a while he will bring over a bronze plaque and ask me to weld 10-24 nuts on the back so he can mount them in a wood frame he makes by routing out a recess. So far I have done about 10 of these, a couple at a time. I have a stick welder and an O/A set and I am just a door yard welder. I don't have much chance to experiment on a method and am nervous about screwing up his piece. So far the best method I have found is the O/A set and 1/16 bronze flux coated rod and catch the nut on 3 sides. I put a stainless screw in the nut an set it in the marker hole he drills after I grind the area off a little (Pic not ground off).

As soon as I catch one side I remove the screw. If I don't the screw gets stuck with flux or bronze wicks to it and I have to grind the nut off when I twist off the screw. When I braze the other sides with the threads open they tend to get crudded up. Most times I can fix it with a bottom tap I made by cutting off a standard tap. The job doesn't come out beautiful but it's best I can do and he is happy.

I keep thinking there must be an easier way and am looking for suggestions. Thanks !

gg

 

[bdhsfz6]

That plaque looks fairly thick. Can't you forget the nuts, drill holes & use a 10/24 bottoming tap?

 

[yomax4]

If you have to use nuts you can use a carbon stick instead of the bolt. Low fuming bronze won't stick to it. Silver solder would work as well or Phos Bronze if you want to use Mig.

 

[bdhsfz6]

Years ago, I added some nuts to a few bronze marine fittings. I put the fittings in a 500 degree oven for a half hour and brazed on brass nuts using silver solder and a Mapp torch.

Not sure if the oven would damage your plaque though.

 

[WranglerX]

If you have to use nuts you can use a carbon stick instead of the bolt. Low fuming bronze won't stick to it. Silver solder would work as well or Phos Bronze if you want to use Mig.

Was thinking this a good solution myself.... IF threads get a little flux in there, it can easily be cleaned with a "bottom" tap....

 

[MTGreen]

You could use weld nuts and keep the heat away from the threads

 

[California]

How about brass nuts, and silver solder?

 

[CalG]

50/50 solder, pre tin the steel nuts. Place them on the work while still hot.

CLEAN metal makes it easy.

 

[2manyrocks]

I apologize for not really understanding, but could you use brass rivet nuts instead and not do any welding? Amazon.com

 

[Langanobob]

I install a lot of similar bronze historical plaques. The foundry man casts raised bosses at each corner. All we have to do is drill and tap them. This is a lot simpler than brazing 4 nuts and you might ask your artist about it. Of course, it will complicate the casting work.