electrolysis

[Dodge]

I have a large brass piece I want to make mountable. Ok, its a large Marine Corps emblem about 5" x 5" but it has no way to mount it to anything, so I thought about silver soldering some threaded couplings to the back of it for mounting purposes. I think the couplers I have may be stainless steel due to the reaction I observed the last time I soldered one to a steel knife tang. My question is, 'will there be a problem with electrolysis by soldering ss or even, perhaps a zinc plated coupler to brass, or is it even a factor I need to worry about?' I should say that this emblem will be subjected to all kinds of weather conditions as it will be mounted to a motor vehicle.

[Ten Hammers]

Scott, I might just go to the hardware store and find some brass machine screws, washers and nuts. If you insulated the fixing point to mount ( between the washers and the vehicle ) with some dialectric grease it might be the answer. Good luck.

[LDW]

We made some large copper sailboats one time and brazed stainless rods to represent the ropes coming from the mast, and they fell off. Had to go back and use copper. Here is a galvanic reaction pdf chart I found on the web. It says the farther apart on the list that the metals are the worse the reaction is.http://www.grabberman.com/Media/TechnicalData/127.pdf

[MooseRidge]

How thick is it? Drill and tap for brass bolts....

[chyancarrek]

Hey Dodge,

Given that it's going to be subjected to the stresses of the road (vibration as well as weather) the guys above may be right in leaning towards a more mechanical means to fasten it down.

The sculptor I work with always uses SS to provide mounting hardware for his bronze pieces. He welds them in place and to date (over 50 years), galvanic reaction hasn't been a problem . . . not sure about brass tho.

Let us know what you find out!

[Dodge]

Thanks for you input guys. What I ended up doing after having no success with silver solder was to braze a 1/2 bolt to the back/inside of the globe. It was cast hollow and too thin to drill anything without drilling through it. This was not an option I wanted to explore except as a last result. As it was, I was worried about melting through it while brazing as this was a gift from a dear friend and I feared I was taking a chance on ruining it. Well, I went for it anyway and managed to only cause in a tiny dimple in the South America part. We will call it a topographical enhancement if it doesn't polish out

[Dan OHare]

Scott, Very nice indeed. I WANT ONE!!! Would that happen to be from Sgt. Grit?Dan
Semper Fi

[Dodge]

I think it might be, Dan. I'll ask the guy that gave it to me. He ordered several but didn't say where from. It originally only had a small loop to hang it on the wall or door etc. Its now on the grill of my truck. With the bolt I brazed on it it mounts just like a regulation sized emblem. Now all I need is a reeely big cover (for you civvies, thats a hat LOL)

[Bentiron1946]

Your a metalsmith, fabricate it! Just a little something to do in your spare time.LOL

[chyancarrek]

Your a metalsmith, fabricate it! Just a little something to do in your spare time.LOL

Hey Dodge, check out Elizabeth Brim's work, using her techniques you could come up with a great looking forged cover!

Make sure to post a pic of the emblem after you mount it.