scadvice
Titanium
- Joined
- Jan 16, 2009
- Location
- "Stuck in Lodi", Ca
We have job that requires silver soldering eight small steel (mostly 1018) assemblies together. (Sorry can’t post a picture because of a NDA)
I can describe it here as, the main body is a piece of one inch square tubing with .125 walls and just over 1.5 inches long. Now set this piece of tubing up on end. 3/16 of an inch down from the top end of that tube will be a .125 inch thick, 1.75 inch square and flange silver soldered. (With an appropriately sized one inch square hole in the flange of course.)
We plan on machining light .002 or .003 grooves and pockets on the mating surfaces inside the boarders to provide space for fill of the solder
At the bottom of the square tube are two rectangles, .062 inches thick by .375 wide and 2.375 long these also get silver soldered. They are running parallel and on edge, along the two opposite sides of bottom of the square tube outward to the side at right angle from the square tubing.
The challenges are:
1. The surface of the square tube and the soldered 3/8 x 2 3/8 bottom rectangles must be within .005 parallel to the top face of the flange and within .005 square to the to the side of the tube.
2. We would like to do this without re-machining, but will if we have to.
We are trying to decide:
1. The best flux
2. The best rod
Our process document will read:
a. Wearing nitrile gloves completely clean all surfaces with Acetone.
b. All parts must be handled with clean, nitrile gloves or tools, and placed on surfaces that are free and clean of oils or other materials that will cause contamination of part.
c. Full immersion etch with the phosphoric acid-based cleaner, Henkel Metalprep 79 per Henkel’s technical sheet.
d. Flush with water then place on a pre-cleaned oven surface, heat to 130F until thoroughly dry. Allow to cool for handling.
e. Heat the appropriate number of parts that will fit in the oven and wet bond the mating surfaces until all are completed. (We have a small but very good PLC controlled oven)
f. Make simple fixturing to hold the parts together.
g. Flux and lay silver solder along the upper facing joints then bring up to temperature and allowing the solder to flow and wick.
h. Cool and inspect parts then apply protective coal and package.
The challenges are:
1. The surface of the square tube and the soldered 3/8 x 2 3/8 bottom rectangles must be within .005 parallel to the top face of the flange and within .005 square to the to the side of the tube.
2. We would like to do this without re-machining, but will if we have to.
In your opinions and experiences, what are?
1. The best flux?
2. The best rod?
3. Will our process work?
a. If we have holes or misconceptions in our process, what are they?
We do not claim to experts in silver soldering by this method and we are looking for peer review and comments.
Steve
I can describe it here as, the main body is a piece of one inch square tubing with .125 walls and just over 1.5 inches long. Now set this piece of tubing up on end. 3/16 of an inch down from the top end of that tube will be a .125 inch thick, 1.75 inch square and flange silver soldered. (With an appropriately sized one inch square hole in the flange of course.)
We plan on machining light .002 or .003 grooves and pockets on the mating surfaces inside the boarders to provide space for fill of the solder
At the bottom of the square tube are two rectangles, .062 inches thick by .375 wide and 2.375 long these also get silver soldered. They are running parallel and on edge, along the two opposite sides of bottom of the square tube outward to the side at right angle from the square tubing.
The challenges are:
1. The surface of the square tube and the soldered 3/8 x 2 3/8 bottom rectangles must be within .005 parallel to the top face of the flange and within .005 square to the to the side of the tube.
2. We would like to do this without re-machining, but will if we have to.
We are trying to decide:
1. The best flux
2. The best rod
Our process document will read:
a. Wearing nitrile gloves completely clean all surfaces with Acetone.
b. All parts must be handled with clean, nitrile gloves or tools, and placed on surfaces that are free and clean of oils or other materials that will cause contamination of part.
c. Full immersion etch with the phosphoric acid-based cleaner, Henkel Metalprep 79 per Henkel’s technical sheet.
d. Flush with water then place on a pre-cleaned oven surface, heat to 130F until thoroughly dry. Allow to cool for handling.
e. Heat the appropriate number of parts that will fit in the oven and wet bond the mating surfaces until all are completed. (We have a small but very good PLC controlled oven)
f. Make simple fixturing to hold the parts together.
g. Flux and lay silver solder along the upper facing joints then bring up to temperature and allowing the solder to flow and wick.
h. Cool and inspect parts then apply protective coal and package.
The challenges are:
1. The surface of the square tube and the soldered 3/8 x 2 3/8 bottom rectangles must be within .005 parallel to the top face of the flange and within .005 square to the to the side of the tube.
2. We would like to do this without re-machining, but will if we have to.
In your opinions and experiences, what are?
1. The best flux?
2. The best rod?
3. Will our process work?
a. If we have holes or misconceptions in our process, what are they?
We do not claim to experts in silver soldering by this method and we are looking for peer review and comments.
Steve