Repairing a cast brass part
Repairing a cast brass part
Say someone screws up the machining of a cast brass part and wants save it. Is there a way to braze, weld or solder some material back into place and then correctly machine the part? If so what materials and tooling are appropriate?
Re: Repairing a cast brass part
Silver Solder.
Re: Repairing a cast brass part
Yep, I agree, but you can't build with silver solder, so you must make a piece that will get soldered to the casting. Surfaces should be good fits, and you can expect the joint to be in the neighborhood of .002" thick. Silver solder is not good at filling, as it flows too easily.
The repair, if done well, may be nearly as strong as the casting. Keep in mind that the heat required will eliminate any hardness that the casting may have, as well as hardness in the filler piece you select.
Silver solder follows heat, so once you have the pieces up to temperature, you can drag the solder around simply by moving the torch. Be careful to not melt the objects in question.
If you don't have any experience with silver solder, be aware that some of it contains cadmium, and can be deadly (fumes).
You will experience the best results by not applying heat to the solder, but to the pieces being soldered.
I highly recommend the black flux over the white flux, as it is more aggressive and tolerates overheating better.
H
The repair, if done well, may be nearly as strong as the casting. Keep in mind that the heat required will eliminate any hardness that the casting may have, as well as hardness in the filler piece you select.
Silver solder follows heat, so once you have the pieces up to temperature, you can drag the solder around simply by moving the torch. Be careful to not melt the objects in question.
If you don't have any experience with silver solder, be aware that some of it contains cadmium, and can be deadly (fumes).
You will experience the best results by not applying heat to the solder, but to the pieces being soldered.
I highly recommend the black flux over the white flux, as it is more aggressive and tolerates overheating better.
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Re: Repairing a cast brass part
I've TIG welded brass using silicone bronze filler rod so that may be an option depending on the repair needed.
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Operating machines is perfectly safe......until you forget how dangerous it really is!
Re: Repairing a cast brass part
The repair is on a 5 inch radius with 3 degrees of taper. A custom form cutter was being used to place a 3/32” concave radius and the initial attempt at grinding the tool was faulty to say the least. The silicon bronze filler may be the best option. My TIG skills are OKish with steel but I have never brazed. Is there a technique one must follow for success? What are the key points?
Again, thank you for your replies. You are all bailing me out of another potential sinking ship!
Again, thank you for your replies. You are all bailing me out of another potential sinking ship!
Re: Repairing a cast brass part
I did it back in the 80's when I had discovered Silicone Bronze filler rod for TIG brazing steel. It was only an experiment, as I had a short piece of 2" brass tubing and a small piece of brass sheet and wondered what would happen if I tried welding them together. It worked pretty well as I was able to get a nice bead. Kind of weird with the green from the zinc though, and it welded a lot like magnesium in that you had to keep the filler rod in the argon and lots quick dabs once you got it to start welding.
I just googled it and found this, but I didn't watch it yet, so it may not help much.
https://www.youtube.com/watch?v=7udYchu ... l=Weld.com
Good luck!
I just googled it and found this, but I didn't watch it yet, so it may not help much.
https://www.youtube.com/watch?v=7udYchu ... l=Weld.com
Good luck!
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Operating machines is perfectly safe......until you forget how dangerous it really is!
Re: Repairing a cast brass part
Thanks for the link, Glenn.
H
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Re: Repairing a cast brass part
You're welcome, Harold.
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Operating machines is perfectly safe......until you forget how dangerous it really is!
Re: Repairing a cast brass part
Thank you Glenn! The video has been viewed and the next step is a little practice on some scrap.