Frank R
Stainless
- Joined
- Dec 18, 2009
- Location
- Dearborn, Michigan
I am starting a new thread because the following question got lost at the end of the http://www.practicalmachinist.com/vb/antique-machinery-history/mig-weld-cast-iron-292522/ thread.
Okay, I am having second thoughts.
For those who recommended brazing: the reason I did not break out my torch is because I have seen brazed cast iron repairs before and there were always globs or beads of braze sticking out of the joint site. I never liked the look of the repair and I did not want that for my handle.
One recommendation mentioned silver brazing. I forgot that I bought some silver braze last winter for another project. That should flow nicely between the jagged broken edges of the handle.
Here are some questions:
Updates:
Here is what I have:
The brazing rod and flux were sold to me by Baker gas. I bought them last winter as I was investigating the repairing of broken back gear teeth. I did not get a chance to use them before the weather warmed up and I left the shop for fishing season.
The last time I brazed was 34 years ago in shop class. I am willing to learn so that I can do these kinds of repairs as they come up.
Here is something helpful I found about preparing the cast iron joint:
Any helpful suggestions?
How should I test the brazed joint? How much pressure should it be expected to handle?
Okay, I am having second thoughts.
For those who recommended brazing: the reason I did not break out my torch is because I have seen brazed cast iron repairs before and there were always globs or beads of braze sticking out of the joint site. I never liked the look of the repair and I did not want that for my handle.
One recommendation mentioned silver brazing. I forgot that I bought some silver braze last winter for another project. That should flow nicely between the jagged broken edges of the handle.
Here are some questions:
- If I use bronze braze, do I have to leave beads around the joint for strength or will whatever gets between the parts be sufficient? Could it be that the brazed repairs I have seen were just not cleaned up because it was considered "good enough" to get the machine back in production?
- The jagged ends were rusted. Is it sufficient to wire wheel the rust off or should I pickle it in acid or use electrolysis? Or should I clamp the parts together and use a carbide disc to cut through the joint and get down to clean metal on both parts?
Updates:
Here is what I have:
- A Port-A-Torch oxy-acetylene set up.
- A tube of Harris Dynaflow Phos-Copper silver brazing alloy
- A package of generic brazing rod. I noticed no label on the bag. It looks like bronze.
- A container of Harris Stay-Silv white brazing flux.
The brazing rod and flux were sold to me by Baker gas. I bought them last winter as I was investigating the repairing of broken back gear teeth. I did not get a chance to use them before the weather warmed up and I left the shop for fishing season.
The last time I brazed was 34 years ago in shop class. I am willing to learn so that I can do these kinds of repairs as they come up.
Here is something helpful I found about preparing the cast iron joint:
Any helpful suggestions?
How should I test the brazed joint? How much pressure should it be expected to handle?