Braze it or weld it?

[Brown David]

(quoted from post at 22:33:58 12/03/23) "Brown David" I'm not sure what you are referring to about being single, but no, we just celebrated 49 years together. And I do know better than putting it in the kitchen oven. I think Old has done that before, but he apparently is the king of his kingdom. Me, I'm just the guy that changes the light bulbs, and plows the snow!!!! steve

I was quoting Old's post, I wasn't responding to you, sorry for the confusion.

 

[buickanddeere]

(quoted from post at 20:22:06 12/03/23) B&D, it's cracked all the way across. It's already cracked into two pieces. Not much travel beyond that. steve

I had the impression that it was a single piece with a crack .

 

[Ozlander]

(quoted from post at 11:21:04 12/04/23)

(quoted from post at 20:22:06 12/03/23) B&D, it's cracked all the way across. It's already cracked into two pieces. Not much travel beyond that. steve

I had the impression that it was a single piece with a crack .

Me too.

 

[stevieb49829]

Sorry about that. I should have taken the photo before I bolted the two pieces together. I wanted to show the fit up, but that was deceiving the actual circumstances. Thanks for everyone's help, though. I'm leaning heavily toward trying the TIG, with some filler wire called EZ Weld TIG wire. I'd like to try the Muzzy Weld, but they are really expensive. At that point I'd spend my money on Fleabay for a used part. I'll be back to post the after pics when I'm done. steve

 

[Dave G9N]

(quoted from post at 10:30:03 12/04/23) Sorry about that. I should have taken the photo before I bolted the two pieces together. I wanted to show the fit up, but that was deceiving the actual circumstances. Thanks for everyone's help, though. I'm leaning heavily toward trying the TIG, with some filler wire called EZ Weld TIG wire. I'd like to try the Muzzy Weld, but they are really expensive. At that point I'd spend my money on Fleabay for a used part. I'll be back to post the after pics when I'm done. steve

have been looking at the possibility of soldering some unstressed cracks in the back of a lift cover on a 2N. You can apparently solder cast iron with a silver tin solder like Stay-Brite silver bearing solder. (~3.6% Ag, ~94% Sn) The cleaning and flux are more tricky with cast iron. I have some reservations about the lift cover, which doesn't generally get very hot and a lot more reservations about a valve cover, which runs hotter. Solder doesn't like much heat.


The nickel containing weld alloy for cast iron is Muggy. The logic behind this is muzzy.

Muzzy -- lacking in clarity and precision
Muggy -- warm, damp, and close
Muggy weld Kit -- $145
1/2 oz Solder Kit -- $14
310 stainless flea bay wire -- $11*


Muggy weld contains a lot of nickel. If you will pardon my muzzy logic, 310 stainless steel contains a lot of nickel (20% Ni, 25% Cr) and you can get some .8mm x 50m wire on fleabay from the country on the other side of the planet. I mention this because I once had a welder rescue a 303 stainless part that had to be welded by using 310 as filler. 303 contains sulfur, which makes it hard to weld. It was an EB weld, not TIG. As the beam went around, the 303 boiled and as it cooled, the crack formed at about the same speed as the weld. He laid a piece of 310 wire over the joint and tried again. The wire disappeared into the joint and the welds didn't crack. Could work with TIG, but there is only one way to find out. If it does, you have something interesting to tell us about that might help others.

Soldering cast iron is not for hot or highly loaded parts. So far, I have found that it may not work on all cast irons. The oil and rust must be completely removed. The flux has to be very active, such as ammonium chloride/zinc chloride, Citric acid/glycerin/potassiuum sorbate/isopropyl alcohol. It can also help to coat the weld area with copper. The same solution can be used to check stainless steels for passivation. When the copper plates out, it isn't passive. I played with it on a steel hammer head (the only small chunk of steel in the lab). If you swab the solution on, it turns a bright copper color, but rubs off easily. If you rub it off and do it again, it is more durable, but still extremely thin. Point being that if I were to try soldering, I would expect better results by applying it, scrubbing it off and reapplying it.

From Machinery's Handbook. "Coppering solution for coating finished surfaces in order that lay-out lines may be more easily seen, is composed of the following ingredeients: To 4 ounces of distilled water (or rain water) add all the copper sulphate (blue vitriol) it will dissolve: then add 10 drops of sulphuric acid. The surface to be coppered should be polished and free from grease. Apply the solution with clean waste, and if a bright copper coating is not obtained, add a few more drops of the solution: then scour the surface with fine emery cloth and apply rapidly a small quantity of fresh solution."

*Ebay store was easy to find and used as an example. It isn't my problem and I'm too lazy to find a better source.

 

[stevieb49829]

I do have some 56% silver solder, and the requisite StaBrite flux paste. I used it on some small stainless parts for a distributor, and it worked really well. It is not likely to melt at engine operating
temps. I had to get the stainless red hot before the silver solder melted, and flowed through the joint. Way hotter than regular solder. I also have some stainless wire for my MIG, and am wondering if that
might be the way to go. I'll have to go look at the alloy numbers and do some more research. steve

 

[Dave G9N]

I was talking about a low temperature, low strength solder. For brazing, 56% silver 'solder' would be a good choice too. It is confusing when the industry calls silver brazing alloys silver solders. Traditional terminology can be a problem.

56% silver solder, BAg-7_AMS_4763_TDS is a brazing alloy that melts in the range of 1145-1205F.

The 96.5% tin 3.5% Silver bearing eutectic solder TDS is a soft solder that melts at 430F.

Edit:
Robert (ID) said to preheat and slow cool. Good advice. Cracking is caused by thermal expansion as the weld cools, which causes the cooling metal to pull away from the surrounding metal. Preheating expands the entire part so that there is less of a temperature gradient as the weld cools to the same temperature as the surrounding material. As it continues to cool, everything is contracting at a similar rate.

While looking for and not finding the exact composition of Muggy Weld, I found two Indian companies with several more variations on the straight nickel and nickel iron compositions. http://www.senormetals.in/cast-iron.php and https://www2.adorfon.com/products-a...ectrodes-wires/electrodes-for-mmaw/cast-iron/ A19 and A18 sound a lot like Muggy Weld.

310 stainless was something of a shot in the dark. There are several nickel iron alloys that might be available in small quantities of wire. They are Alloys 36 (Invar), 42, 48, 52, Balco, Mu-metal and Permalloy. Lots of expensive toys to play with. The alloys are listed in order of Ni content and the numbers are the nickel content. They are low expansion alloys, but mixing with the base metal will change that a lot, since the low expansion is highly dependent on high purity.

This post was edited by Dave G9N on 12/05/2023 at 03:51 pm.