There would be joy among collectors of old tools if cast iron could be welded so it looks original. I can do pretty well with nickel rod, if you don't mind SEEING the weld, but a restoration job is a whole 'nother thing. I know there is a way--would it be feasible for a dedicated beginner to learn how? What would be involved? Do any of you do this?
I collect a lot of old tools. Some I use because I prefer the old ones and some I just collect because I love them.
Welding cast iron is a problem. the main issue is in the expansion and contraction at the edge of the heat affected zone (HAZ) which causes the brittle cast iron to crack. Heating the whole piece to low red heat in an oven before and after welding can take care of this but often creates its own problems. Peening the area with a ball-peen hammer after welding can also relieve the stress. Neither of these issues is acceptable if you are collecting for aesthetic reasons rather than utility.
On "collector" pieces I've had great luck with clear epoxy. The surface must be CLEAN for the glue to work well. I use Acetone for cleaning prior to epoxy.
I'm a woodworker, and I deliberately collect cracked plane bodies to practice my nickel stick welding.
Two ideas I haven't tried yet:
A good gunsmith's supplier like Brownells offers a range of cold blues and blackening potions, including some which work on silver solder, brazing and also on nickel. They don't have an appreciable effect of ferrous metals. These might help for camouflage.
Electroless nickel plating is a simple process and you can buy kits for a relatively low cost from Caswells etc. For a user tool, I would have no objection to an overall nickel plate.
Anyone tried either of these, in the context of woodworking tool bodies ?
BTW - I don't peen repaired plane bodies. That's just asking for trouble.
The best colour match I have seen is when you oxy - acetylene weld the cast iron piece using cast iron welding rod. The rods are sticks of gray cast iron. Flux is used. The flux is similar in appearance to the brazing flux available in cans but is formulated for iron welding. To weld you need to heat the casting to near red heat so it is impractical on large complicated castings. Since you are depositing cast iron in the repair the colour match is very good. The casting has to be cooled very slowly to ensure that there are no hard spots or shrinkage cracking. I have done it a few times simply out of curiosity but never restored anything important. I primarily braze or weld with electrode.
Randy
"Leo Lichtman" wrote in message news:wrh9d.505354$ snipped-for-privacy@bgtnsc05-news.ops.worldnet.att.net...
If I may add to Mr. Zimmerman's comments, when you start looking for those cast iron rods they are usually square and about 18" long. Get the 1/8" if possible. When finishing your repair, get creative and grind and sand to match the adjacent area's texture. I have used a center punch to replicate pitting. Maybe a course stone in my die grinder to rough things up. Then sand paper to tone them back down. Study the casting. Look at the parting lines. Are they straight? or irregular? yours should match. Old cast iron needs to be treated slow.
The only way to make a seamless repair on cast iron is by gas welding it with oxy-acetylene. You need cast iron filler rod. It comes in many sizes, and they are all about 14 " long and square in cross section. At school we have 1/8", 3/16" and 1/4" cast iron filler rod. I watched by boss at school weld up a broken Stanley Bailey jackplane once. He was gas welding it for exactly the reason you state. So there was no seam.
It does take a lot of practice.
You have to strip the entire piece down to just the cast iron bits. V-grind out the crack, preheat all the parts to dull glowing red and proceed to gas weld the parts together. Works best if you can keep the parts from cooling down at all. They bury the piece in powdered lime or vermiculite to let cool slowly overnight.
Once cool, just grind off the surface.
Then you can try restoring the original patina.
Where was it broken ? Through the side, and into the mouth ? The trouble with welding planes is that you really need to avoid distortion and this location is terrible for introducing it. I'm a better gas welder than I am stick welder, but I've had much better results distortion-wise with nickel and stick than with gas and CI.
m -> b ? How are the typing fingers healing ?
"Andy Dingley" wrote: (clip) I've had much better results distortion-wise with nickel and stick than with gas and CI. (clip) ^^^^^^^^^^^^^^ So have I, since I have never even known how to gas weld CI, and that was the reason for my question (I am the OP.) The problem with nickel rod is its color, in stark contrast to the look of old CI, and that is what shaped Ernie's answer. Thanks, Ernie--and I hope your remaining finger parts are functioning again. Or is it still too soon?
Yep, right through the middle. When he was done it was pretty flat and true, but then again, my boss at school has been welding for about 50 years.
Oh sure, pick on the cripple...
Just kidding. My biggest typing problem is that my right hand is down to my ring finger and thumb. Every once and a while what's left of my index finger makes a reflexive dive for a key, and besides being an inch too short, the end is now bigger than 1 key wide, so it leads to interesting typos.
It is going to be many months before I get much use from my damaged fingers. Besides being stiff and sore they are still swollen.
I am excersising them brutally, per the hand surgeon's instructions, but until the swelling goes down it is slow going.
Have you considered making an slip-on extension for your index finger for typing use??
Harvey
Already working on it.
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