Restoring pitted cast iron?

[ian maybury]

The opening premise Mel was that it's unlikely to make commercial/time sense to fill the pits on a corroded plane with even a soft solder. I'm not in the market to do so, but since i have an interest in welding and soldering processes thought it would be interesting to take a look. Guess the various recommendations to leave the pits alone' or use 'JB Weld or epoxy' seemed to be raising the question of whether or not a repair was feasible - a red rag to a bull. The products mentioned are the possibilities coming up from a quickie web search and no more - i've not tested them, nor verified the information. Who knows if they might work, or how well? For sure leaving pits alone, or grinding the sole is the cost/time effective way out.

I'm not sure about cadmium containing materials Tom, but suspect they are pretty much off the market all over. I've minimal experience with silver solder, but did a lot of oxy acetylene bronze welding of motorcycle frames for racing back in the 80s. For sure putting in too much heat with that is deadly - it makes the steel brittle and anyway destroys the shape of the fillet by melting it. Braze metals tend to have a solidus temperature range - where they flow, but are not yet fully liquid. Don't know if silver solder behaves this way. Forming well shaped weld fillets as in the photos in the link to a pic of a bronze welded motorcycle frame in no. 9 above entails holding it this (narrow) temperature range. It still penetrates fine, probably because it's getting most of its heating from the steel underneath. (you heat the steel rather than the brazing rod) My assumption was that silver soldering or brazing cast iron might be best done in a similar way to minimise the heating.

Who knows on the availability of the All State/ESAB products other than that they are listed in their web catalogue. The All State/ESAB catalogue i read from in extracting the info for post 12 above was this one: http://www.esabna.com/shared/documen...talogemail.pdf

ESAB (an international welding supplies company) seems to own All State, but has retained the name of the company and of some products - maybe for marketing reasons. I didn't find much on the All State No. 7 solder beyond a (possibly obsolete) mention in an ESAB tech manual that it is suitable for cast iron, but the DynaGrip 430 solder is prominent in the sales literature and is listed as 'best choice' for cast iron. It's very possible the no. 7 has been phased out or superseded, or it could even be the same as the DynaGrip. The name Dynagrip 430 seems to be used interchangeably to refer to a solder, a flux and a lead and cadmium free kit combining both. It's on p4 is described as being of a 'bright colour' similar to stainless steel. All State Duzall, or Dynagrip 430 fluxes are both listed as being suitable for use with it.

Beyond that it's a case of calling the company to verify everything, as who knows what the current reality is.

PS All State also list a hard brazing alloy no. 13 as suitable for (1,300 deg F) cast iron with their 1113 flux which may also be an option for repairing cracks/breaks. (not for filling pitting as above) There seemed to be little information as to it's composition, so I don't know if it has any fancy properties to make it suitable for cast iron as claimed for the Johnson Matthey ArgoBraze 49H silver brazing alloy linked in 12 above. The ArgoBraze's claim to suitability for cast iron seems in comparison very well documented, and it's likely a better colour match.

[Mike Brady]

Any kind of heating of an iron casting such as plane body is questionable. The likelihood of warping the casting is very high, which would ruin the functionality of the plane. Pitting is as cosmetic problem only, unless it occurs around the mouth of the plane. Corrugation is just well-organized pitting. With most planes found today, replacement bodies or entirely different planes of the same type can usually be found. When I was collecting my planes, I would reject ones that had cracked wood because I knew that better examples would come up. As a result I never had to repair a plane in my collection.

I do wonder about the possibility of having a new plane body cast at a foundry, using the old body as a master to make the casting mold. Does any know if this has been done? There certainly are folks in the woodworking community who could grind a casting for you. One of them posted here.

[ian maybury]

For sure any sort of heating Mike risks a degree of stress relieving and hence warping. Definite trouble starts at or above the 1,300 deg F transition temperature mentioned earlier - the point at which the arrangement of the graphite/carbon in the iron starts to change and likely drastically alter the properties.

Casting a new body is good lateral thinking. Wonder who casts the ductile iron stuff for the modern day big guys? With the benefit of hindsight it's perhaps surprising that somebody hasn't set up to do a run of replacement bodies for some of the more highly regarded older planes. Trouble is it'd need to include machining and maybe painting, and it could be that the cost (given the presumably moderate quantity) might end up not all that far if at all off that of a complete modern...

[Ron Hock]

Has anyone tried this: http://www.castaloy.com/castironrepair.htm? I have not but I am curious:

"The relatively low, safe temperatures of the Castaloy rod allow it to flow freely at just 500 degrees F. Repairs are quickly achieved simply by heating the pieces to be repaired to that point and then joining them together, or directing the flowing Castaloy to the cracks or areas to be repaired. Then simply allow the area to cool. The result? A Castaloy weld that is permanent, stronger than the original cast material, and ready to be filed, painted, antiqued or finished anyway you choose. It's also ready to go to work! An instant repair -- with no special skills or abilities -- for just pennies!"

[ian maybury]

Hi Ron. That's another low temp option for the list - it melts around the same temperature as the DynaGrip product mentioned earlier. It's presumably also a fairly soft solder. The question is again what sort of visuals and physical properties it might deliver.

None of these guys publish much regarding the composition of their materials, or even it's performance. It's a pity, as it'd make it a lot esier to figure out how suitable or not they might be...

[Allen Jordan]

Maybe electrolytic plating (electroplating)? I managed to plate an old razor with mild steel by accident when I was trying to remove rust (wrong electrolite solution, I think), but it came out nice and shiny. I imagine you could plate with a sacrificial piece of cast iron... make a thick plating and grind it flush.