How about repurposing a microwave transformer instead of making your own.? There is a ton of information on the wed about cutting the secondary windings off a salvaged microwave transformer for home brew EDM machines, spot welders, arc welders, etc.? Seems like a no brainer to do the same for a blade welder.? Some designers are even using several transformers together for increased power.
A simple google search turned up hundreds of pages about repurposing and rewinding the secondary of microwave transformers.
I have been attempting to repair broken blades using silver solder and a torch. Results have been somewhat uneven. Some blades held up pretty well while others broke again at the joint. I did some net research on blade welders but found they are outside my price range. I did find some used ones on eBay but still rather pricey. While searching I came upon the website below which describes a homemade blade welder. It looks to be a rather challenging project but doable. Has anyone built one of these and if so, what was the result? The author wound his own transformer for the power supply. I doubt a transformer like this is available and winding your own is probably the only alternative. I've rewound transformers in the past but nothing of this type. I find this intriguing but before I forge ahead I thought I'd solicit opinions from the group. I await your response!