Hello fellow blacksmith,

I'm very close to purchase an induction forge for my hobbyist activity as a blacksmith (mostly knife making, bottle opener, some small jewellery etc).

I found a promising one at US SOLID: https://ussolid.com/fr/products/u-s-solid-15-kw-haute-frequence-induction-chauffeur-30-80-khz-16-1-tours-ratio-single-phase-110v-or-220v-html?variant=46324229734655

The 15kw fit the amperage that I have at home (Switzerland) but I realise that there's two models of the same. One with 16:1 turn ratio and the other with 16:2 turn ratio.

Could anyone advise me one the preferable one?

Also, aside from the induction forge and the cooling system, is there any special piece of equipment I should consider purchasing straight from the get go?

Thanks in advance!

 

Arnaud Moutinot

On 7/2/2025 at 3:07 AM, Blaubaer said:

One with 16:1 turn ratio and the other with 16:2 turn ratio.

Could anyone advise me one the preferable one?

Hello Arnaud,

The 16:1 ratio is commonly used by blacksmiths. Although I do not have a note of the source, when I had the same question, my research turned up references for the 16:2 ratio heaters being intended for melting rather than forging applications. You'll likely be able to find the source at either LiHua (the LH-15A) or Shenzhen Shuangping (the SP-15A) as I believe these are the predominant manufacturers of these units. This site doesn't like links to other commercial sites, thus no URLs.

You might consider the coil quick disconnect system from Cluaran Forge.

I purchased the 16:1 220 volt unit with 25L cooler from US Solid and was pleased with both the packing and build quality. I took the additional step of removing the sheet metal enclosure on the heater to inspect. Here are some of my notes:

Chinese induction forge. Very impressive build with obvious attention to detail. Even simple stuff like the sheetmetal case is impressive: instead of using sheetmetal screws, they put bolsters behind every hole, drilled, tapped, and used machine screws. Although the name on the box is U.S. Solid, this is really made by LiHua. It is interesting to note that they produce all the boards as well as the high current components. Everything very neatly assembled & I don't see any shortcuts having been taken. They've been making these units for many years, but apparently still enhancing the product as the boards all show revision dates of 2024 or 2025. Since it is water cooled, I wanted to check the internal plumbing and am glad I did as I found a little corrosion that is better to be cleaned up now rather than risking a leak later.

This was a recent purchase and I have not had the chance to use it yet.

--Larry

Larry,

Tap water is super cheap where I live.  Do you know if a tap water supply would be adequate to cool one of these things?

Hi Nate,

I think you're asking about avoiding the cooler and just using tap water to cool the unit? Using tap water as the coolant is discouraged due to minerals etc. & I would think that would apply to your scenario as well.

When I opened mine up and observed all the plumbing running around inside, I did not hesitate to buy distilled water for the cooler. I use distilled in my TIG cooler for the same reason. I'm conservative, so whatever I can do to reduce the potential for drips inside high current devices seems like a worthwhile option to me. There is a temp sensor on the water loop which apparently will cause the unit to fault if the coolant gets too hot, but I'd rather err on the side of more rather than less cooling capacity. From what I've read the 25L TIG coolers that US Solid now sells replaced the smaller units because they were not cooling sufficiently resulting in thermal shutdown.

Coal Iron Works sells their machines with refrigerated coolers which they claim allow a 100% duty cycle vs 80% for the others. Probably lots of marketing hyperbole with all these units & a look at the number and range of variant products from LiHua and Shenzhen Shuangping which then get marketed by others...a bit of a "wild west" situation.

--Larry