Question about Midas Ina usage for restoration work

Check the manufacturer's specs first.

I found Midas Ina works best on oak, but it's very aggressive on mahogany. You might need a pre-treatment sealant to stabilize the tannins before applying it. Also, always test on an inconspicuous area, like the underside of a drawer. Dilution ratios vary wildly depending on the ambient humidity, so don't rely solely on the bottle instructions. For natural tannins, a mild vinegar wash followed by a neutral pH buffer is usually safer than mixing chemicals directly. I prefer using a commercial shellac solution instead, as it offers a more predictable finish and is less reactive with aged wood. This process takes patience, but the results are worth the time.

Avoid it entirely. Shellac is better.

Did you check if your varnish is oil-based or spirit-based? Compatibility is key.

I used it on a Queen Anne commode. It was tricky. You must mix it 3 parts to 1 part solvent, and let it cure for at least 48 hours before applying varnish. Otherwise, the tannins will cause clouding.

The tannins are the biggest issue. They react with most acidic resins, leading to discoloration. If you are dealing with walnut, I highly recommend a specialized wood filler designed for dark woods, followed by a neutral wax polish rather than a varnish. Wax provides depth without the chemical conflict that Midas Ina can cause. It's a much gentler, period-appropriate finish.

Try a boiled linseed oil mix.

Be careful with the ratios.

My experience was poor. It stained the wood deep yellow. I ended up using a modern polyurethane blend instead. It was overkill, but it was foolproof. Just remember to sand progressively with fine grits.

It's a nightmare.

I think you should research 'French polish' techniques. It's labor-intensive but achieves a stunning, natural luster that is far superior to any modern chemical sealant. It requires specialized materials, but the outcome is unparalleled for period pieces. It's a whole different skillset, though, so be prepared for a steep learning curve. You'll need pure shellac and fine abrasives.

Use a pH neutral buffer.

I'd recommend a commercial furniture wax blend instead of attempting to chemically seal it. Waxes are designed to penetrate and nourish without the aggressive chemical interactions that Midas Ina can sometimes cause, especially when dealing with multiple wood species in one piece. It provides a lovely satin finish and is much safer for delicate, highly figured woods.