tool restoration: how do I spot paint without the rest flash rusting?

[Adam Woznicki]

I am looking to restore my miller falls #2 hand drill.

This means fresh paint.

My problem is the wheel, the center get paint but the rim and teeth stay bare.

I was going to paint it as soon as I pulled it out of the electrolysis, but in the time it takes for the paint to cure I would think It will have some flash rust on the bare parts.

How do I deal with this?

Normally I keep the teeth coated with a very thin coat of oil, but I can't do that before I paint.

Should I just put it in for another round of electrolysis once the paint is cured?

[Greg Crawford]

The guy at Evap-O-Rust said to try rinsing in water with some rubbing alcohol added. I can't remember how much, but I tried it and it works fairly well with the E.-Rust. I've also rinsed in mineral spirits instead of water and that helped. With the Evap-O-Rust, he said it must be rinsed off with water eventually, so the min spirits rinse is best for the electrolysis.

[Jim Koepke]

My experience with trying to dry a plane body quickly after a rust removal bath showed me what not to do. So, after the plane body was removed from the oven, there was a lot of "flash" rusting to remove. Did this with steel wool. Then painting was easy.

So, from my limited knowledge, it may be better to let the cast iron dry a day or two before painting. Then clean lightly with steel wool and paint immediately after cleaning.

I think the flash rusting happens because of moisture held in the cast iron's porosity.

jim

[Richard Darjes]

I took a different approach when I painted the wheel on my Goodell Pratt breast drill. I covered the teeth with plastercine and then spray painted the whole wheel with engine enamel. It worked but next time I would look for a better product to mask the teeth. It took a long time to get the plastercine where I needed it (two speed drill so two sets of teeth) and it was very messy to remove. I think you want to mask the teeth rather than try to clean the paint off of the teeth afterwards.

For what it is worth, on my drill the original paint looked like it was applied with a brush by the factory workers who got a little paint in the edge of each tooth groove. I know it was original paint because there was a tiny amount of the original decal on the front of the wheel.

Rick in Oakville Canada

[dan sherman]

I use Evapo-Rust for rust removal, and I have found that the trick for preventing flash rust is rinsing with hot water. I mean really how water, like close to boiling. Usually I let the parts soak in Evapo-Rust overnight. The next day I fill a container, big enough to fully submerse the part maximum temperature tap water.

We have the water heater turned all they way up at my house so, full hot is about 190 degrees. To protect my hands from the heat I wear two layers of gloves, cotton work gloves, and then thick rubber gloves over top.

Once I'm ready, I transfer the part from the Evapo-rust, directly to the hot water. Working with the part fully submerged, I use a wire brush to remove the black film from the de-rusting process. Once I've got the film off I pull the part, and start padding it Down with towels at first, and then shop paper towels. I keep switching out paper towels for new ones, until I no longer see traces of moisture.

Because the water is so hot, it heats up the part while it's submerged. The high heat seems to help remove surface moisture during the drying phase. It's kind of like flicking water on a hot cast iron skillet, it flash off so fast it doesn't have time to cause rust. Attached are a before and after pic of the last project I used this method on.

[Mike Holbrook]

I wonder if bees wax would work. If you have a warm piece of metal the wax should go into the cracks fairly easy and harden more as it cools. When you want to remove the wax you could just warm the metal up again. Bees wax might also protect and help lubricate the teeth. There is also a wax called Renaissance Wax that Highland Hardware sells especially for protecting metal tools, paint may not stick to it either. I would think that some combination of wax and masking tape would do the job. I have been wondering about this too as I have quite a few drills I am restoring.

Another alternative for protecting iron from rust is baking on vegetable oil. It works very well on iron skillets, pots, pans... It works very well on my smoker/cooker grill and interior too. You turn an oven on bake at something like 200. Brush the oil on the teeth and leave it in there for a couple or three hours, reapplying oil once or twice. The oil bonds to the metal forming something like a patina.

Some of the drills I have seem to have a fair amount of paint in the teeth that I think is there from the factory. The North Bros./Stanley 1530AX I am working on has much of what I believe to be the original paint. The handle is still the plumb color and the main gear is a unique blue gray that I don't think anyone would have matched. There is significant paint still in the teeth and even some up in the hole where the main gear attaches to the frame. This may be how the teeth stay protected from the factory.

I am also wondering if some form of wax might provide the long term solution to keeping the teeth from rusting while the drill is in service?

[Jim Koepke]

Originally Posted by Mike Holbrook

I wonder if bees wax would work. If you have a warm piece of metal the wax should go into the cracks fairly easy and harden more as it cools.

I would be worried that if the metal wasn't completely dry, the wax could trap water in the cast iron's pores.

jim

[Erik Manchester]

I have resored a few Millers Falls hand drills and I used a citric acid bath followed by very hot water rinse and steel wool/water paper to remove the oxide. Masking tape worked well to protect the bare areas and there was no issue with rust afterwards.