Way back in 2012, I posted with great excitement about a new to me sewing tool that Mr. Q called the Cast Iron Crinkle Cutter. These antique specialty irons are actually called fluting irons.
Here is mine, in action!
Despite my best intentions of actually creating trim with my fluting iron, instead it has been used as a door stop and decorative item (near my modern iron in my sewing room!) since I’ve owned it. I’m currently working on a project from 1875 that has pleated trim around the skirt and I thought that perhaps instead of knife pleating I would try a sample with my fluting iron! I figured that if I liked it (and I could get it to work) I’d use it for the trim on the dress.
Brief History
Specialty irons have been used for hundreds of years to create different types of ruffles and trims. I came across two sites that had really interesting information about the fluting iron I have as well as many other types of irons from around the world and for the last few thousand years. This one is summary of ironing throughout history. This one is more about types of historical irons. Also, this video from the Oshawa Community Museum looks specifically at some ironing tools that were used to create late Victorian ruffles, including various types of fluting irons.
Along the way to learning more about fluting irons, I also learned that flat cast iron irons are called sad irons. (I might have read that before but didn’t remember the term, so it feels like new information!) They’re called that not because they’re melancholy, but because in the past ‘sad iron’ meant the iron was solid as opposed to hollow (to be filled with heating devices, such as charcoal). The word ‘sad’ also meant heavy and a sad iron could weigh up to 15 pounds. That only further reinforces the fact that laundering in the 19th century was strenuous work (hand scrubbing, hauling buckets of water to heat, maintaining the stove or fire, harsh soaps, refreshing the rinsing water… hard work!). *This is edited from my original description of sad iron. To read all about the etymology of the terms ‘sad’, ‘sad iron’, and ‘box iron’ (the term for a hollow iron), check out this post, published after the one you are currently reading.
Practical thoughts about getting started
In terms of my fabric, I had the strips I wanted to flute prepared and ready to go before ironing them. I had hemmed one long side and just pressed the other edge under (that would become the top edge). With the crisp silk I’m using I probably could have gotten away with just pressing under both the hem and the top edge, but oh well. I prepared and hemmed these long before I officially decided to flute them.
In terms of the fluting iron, I followed these steps (or considered them, anyway):
Cleaning: I used dish soap and a toothbrush, to really get into all the grooves on both pieces of my fluting iron and remove the accumulated dust and grime (I don’t want those on my silk fabric!).
Drying: To prevent rust from forming, I carefully dried the iron and then also let it air dry overnight (though I realized that if I were to immediately use it the heat would cause all of the water to evaporate anyway…).
Seasoning: This is done on non-coated cast iron pans to keep them from rusting. I chose not do this with my iron at this time. I might do it later (I read that well-seasoned cast iron will not release oil onto your fabrics), but right now I just wanted to get started on my experiment.
Supplies
It’s worth noting that the cast iron gets much too hot to hold with bare hands or put directly on the counter to use, so in addition to the two parts of the iron, I also used a variety of other kitchen tools in this experiment.
I used the baking sheet, cookie drying rack, and cast iron frying pan you’ll see in photos at various points, as well as the silicone baking supplies pictured below: a hefty mitt, a small trivet, and a large trivet.

I also used a spatula to help get a grip on the base of the iron while lifting it out the frying pan, a small spray bottle, white vinegar from my pantry, and tap water.
Method #1 (the slow and steady way to heat the fluting iron)
Heating/Using: I used my conventional oven to heat both parts of my fluting iron on a baking sheet. I could not find specific directions for temperature or length of time, so I started conservatively with 175 F for 15 minutes. (Partly due to the basic information on Wikipedia about specific temperatures for different types of fabrics, but also check out the image of the tailor’s stove on the right side of the page: a multi-sided stove to heat sad irons simultaneously makes so much sense if you’re ironing a lot, as tailors would be!).

When tested on my silk this hardly made an impact. So I put the iron pieces back in the 175 F oven for another 10 minutes. This was better, but not as effective at getting tight flutes as I wanted. On the left are the barely visible results from the first 10 minutes of heating and on the right after the second 10 minutes of heating.

I increased the temperature to 225 F and put the iron pieces back in the oven for 10 more minutes. This time I also decided to use vinegar to help set the flutes. I mixed ½ white vinegar and ½ water in a spray bottle and then sprayed the section of silk I intended to iron. Here you can see the sprayed silk ready to feed into the iron on the left and the results coming out on the right.

This worked much better, but still feeling like I needed more heat to get a good sizzle and press, I increased the oven to 275 F and put the pieces in for another 10 minutes. This seemed like the right temperature! A bit of sizzle from the evaporating liquid on the silk and tight flutes as a final result.
Here is a comparison of two silk samples. The one on the bottom used vinegar and lower heat: 175 F and 225F. The one on the top is the sample that used vinegar and 275 F for heating.

Reheating: I found that the iron lost heat pretty quickly. I reheated it for 10 minutes after every 5 minutes of use. It wasn’t the most efficient process (I can really understand why you would have a set with multiple irons to keep them heating while not in use), but it got the job done on a Saturday afternoon. Experimenting with temperature and fluting 106″ of fabric took about 4 hours.
Setting: In addition to using vinegar (which made huge difference in terms of getting crisp flutes!), I also found it quite important to move the iron very slowly over the base to create the flutes. A quick pass did not do the job and getting each and every flute to line up perfectly to go over it multiple times is much easier to say than to do! I rocked the iron from one side to the other, trying to hold each little section in place for at least a few seconds before moving to the next. I got through about two full rocks with the iron before needing to reheat it.
Method #2 (the much more efficient way)
Heating: After I completed the first of three 106″ sections of trim, a science-minded friend suggested that I would have much more efficient transfer of heat to the iron pieces if I were to heat them directly on my stove in a cast iron pan. This was genius!

I started with my pan on pretty low, as it’s much easier to heat cast iron up than cool it down. This particular burner on my stove gets super hot, so I kept the pan around 2 out of 10 in terms of heat. Harder to translate for other people, but I let the iron heat up for about 10 minutes, until I could feel radiant heat coming from the base when it was out of the pan and I held my hand 1″-2″ away. Another way I tested the head was with a drop of water. At this temperature it quickly evaporated when dripped onto the cast iron.
Reheating: Using the cast iron pan was much more efficient than the oven! I still reheated the iron after about 5 minutes of use, but now I only had to let it reheat for 5 minutes. And because I wasn’t lifting a pan in and out of the oven it was much easier to let the top part of the iron sit on the pan while I moved the fabric along the base piece of the iron. Because the iron was warmer than with the oven, and I’d had more practice at using it, I was able to do three or four full rocks of the iron before needing to reheat it. That meant that my second and third 106″ lengths of fabric only took about 1 hour each. So much faster than with the oven!
You can see the crisp flutes that this method acheieved.

Setting: I used the vinegar/water spray to help set all of these flutes. It should help the fabric to keep this shape permanently (short of me completely soaking the fabric). I experimented with a light spritzing, but the heat quickly evaporated the liquid so I started just making it pretty soaked. Sometimes I even sprayed a bit on the fabric right under the iron if it evaporated before I reached that section of the rocking motion.
Here’s another view of the half finished strip of fabric.

Post Experiment Thoughts
This was fun! I would definitely like to use my fluting iron for more projects–and it should be easier now that I’ve figured out how.
I will say that practice makes a huge difference in terms of being able to flute quickly, so that the iron doesn’t cool down. You don’t have too long to think once you take the iron off the heat source!
A finished pile of about 318″ of fluted trim! I’m curious about how I will sew this on. I think that a sewing machine would crush the flutes (and I don’t think I want a line of machine stitches anyway), so I will likely sew it on by hand, catching only the valleys and not the hills in the fabric. Good thing I like hand sewing!

I came across few people trying out antique fluting irons while looking for information to get started on this experiment. For the sake of anyone else who might be looking, here are a few other practical experiments to check out:
Katherine of The Fashionable Past tried out a fluting iron in 2011 and posted about it on her blog here, including a video.
@isabel.northwode tried out a fluting iron in 2018 and posted about it on Instagram here.