Tuesday, October 22, 2013

Roubo red dye experiment (horse based), conclusion.

I prepared some sample boards to test the dye on different types of wood. I am not sure that all would have been used as furniture wood back in Roubo's days, but these were the types I could find.
From left to right on both pictures, the species are:
Birch plywood, Ash, Elm, Oak (old), Pine, Beech, Larch.
The oak was something I acquired some years ago, I think it is from the 1950'ies, it was intended to be for the back of a chair, hence the hourglass shape.

To complicate things a bit, I tried tested the dye twice.

First test:
This was carried out a little more than a week ago, and the smell of the dye was unpleasant, kind of like the smell when you empty a dry closet for a caravan or an old highway type public rest room. The smell stayed in the workshop for a couple of days, and then it fainted.

The wood didn't take much color once the dye had dried. The Ash looked like it had responded best to the treatment.
Regarding the color, I wouldn't call it red, but it does darken the wood a little bit, but I think the same effect could be had with tea or coffee. But I suspect that horse dung and urine was easier obtainable in those days tan tea and coffee (perhaps the good ole days weren't that good after all?)

First treatment.

Second test:
I was a bit disappointed that the first test didn't produce some blood red or similar colors, so I decided to give it another go. This time I re-poured the liquid from the lower bucket over the rotting dung, to see if perhaps it was too thin a mixture. The first batch was flushed through using the urine sample described in the last post on this subject.
After seeping through, the liquid looked a little darker.
When I poured it into my small jar, I noticed that the smell wasn't nearly as bad as before.
During brushing on, It didn't smell like what it was made of, but more kind of like.. a horse. Not altogether unpleasant, but not something you would want for a cologne.
While the pieces were drying I sniffed again, and there was hardly any smell left.
Therefore I think this is more like what Roubo had in mind.

I applied the stain to the same pieces, and this second treatment produced some darker results, It is not jatoba or mahogany, but clearly a darker type of wood now (or so it seems).
For some reason the elm seems to respond better on one side of the board than on the other, probably the density of the wood is the cause of it. But the rest of the pieces looked OK, I would even call it a moderate success.
To make sure that the darker tone still wouldn't come from one treatment, I applied some dye to another piece of pine, but the color looked like the color in the first test.

Second treatment.

The red color is not Salem red, but the dye does darken the wood some. I found it necessary to apply the dye twice to get a satisfying result. 
If the dye is re-poured, it does not smell bad nor does it leave a smell behind. If you use the dye too soon, it is not nice..
If you happen to have some horses on hand, it is a cheap and easy way to make a dye.
If you haven't got some horses on hand, it is a lot cheaper to buy the dye you need.


  1. Going were few man have gone before ... this century. Thanks for reporting

    1. Thanks, it was an honor to be able to serve mankind in this matter :-)

  2. interesting results, though I was hoping for a bold red color for the amount of effort required for you to get this. I wonder if this is akin to eboniizing wood woods with iron buff, where there is a chemical reaction in the wood, that may account for the variability in wood species due to differing tannin (or something else) content.

    1. I had hoped for a nice blood red color as well, but I have an thought that maybe the problem is that I have used plastic buckets.
      My theory is that in the Roubo days, a bucket would normally be made out of iron, so a bit of rust may have helped to make the color more reddish. I haven't got any plans on repeating the experiment though, because I haven't got two iron buckets.
      I don't think there is any chemical reaction taking place with this stain, but I can't be sure though. All the test boards seemed to take the dye equally well save for half the elm board.


  3. I'm wondering, does it need some type of bonding agent such as lime, or a base like Linseed Oil? I am completely guessing of course, and adding linseed oil may produce a bomb rather than a stain. I'll give you high marks for creativity, but for my part I am sticking to Minwax. :)

    1. I don't think it needs any bonding agent. My solution would be to finish it with some shellac or some varnish, since the wood is genuinely colored and it doesn't come off by e.g. touching the stained area.
      I will probably change over to Minwax or another brand as well..

  4. Jonas, r u sure you didn't make a mistake along the line? André can't be wrong! Usually it's common practice to repeat at least twice - 3 times is better - an experiment to validate it... just my 2 cents...
    take care!

    1. I am convinced that I didn't make any mistakes. Since André is de facto fail safe, I think that we can "safely" blame the translator team :-)
      There could be an issue with me using plastic buckets. I expect that buckets were made out of plain iron at that time, so some of the red color could have come from iron oxide (rust) from the buckets.
      I like your suggestion about repeating the experiment at least a couple of more times, and I believe that you are correct that it would be the proper thing to do. However I am not so sure that my wife agrees. She is the one in control of the stable, and she actually suggested that I moved the experiment into the workshop which I talked my way out of. But I doubt I can do that again.
      If you would like to try the experiment for yourself, then I will be more than happy to provide you with a "raw materials kit" Just let me know if you are in the northern part of Denmark :-)
      Thanks for the support throughout the experiment.

    2. oh man! what a laugh I had reading your comment :-) still crying here....
      ok I will check if Schwarzy and his team made the correct translation since I am kind of fluent in Molière's language...
      You are probably right about the iron oxide!
      Anyway thanks for the offer but I am little bit too far from your place, but you know Brian is closer, much closer!
      Au revoir

    3. Sure, bring some over! I'm sure my wife will have no problem with me carrying this out in our spare bathroom!

      Just in case, that was sarcasm. Please bring no horse poo to my house.

  5. Because of the difficulty of finding iron, would the buckets not have been stave constructed wood?

  6. That could have been a possibility as well. I actually didn't think of that. But maybe as someone mentions on Lost Art Press' blog, it could depend on what the horse is fed.
    Our horses feed on hay and some pre-mixed horse feed called "Hestekraft" which is a direct translation of Horse power.

  7. Hi!

    I can understand the horse manure -- but however did you "harvest" the horse urine?

    Also: instead of an iron bucket, how about some scrap iron resting in the plastic buckets, amongst the horse extracts? :)


    1. The urine was without question the hard part. http://mulesaw.blogspot.com/2013/10/the-horse-dung-and-urine-experiment.html
      I made sure always to have a small 5L (1.5 gallon) bucket ready whenever I was in the stable. But too often I could not get near the horse peeing in time.
      My incredibly understanding wife who is "in charge" of the horses told me that in the evening time when the horses would be fed their late night supper, the mare would often pee shortly after the lights were switched on.

      I went with my wife to the stable one evening and raced to the box for the aforementioned mare. She looked a bit puzzled and then after a couple of minutes she peed, and I acquired the last ingredient for the experiment.

      I like the idea of some scrap iron pieces in the buckets. To make it easier for me, I could just put some in the already finished stain, then I didn't have to repeat the entire experiment.

      Thanks for commenting