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If you want to apply a maker’s mark or other repeated pyrogram to wooden goods, but can’t justify the expense of a custom branding iron, a practically identical effect can be achieved by applying a strong solution of ammonium chloride, for instance using a foam rubber stamp, followed by relatively mild heat.

On heating, ammonium chloride decomposes into ammonia gas and strong hydrochloric acid. Ammonia diffuses away into the atmosphere, leaving the strong acid behind, which burns the wood. The resulting chemical burn is indistinguishable from a heat burn for all practical purposes.


Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.



  1. Brad Huffman says:

    This is awesome.  I’ve considered getting a custom wood burning stamp/iron for marking my better projects.  This could replace that as stamps are fairly easy to make.  Good stuff.

  2. Jerry Carter says:

    The caution to use thorough ventilation can’t be overstated here, as well as wearing gloves and goggles.  pushing the chemical around with heated air might cause a bit of blow back and you don’t want to wear the byproduct. Also, do it somewhere besides the shed / garage you store your gas in unless you are WELL ventilated.  Gasoline + HCl -> boom.

  3. Mike Donovan says:

     So, who will be the first to make a Chemical Woodburning Marker Pen?

  4. Funnily enough, ammonium chloride is also what we eat in finnish candy, see

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