Background :


Wood is often used as a material for trivets, it has a low heat transfert coeficient and do not alter or suffer from temperatures as high as 100°C. (& probably often more for trivets)

Because of this properties, I am using it to make a saponification mould, which will recieve visquous liquids ranging from 50 to 80°C.

I want to apply a finish to the wood, namely Tung oil (also called abrasin oil), to stop it from absorbing too much of the liquid, and to prevent the solidified liquid to stick to it too much. (even though for this purpose, a supplementary release agent will probably be applied each time, on top of the permanent oil coating)

Question :

I wanted to have a hint of an average value for maximum temperatures an oxydation-based solidified oil on wood can handle before changing properties / degrading ? If no such value seems available, do anyone know from experience if they become tacky or tend to turn back to a "liquid" form at temperatures around 80-100°C ?

Thanks for the insights !

  • 2
    Hi, welcome to Woodworking. If you try a search you'll see that oils are actually terrible waterproofers for wood (including the over-hyped tung oil which is supposed to have better waterproofing potential than linseed oil).
    – Graphus
    Dec 21, 2021 at 17:49
  • 2
    A recent question is relevant woodworking.stackexchange.com/questions/13325/…?
    – Volfram K
    Dec 22, 2021 at 9:26
  • 2
    Since I think you'll want to ditch the idea of oiling the wood you might want to come at this a different way, and look at whether this sort of thing to be waterproofed at all. Cheese moulds, papermaking frames, bamboo steamer boxes, buckets, wooden troughs and many other things used wet or actually intended to contain water were always bare wood traditionally (and 99.9% still are from what I've seen).
    – Graphus
    Dec 22, 2021 at 16:40
  • 3
    Also soap finish is a thing (popularwoodworking.com/finishing/soap-making-clean-finish-2) so your mold will naturally get it
    – J.R
    Dec 22, 2021 at 19:15
  • @Graphus Ok, yeah i came across this info after posting here. Also, thanks to you, i'm getting pretty convinced that a finish probably won't be necessary (moreover, it is quite a dense wood that i use, so it's not very spongy already)
    – Osamoele
    Dec 26, 2021 at 11:39

1 Answer 1


From images available online soap moulds are not finished.

If exposed to liquid mixture wood will not absorb more soap after first time so no need to seal for that reason, and exposure to water is not a problem for bare wood. Mould will last many years if dried between uses, same as wooden drying racks for plates or laundry.

But from my researches lining wood moulds seems normal, so mould may remain dry!

From How to Find a Soap Mold That’s Right for You:

If you want to make melt & pour soap in a wood soap mold, I would definitely use a silicone liner. Melt & pour soap is too thin when hot and will seep through the seems of the freezer paper.

  • Thank you very much. I just ended carving the the mold, and thus, applied no finish to it. I'll try it soon and give a quick update here on how it went.
    – Osamoele
    Jan 4 at 11:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.