Spalted Wood - Practical solutions

[davidjames]

Hi!

I have some spalted elder off my dad which I'd like to use as a knife handle for a gift for some friends of ours (a kitchen knife, they just purchased their first home).

The condition is good, i don't see any flaking / obvious rot, like I have on some of the spalted wood he's had in the past (if that makes sense). It seems structurally sound overall. But I am aware spalted wood can be a touch weaker and it seems to be quite porous on the end grain.

I don't have the equipment to properly stabalise any wood, but I was wondering if anyone could recommend me a similar sort of product that might harden /support the wood?

I have looked up wood hardeners but most seem marketed at rotten, outdoor timber.

So I was wondering / hoping some of you may be able to recommend me something I can use at home that may help with this type of wood?

I have enough for maybe a couple of knives, so one lot could be a test piece, but would obviously prefer not to waste it! It is quite pretty.

Thanks!

p.s. I am in the UK, but I can usually source most things.

[dai sensei]

Spalted wood needs to be dried completely to kill the bacteria/mould that caused the spalting and then treated to seal it effectively, normally in knives by stabilising, but you can impregnate the surfaces with a hardener of some sort. The easiest way is with a thin CA (not the $2 crap.) to penetrate the surfaces immediately after it has been dried and cooled (in a clip lock bag so the moisture doesn't re-enter) to maximise penetration. If you have issues with CA you can get the new no fumes version it just costs a lot more.

[davidjames]

Spalted wood needs to be dried completely to kill the bacteria/mould that caused the spalting and then treated to seal it effectively, normally in knives by stabilising, but you can impregnate the surfaces with a hardener of some sort. The easiest way is with a thin CA (not the $2 crap.) to penetrate the surfaces immediately after it has been dried and cooled (in a clip lock bag so the moisture doesn't re-enter) to maximise penetration. If you have issues with CA you can get the new no fumes version it just costs a lot more.

Thanks Neil. The wood has been air dried for several years, so should I assume the bacteria is dead / stable? My dad does have a moisture reading gadget which I could use to compare to some kiln dried wood I have.

Could you tell me what you mean by CA? And if there is a particular brand you recommend? Other than avoiding the really cheap stuff.

Thanks!

[dai sensei]

Thanks Neil. The wood has been air dried for several years, so should I assume the bacteria is dead / stable? My dad does have a moisture reading gadget which I could use to compare to some kiln dried wood I have.

Could you tell me what you mean by CA? And if there is a particular brand you recommend? Other than avoiding the really cheap stuff.

Thanks!

When I say completely dry, I mean 0%MC not OMC in your back yard that will still be 8-14%MC, that can only be done in an oven at ~120C until it stops losing weight. CA is short for Cyanoacrylate glue i.e. Super Glue, but they generally don't call the good stuff superglue. Not sure what brands you have in the UK, they are all pretty much the same from the good shops, but I buy mine in bulk from the US http://www.e-zbond.com

[davidjames]

When I say completely dry, I mean 0%MC not OMC in your back yard that will still be 8-14%MC, that can only be done in an oven at ~120C until it stops losing weight. CA is short for Cyanoacrylate glue i.e. Super Glue, but they generally don't call the good stuff superglue. Not sure what brands you have in the UK, they are all pretty much the same from the good shops, but I buy mine in bulk from the US E-Z Bond, super glue, Cyanoacrylate supplier, bonding material (http://www.e-zbond.com)

Thanks Neil.

In the past, my dad has used a microwave for his wood turnings that are spalted, so I assume this kills everything off. But for the piece I have, it was from a local woodworker, so I don't really know it's exact treatment. It seems very dry and stable but I may need to zap it in the oven as you suggested to be sure.

Thanks for elaborating as well, on the CA. Unfortunately, I read that this isn't compatible with an oil finish... as the oil will resist the CA. I think I may just have to accept that I either need "perfect" spalted wood, without any structural issues, or I just need to avoid spalting at all for this project, as I do want to use an oil finish.

Thanks for your help.

[dai sensei]

In the past, my dad has used a microwave for his wood turnings that are spalted, so I assume this kills everything off. But for the piece I have, it was from a local woodworker, so I don't really know it's exact treatment. It seems very dry and stable but I may need to zap it in the oven as you suggested to be sure..

Yes once the timber is dried the spalting will stop, it is only if it gets wet again, does the spalting re-establish/continue. By true stabilising, it is killed in the drying process, then the wood is sealed from accepting the majority of moisture.


Thanks for elaborating as well, on the CA. Unfortunately, I read that this isn't compatible with an oil finish... as the oil will resist the CA. I think I may just have to accept that I either need "perfect" spalted wood, without any structural issues, or I just need to avoid spalting at all for this project, as I do want to use an oil finish.

Yes using CA will make the wood sealed and impervious so the oil will not penetrate the timber.