Hardening up spalted beech?


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Established Member
10 Nov 2017
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I find it hard to select spalted beech - too far and its a mush, not far enough, and its not so interesting.

Anyway, i have this part -


The white bits on the right are soft. I sanded them quickly by hand to get an idea, and then had a bit of a dig about with a blade at the end -


The above required some digging with the blade, so its not just falling out on my fingers, but it is softer. Im guessing anyone who deals with spalted beech will know exactly what im talking about?

I was wanting to cut this sort of thing from them -


The above part is oak, with a bit of Fistulina hepatica activity.

I think that people often use cyano acrelate glue to treat spalted beech, but im thinking that id need a lot of it...

Do things like osmo polyx soak in enough and harden enough to do similar?

Thank you.
I've had success with decking wood hardener from screwfix, it can gum up the sand paper afterwards if you're too heavy handed but it does the job.
You can buy wood hardener, which is designed for rotten window sills and the like.
I've no idea whats in it or how it works.
Says "penetrates deeply" but i think thats likely to mean pretty much surface and not for the task of hardening entire boards to full thickness. I dont know though. Its there as an option.

Maybe if it was for turning, and you could fit it in a pressure pot under vacuum it would soak right in, but just painting it on I couldnt say.
@TRITON that's the stuff I meant, it does soak in deep, I had an 6" thick piece of very spalted birch, it soaked through the whole thing, granted it was end grain not side grain but all the same it soaks in well.
Thank you.

We have a friend who is a decorator. She poured some of that stuff onto our window frames when she was here, so i know exactly what youre on about.

Ill see if she has any that i can test with.

Another thought i had was if some of that deep pour epoxy would work? I use it for other stuff, and it creeps enough to cause me to swear quite often (when you come back in the morning, and its all leaked out though some crack that you couldnt even see before!)

...but i dont know if it will suck into what i have. Ill test that also.

Thank you all again.
Ok, so i just ran a quick test, and got a way better result than i expected -

I welled off a section, but, instead, thought id test with just a drop -


It spread within seconds -


And, within not longer than a couple of mins, basically dissapeared -


I tried the same on a more "fluffy" section of wood, same sort of drop size, and it pretty much just ended up looking like a slight mark -


This is one of the thin 2" pour resins.

By how rapidly, and comprehensively, the resin was absorbed, im pretty convinced this is a good solution.

Ill give the job a quick sand tomorrow to get off the junk, and then well off some larger areas, and see what becomes of it.
I think you would be better taking a small section, placing a spot on that. Allow it to soak in then cut the piece across that area to see how far it was penetrated.

When you do that with oil or shellac, you find its only soaked in about a millimeter. Best test something first.

Alternatively to aid penetration. You could coat the area. Place some polythene over it, taped all round then suck out the air with a hoover or extractor to create a vacuum.
Woodturners use sanding sealers of which there are 3 main types:
Acrylic - water based
Shellac - can be thinned with methylated spirits
Both the above take 20+ minutes to dry
Cellulose - dries in 30 seconds
Chestnut say that sanding sealers shouldn't be thinned but most users find thinning up to 25% acceptable.
Cellulose thinners should be pure not recycled or as sold for gun wash.
Wood hardener is fine if you only need to sand it afterwards - it's very hard on tools. I've turned really spongy stuff and used cellulose sealer but it needs reapplying ever cut or two. Incidentally the club I belonged to diluted their 50/50.
If you want epoxy to soak in further, you can try thinning it a bit with acetone. Big no no for casting, but works great for use as a hardener.