Filling/sealing very porous light wood

Aug 16, 2008 13 Replies

Is there a good process for treating very light, porous wood (like balsa, light driftwood, basswood) to harden the surface? I'm thinking that there must be something that would be absorbed, then polymerize. But it would have to start off low enough viscosity to permeate the surface.



I know that heavy two-part surface coats (epoxy, polyester) could essentially 'plate' the surface, but I'm hoping for something that would integrate with the wood to be just a bit more natural.


Some friends use epoxy, they just scrap out the excess with a credit card (Visa recommended). That makes a stable base for future finishing. Cheers Benoit

I am not sure it this is what you are looking for. There is a product called Wood Hardener, I believe it is made by Minwax. I have seen it in all the Borgs. It is in with the stains and polys. I believe the product is a treatment to harden decayed wood. Ron

Bob wrote in news:c1cda4dmto0bhp39288bugd9k5kbh99dnf@

4ax.com:

A lot of modelers use CA (cyanoacrylate, superglue) to harden balsa. There are several thicknesses; thin would work best for this. You could also use epoxy thinned with isopropyl alcohol (100% IPA from the hardware store, not the watered-down stuff from the drug store).

Woodturners turn some pretty punky wood. For small areas thin CA glue works but for larger stuff there's a product I think is called pentacryl or something like that. Immerse, soak for several hours, dry and turn.

Thanks to all for the replies. Looks like a couple recommendations for cyanoacrylate. That would require a lot of superglue though.

Thanks. I found this:

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looks like Polycryl would be closer to this app. Also, it says Pentacryl could take from 2 weeks to a couple years to dry (!) so that's not good. Not sure about drying time for Polycryl.

That's the kind of product that I was thinking of though.

Epoxies like System 3 are fairly low viscosity and because they are slow cure, they soak into the wood well. You can lower the viscosity more by adding a little ethanol, but I don't think that is necessary.

Dave Hajicek

Sounds like you have had good luck with that stuff. I'll try to find it then.

They have several products. Which are you referring to above? I'm guess that it's "Clear Coat":

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I found that they have a 'rot fix' product that may help. The wood isn't rotted, but same kind of thing:

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do you buy it, David?

Bob:

That's the stuff. Mix 2:1 by either weight or volume. So it is pretty easy to mix up. The other stuff I us is mixed at 3.5:1, possibly challenging you math skills. ;>)

Dave Hajicek

Epoxy thinned with lacquer thinner. Any way you could get the piece into a vacuum chamber?

If the epoxy is really slow cure (like 24 hour), it has time to evaporate before the epoxy is really hard. But the stuff we talked about wicks into the wood pretty well on it's own without being thinned.

Dave Hajicek

I would expect the epoxy to be much stronger.

Dave Hajicek

Bob.. Try a couple coats of sanding sealer. WW

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