# Wood Hardener



## jkeithrussell (Mar 16, 2009)

There is an article on the internet that shows how to use hot water to speed up the process of stabilizing wood with MinWax Wood Hardener.  You basically put the blanks in a glass jar with the lid on loose, then put that jar inside a pot and add hot water until the wood hardener is bubbling, then take out the glass jar, screw the lid down tight, and put it somewhere cold.  

If you try it, let me save you some clean up with this tidbit:  don't let the wood hardener get too hot.  Small bubbles coming up from the bottom are fine.  Big bubbles coming up from the bottom are not fine.  Once it starts to boil, it does not stop until you've made a really big mess that doesn't clean up easily.  And it boils at a lower temperature than water.  Trust me.


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## Lenny (Mar 16, 2009)

Kinda reminds me of the first time I made homebrew. I had been warned but it still got me. Happens real fast!
So, how did the hardening process work out for you. I have some spalted maple, much of which might benefit from this process.


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## Manny (Mar 16, 2009)

*huh*

So did it bubble over? (Meaning you didn't close the jar early enough)
Or did the jar break after closing? (Wrong type of jar)

The intent of this process is to create a vacuum in the jar with heat. Similiar to when you preserve jam.

Just curious


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## jkeithrussell (Mar 16, 2009)

Yes, it worked.  I cut the blanks in half and drilled them through with a 6mm drill bit.  Most of them sank to the bottom and started frothing as soon as the first hot water was applied.  

The glass jar did not break, but it started bubbling very aggressively and spilled wood hardener all over the inside of the pot.  I took the glass jar out to stop it from bubbling further, and that led to wood hardener being spilled all over my driveway.  I was able to get it under control, but I lost about half of the wood hardener and made a big mess.  

I will use the process again, with a little extra caution. 

I've also used wood hardener in the past the slow way -- just drop a heavy nut or two on top of the blanks to get them to sink and leave them submerged for a couple of weeks.  It really helps with cross-cut, soft, spalted, and/or punky wood.  Also helps add some weight to light woods.


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## Larryd (Mar 16, 2009)

Sounds like a mess I would make.  Can you post the internet site?


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## Chasper (Mar 16, 2009)

I read about doing this recently, sort of like canning wood blanks with wood hardener.  I bought some wood hardener last week, planning to do it when I get a chance.  The tutorial I read said to put the jar(s) of blanks and hardener in something like a canning pot and add preheated water, that sounds like what you did.  How hot is too hot?  Should I add boiling water to a half pot of room temp water.  It needs to get pretty hot to push all the air out so the canning lids will ping.


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## jkeithrussell (Mar 16, 2009)

http://www.northcoastknives.com/northcoast_knives_tutorials_hints_tips3.htm

That's the tutorial that I followed. I will repeat that if you add water that is hot enough to make those big bubbles, you've already gone too far. Something less than boiling. I used an electric water heater (the kind you use to warm up water for a cup of tea) and waited until the water was bubbling at a good rate -- probably just short of a full boil. That's too hot. 

I don't know a thing about science, but I can tell you to a certainty that the wood hardener will go into a rolling, violent boil at a temperature that is less than a full boil for water. 

When I do it again, I'm going to heat the water to about what you get out of a coffee pot. 

Use a glass jar and a pot for the water that you don't mind throwing away if it blows up. 

Seriously, I'm confident that the method works and that it can be done safely as long as the water is hot but not boiling.


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## seawolf (Mar 16, 2009)

*Wood hardner*

The wood hardner will boil at 135 degrees, or so I have been told.


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## spiritwoodturner (Mar 16, 2009)

My questions are 2. First, once you've heated it, can it cool and be reused again? For 2 months now, I've been stabilizing literally hundreds of my blanks, and just add more to the next batch or when I turn them upside down to vacuum again. This might be good for one batch, but I wonder if you don't turn this stuff to goo after heating and then cooling it. Secondly, I wonder if it's really that much faster?! I don't predrill and cut, and wonder if it's been tested the same way. Keith, you mentioned you cut and pre-drilled. Have you ever tried it without doing that?

Anyway, interesting, but seems potentially messy and even dangerous to me, given that it works great if you can wait a a few days.

Dale


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## jkeithrussell (Mar 16, 2009)

spiritwoodturner said:


> My questions are 2. First, once you've heated it, can it cool and be reused again? For 2 months now, I've been stabilizing literally hundreds of my blanks, and just add more to the next batch or when I turn them upside down to vacuum again. This might be good for one batch, but I wonder if you don't turn this stuff to goo after heating and then cooling it. Secondly, I wonder if it's really that much faster?! I don't predrill and cut, and wonder if it's been tested the same way. Keith, you mentioned you cut and pre-drilled. Have you ever tried it without doing that?
> 
> Anyway, interesting, but seems potentially messy and even dangerous to me, given that it works great if you can wait a a few days.
> 
> Dale


 
Yes, it can be reused.  I think it is faster.  Precutting and predrilling does make it faster whether you use this method or just put it in a jar for a week or two.  Same result either way, as far as I know.


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## titan2 (Mar 18, 2009)

jkeithrussell said:


> There is an article on the internet that shows how to use hot water to speed up the process of stabilizing wood with MinWax Wood Hardener. You basically put the blanks in a glass jar with the lid on loose, then put that jar inside a pot and add hot water until the wood hardener is bubbling, then take out the glass jar, screw the lid down tight, and put it somewhere cold.
> 
> If you try it, let me save you some clean up with this tidbit: don't let the wood hardener get too hot. Small bubbles coming up from the bottom are fine. Big bubbles coming up from the bottom are not fine. Once it starts to boil, it does not stop until you've made a really big mess that doesn't clean up easily. And it boils at a lower temperature than water. Trust me.


 
Keith,

Using this method, how long do you let your blanks soak/cool before removing them?  How long and how do you let them dry after taking them out of the hardner?

TIA,

Barney


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## titan2 (Mar 19, 2009)

*Wood Hardner*

Well, I broke down and went to Home Depot and got 2 cans of MinWax Wood Hardner. Appropriated one of my wife's pint canning jars (a nice square one).......she rolls her eyes!!!!

Put 6 punky/wormy blanks that I had in the jar....poured one can in and a little bit more to fill it up. Stuck all that in a big pot (yep, in the kitchen) of hot water and watched her bubble up.........let it sit in there until the water wasn't as hot........removed the jar from the pot and stuck it waaay out of the way.......fired up the pot again (a little hotter this time)......stuck the jar back in........started to bubble real good this time. Got it all pretty hot. Took the drain filter from the gargage sink (it always plugs up with lint anyway and causes overflows) and cut it from the metal ring around it and placed it on top of the blanks so that they are all kept down in the hardner while the lid is one the jar. Took the jar out of the hot water (didn't want it to get away from me) and screwed the lid down tight, put the jar in a plastic pale and put everything outside where it can start it's cool down. Felt the jar and it was pretty hot so all should be well!!!

How long should I keep everything in the jar? Anything to look out for when removing everything from the jar to air dry?

Cann't wait to see how everything turns out!

TIA,

Barney :bananen_smilies022:


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## gomeral (Mar 19, 2009)

seawolf said:


> The wood hardner will boil at 135 degrees, or so I have been told.



The Minwax wood hardener is ~72% acetone / 3% methanol and boils at 133ºF.  It's also worth noting that its vapors are twice as heavy as air and will therefore sink and stay at floor level - be cautious using around ignition sources!



daniel


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## ldb2000 (Mar 19, 2009)

You could try this and not take any chances . http://www.penturners.org/forum/showthread.php?t=39664  , I've done a couple of dozen blanks using this setup and all have come out good .


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## titan2 (Mar 19, 2009)

gomeral said:


> The Minwax wood hardener is ~72% acetone / 3% methanol and boils at 133ºF. It's also worth noting that its vapors are twice as heavy as air and will therefore sink and stay at floor level - be cautious using around ignition sources!
> 
> 
> 
> daniel


 
Yep, that's why I left the doors opened!


Barney


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## titan2 (Mar 19, 2009)

*Hardner - Topping Off*

Checked my jar after it cooled for a few hours and it is down about 1½ to 2 inches from the top.......from where it started.

Do you break the vacuum seal and top it off or just rotate the jar occasionally to get everything wet?

TIA

Barney


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## Fred (Mar 19, 2009)

Do not brek the initial seal. Just invert the jar for a period of time - maybe overnight - and let them soak. The vacuum is what is doing the job for you right now.

When the blanks don't 'float' then they are getting the full treatment. Predrilling will definitely quicken the process of a thorough soaking. Just take your time and let things work for a few days.

Be sure to let us know how you did!


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