I am working with spalted wood of varying density, using Zinsser sealcoat shellac diluted 50% with alcohol to firm up the punkiest parts. Is there any advantage in terms of stiffness or speed of setup in using cellulose lacquer or sanding sealer (or any other material) for this purpose? I'm not interested in using epoxy or wood hardener as a rule.
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hardening wood with snding sealer
- Thread starter Kevin Jenness
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I use a thin shellac 2x the alcohol. Probably similar to your mix.
It does the trick on many punky woods.
It dries to turning in a minute +-
Some folks get similar results with thin lacquer.
It does the trick on many punky woods.
It dries to turning in a minute +-
Some folks get similar results with thin lacquer.
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I don't know anything about this but someone in our club mentioned it once. was reminded when I saw your topic. minwax wood hardener
Minwax wood hardener is something like 80% thinner. It's not going to add much resin in each application.
Shellac will not smell up the shop as badly as lacquer. Neither are healthy since they use methanol now in denatured alcohol thinner. Methanol is flammable, toxic, and poisonous if ingested, inhaled, or in contact with the skin. A much safer option, buy not necessarily fast, is thinned white glue.
| Acetone Methanol | ≥50 - ≤75 4.2 |
Hardening wood is an interesting topic. I’d be keen to know of a really good solution (pun intended) but I’m a little concerned about the dust produced when final sanding. Wood dust on its own can be bad enough and hopefully most of us take care with extraction/respirators. Chemical additives in wood dust is another matter.
I have used PC wood hardener on punky / spalted maple with good success. It is water based and odorless. It was recommended here some time ago in another thread.
Sounds good Bernie. 
Being water based and odorless is not an indication of safety. It means they use different carriers and solvents. If you are referring to PC's Wood Petrifier, here are the warnings on the SDS document. https://www.pcepoxy.com/wp-content/uploads/2019/07/SDS-Petrifier-Canada-Eng-2018.pdf
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Well spotted Richard.
Edit: I bought some very thin superglue for strengthening wood prior to routing fine detail. I’ve not tried it yet but obviously there won’t be any sanding afterwards. I’ll still be using extraction though for the chips, some of which can be quite fine.
Edit: I bought some very thin superglue for strengthening wood prior to routing fine detail. I’ve not tried it yet but obviously there won’t be any sanding afterwards. I’ll still be using extraction though for the chips, some of which can be quite fine.
On spalted wood, I like to use water base poly (diluted with water) as a hardener. It keeps the white areas whiter. But slower to dry. Lacquer and shellac are not bad alternatives, just a little amber tone that I try to avoid.
Every time I see a post like this, I keep mentioning a fantastic product called PC Petrifier made by Protective Coating Co in Allentown, PA. Saw it in a Home Hardware flyer about ten years ago and absolutely love it. It is a water base polyurethane with no odor and no staining. Excellent on spalted maple or other light coloured woods. Looks not unlike the water based poly that Michael Nathal mentioned earlier today.
Use Everclear if denatured alcohol is concerning. Around here it’s not prohibitively expensive.
This eliminates a lot of answers/recommendations you’ll likely get. Diluted wood glue is one option, though penetration won’t be very good. I’ve used a brush to apply it and then used compressed air to blow it deeper into the punky wood. It’s not an exact science…. Another option is thin CA glue but for many people the potential color changes CA can bring are a bridge too far for their tastes.
I almost exclusively turn crap/spalted/punky/rotten/moldy/bug ravaged garbage wood most people wouldn’t even deem worthy of firewood or mulch. There’s a lot of ways to save “bad” wood but most involve some kind of epoxy or wood hardener.
So don’t use it as contact lens solution or as an exfoliant in the bath tub or as a chaser in a Tijuana bar….
Let’s make sure we all diligently keep the giant factory supplied safety cages mounted on our lathes, too…
Risk vs reward… we all play the game with different personal tolerances in the name of “safety.”
Personally, I wouldn’t worry too much about PC’s wood hardener or minwax hardener, or lacquer, or glue, or CA, or polyurethane, or bondo, or epoxy, or miliput, or cactus juice, or pretty much anything else used to stabilize wood in the amount needed for a woodturning project in a reasonably ventilated shop/area.
But I’m the same guy who has worn full body motorcycle gear/armor and helmet in order to turn big 100 pound hunks of wood that I thought had a pretty good chance of blowing apart… they didn’t ever blow up…. But better safe than sorry!
I'm not trying to turn really punky wood, just soft areas in otherwise sound material with a minimal time investment. Life is short and I don't want to turn plastic wood. I will try some of the waterborne acrylic lacquer on the shelf- probably will set up a little slower than solvent lacquer with little color change.
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If it’s just a little punky - water often does the trick
I have mister type bottle. The water swells the fibers. If they are tight they cut rather than pull.
You can discount chemical hazards all you want. My brother died at the age of 48 from colon cancer and I'd bet my life savings that is was caused by farm chemicals. Ask my brother's kids how they feel about his death at the age of 48. Most people think skin is a barrier, and that is far from the truth. The same thing goes for nothing ever absorbing through your eyes. Anything on the skin, in your lungs, or if you rub your eyes, goes into your body and is filtered from the blood. There is no way for the liver to purge all that crap from it. So it sets in your liver and kidneys. You are lucky if that doesn't start cancer, but I like to help the odds as much as I can. I've been working around chemicals and dust for over 50 years. I have a list of issues, mostly autoimmune. But a suspicious thyroid and prostate have me on the watch list for cancer. Chemicals aren't healthy, and I suggest you help others, especially beginners, understand that instead of suggesting there is no downside.
I'm working with Flame Box Elder which has some black (softer) spots in it. I noticed that sanding this, without any reinforcement lead to some uneven edges on the salad bowl. Any suggestions other than the ones above for Shellac or Epoxy/Glue? Looking for something that doesn't discolor the wood much, but as these areas are the darker black/grey not sure if that matters much. 
Thanks!
Thanks!
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My experience from using Minwax Wood Hardener is that it is excellent for penetrating deep into punky wood. I found it to be especially useful for things like window sills and porch columns. In order to penetrate deeply into punky wood, the hardener needs to be very thin. Otherwise, it wouldn’t penetrate very deeply. Products like lacquer and shellac are probably hard enough for woodturning, but wouldn’t work well for architectural repairs. The resin in Minwax Wood Hardener cures to a very hard plastic, maybe even too hard for woodturning purposes because it can rapidly dull turning tools. Light cuts are necessary to avoid chipping the hardened wood.
I love Myland's cellulose sanding sealer for this purpose. Sometimes full strength, but often cut with 20-25% alcohol. The thinned version flashes off very quickly, leaving the solids behind, a technique that makes stiffening up spalted wood a less onerous process, with 5 minutes between coats in a warm shop. Thin coat(s) on dry, finished-turned spindle products help sanding without much change in color. "Cellulose" just seemed logical. 
A ketchup bottle with a night's worth of turning works great, and will still be there the next day if needed (cap closed).
A ketchup bottle with a night's worth of turning works great, and will still be there the next day if needed (cap closed).
just got my pint. Now I need some punky wood!
not exactly the answer you're looking for but I've found if I use a soft backed sanding pad-this includes my fingers holding just the paper-it will sand the soft areas more deeply. If you can use a bit firmer sanding pad behind the paper it seems to not go deeper than the firmer wood on either side of the spalting-if that makes sense. hope that helpsI'm working with Flame Box Elder which has some black (softer) spots in it. I noticed that sanding this, without any reinforcement lead to some uneven edges on the salad bowl. Any suggestions other than the ones above for Shellac or Epoxy/Glue? Looking for something that doesn't discolor the wood much, but as these areas are the darker black/grey not sure if that matters much.