Wood Hardener & Filler- Some Inexpensive DIY Ideas To Share

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PJB12

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Hello All!
I hope this is in the correct place on the forum list. It seems like a general fix-up topic. It's about DIY wood hardener & filler.

Since wood hardener is so expensive, I sought out alternatives and, after much experimenting, discovered some successes that I would like to share.

Wood hardeners are usually a plastic of some sort dissolved so that the liquid is very thin and will penetrate wood fibers, sealing them against moisture and stiffening them for repairs. Store bought wood fillers are usually either wood flour mixed in a binder, epoxy glue or auto body fillers.

The successes were tested on pine, fur, balsa, cardboard, fiberboard and even paper. One of each test piece was soaked underwater for several days and compared to the un-soaked control sample for water resistance and stiffness.

General Items For Safety & Success:
Work Outdoors & keep pets & children away from the Not Earth or Lung Friendly options.
Read & Understand the safety requirements in the Material Safety Data Sheet for each component (MSDS or SDS)
Wear ear, eye, skin and lung protection.
. (Lungs need the proper cartridge in your well fitted respirator. Dust masks not allowed!)
Let the wood dry completely before proceeding.
Optional: Bleach the wood to kill mold spores & let it dry.
Optional: Copper Sulfate painted on the wood will prevent mold from growing should moisture enter from
. the un-treated side. Let it dry before putting the hardener.

Not Earth or Lung Friendly, But Similar To Store Bought: Fast Drying
Put acetone in a glass or metal jar with a tight sealing metal lid. (A plastic jar will melt.)
Cut up a plastic container that is made from polyethelyene terephthalate PETE plastic. (Number 1 will be on the recycle code symbol).
Water & pop bottles are usually this material. Check the 3-Arrow symbol on the plastic for a "1".
Insert the cut up plastic pieces into the acetone until it can dissolve no more. This is called a "saturated solution".
It may take many minutes for the plastic to dissolve.
Remove the last piece that could not dissolve.
Now you have good wood hardener that is similar to the store bought! It absorbs very well into the dry wood & dries hard & somewhat brittle.

Not Earth or Lung Friendly Version Two:
Polystyrene (Recycle number 6), commonly called "styrofoam" melts much faster than the PETE and is fun to watch.
The non-corn starch packing peanuts work great.
Result? Same absorbancy in wood and same water proofing. But, the final piece is not as stiff or brittle as with PETE.

Dry Time before testing was 7 hours for each the PETE and the polystyrene samples.

Earth & Lung Friendly:
Type 1 PVA glue, such as Titebond III diluted 50:50 with white vinegar. Simple & quick!
Result: It absorbs very well into the dry wood, paper, etc. Water beads up on it. Soaked paper coated with this did not dissolve. (Dry time was 17 hours before testing.)
Paint adheres better than when painted directly on the plastic wood hardeners above.
The negative is that the wood is not as hard to the touch as with the melted plastic. Perhaps this slight flexibility makes it better for items that heat and cool, such as sun drenched siding.

WOOD FILLER- Not Earth & Lung Friendly: Very Fast Drying
The "Go To" for wood repairs is often body filler (AKA Bondo). Most are not waterproof. Water won't wreck them, but will go through tem if not painted. They can be a bit hard to paint without scarfing and sometimes using an etching primer. White filler with white hardener make painting a bit easier. Of course, these are hard on the earth & lungs.
I used Advantage brand #801 for testing. It's about 29.00 USD per gallon and easy to sand. For waterproof filler, I used Duraglass. It is harder to sand and costs more, but is 100% waterproof.

WOOD FILLER- Earth & Lung Friendly:
No pre-mixed wood fillers that I found are waterproof, so I tried to make one as close to waterproof as possible.
The Experiment was Durham's Water Putty, but mixed with 50:50 Type I PVA glue and white vinegar. Dry time was 16 hours before torture testing.

The test bowls at 1/4" thick putty that I made did not dissolve when soaked for 2 days underwater, but the surface could be scratched with a fingernail. Water left in the bowls overnight did not wick through to the paper that the bowls sat upon.

After painting the "test dummies", they did not get at all soft when soaked. Although harder to sand than body filler, Durhams paints like a dream with latex! Also, it can be mixed to whatever consistency works best for your project.

I hope these ideas will help you with a project or two!
Paul
 
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I want to follow this but had trouble understanding. Pics of your process would help.
 
I want to follow this but had trouble understanding. Pics of your process would help.

Thank You for writing Flyover. Sometimes I'm not the best explainer of things. Photos will end up being me sticking plastic into jars or of me mixing vinegar & glue.

Using Proper Safety:
The acetone ones are just placing cut up plastic or styrofoam into a glass jar with acetone & waiting for the pieces to melt. When no more pieces can melt, stop adding pieces and paint it on the bad wood. (Use real acetone from a hardware or paint store. One can't use nail polish remover because the acetone is diluted & usually has some oil & fragrance added.)


This One I Like Far Better Than The Acetone Method:
The glue wood hardener method is to take exterior, waterproof carpenter's glue and diluting it half and half with vinegar. For example, 2 tablespoons of glue & 2 tablespoons of vinegar. Paint that on the dry, bad wood & let it absorb and dry.

The earth friendly wood filler is made with Durham's Water Putty (a powder). Instead of mixing with water, make some 50:50 glue/vinegar, like explained above, and use that for mixing the Durham's powder. Put it on the newly hardened wood with a putty knife.

I like the glue hardener method better than the acetone method. It does less damage to the earth, air and potentially lungs. It isn't flammable, either. Same with filler: I like Durham's better than body filler.

Just in case I still didn't explain well. which method(s) would you like explained better? I'll be happy to re-word stuff.
Enjoy This Day!
Paul

PS: I forgot in my first post to mention that a working fire extinguisher should be handy when working with acetone or body filler. Learn how to use it before starting the project.
 
I want to follow this but had trouble understanding. Pics of your process would help.

Thank You for writing Flyover. Sometimes I'm not the best explainer of things. Photos will end up being me sticking plastic into jars or of me mixing vinegar & glue.

Using Proper Safety:
The acetone ones are just placing cut up plastic or styrofoam into a glass jar with acetone & waiting for the pieces to melt. When no more pieces can melt, stop adding pieces and paint it on the bad wood. (Use real acetone from a hardware or paint store. One can't use nail polish remover because the acetone is diluted & usually has some oil & fragrance added.)


This One I Like Far Better Than The Acetone Method:
The glue wood hardener method is to take exterior, waterproof carpenter's glue and diluting it half and half with vinegar. For example, 2 tablespoons of glue & 2 tablespoons of vinegar. Paint that on the dry, bad wood & let it absorb and dry.

The earth friendly wood filler is made with Durham's Water Putty (a powder). Instead of mixing with water, make some 50:50 glue/vinegar, like explained above, and use that for mixing the Durham's powder. Put it on the newly hardened wood with a putty knife.

I like the glue hardener method better than the acetone method. It does less damage to the earth Trusted Wood Repair Solutions, air and potentially lungs. It isn't flammable, either. Same with filler: I like Durham's better than body filler.

Just in case I still didn't explain well. which method(s) would you like explained better? I'll be happy to re-word stuff.
Enjoy This Day!
Paul

PS: I forgot in my first post to mention that a working fire extinguisher should be handy when working with acetone or body filler. Learn how to use it before starting the project.
No leaks in conservatory so reluctant to change. Less than half a metre of rotten wood. I am clueless and not practical. I have been told it can be treated by a solution without needing to remove wood. Is this true ? Suggestions gratefully received.
 
No leaks in conservatory so reluctant to change. Less than half a metre of rotten wood. I am clueless and not practical. I have been told it can be treated by a solution without needing to remove wood. Is this true ? Suggestions gratefully received.
If I don't want to mess with chemicals & a respirator or mixing concoctions; to harden rotten wood I find PC Petrifier to be a good product to use. The end result is the same as those given by things like Minwax, but the high VOC content is absent from the PC Petrifier. Dry time is longer, however, because it is water based.

Brush away only the loose rot & crumbly wood. (Only the stuff that falls off with a brushing) You can leave the soft, spongy wood in place.

Remove any paint that's adhered to the rot. Usually a fingernail will flick it off.

Let the wood dry if it is water soaked. A heat gun or hair dryer speeds this up.

Apply PC Petrifier with a brush. I use a flux brush because it's small. For really small areas, a cotton ball bud (like Q-Tip style) works. For vertical, I inject PC Petrifier with a syringe fitted with an 18 gauge needle.

Let it absorb for a few minutes, then repeat, wait, repeat, etc. until no more is absorbed. Usually 3 coats does the job.
Cleanup of brushes is with water.

Wait 12 or so hours for the product to dry. The soft wood will now be rock hard & stable. PC Petrifier gets absorbed really deep into the good wood behind the bad stuff.

Use your choice of fillers, primer and paint.



It's rather satisfying to see soft, spongy wood turn rock-solid. I've used PC Petrifier on exterior trim many times. Years later, the wood repairs are still invisible.
 
Hello All!
I hope this is in the correct place on the forum list. It seems like a general fix-up topic. It's about DIY wood hardener & filler.

Since wood hardener is so expensive, I sought out alternatives and, after much experimenting, discovered some successes that I would like to share.

Wood hardeners are usually a plastic of some sort dissolved so that the liquid is very thin and will penetrate wood fibers, sealing them against moisture and stiffening them for repairs. Store bought wood fillers are usually either wood flour mixed in a binder, epoxy glue or auto body fillers.

The successes were tested on pine, fur, balsa, cardboard, fiberboard and even paper. One of each test piece was soaked underwater for several days and compared to the un-soaked control sample for water resistance and stiffness.

General Items For Safety & Success:
Work Outdoors & keep pets & children away from the Not Earth or Lung Friendly options.
Read & Understand the safety requirements in the Material Safety Data Sheet for each component (MSDS or SDS)
Wear ear, eye, skin and lung protection.
. (Lungs need the proper cartridge in your well fitted respirator. Dust masks not allowed!)
Let the wood dry completely before proceeding.
Optional: Bleach the wood to kill mold spores & let it dry.
Optional: Copper Sulfate painted on the wood will prevent mold from growing should moisture enter from
. the un-treated side. Let it dry before putting the hardener.

Not Earth or Lung Friendly, But Similar To Store Bought: Fast Drying
Put acetone in a glass or metal jar with a tight sealing metal lid. (A plastic jar will melt.)
Cut up a plastic container that is made from polyethelyene terephthalate PETE plastic. (Number 1 will be on the recycle code symbol).
Water & pop bottles are usually this material. Check the 3-Arrow symbol on the plastic for a "1".
Insert the cut up plastic pieces into the acetone until it can dissolve no more. This is called a "saturated solution".
It may take many minutes for the plastic to dissolve.
Remove the last piece that could not dissolve.
Now you have good wood hardener that is similar to the store bought! It absorbs very well into the dry wood & dries hard & somewhat brittle.

Not Earth or Lung Friendly Version Two:
Polystyrene (Recycle number 6), commonly called "styrofoam" melts much faster than the PETE and is fun to watch.
The non-corn starch packing peanuts work great.
Result? Same absorbancy in wood and same water proofing. But, the final piece is not as stiff or brittle as with PETE.

Dry Time before testing was 7 hours for each the PETE and the polystyrene samples.

Earth & Lung Friendly:
Type 1 PVA glue, such as Titebond III diluted 50:50 with white vinegar. Simple & quick!
Result: It absorbs very well into the dry wood, paper, etc. Water beads up on it. Soaked paper coated with this did not dissolve. (Dry time was 17 hours before testing.)
Paint adheres better than when painted directly on the plastic wood hardeners above.
The negative is that the wood is not as hard to the touch as with the melted plastic. Perhaps this slight flexibility makes it better for items that heat and cool, such as sun drenched siding.

WOOD FILLER- Not Earth & Lung Friendly: Very Fast Drying
The "Go To" for wood repairs is often body filler (AKA Bondo). Most are not waterproof. Water won't wreck them, but will go through tem if not painted. They can be a bit hard to paint without scarfing and sometimes using an etching primer. White filler with white hardener make painting a bit easier. Of course, these are hard on the earth & lungs.
I used Advantage brand #801 for testing. It's about 29.00 USD per gallon and easy to sand. For waterproof filler, I used Duraglass. It is harder to sand and costs more, but is 100% waterproof.

WOOD FILLER- Earth & Lung Friendly:
No pre-mixed wood fillers that I found are waterproof, so I tried to make one as close to waterproof as possible.
The Experiment was Durham's Water Putty, but mixed with 50:50 Type I PVA glue and white vinegar. Dry time was 16 hours before torture testing.

The test bowls at 1/4" thick putty that I made did not dissolve when soaked for 2 days underwater, but the surface could be scratched with a fingernail. Water left in the bowls overnight did not wick through to the paper that the bowls sat upon.

After painting the "test dummies", they did not get at all soft when soaked. Although harder to sand than body filler, Durhams paints like a dream with latex! Also, it can be mixed to whatever consistency works best for your project.

I hope these ideas will help you with a project or two!
Paul
Hello!
I found this thread when I searched for alternatives to pc petrifier, and you seem to know your stuff, so I hope it’s ok to ask you for advice!
I do some crafts with paper, and I’ve seen pc petrifier being recommended as the perfect solution to for example dip paper beads into in order to make them hard and waterproof. The thing is, I live in Sweden and we do not have pc petrifier here (I can order a small bottle from Swedish Amazon if I pay twelve million dollars and promise them my firstborn), and I am looking for alternatives, which is difficult when I’m not really sure what’s in it and how it behaves. From what I understand, it soaks into the paper and hardens. Will any of the methods you mentioned do the same thing? We do not have Durhams putty either.

I would be really grateful if you have any tips about this!
 
Hello!
I found this thread when I searched for alternatives to pc petrifier, and you seem to know your stuff, so I hope it’s ok to ask you for advice!
I do some crafts with paper, and I’ve seen pc petrifier being recommended as the perfect solution to for example dip paper beads into in order to make them hard and waterproof. The thing is, I live in Sweden and we do not have pc petrifier here (I can order a small bottle from Swedish Amazon if I pay twelve million dollars and promise them my firstborn), and I am looking for alternatives, which is difficult when I’m not really sure what’s in it and how it behaves. From what I understand, it soaks into the paper and hardens. Will any of the methods you mentioned do the same thing? We do not have Durhams putty either.

I would be really grateful if you have any tips about this!
Hello Sneezing Angel,

For paper beads that she makes, my wife uses something called Mod Poge. She'll stick the beads on a thin rod and paint the Mod Poge on with Gum Soft Piks. I suspect a pipe cleaner or a cotton ear cleaning swab would also work.

Here is a nice article that someone wrote about sealing beads: https://www.instructables.com/Glazing-and-Drying-Paper-Beads/

Judging by a crumbled piece of paper that I once tried, dipping in clear shellac works well. The paper got very hard, but if water touches shellac, it turns white. I have heard, but never tried, that while craft glue thinned down also is used on paper beads. What comes to mind is Elmer's School Glue. That glue is a PVA glue.

Durhams Water Putty is easy to make yourself. It's made of > 85% molding plaster and less than 15% dextrin. A prebiotic product called Benefiber is made of wheat dextrin.

I tried an experiment once: 80 grams of molding plaster and 16 grams of Benefiber. It worked great on a repair! Hopefully you can get Benefiber or a similar product where you live. Molding plaster is sold at hobby shops and some hardware stores.

Hope This Helps!
Paul
 
Hello Sneezing Angel,

For paper beads that she makes, my wife uses something called Mod Poge. She'll stick the beads on a thin rod and paint the Mod Poge on with Gum Soft Piks. I suspect a pipe cleaner or a cotton ear cleaning swab would also work.

Here is a nice article that someone wrote about sealing beads: https://www.instructables.com/Glazing-and-Drying-Paper-Beads/

Judging by a crumbled piece of paper that I once tried, dipping in clear shellac works well. The paper got very hard, but if water touches shellac, it turns white. I have heard, but never tried, that while craft glue thinned down also is used on paper beads. What comes to mind is Elmer's School Glue. That glue is a PVA glue.

Durhams Water Putty is easy to make yourself. It's made of > 85% molding plaster and less than 15% dextrin. A prebiotic product called Benefiber is made of wheat dextrin.

I tried an experiment once: 80 grams of molding plaster and 16 grams of Benefiber. It worked great on a repair! Hopefully you can get Benefiber or a similar product where you live. Molding plaster is sold at hobby shops and some hardware stores.

Hope This Helps!
Paul
Thank you so much! Mod Podge is what I use right now, and it makes them look great, but someone commented in a video that paper jewelry always has a shelf life since they are not waterproof on the inside, which made dipping them in the pc petrifier seem like a good choice. I haven't been doing this for very long, so I have no idea if my pretty beads will turn soggy or smelly or something (not sure exactly what would happen to them) if I do not get something to coat them on the inside.

The person showing the pc petrifier strung the beads on a fishing wire and dipped them, and when dried, she could simply break them apart - I am quite sure that this would not work with Mod Podge, it is more elastic and the edges would not look great if they dried touching each other. Dipping them looked like a very leisurely alternative to brushing Mod Podge on each of them individually, as I do now.
 
PC Petrifier is a urethane hybrid polymer mixed with glycol ester. That's probably why it penetrates so well. Maybe near you there is a low to no VOC rotted wood restoring product that will give similar performance.

Your question brings to mind trying a water based finish for wood floors.
Artists who make sculptures out of cardboard dip in baths of those products to protect & preserve their pieces

One water based urethane floor finish that I used was crystal clear, quite glossy, penetrated the wood very well and has been rock-hard for years. The particular item was Rust-Oleum Profin. The base is water and the finish was two glycol esters.

Clean up of tools was soap and water. The VOC level was quite low and each coat (after the first) dried in about an hour. The first coat dried in minutes, perhaps because it was absorbed by the bare wood.

I remember using some on a natural fiber rope to seal the ends against water. I still use the rope.
There is wood trim that runs along the stone window sills at my house. Snow piles there and melts into the stone. The wood trim wicks the water up, the paint pops off and the trim rots. Over and over. I coated the new trim on all 6 sides with that floor finish before installing and painting. It's lasted 20+ years. (Before I knew of PC Petrifier)

Maybe it would be fun to experiment with something similar, perhaps thinning if needed.
 

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