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Beyond safety issues, my fear would be the introduction of water or water vapor. As I said, even small amounts of moisture can cloud or damage resin in the curing stages.
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Stabilizing Wood: Physics, Chemistry, Materials, Techniques, and Performance: "Just the facts Man"
- Thread starter Cushing H.
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Beyond safety issues, my fear would be the introduction of water or water vapor. As I said, even small amounts of moisture can cloud or damage resin in the curing stages.
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My set should work like this. I will evacuate the air in the chamber with a vacuum. When I get the vacuum that I like I will hold it under vacuum for some amount of time(this is where the testing comes in) When the vacuum is finished I will open the line to the resin so it will be pulled into the chamber. Hopefully without any reintroduction of air. But I will fine tune the prosses over time.
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Yes and as of now I don't really know how to keep it free of water/water vapor. K&G does it pretty well. It will have to come down to more research and technique
That seems reasonable. I assume the liquid resin is not very compressible, so even at the high pressures there is not really a huge safety concern. How will you generate the pressure?
Maybe you could apply vacuum to the resin tank as you pull vacuum on the wood to get the air out of the resin. When you are ready to impregnate the wood, close the valve on the resin tank that connects the line from the vacuum pump, open the valve between resin tank and the chamber that holds the wood and then slowly open a valve between resin tank and atmosphere to get the resin to flow. The resin tank would only ever see one atmosphere of pressure, so it would not have to be anything fancy. I'd still put a safety release valve on it, this scheme has a potential to accidentally pressurize the resin chamber if the valves are not set right when you start pressurizing the chamber that holds the wood.
I'd like to see some pictures of your setup when you get it going. Very interesting.
Cushing H.
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If you are truly able to keep any significant amount of air out of the chamber as it fills with resin, then you should be at least safer with the pressure (though note I did not say “safe ... because I just do not know).
what makes pressurized tanks like scuba tanks dangerous is not the pressure per se, but the amount of gas compressed under pressure. If the tank ruptures, that gas goes flying out, Ripping the tank wide open, and potentially Driving shrapnel with it. If the valve breaks off, you have a rather impressive little rocket engine driving the whole tank in an unpredictable trajectory (probably what happened to that boat).
such tanks are pressure tested using a hydrostatic test - they are filled with water, then put under pressure above their rated value. Water is not compressible - so should the tank rupture, it just kind of goes “pft “ and nothing really dangerous happens.
So, if your tank is really only filled with resin, you should be in a safer place - but still that is a lot of pressure - I would take all due safety precautions...
what makes pressurized tanks like scuba tanks dangerous is not the pressure per se, but the amount of gas compressed under pressure. If the tank ruptures, that gas goes flying out, Ripping the tank wide open, and potentially Driving shrapnel with it. If the valve breaks off, you have a rather impressive little rocket engine driving the whole tank in an unpredictable trajectory (probably what happened to that boat).
such tanks are pressure tested using a hydrostatic test - they are filled with water, then put under pressure above their rated value. Water is not compressible - so should the tank rupture, it just kind of goes “pft “ and nothing really dangerous happens.
So, if your tank is really only filled with resin, you should be in a safer place - but still that is a lot of pressure - I would take all due safety precautions...
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Cushing H.
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Hi john. Thank you- I’m glad you enjoyed my little effort. Regarding your question - I believe the answer is “no”. If you recall the mention above about “capillary condensation”, the small capillaries will allow the presence of liquid water even in the face of a vacuum. Maybe ultimately the water would evaporate, but that would take a long time.
(more nerdy, technical, answer: water turns to gas when it’s molecules have enough energy to move in many directions for larger distances (more “degrees of freedom “). Reduce the temperature or increase pressure on them and you inhibit that motion. The small capillaries place a physical barrier that limits both direction and distance the molecules can move, “robbing” them of potential degrees of freedom they might otherwise try to take, and thus not allowing the transition from liquid to gas. It’s almost like the capillaries actually “act” as a pressure put on the liquid ... thus negating the effect of vacuum pulled from the outside.
does that make sense? )
(more nerdy, technical, answer: water turns to gas when it’s molecules have enough energy to move in many directions for larger distances (more “degrees of freedom “). Reduce the temperature or increase pressure on them and you inhibit that motion. The small capillaries place a physical barrier that limits both direction and distance the molecules can move, “robbing” them of potential degrees of freedom they might otherwise try to take, and thus not allowing the transition from liquid to gas. It’s almost like the capillaries actually “act” as a pressure put on the liquid ... thus negating the effect of vacuum pulled from the outside.
does that make sense? )
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Cushing H.
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Sounds good. Thank you!
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milesofalaska
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I appreciate the discussion here and am learning a lot. I've paid to have wood stabilized, then done it on my own. I have a few hundred pounds of experience stabilizing over a decade of time. I wish to share some information others have not, that may offer ideas to some, while others will be all the more convinced I am an idiot. (smile) Professionally done is the best quality, I agree. As some are asking, "But what is 'good enough.?" I address this. I have a strong need for quality personal knives, and I sell custom knives. A personal one of a kind, the unique knife is a priority. "The best" is not.
So anything I do to help stabilize softer woods will be an improvement over the raw, which may not even be usable. I use cactus juice. No equipment. (?) I soak a long time, depending on the wood. I commonly set half a dozen blocks set in a coffee can of cactus juice for a month. But sometimes only overnight. I find all my own wood, cut my own blocks. I deliberately select wood with soft and hard spots like splauted birch, poplar burls with some slight rot. I use dye in the resin. Only half the wood is submerged. Resin wicks its way up the wood with the dye in patterns, following the soft spots. I flip the wood over and set it in another can of cactus juice with another color dye. This as well wicks up the wood and overlaps the previous soak. I bake it as instructions dictate. I prefer 212 degrees to ensure set up for 2-3 hours. This just works well for me.
I cut the block. If I am not happy, I soak again, maybe after I cut the blocks into rough handles. Even finished handles. No, I do not even seek uniform penetration. My goal would be uniform hardness. So what was once soft is now as hard as the surrounding wood. Thus it takes an even uniform polish. I feel this even hardness also helps with stability, as time has shown me. I might add I am in interior Alaska, a very dry climate.
If a customer has the main priority that this handle will last forever, I use wood known for this feature like ironwood. I do feel my methods offer some unknowns. I agree.
I add I sell knives. I can offer a finished custom product in the $100 range and still make a profit. The product is not a $5,000 product and is not sold as such. It will however, be better in every way than a factory knife. I use the brass rod swipe test. Factory knives test at 50 strokes on average. My minimum requirement for the steel is 200 swipes, getting 4-500 on some. I have the same standards for the handle materials. "Better than average, not as good as the best." (In the $100 to $300 price range) I can not afford the best-stabilized handle materials on these price range knives. It' s my bread and butter. The bottom line for me selling is how low you can go. To make a living, I have to go with the flow. It is nice to say, "price is no object!" "I want the best of everything at the highest price!" The reality, for me is not to make a profit. S this has a lot to do with explaining how to do the stabilizing on a low budget, come up with a very unique product that is better than natural for not a lot of talent or outflow of funds. An advantage is it's truly your product, unique to you.
I do something I do not hear about much. I restabilized the handle when the knife is finished. Or maybe it is only a finish. I use super, thin Loctite glue. I use the star bond brand. I get the wood down to a 00 steel wool finish. I squirt a liberal amount on and rub with tissue till it dries about half a minute. What this does is fills tiny gaps, soaks in the most in the softest spots, hardens anything needing hardening, penetrating deep, and when this hardens is more than just an oil finish. This somewhat weather resists better than other coatings. Water beads up on the surface, not easily penetrating. I agree with others here; this is never waterproof. There is no such thing. If you toss it in the sink of water and eave it to clean later, it gets water-soaked. By this 'superglue' method, the surface is hardened, and so it does not matter as much if my stabilizing is perfect. In this way, I do disagree the stabilizing absolutely must no if and or but penetrate uniformly. No, it is not absolutely necessary. No, I do not get as heavy a product as professionally did. 'Weight' is not always taught after by, my customers. Some prefer a lighter weight knife, and sometimes light does Ballance better in the hand, depending on the blade. The method does offer the option to have a lighter handle like, say, on a fishing knife that could potentially float. My cost is about 1/5th the cost of professionally done and 'the very best,' is not always the answer. If the question is, "Would you like this $100 knife over here, or this $500 knife in the next tray." Are we only going to talk about making the best of the best here, or is it worth discussing knives that sell, including 'good enough.' or I word it 'one of a kind unique totally done by me.' Anyhow hope some of my ways help others who are wondering what to decide. Some may say, "Holy cow, this sure helps me make up my mind I need the pro to do it!!" WEll. Ok. Glad to be of help.
I estimate my average handle of stabilized wood cost me an average of $3. I do all the work, find the wood cut it etc. Time? Perhaps half an hour per finished handle. A bottom line for me in business is what does it cost how much time, what's the profit, how is business going, what economically works, how satisfied are customers. Any complaints etc. I'd add I usually use mammoth ivory or some other material then stabilized wood on my higher end knives. I got kind of wordy here, again, hope this adds a helpful view for others to ponder.
So anything I do to help stabilize softer woods will be an improvement over the raw, which may not even be usable. I use cactus juice. No equipment. (?) I soak a long time, depending on the wood. I commonly set half a dozen blocks set in a coffee can of cactus juice for a month. But sometimes only overnight. I find all my own wood, cut my own blocks. I deliberately select wood with soft and hard spots like splauted birch, poplar burls with some slight rot. I use dye in the resin. Only half the wood is submerged. Resin wicks its way up the wood with the dye in patterns, following the soft spots. I flip the wood over and set it in another can of cactus juice with another color dye. This as well wicks up the wood and overlaps the previous soak. I bake it as instructions dictate. I prefer 212 degrees to ensure set up for 2-3 hours. This just works well for me.
I cut the block. If I am not happy, I soak again, maybe after I cut the blocks into rough handles. Even finished handles. No, I do not even seek uniform penetration. My goal would be uniform hardness. So what was once soft is now as hard as the surrounding wood. Thus it takes an even uniform polish. I feel this even hardness also helps with stability, as time has shown me. I might add I am in interior Alaska, a very dry climate.
If a customer has the main priority that this handle will last forever, I use wood known for this feature like ironwood. I do feel my methods offer some unknowns. I agree.
I add I sell knives. I can offer a finished custom product in the $100 range and still make a profit. The product is not a $5,000 product and is not sold as such. It will however, be better in every way than a factory knife. I use the brass rod swipe test. Factory knives test at 50 strokes on average. My minimum requirement for the steel is 200 swipes, getting 4-500 on some. I have the same standards for the handle materials. "Better than average, not as good as the best." (In the $100 to $300 price range) I can not afford the best-stabilized handle materials on these price range knives. It' s my bread and butter. The bottom line for me selling is how low you can go. To make a living, I have to go with the flow. It is nice to say, "price is no object!" "I want the best of everything at the highest price!" The reality, for me is not to make a profit. S this has a lot to do with explaining how to do the stabilizing on a low budget, come up with a very unique product that is better than natural for not a lot of talent or outflow of funds. An advantage is it's truly your product, unique to you.
I do something I do not hear about much. I restabilized the handle when the knife is finished. Or maybe it is only a finish. I use super, thin Loctite glue. I use the star bond brand. I get the wood down to a 00 steel wool finish. I squirt a liberal amount on and rub with tissue till it dries about half a minute. What this does is fills tiny gaps, soaks in the most in the softest spots, hardens anything needing hardening, penetrating deep, and when this hardens is more than just an oil finish. This somewhat weather resists better than other coatings. Water beads up on the surface, not easily penetrating. I agree with others here; this is never waterproof. There is no such thing. If you toss it in the sink of water and eave it to clean later, it gets water-soaked. By this 'superglue' method, the surface is hardened, and so it does not matter as much if my stabilizing is perfect. In this way, I do disagree the stabilizing absolutely must no if and or but penetrate uniformly. No, it is not absolutely necessary. No, I do not get as heavy a product as professionally did. 'Weight' is not always taught after by, my customers. Some prefer a lighter weight knife, and sometimes light does Ballance better in the hand, depending on the blade. The method does offer the option to have a lighter handle like, say, on a fishing knife that could potentially float. My cost is about 1/5th the cost of professionally done and 'the very best,' is not always the answer. If the question is, "Would you like this $100 knife over here, or this $500 knife in the next tray." Are we only going to talk about making the best of the best here, or is it worth discussing knives that sell, including 'good enough.' or I word it 'one of a kind unique totally done by me.' Anyhow hope some of my ways help others who are wondering what to decide. Some may say, "Holy cow, this sure helps me make up my mind I need the pro to do it!!" WEll. Ok. Glad to be of help.
I estimate my average handle of stabilized wood cost me an average of $3. I do all the work, find the wood cut it etc. Time? Perhaps half an hour per finished handle. A bottom line for me in business is what does it cost how much time, what's the profit, how is business going, what economically works, how satisfied are customers. Any complaints etc. I'd add I usually use mammoth ivory or some other material then stabilized wood on my higher end knives. I got kind of wordy here, again, hope this adds a helpful view for others to ponder.
Cushing H.
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Going right to the nerdy answer: yes and no. Raise the temp a little and you drive water out of the bigger capillaries, but it stays in the mid size and smaller capillaries. Raise the temp somewhat more, and you drive water out of the mid size capillaries. Raise it even more and you drive it out of the smaller capillaries, but there will likely be smaller capillaries yet that retain water. I can’t really be quantitative except to say the only sure way to drive out virtually all the water is to burn the wood to ash.
that said, there has to be a limit of acceptability. For example, I believe that K&G does NOT heat wood to dry it ... rather they just put it in front of a fan at room temperature (but then again, this is Texas, so that might be a little elevated!). They go more by measured moisture content, where I believe 5-10% is acceptable (but don’t hold me to that...) ... but it is DEFINITELY not zero. Yet their product is considered extremely good ... so let that guide you I guess?
milesofalaska
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They go more by measured moisture content, where I believe 5-10% is acceptable
My reply: I have wondered what the moisture content needs to be and can say what happens if there is to much moisture. The cactus juice sets poorly and is cloudy, with potential bubbles within a softer wood. Thus some sort of reaction chemically to the moisture. Much like trying to glue anything when the instructions say it needs to be dry. also if wood is not dry enough, raising it to cactus juice setting temperates of 200 degrees can warp the wood. I agree Texas may be dry enough because In Alaska I can get wood naturally dry enough to accept the resin. I usually dry my wood a year. I have a wood stove to heat the shop in winter and sometimes set a de dozen blocks on the woodstove and leave it a day while I work, to get any suspect wood even drier. I also cut my knife scales and leave to dry another couple of weeks in big batches. It is important to me to have a lot of wood to choose from for a project. I look at the steel patterns and look for a pattern match. The more choices the better I feel about having a finished product that has the look I want. So I may move what to me are large batches of wood through the process I can also afford to toss out some % of the final product if I am not satisfied because I have little cost and time into it. I try to learn and figure out why it failed. Often it is just not the colors i had hoped for. Stabilizing does change the color a little.
My reply: I have wondered what the moisture content needs to be and can say what happens if there is to much moisture. The cactus juice sets poorly and is cloudy, with potential bubbles within a softer wood. Thus some sort of reaction chemically to the moisture. Much like trying to glue anything when the instructions say it needs to be dry. also if wood is not dry enough, raising it to cactus juice setting temperates of 200 degrees can warp the wood. I agree Texas may be dry enough because In Alaska I can get wood naturally dry enough to accept the resin. I usually dry my wood a year. I have a wood stove to heat the shop in winter and sometimes set a de dozen blocks on the woodstove and leave it a day while I work, to get any suspect wood even drier. I also cut my knife scales and leave to dry another couple of weeks in big batches. It is important to me to have a lot of wood to choose from for a project. I look at the steel patterns and look for a pattern match. The more choices the better I feel about having a finished product that has the look I want. So I may move what to me are large batches of wood through the process I can also afford to toss out some % of the final product if I am not satisfied because I have little cost and time into it. I try to learn and figure out why it failed. Often it is just not the colors i had hoped for. Stabilizing does change the color a little.
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Cushing H.
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Your interpretation of what could happen seems right, but As I understand it, K&G does use a vacuum step before applying pressure, so a lot of the air in the pores does bubble out.
Re. Residual moisture, K&G does insist on and measure a minimum moisture content (10% ? Though I might be remembering slightly incorrectly.) if samples don’t meet that criteria, they say they put them on a rack in front of a fan until they do. Yeah, by baking the samples more moisture would be taken out, but that would add more time and expense to their process. Can’t really argue with success … perhaps they could get more resin into their samples … but my guess is they (consciously or not) decided their current approach is “good enough?
weo
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This is what they told me 5-6 years ago too. And IIRC, they look for under 10% moisture.