kuraki
Fimbulvetr Knifeworks
- Joined
- Jun 17, 2016
- Messages
- 4,679
This is kind of a fun spinoff for me. I get a kick out of doing it. I don't do it to save money or whatever. I do it because I want to, and because I can make use of pieces of wood I might otherwise throw away.
The first step is to start with stabilized wood. Do it yourself, send it to K&G or whatever. Just do that first, for two reasons. One, the urethane resin is adhesive, but not to the degree of the structural epoxy we typically use, and wood that shifts like a leaf in the breeze with every humidity change will eventually break the bond. Two, stabilizing the wood after casting just isn't viable because the urethane won't withstand the curing temperatures of the stabilizing fluid.
So, sneak into Stacy's workshop some night and steal some of his firewood, like this:
The other materials you need are Alumilite Clear or Alumilite Clear Slow, which I'm using here because I appreciate the extra 5 minutes of pot life, a cheap food scale, some cups and mixing sticks:
Then you need some dye and or pigment. I use Alumilite brand dye, and the pigment is either Alumilite or Pearl Ex. Generally, dyes give you a "base" color and pigments give you pearlescent accents, however you can use only dye, or only pigment, or any combination of the two. Get creative. One word of advice, is stay simple. The varying density of the pigment gives a good degree of coloration variability, using too many colors just gets busy and generally looks like crap.
You need some molds. UHMW cutting boards from Walmart work fine. The resin does not adhere to it. Screwing them together makes it easy to demold. I have a few different sizes made up for different size blocks/scales now. 2 large cutting boards will make 8 or 12 different molds.
Nosy helpers hovering around your feet, optional.
So you begin by pouring equal amounts by weight, side A and side B into their own cups. At this point I like to dye side A and mix thoroughly. Now is when you lay everything out, cross your Ts, dot your Is, make sure your beer is handy because once you put them together you're on the clock. I like to lay everything out so I'm not searching for it after mixing, because even when I'm not on the clock I'm the kind of guy who sets his caliper down on the bench and then spends 60 minutes looking for it. Note I've taped the seams of the molds. These are new, I just made them up. They don't quite seal. I would have put silicone in the joints but I was out. Resin will infiltrate the joints and cure, sealing them for down the road, so I just taped them up with Gorilla tape. Science has only ever proven two things, one being that leather dye can stain anything, and anything leather dye can stain Gorilla tape will stick to whether it's UHMW or greased teflon. This is also where you make sure your pressure pot and compressor are ready, so you're not running around like a crazy person trying to find a different QD fitting for your regulator after finding out your new hose has a coupler that's not quite to the same spec.
Set a timer. With "Clear" you have 7 minutes. With "Clear Slow" you have 12. I prefer to have the molds in the pressure pot in 5 minutes, so I play a song I know well and don't have to watch a clock. You can play a different song than I do but your project will probably be a complete failure because as I was typing this science proved a third thing and that's that Alumilite prefers metal. But your choice.
Combine side A and B and MIX. Mix mix mix. Both colors if you're doing multiples. A good 30 seconds. Every failure I've had has been from incomplete cure from incomplete mixing. It's more vital than mixing your epoxy well. While you're mixing, try (you'll fail) to keep from creating bubbles by stirring. You can't eliminate them completely but you can be mindful about not frothing it up like a freshly tapped half barrel.
Once A and B are mixed, I divide them back into 2 cups and add pigment to each if I want a combined effect. Then mix some more. At this point, you can mix as much or as little as you want to achieve the desired effect.
And then you pour. Try to pour from one side to allow air to escape. Pour your two pigmented cups together to get them to swirl into each other, or don't, depending on what you're trying to accomplish.
I always combine my leftovers into a cup and let it cure on the counter. I'll throw these into the lathe and make trinkets out of them here and there. Today was particularly wasteful because I was guessing how much I would need to fill my old, larger molds and not these new, closer sized molds.
Songs almost over, beer is almost empty, get them in the pot.
Your pot needs 2 ball valves. One closing off the regulator (in) side, and one for exhaust for when they've cured. Make sure that one is closed before turning the input side open, especially when it's winter and you're doing this in the house with a little pint sized compressor and not your 20 cfm shop monster that can make up for blowing 2 gallons of air into space in 2 seconds.
Are you done yet? I haven't eaten for minutes. MINUTES.
Yes, we're done for tonight. I always let them cure overnight, because I've been burned by cool temperatures slowing the cure and my insatiable impatience to see what I've created. So I pressurize to 60 psi and find something else to screw up for the evening.
The next morning, I demold. Note, taping the seams was necessary. I think if we had invented Gorilla glue in WW2 it would have had a significant impact on aerial combat, because any plane that made it back to base without exploding could have been patched back up, topped off and flown right back out no matter how many holes it had in it.
So now it's time to clean them up. I didn't take any pictures here. You all have sanders. Normally I just cut all of the excess off with a 36 grit belt and call it good but I took these up to 600 grit and then hit them with pink scratchless to really see how they turned out.
The blue didn't turn out how I'd hoped. That's learning. Coloration isn't an exact science. For the smaller, totally enclosed spaces like that piece had, I should have used lighter colors. But overall, not bad. And now firewood, is knife wood. I've never really beat this stuff up, I don't know how durable the bond is. I'm primarily doing this for kitchen knives that will spend their lives indoors. I think if anything was to defeat the bond, it would be freezing temperatures combined with shock. But so far, like I said, the only failures I've had were from improper mixing and the resulting poor cure.
Thanks for looking.
The first step is to start with stabilized wood. Do it yourself, send it to K&G or whatever. Just do that first, for two reasons. One, the urethane resin is adhesive, but not to the degree of the structural epoxy we typically use, and wood that shifts like a leaf in the breeze with every humidity change will eventually break the bond. Two, stabilizing the wood after casting just isn't viable because the urethane won't withstand the curing temperatures of the stabilizing fluid.
So, sneak into Stacy's workshop some night and steal some of his firewood, like this:
The other materials you need are Alumilite Clear or Alumilite Clear Slow, which I'm using here because I appreciate the extra 5 minutes of pot life, a cheap food scale, some cups and mixing sticks:
Then you need some dye and or pigment. I use Alumilite brand dye, and the pigment is either Alumilite or Pearl Ex. Generally, dyes give you a "base" color and pigments give you pearlescent accents, however you can use only dye, or only pigment, or any combination of the two. Get creative. One word of advice, is stay simple. The varying density of the pigment gives a good degree of coloration variability, using too many colors just gets busy and generally looks like crap.
You need some molds. UHMW cutting boards from Walmart work fine. The resin does not adhere to it. Screwing them together makes it easy to demold. I have a few different sizes made up for different size blocks/scales now. 2 large cutting boards will make 8 or 12 different molds.
Nosy helpers hovering around your feet, optional.
So you begin by pouring equal amounts by weight, side A and side B into their own cups. At this point I like to dye side A and mix thoroughly. Now is when you lay everything out, cross your Ts, dot your Is, make sure your beer is handy because once you put them together you're on the clock. I like to lay everything out so I'm not searching for it after mixing, because even when I'm not on the clock I'm the kind of guy who sets his caliper down on the bench and then spends 60 minutes looking for it. Note I've taped the seams of the molds. These are new, I just made them up. They don't quite seal. I would have put silicone in the joints but I was out. Resin will infiltrate the joints and cure, sealing them for down the road, so I just taped them up with Gorilla tape. Science has only ever proven two things, one being that leather dye can stain anything, and anything leather dye can stain Gorilla tape will stick to whether it's UHMW or greased teflon. This is also where you make sure your pressure pot and compressor are ready, so you're not running around like a crazy person trying to find a different QD fitting for your regulator after finding out your new hose has a coupler that's not quite to the same spec.
Set a timer. With "Clear" you have 7 minutes. With "Clear Slow" you have 12. I prefer to have the molds in the pressure pot in 5 minutes, so I play a song I know well and don't have to watch a clock. You can play a different song than I do but your project will probably be a complete failure because as I was typing this science proved a third thing and that's that Alumilite prefers metal. But your choice.
Combine side A and B and MIX. Mix mix mix. Both colors if you're doing multiples. A good 30 seconds. Every failure I've had has been from incomplete cure from incomplete mixing. It's more vital than mixing your epoxy well. While you're mixing, try (you'll fail) to keep from creating bubbles by stirring. You can't eliminate them completely but you can be mindful about not frothing it up like a freshly tapped half barrel.
Once A and B are mixed, I divide them back into 2 cups and add pigment to each if I want a combined effect. Then mix some more. At this point, you can mix as much or as little as you want to achieve the desired effect.
And then you pour. Try to pour from one side to allow air to escape. Pour your two pigmented cups together to get them to swirl into each other, or don't, depending on what you're trying to accomplish.
I always combine my leftovers into a cup and let it cure on the counter. I'll throw these into the lathe and make trinkets out of them here and there. Today was particularly wasteful because I was guessing how much I would need to fill my old, larger molds and not these new, closer sized molds.
Songs almost over, beer is almost empty, get them in the pot.
Your pot needs 2 ball valves. One closing off the regulator (in) side, and one for exhaust for when they've cured. Make sure that one is closed before turning the input side open, especially when it's winter and you're doing this in the house with a little pint sized compressor and not your 20 cfm shop monster that can make up for blowing 2 gallons of air into space in 2 seconds.
Are you done yet? I haven't eaten for minutes. MINUTES.
Yes, we're done for tonight. I always let them cure overnight, because I've been burned by cool temperatures slowing the cure and my insatiable impatience to see what I've created. So I pressurize to 60 psi and find something else to screw up for the evening.
The next morning, I demold. Note, taping the seams was necessary. I think if we had invented Gorilla glue in WW2 it would have had a significant impact on aerial combat, because any plane that made it back to base without exploding could have been patched back up, topped off and flown right back out no matter how many holes it had in it.
So now it's time to clean them up. I didn't take any pictures here. You all have sanders. Normally I just cut all of the excess off with a 36 grit belt and call it good but I took these up to 600 grit and then hit them with pink scratchless to really see how they turned out.
The blue didn't turn out how I'd hoped. That's learning. Coloration isn't an exact science. For the smaller, totally enclosed spaces like that piece had, I should have used lighter colors. But overall, not bad. And now firewood, is knife wood. I've never really beat this stuff up, I don't know how durable the bond is. I'm primarily doing this for kitchen knives that will spend their lives indoors. I think if anything was to defeat the bond, it would be freezing temperatures combined with shock. But so far, like I said, the only failures I've had were from improper mixing and the resulting poor cure.
Thanks for looking.
