Question about open molds

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Tarranttx

Member
Joined
May 22, 2021
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16
Location
Fort worth, Texas
Is it necessary to use a pressure pot or can I use a open mold? I have quite a lot of burl cut offs that would make awesome pens. I was thinking of buying the silicone kit and the cavity dimensions are 5.25"x1.25"x1.25.

Ideally I'd try to fill the cavity with as much wood as possible then throw clear epoxy into it to fill crooked cuts. Same with the width. Make it large enough that epoxy would fill gaps but when turned, most of the epoxy on the outside come off after trimming the width. Keep in mind I'll be cutting these up with a small Japanese saw, so that's why I wanted the mold to have extra width.

I've got willow, buck eye, cherry, maple, and FBE burl cut offs. A lot of them are decently long pieces that wouldn't need hardly any epoxy to fill in gaps. I also have 2 seperate gallon bags of long red cedar and black walnut shavings that I was thinking of making into a blank.

I'd like to be able to sell them in the future but I'd be willing to ship a few blanks to a few trusted community members to test how they turn and to give a quality opinion before I try to sell to the community.

I no longer have a shop or means to turn a pen. I do have wood and epoxy that I'd hate to throw/give them away.


Thank you for your opinions!
 
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Without pressure you may trap air inside the cast, then find voids when you turn the blanks. Alternate to pressure, you could try vibration to work out any bubbles. But this method is not as effective as pressure. DAMHIKT!
 
Dalecamino said:
Without pressure you may trap air inside the cast, then find voids when you turn the blanks. Alternate to pressure, you could try vibration to work out any bubbles. But this method is not as effective as pressure. DAMHIKT!
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Interesting! I wonder if using a vacuum chamber before it starts gelling would stop it? Maybe a mixture of vibration and a vacuum pump? I have some old PlayStation 4 controllers I may take it apart to use their vibration mechanics.
 
If it gets too thick the bubbles won't move. I used my scroll saw one time. Tape your mold down to the table, and crank it up. The vacuum will work if the resin is thin enough. Since you're down to two options, take your pick. If you have enough juice, try it both ways, and determine which worked the best.
 
I would use an epoxy resin. It is the thinnest and will flow in cavities well. Forget the vac. If you want you can do some vibration with a tool such as a sander. This would not take long. As for bubbles being a slow setting resin the bubbles will rise and any ones you shake lose with vibration too should be gone. I like to use Liquid Diamonds resin. Has worked well for me for other things. That stuff sticks to everything. Experiment and see what works well for you. Good luck.
 
Dalecamino said:
If it gets too thick the bubbles won't move. I used my scroll saw one time. Tape your mold down to the table, and crank it up. The vacuum will work if the resin is thin enough. Since you're down to two options, take your pick. If you have enough juice, try it both ways, and determine which worked the best.
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Yea, that's a good idea! I think I have a belt sander I may turn upside down on a table.
 
jttheclockman said:
I would use an epoxy resin. It is the thinnest and will flow in cavities well. Forget the vac. If you want you can do some vibration with a tool such as a sander. This would not take long. As for bubbles being a slow setting resin the bubbles will rise and any ones you shake lose with vibration too should be gone. I like to use Liquid Diamonds resin. Has worked well for me for other things. That stuff sticks to everything. Experiment and see what works well for you. Good luck.
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I have a 1:1 by super clear that I wanted to experiment with before purchasing allumite. I know that'll be a favorite for turners. I also won't need much because I'm going to stuff as much wood as I can into each cavity
 
John's right about Liquid Diamonds. Different stuff from Alumilite. I think it's made in Florida. Look it up.
Do you have a jitterbug sander? They have outstanding vibration. Clamp it to your table or whatever.
 
Dalecamino said:
John's right about Liquid Diamonds. Different stuff from Alumilite. I think it's made in Florida. Look it up.
Do you have a jitterbug sander? They have outstanding vibration. Clamp it to your table or whatever.
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I do not. The belt sander is old, it might put out enough vibration. Have either of y'all used super clear before? I've used it for thin table pours but I haven't looked up how it turns
 
After researching, I can't find anything about someone using it to turn blanks. Most of it is about their use as flood coat or doing river tables with their 2:1
 
My casting is limited, and far into my past. I don't know why you couldn't use Super Clear for turning.
I don't find anything on Super clear. Are you referring to Water Clear?
 
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I use open molds quite often and this seems to work for me. Mix in colors slowly so as not to create too many bubbles, pour into mold in stages allowing liquid to seek its own level and not trap much air. Vibration is good, I learned the hard way not to vacuum, looked like I grew a hornet nest.
 
Tarranttx said:
I do not. The belt sander is old, it might put out enough vibration. Have either of y'all used super clear before? I've used it for thin table pours but I haven't looked up how it turns
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I have not so can not comment on it. I see it is a bar top resin so should be tough and scratch resistant. Looks like you can make deep pours with it so that is a plus. What the open time is on it , have no idea. Suggest you give it a try. Can not hurt anything. Good luck.
 
tomtedesco said:
I use open molds quite often and this seems to work for me. Mix in colors slowly so as not to create too many bubbles, pour into mold in stages allowing liquid to seek its own level and not trap much air. Vibration is good, I learned the hard way not to vacuum, looked like I grew a hornet nest.
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I had watched a YouTube video with similar results with a vacuum system. I don't plan to use coloring. All I have is a candy red mica, but I just wanted to use it clear to make sure any gaps are sealed.
 
jttheclockman said:
I have not so can not comment on it. I see it is a bar top resin so should be tough and scratch resistant. Looks like you can make deep pours with it so that is a plus. What the open time is on it , have no idea. Suggest you give it a try. Can not hurt anything. Good luck.
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So I read the pot time is about 30 mins. Do I need to pour in stages if I'm just filling in small gaps?
 
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