If you have any suggestions/advice for better/other ways of making gaskets, post them in the comments below! Edit: I don't bother with vacuum degassing the flex 60 now, it's a waste of time if you're putting them in a pressure pot, and with such a short pot life, you really need that extra time. I also don't bother baking the gaskets any more, I just put them in a pressure pot for 2 hours to cure at 60 p.s.i. I've also recently switched to Alumilite's Flex 80. It's noticeably firmer, more like roller blade wheel and works much better for my purposes.
Regarding your original idea on injecting a clamped mould. Perhaps if you simply added more holes and blocked each one once the liquid started to enter, it may have worked. Or you could have tried to suck air out of the mould at the same time as injecting.
Great video. And thanks for touching on what didn’t work. The cure inhibitors in the resin print has tripped me up in the past; I’m excited to try baking
1:26 did you add a hole at the other end of the mold for the air to escape? Looks like you are fighting against the pressure created by compressing the air inside of the mold.
The vent hole is actually next to the injection port. I figured if I made the hole on the other side the silicone wouldn't go all the way around to fill the mold.
The gasket would be, but there's more to it than that. How the gasket fits, how well the parts fit together, what they are made of, the design of the parts, all of that will factor in. Most waterproof items with gaskets have the gasketed part held in place with screws, you couldn't just pop it on. Think of the back of a waterproof watch, the way it's screwed in place with a rubber gasket underneath it.
@@RichardThompsonCA wonderful! yeah it's just the gasket I needed to know about, planning on doing some small scale production with selective laser sintered vapor smoothed nylon held together with screws, just needed to know if the gasket would be up to the task theoretically. Many thanks for the video!
Hi Richard, are you cating the urethane into a silicone mould for ease of removal only? I'm thinking of doing something similar but casting straight into a SLA print which will be rigid, thanks.
There were a few reasons, ease of removal was one. The shape of the gasket has a severe undercut and it may not pull out from an inflexible mold. Number 2 is inhibition. I had problems in the past with silicone and resin prints, and while I haven't tested this urethane with 3d resin, I didn't want to risk it.
If you do create custom gaskets remember to make them available to your customers. Gaskets always wear out and are considered disposable. Add identification to the parts so people know which gasket they need.
This is the SDS sheet for the product: msdsdigital.com/system/files/ALUMILITE%20FLEX.pdf . It doesn't explicitly state one way or another. So I'm not sure. When I search for "is urethane elastomer food safe" I get this: "Polyurethane is resistant to mineral and vegetable oils, and aromatic hydrocarbons, making it a perfect choice for food grade applications."
The shape will be the problem. I designed the profile of these gaskets to be flat on all sides, this allows for the open face mold. The o ring is a cylinder, I suspect you would need some kind of injectable mold for those. I tried injection molds and couldn't make it work.
@@RichardThompsonCA thanks, I'll keep that in mind. I'm trying to get a seal for a Stanley food jar. I just purchased an oring for it. If the oring doesn't work, I'll make a seal copy by the procedure you did.
Would’ve been nice if you mentioned in the video that you also need a vacuum/pressure chamber and not only “put it in the oven” And also would be very nice if commented on toxicity of urethane and the fact that you need to do it in a well ventilated area (not in your apartment) and probably wear some respiratory protection?
I haven't done any tests, for my purposes the gaskets don't need to survive either, and I couldn't find any information about heat or chemical resistance on Alumilites websites. I guess those properties could be found in your materials SDS sheet, assuming you can find one🙂
I used to degas it in a vacuum chamber and then put it into the oven. But I wasn't sure that was helping any and since this stuff has a pot life of only 4 minutes I don't waste time on that any more. Now I inject it into the mold and put that in a pressure pot to handle any bubbles. This has been working well for me so far.
If you mean using an FDM printer to make a tpu gasket, I'm not sure if that would work. I don't have an FDM printer that can print tpu (you need a direct drive printer for that). But based on standard FDM prints I don't think it would be airtight due to the layer lines. I also don't think you would get the tolerances needed. When I print these things they have to be within 0.1 mm or they don't fit correctly. I don't think that could be achieved with any reliablity with an FDM printer.
Thanks for answering Richard ! I mean to print a gasket directly on SLA with a resin equivalent to fdm tpu, ¿would be repeatable once you find the right settings and size? Or you think would be any problem with that kind of print . I.e. to print a conical gasket like the one you used for make the molds and use it directly to seal. Thanks
@@aquamansurfer It's really going to depend on the resin. I don't know if anyone is making a UV curing resin that's as tough/strong as casting urethane. It would require a lot of experimentation with different resins to see what works. It also might be a problem if you need something food grade as I don't think any of the 3d printer resins are. Also, you would probably have to keep it out of the sun and away from UV light sources. All the printer resins I've used will get more yellow and brittle if you post-expose them under UV light too long. Also it may not be as chemical/heat/abrasion resistant as a cast one. The chemistry is quite different between thermoset elastomers and UV curing resins. So there would probably be a lot of compromises to 3d print them. Just something to think about.
@@RichardThompsonCA TPU gasket printing for engines is already a thing, they are oil, air and fuel resistant and good up to 100C. You can find several TH-camrs already have content up on the very thing. Direct drive is desirable, but not absolutely necessary, it all depends on the shore hardness of the TPU you use.
a grease gun and a fixed mold casing such as a section of rectangular steel tubing schedule 40 a slice of steel spacing material and wedges to apply clamping pressure, a grease fitting on one orifice and a vacuum port with a manually operated check valve. Suck the air out and the media in as you apply pressure with the grease gun loaded with an old tube cleaned and re filled with 1 part or two guns filled with parts A & B of a 2 part media,
Good question. I'm not really sure. This is the SDS sheet for the product: msdsdigital.com/system/files/ALUMILITE%20FLEX.pdf . It doesn't explicitly state one way or another. So I'm not sure. When I search for "is urethane elastomer food safe" I get this: "Polyurethane is resistant to mineral and vegetable oils, and aromatic hydrocarbons, making it a perfect choice for food grade applications." I've read that platinum silicone is food safe, but I think that would be way too soft for a gasket like this. I recently switched from the flex 60 to flex 80, it actually seals better when it's harder.
If you mean "which one is better?", I guess it would depend on the mechanical needs of your part and how quickly you need to cast parts. I don't know what the hardest silicone is but urethane can be as hard as epoxy. Also, the urethane I have sets in 4 minutes, I've not seen a silicone product that was that quick (although I could be completely wrong, I've only limited experience casting).
If you look closely at it you'll see the air vent is actually right next to the filling port (it's smaller) . My idea was that the silicone would make a full lap and come back around to vent, making a compete loop. I thought if I put the vent on the other side it would just fill half the mold.
@@Anton-zb9dc It wasn't the air vent getting filled that caused the problems, it was the viscosity of the silicone being too thick causing too much pressure. The silicone would squeeze out of the mold before it even got to the vent.
@@RichardThompsonCA, ok, but I encourage you to lern more about infusion and rtm, the principles are the same. There could be suction on the other side while silicone gets injected
@@Anton-zb9dc I certainly plan on coming back to injection molding in the future. I bought a 3 ton arbor press to convert into a home made bench top machine (future video project). For the purpose of making gaskets for my projects though I don't think it's the way to go. I find that due to shrink of the resin during curing and stretch of the urethane rubber during fitting I have to make several sizes to see which ones fits best. Doing multiple iterations with these 3d printed molds turned out to be far more labour intensive than I expected conpared to casting. Also I have to use a very slow curing silicone. The urethane I use for casting sets up in 4 minutes which isn't enough time to do it with injection. Maybe if I get the arbor press working and I can find a thermoplastic that's more rubber-like it would work. Also, I don't know how well resin molds will stand up to the clamping forces I would need to eliminate flash.
I tell you what, if you started making waterproof gaskets for battery compartments on e scooters, you'll make a fuck ton of money as there's a high demand for e scooter owners to waterproof their expensive purchases.
It's a great idea, but the problem with something like that is you need access to the actual machines to test fit and iterate different designs. Thanks for watching!
The limitation is the size of the gasket. I have to be able to print it on my resin printer and I think a valve cover gasket would be way too big. Also it would have to be a pretty rare gasket, I'd estimate the block of silicone you'd need for something that size would cost you a $100 at least. Usually valve cover gaskets are a lot cheaper than that. I've made valve cover gaskets in the past with a tube of RTV sealant, they don't need to keep in a lot of pressure.
Great vid. Please consider using real music as opposed to the free stock music. It makes a huge difference to the quality and doesn't put musicians out of a job.
If you have any suggestions/advice for better/other ways of making gaskets, post them in the comments below! Edit: I don't bother with vacuum degassing the flex 60 now, it's a waste of time if you're putting them in a pressure pot, and with such a short pot life, you really need that extra time. I also don't bother baking the gaskets any more, I just put them in a pressure pot for 2 hours to cure at 60 p.s.i. I've also recently switched to Alumilite's Flex 80. It's noticeably firmer, more like roller blade wheel and works much better for my purposes.
Regarding your original idea on injecting a clamped mould. Perhaps if you simply added more holes and blocked each one once the liquid started to enter, it may have worked. Or you could have tried to suck air out of the mould at the same time as injecting.
Thank you for this.
I was just browsing my TH-cam main page, and then TH-cam recommended this. I never knew that this was doable.
You're welcome.
Great video. And thanks for touching on what didn’t work. The cure inhibitors in the resin print has tripped me up in the past; I’m excited to try baking
Thanks for the video - I did not know this was even possible.
Glad to help
Great job
Great video. Subscribed. Cheers.
1:26 did you add a hole at the other end of the mold for the air to escape? Looks like you are fighting against the pressure created by compressing the air inside of the mold.
The vent hole is actually next to the injection port. I figured if I made the hole on the other side the silicone wouldn't go all the way around to fill the mold.
Thanks Sir
Cheers for the video, mega useful! do you think this would be good enough for waterproofing up to a few meters in depth?
The gasket would be, but there's more to it than that. How the gasket fits, how well the parts fit together, what they are made of, the design of the parts, all of that will factor in. Most waterproof items with gaskets have the gasketed part held in place with screws, you couldn't just pop it on. Think of the back of a waterproof watch, the way it's screwed in place with a rubber gasket underneath it.
@@RichardThompsonCA wonderful! yeah it's just the gasket I needed to know about, planning on doing some small scale production with selective laser sintered vapor smoothed nylon held together with screws, just needed to know if the gasket would be up to the task theoretically. Many thanks for the video!
Hi Richard, are you cating the urethane into a silicone mould for ease of removal only? I'm thinking of doing something similar but casting straight into a SLA print which will be rigid, thanks.
There were a few reasons, ease of removal was one. The shape of the gasket has a severe undercut and it may not pull out from an inflexible mold. Number 2 is inhibition. I had problems in the past with silicone and resin prints, and while I haven't tested this urethane with 3d resin, I didn't want to risk it.
very useful
Glad you think so!
If you do create custom gaskets remember to make them available to your customers. Gaskets always wear out and are considered disposable. Add identification to the parts so people know which gasket they need.
Is this food safe? I need a particular part for a coffee mug, it'll be in contact with boiling water for quite a bit
This is the SDS sheet for the product: msdsdigital.com/system/files/ALUMILITE%20FLEX.pdf . It doesn't explicitly state one way or another. So I'm not sure. When I search for "is urethane elastomer food safe" I get this: "Polyurethane is resistant to mineral and vegetable oils, and aromatic hydrocarbons, making it a perfect choice for food grade applications."
Can this mixture be used to create gaskets for automotive parts.
Say like a front cover for a water pump?
I don't see why not. It would depend on the requirements for heat resistance, chemical/oil resistance, uv resistance, etc.
I read the title as "How to cast a custom casket" and was very confused!
That would be a LOT of silicone :-)
Can you tell me where to get that wax pen, have seen others but not that one
I got it from Amazon. Just search for "electric wax carving knife/pen/machine" There's a lot of them on there.
Im looking to male some GITD O rings for a flashlight with some of the brightest glow powder on the market. Would this method work for that?
The shape will be the problem. I designed the profile of these gaskets to be flat on all sides, this allows for the open face mold. The o ring is a cylinder, I suspect you would need some kind of injectable mold for those. I tried injection molds and couldn't make it work.
Rich, can you provide the links for all the products you used to copy gasket?
Sure, mold max 30 silicone: sculpturesupply.com/products/mold-max-30. Alumilite flex urethane: plasticworld.ca/product/alumilite-flex-80-32-oz/
@@RichardThompsonCA thanks, I'll keep that in mind. I'm trying to get a seal for a Stanley food jar. I just purchased an oring for it. If the oring doesn't work, I'll make a seal copy by the procedure you did.
@@tman3944 I hope the oring fits, you'll probably have to spend ~$100 on silicone and urethane to reproduce that gasket. These supplies aren't cheap.
@@RichardThompsonCA if that's so it would be better to just get a new jar
Would’ve been nice if you mentioned in the video that you also need a vacuum/pressure chamber and not only “put it in the oven”
And also would be very nice if commented on toxicity of urethane and the fact that you need to do it in a well ventilated area (not in your apartment) and probably wear some respiratory protection?
How does it stand up to chemicals and heat?
I haven't done any tests, for my purposes the gaskets don't need to survive either, and I couldn't find any information about heat or chemical resistance on Alumilites websites. I guess those properties could be found in your materials SDS sheet, assuming you can find one🙂
How well can this rubber deal with solar radiation ? I want to make gaskets for a kit car.
You'd have to contact the manufacturer (Alumilite) to get that information. It doesn't say anything about that on the label or in the SDS.
What equipment or method do you use to degas the urethane casting material before injecting it into the mold?
I used to degas it in a vacuum chamber and then put it into the oven. But I wasn't sure that was helping any and since this stuff has a pot life of only 4 minutes I don't waste time on that any more. Now I inject it into the mold and put that in a pressure pot to handle any bubbles. This has been working well for me so far.
Hi, ¿what about using directly the tpu 3d printed gasket? Is it's quality enough to be air and water tight? Thanks
If you mean using an FDM printer to make a tpu gasket, I'm not sure if that would work. I don't have an FDM printer that can print tpu (you need a direct drive printer for that). But based on standard FDM prints I don't think it would be airtight due to the layer lines. I also don't think you would get the tolerances needed. When I print these things they have to be within 0.1 mm or they don't fit correctly. I don't think that could be achieved with any reliablity with an FDM printer.
Thanks for answering Richard ! I mean to print a gasket directly on SLA with a resin equivalent to fdm tpu, ¿would be repeatable once you find the right settings and size? Or you think would be any problem with that kind of print . I.e. to print a conical gasket like the one you used for make the molds and use it directly to seal. Thanks
@@aquamansurfer It's really going to depend on the resin. I don't know if anyone is making a UV curing resin that's as tough/strong as casting urethane. It would require a lot of experimentation with different resins to see what works. It also might be a problem if you need something food grade as I don't think any of the 3d printer resins are. Also, you would probably have to keep it out of the sun and away from UV light sources. All the printer resins I've used will get more yellow and brittle if you post-expose them under UV light too long. Also it may not be as chemical/heat/abrasion resistant as a cast one. The chemistry is quite different between thermoset elastomers and UV curing resins. So there would probably be a lot of compromises to 3d print them. Just something to think about.
Thanks a lot again for your thoughts Richard ! Any news i let you know!
@@RichardThompsonCA TPU gasket printing for engines is already a thing, they are oil, air and fuel resistant and good up to 100C. You can find several TH-camrs already have content up on the very thing. Direct drive is desirable, but not absolutely necessary, it all depends on the shore hardness of the TPU you use.
a grease gun and a fixed mold casing such as a section of rectangular steel tubing schedule 40 a slice of steel spacing material and wedges to apply clamping pressure, a grease fitting on one orifice and a vacuum port with a manually operated check valve. Suck the air out and the media in as you apply pressure with the grease gun loaded with an old tube cleaned and re filled with 1 part or two guns filled with parts A & B of a 2 part media,
Is the finished gasket food grade?
Good question. I'm not really sure. This is the SDS sheet for the product: msdsdigital.com/system/files/ALUMILITE%20FLEX.pdf . It doesn't explicitly state one way or another. So I'm not sure. When I search for "is urethane elastomer food safe" I get this: "Polyurethane is resistant to mineral and vegetable oils, and aromatic hydrocarbons, making it a perfect choice for food grade applications." I've read that platinum silicone is food safe, but I think that would be way too soft for a gasket like this. I recently switched from the flex 60 to flex 80, it actually seals better when it's harder.
urethane vs silicone gasket?
If you mean "which one is better?", I guess it would depend on the mechanical needs of your part and how quickly you need to cast parts. I don't know what the hardest silicone is but urethane can be as hard as epoxy. Also, the urethane I have sets in 4 minutes, I've not seen a silicone product that was that quick (although I could be completely wrong, I've only limited experience casting).
The first method was great, but I haven't seen you created air vent on other side for air to escape. It could be placed on the top
If you look closely at it you'll see the air vent is actually right next to the filling port (it's smaller) . My idea was that the silicone would make a full lap and come back around to vent, making a compete loop. I thought if I put the vent on the other side it would just fill half the mold.
@@RichardThompsonCA but as you can see on the video then this ait vent gets filled everything messes up. Put it on the opposite side
@@Anton-zb9dc It wasn't the air vent getting filled that caused the problems, it was the viscosity of the silicone being too thick causing too much pressure. The silicone would squeeze out of the mold before it even got to the vent.
@@RichardThompsonCA, ok, but I encourage you to lern more about infusion and rtm, the principles are the same. There could be suction on the other side while silicone gets injected
@@Anton-zb9dc I certainly plan on coming back to injection molding in the future. I bought a 3 ton arbor press to convert into a home made bench top machine (future video project). For the purpose of making gaskets for my projects though I don't think it's the way to go. I find that due to shrink of the resin during curing and stretch of the urethane rubber during fitting I have to make several sizes to see which ones fits best. Doing multiple iterations with these 3d printed molds turned out to be far more labour intensive than I expected conpared to casting. Also I have to use a very slow curing silicone. The urethane I use for casting sets up in 4 minutes which isn't enough time to do it with injection. Maybe if I get the arbor press working and I can find a thermoplastic that's more rubber-like it would work. Also, I don't know how well resin molds will stand up to the clamping forces I would need to eliminate flash.
wax pen? wax PEN??!! subbed subbed subbed
name of chimecal raisen and how buy
The gasket material is a urethane elastomer called Flex 60, it's made by Alumilite. I get it here in Canada from a company called Sculpture Supply.
what program @ 1:48? Thanks!
That's Modo, you can find it at www.foundry.com.
I tell you what, if you started making waterproof gaskets for battery compartments on e scooters, you'll make a fuck ton of money as there's a high demand for e scooter owners to waterproof their expensive purchases.
It's a great idea, but the problem with something like that is you need access to the actual machines to test fit and iterate different designs. Thanks for watching!
There’s so much easier ways to do that. I can’t believe you went through so much trouble.
Are you going to let us know the better way to do it?
@@TheRealJavaheadyeah I'd really like to know too! Lol
Can you make a valve cover gasket if so text me
The limitation is the size of the gasket. I have to be able to print it on my resin printer and I think a valve cover gasket would be way too big. Also it would have to be a pretty rare gasket, I'd estimate the block of silicone you'd need for something that size would cost you a $100 at least. Usually valve cover gaskets are a lot cheaper than that. I've made valve cover gaskets in the past with a tube of RTV sealant, they don't need to keep in a lot of pressure.
Great vid. Please consider using real music as opposed to the free stock music. It makes a huge difference to the quality and doesn't put musicians out of a job.