Annealing TPU to increase its heat resistance?

In this video I do more experiments following up on my first video about making TPU gaskets. I answer some questions and explore more about this material to see in what applications in can be used. I attempt to heat treat or anneal the TPU to make it more resilient at higher temperature. I compare the heat treated gasket to ones straight off the printer using a Shore A Hardness Durometer. I also try to test them at temperature while torqued and finally take the temperature of my lawn mower test subject to see where else we can use the gaskets.
Thanks to ‪@wktodd‬ for the suggestion for this video and ‪@CNCKitchen‬ for the inspiration to do more home grown "scientific" tests.
If you have not all the videos here are the links:
Can you print 3D gaskets? Should You? - • 3D printed gaskets? An...
Will 3D printied gaskets melt? - • Will 3D printed gasket...
3 ways to design a gasket in for 3D printing - • 3 ways to design a gas...
Tools used in this video:
Sovol SV01 -amzn.to/3LwYxN0
Creality Ender 3 Pro - amzn.to/3iNQPld
TPU Filament I used - amzn.to/3RV0vLC
UNI Multimeter with temperature sensing
amzn.to/3O9tU2e
High temp probe
amzn.to/3v5zeuH
The previous links are affiliate links, the channel gets a small referral fee if you use them and buy anything, it costs you nothing.
Video chapters
00:00 Intro to the tests
01:12 What is a Shore Durometer and scale and how to use them?
03:15 Comparing TPU to other rubber gasket materials
03:59 What is heat treating TPU and how to do it
08:35 Comparing heat treated to non treated TPU
10:44 Torque testing
12:40 How hot does a Brigg & Stratton mower engine get?
15:22 Clarifications and final thoughts

[@microcolonel]

That shape looks highly efficient.

[@denpo]

oh, come on mate, don't be such a gasket :P

[@negativeview]

Of course, he's an engineer, not an architect

[@WhenDoesTheVideoActuallyStart]

TPU is a thermoplastic, a bundle of unlinked hydrocarbon chains, so repeated cycling (Especially at high heat) is going to permanently deform it. Thermoplastics in general are awful for applications where creep resistance is important. Heat-treating plastics usually means forcing semi-crystalline polymers to crystallize, increasing the number and size of the hard segments where the polymer chains organize into tightly-packed formations. For instance, heat treating some blends of PLA can raise it's softening temperature closer to the melting point (Which is the point where the crystal-like formations in semi-crystalline polymers dissolve), making possible to use it in hotter environments like inside a car. But TPU is an amorphous polymer, it's chains don't pack together into such formations. Since there are no hard segments holding it together, it just gets softer and softer as the temperature increases, until the temperatures it's printed at, where it's close to liquid. As you said, you're just kinda remelting it to pack the chains (and especially the layer lines, which usually are the spots which score lower in shore hardness tests) tighter together, so it won't do as much as it would for a semi-crystalline polymer. An alternative that solves most of the problems you seem to be having with TPU is to 3D print a mould for a gasket, instead of the gasket itself, seal the layer lines of the mould with some wax, and cast some thermosetting resin into it - either a silicone or a thermosetting polyurethane. That way you can still prototype gaskets that are removable, but with a material that is suitable for the job. And there'd be no layer lines weakening the material. I'd also look into polyurethane resins anyway - you might think TPU is cool but I'd say thermosetting polyurethane is amazing. Not only can you find it in a wide variety of shore hardnesses, including hard and rigid PU (There are PU resins designed to mimick ABS for prototyping of injection-moulded parts), it can be quite strong for a plastic (I've seen resins that promise ≥80MPa tensile strength), and high-quality mid-strength PU resist almost everything (From UV and abrasion to most chemicals). And as it's a liquid, you can try mixing some ceramic powder or short glass/kevlar fibers into it to change the stiffness, although you'd need a pressure pot to squish the bubbles you'd inevitably introduce. The only problem is that it's a toxic 2-part resin, so gloves, masks, an accurate scale and a ventilated work environment are requirements.

[@nathanielreid4967]

Wonderful 👏👏👏👏👏👏👏👏👏👏

[@theeddies]

Great breakdown. Thanks! This is certainly not the right material for industry scale or critical applications. Creep resistance (I like that term) is going to be what makes or breaks it on my mower test for sure. From anecdotal evidence from the comments and my own testing and experience it can certainly take the place, at least in the short term, of other materials in some use cases. But never would I suggest that it would be the end of properly designed gaskets, RTV or other materials, especially for high heat/pressure applications. I would be interested on your thoughts on heat treating as it relates to this. I actually went back and forth over whether to call this heat treating or annealing. I went with heat treating because that is what the more scientific research on the topic which I found called it and it is frankly easier to understand for a video title, though some others referred to it as annealing. I used the term fully realizing it did not seem entirely accurate. In my experience you anneal to soften as with copper or after heat hardening steels. It is used to temper the material to a usable hardness. So what process is happening here do you think? It obviously increased its performance at higher temps slightly. My simple tests and several others I found that seem to show that. As you suggest since this is amorphous and has no real structure, is this extra heat deflection just that the layers are melted together tighter perhaps?

[@joshmyer9]

I love it when I click on a video with a thumbnail like this one and find a commenter leaving a brilliant, clear rundown of the background science and engineering. Thanks for sharing your knowledge and experience with everyone!

[@hayze3143]

what a response. Thank you sir.

[@emosavagerabbit]

I don't know what you do for a living, but I'm guessing they don't pay you enough. Appreciate the detailed response

[@Im_The_Slep]

That gasket has great personality

[@MicksWorkshop]

Nice! I'm glad you did this series, it never occurred to me that TPU could be so versatile.

[@theeddies]

Thanks Mick! I have gotten so many suggestions for other uses and so much interest in these videos I may have to a few more.

[@cmendla]

I have a 20 year old craftsman snow blower that blew a head gasket. When I ordered the head gasket, I ordered all the other gaskets I thought I would need including a carb gasket. Everything came in except the carb gasket. That seems to be on a perpetual delay (About 2 months or more) I have gasket material and exacto knives but if I don't get the gasket, I'll try printing it. I have printed stuff on my new ender neo using TPU Given what you said about density, I'm thinking about radically increasing the infill density. I can't imagine it would take too much material. As far as time, I can just start the print and walk away. Anyway, with the supply chain being erratic, this is an excellent tool in the toolbox.. or maybe gasket in the gasket box or whatever Thanks again.

[@pure6450]

I'm glad someone out there is doing this TPU deep dive, with less pages and jargon. Keep up the good work, your results have been interesting so far.

[@theeddies]

Thanks!

[@psgflier]

All scientific technical jargon goes right over my head anyway. You kind of answered my questions about whether the material would squish out of shape too much under compression of torque, or if it hardens up and fractures out under repeated heat cycles. Looks like it would work ok for most gaskets except head, exhaust and carb/fuel.

[@theeddies]

It is not going to hold any more torque than a regular rubber gasket without some sort of stiffening. I think for my climate, heat cycles will perform as good as rubber as well but in your part of the world I don't know. Going from -10 to 190F and back again over a time might make it as leaky as an old garden hose rubber washer pretty quick. If you think of anything you might want to try it out on, let me know. And no, I do not mean anything on the plane except maybe a cup holder, :-)

[@NeverSnows]

I'm loving the TPU series. Keep it up.

[@theeddies]

Hey thanks! That means a lot. All the best!

[@theeddies]

A few notes: ---Thanks @Bill Todd for the idea for this video. ---All these gaskets were printed solid with 100% infill. You can vary the hardness by adding less infill.

[@Muscleincharge]

GREAT VIDEO!! Thank you for sharing your insights, understanding and experiments.

[@theeddies]

Thanks!

[@ebptube]

Thank you for sharing your TPU knowledge! I am new to TPU and do some initial test of my own and I find that skipping the walls all together is the way to get a gasket with equal softness all over the area. So I print only concentric Infill and no walls or top-bottom layers. Even better is only top-bottom layers together without infill. I am using a higher temperature and flowrate to make lines melt together better but that is probably environment-printer related (CR-10 Smart Pro in a chilly room). Right now I am annealing a coupple of gaskets, they look nice glassy and smooth after 20 min at 200 C - high and fast, I will reduce to 130C next time

[@SeanCMonahan]

I've had good success enabling ironing on all flat surfaces (not just top surfaces!) when printing TPU. Granted, my nozzle tip is super non-stick (PCD), so this might not be feasible with brass nozzles.

[@skinife]

"If you haven't seen those other videos I'll put a link in the description. This one stand on its own but if you want a background those will help you out" This is the kind of thing I like to hear on KZbin. A perfectly complete video, but more content backing it up for those who really got interested

[@theeddies]

Thanks. This is kind of an evolving topic with each video raising new questions. But I want them to each sort of answer that question and be a complete thought. They are all related but are not saying the same exact thing. Thank you for noticing.

[@icesystem7]

Thanks for your work buddy! Very informative!

[@theeddies]

Thanks!

[@justRD1]

This is awesome!

[@theeddies]

Glad you liked it.

[@bluedraethbluedraeth6470]

Really nice series! Like it!

[@theeddies]

Thanks!

[@Mrshotshell]

When using a long metal sleeved thermocouple probe like that in ambient air the entire sleeve is acting as a heat sink and lowering the temperature readings somewhat even with the actual sensing part in the tip.

[@TheKnacklersWorkshop]

Hello Eddie, Great video... very interesting experiments... Keep up the good work... I am back in the workshop the second half of next week and will catch up soon. Take care. Paul,,

[@theeddies]

Thanks Paul. Looking forward to it.

[@FPVSlacker]

I've printed TPU gaskets for jar lids and for my ATV intake manifold. I've printed TPU chain rollers with inserted ball bearings. Soft feet for floor standing speakers, drone parts, etc... My 3d printer has become one of those tools that I won't be without.

[@theeddies]

Thanks John! I agree completely.

[@johnstrange6799]

That was great!

[@theeddies]

Thanks!

[@Oiirnplays]

well first off thanks you for runing these tests I watched one of the earlier vid on this subject, now secondly the fact that the pp shrinks with more tep lol

[@MattysWorkshop]

Gday Eddie, interesting findings, I think it’s a good thing, if the guy at home on the weekend and simply make a gasket to get the machine going and save money then it’s a bloody good thing, top job, Cheers

[@theeddies]

That's my thinking as well Matty! Cheers!

[@AutoworksParts]

I just started using Taulman alloy 910 to print various parts with. They also have a high heat version as well. Amazing strength and flexibility is like nothing else I have printed with. I think for the gaskets you are making this may be a great choice. Love to see your take on the filament. Great job on the videos. I am going to try annealing and see how I go

[@theeddies]

I have not done any nylon yet but it looks like my Sovol printer could handle it. For a stiffer gasket I think you are right, nylon would be a great choice. I have a product that I have been making in PETG but nylon would be better for it as well. Except for a dry box, any other tips using it?

[@joshmyer9]

FYI: when you hit a pay wall on an academic paper, try plugging the URL into sci-hub. If the URL doesn't work, you may need to search by the title or DOI (universal numbering scheme for academic papers).

[@theeddies]

Thanks Josh!

[@Skywave400LTDABS]

Hello. An interesting experiment. 3D printers are useful! : D Thank you my friend.

[@theeddies]

Thank you! Cheers!

[@tiger12506]

I have a moped that had an intake baffle made of rubber attached to it. I think TPU would be an excellent choice as a replacement! Thanks!

[@machinenutdel6764]

Hi Ed, I see you have been busy, a lot of research went into that !

[@theeddies]

Thanks, yes, I actually have a lot going on otherwise as well. Going to do a fiddlybits episode soon to explain. Apologize for not commenting on your last couple videos, I did watch them though, just on my TV while trying to relax a bit. Best!

[@machinenutdel6764]

@@theeddies That thumb nail picture gives me an idea, a bit of gold paint and a safety pin, could be a nice addition to my bling !

[@theeddies]

@@machinenutdel6764 I think I can see where you are going, lol. I knew you would get that pic😂. I actually have some gold/brass shiny plastic, I should print some brass knuckles like your brick layer ones. Can't think of what mine would say though...

[@illitero]

My mind keeps wandering to channels like Project Farm and how he could probably save a BUNCH in materials cost while still ensuring consistent results in his experiments.

[@theeddies]

If I understand your thoughts (and that is sometimes hit or miss in KZbin comments). I would agree this would be great for multiple experiments that involve removing pieces over and over while remaining consistent and intact. Thanks!

[@illitero]

@@theeddies exactly this, yes. It seems that it may not work for head gaskets (too hot despite the small size of the mower engines?) and exhaust stuff, but it shouldn't be unreasonable for everything else. I'd hate to see his expenses on constantly replacing things like these

[@microcolonel]

I am looking at 3D printing TPU for adding more vibration dampers on my (single cylinder) bike. O rings were one of the things I thought of, though I think you want to be careful with that, because surface continuity is an important part of how O rings work (there are engineering sims of O rings on KZbin which should show you the effects that I'm concerned about).

[@theghcu]

My curiosity asks about water pump gaskets. Your raw data seems to suggest a no-go, both for being a little high in temperature and for ranging in my experience usually between 35-60 ft lbs torque. A material that could make that kind of reusable gasket inexpensively and easily at home would open the possibilities for many appliance parts like dishwashers and washing machines to say the least. A guy can dream, I guess. Thanks for the content!

[@theeddies]

Hello, a water pump on an engine running around 200F is definitely getting close to the yield point at 35-60 ft lbs and is probably out of an engineers accepted tolerance spec. I personally would want something rated to at least 350F or so and able to hold torque at that temp. A water pump in an appliance or the like would probably be fine. Thanks for watching!

[@DarkLinkAD]

A rear diff cover gasket might be usable. I see these things leaking on trucks all the time, even after a fresh gasket replacement. Seems to be a quality control issue on the market. Also, mabye something small would be the carb on your lawnmower has a solenoid, that solenoid has as a gasket

[@deftdawg]

Snow's about to start falling where I am, did your gaskets make it through the season in good shape?

[@theeddies]

Yes, life got in the way of follow up but they all performed well. I still plan to do a video on them but there really were no issues. Thanks!

[@issanesheiwat1396]

I gotta buy myself some TPU!

[@theeddies]

There is a link in the description :-)

[@Xubor]

So is it a good Idea to 3D print gaskets for my espresso cooker? 🤔

[@theeddies]

That is a question you may have to answer yourself.🙂

[@Xubor]

Some sources say it is safe until 110 C°. I'll try :)

[@theeddies]

@@Xubor Give a shot. I think it will probably be too soft at 110 but it all depends on where on the cooker it is used. I did do a gasket for a slow cooker lid handle and it held up (the PETG handle did not) but don't think it got above 90.

[@Night__Rider__]

i want to see if its able to stand up to oil temps / being used as a oil pan gasket

[@theeddies]

The valve cover test on my mower will be near or at those temps.

[@forrestallison1879]

soaked?? or baked?

[@Blooest]

That heat treating process you're doing is annealing. You were actually probably hitting them a bit too much, 110C is the temperature I've always seen referenced for annealing most TPU blends. If you haven't been, burying them in sand when you anneal should help them maintain their shape.

[@Spectt84]

Cool idea. Along with showing what it can do, you should show what it looks like when used for something beyond its capabilities. It may make for a more eventful video showing it catastrophically fail. Maybe in an exhaust system that way there is no risk of damaging your engine. You could record how long it lasts and to what temp it reaches before it liquefies and drools out of the connection. Also, it may surprise you and last longer than expected before springing an exhaust leak.

[@theeddies]

Not a bad idea, I will see if I can come up with something. Thanks!

[@Spectt84]

@@theeddies can't wait. 👍

[@jamieforrester7108]

I'm curious if you think this material could be used to make bushings for things like body mounts

[@theeddies]

I don't see why you couldn't. They make them from polyurethane which is a similar material. I guess they would be a little on the hard side printed solid but you could play with infills to get the hardness or softness you want.

[@ABG_3D]

Firstly, I want to commend you on this video series, every video is very informative and I can see you are doing proper research before attempting anything. Keep up this fantastic series. I'd like to know if the general run of the mill available TPU can be printed and used for a throttle body gasket on a forced induction vehicle where the throttle body is mounted on a aluminum intake manifold. On a normally aspirated and carburetor application I can see this lasting quite some time and still be reusable, however with added pressure from the inside pushing outward, how would it perform and hold up. I would try it but my engine was recently rebuilt and cannot afford another rebuild anytime soon 🤣 The OEM gasket is a thin paper gasket (about 2mm thick) that is obviously not reusable, once the throttle body has been torqued down and you remove the throttle body after, that gasket tears and needs to be replaced. If one could use a TPU gasket, it would make life so much easier when servicing the throttle body because this specific gasket is becoming hard to source.

[@theeddies]

Thanks, that means a lot. I am currently working on another video that will be right in line with what you are thinking of. It should be out in the next day or so. I was not going to do another until the mowing season was over but in making the last piece (the valve cover gasket) I hit on an idea to make the working effect of the gasket a bit softer (to conform better). Also that gasket is 2mm thick and is metal cover to aluminum head, so it will get up to around 70C. And will get a bit of pressure as well. It will be an interesting test.

[@ABG_3D]

@@theeddies Really looking forward to the next episode, sitting here like a kid in a candy store not knowing what to do with myself lol.

[@helipad4050]

you should contact "CNC Kitchen"

[@hayze3143]

the dick joke got even funnier when you mentioned shrinkage lol

[@tentative_flora2690]

Is there any use in printing a lattice to turn the RTV silicone into a removable/reusable gasket?

[@theeddies]

If you mean making a mold for RTV gasket, others have suggested this and I have seen a few video on it. As far as it being removable and reusable, probably depends on the application. If you mean using TPU as an integral framework for the silicone, I am not sure what advantage that would have, at least in a hot situation, as you would still be limited by the properties of the TPU. It certainly could be something to explore, TPU is stiffer and seems tougher than RTV so adding that resilience to an RTV gasket would be advantageous in some uses. Thanks!

[@tentative_flora2690]

@@theeddies I was thinking of it being integrated. I keep thinking about how aggregates can change the structural properties of things like concrete or resin. And I think while the TPU would be the thermal weakness of the gasket it wouldn't necessarily be as weak as the TPU alone. And with 3d printing, you get to shift and control where those weak points are depending on the application.

[@theeddies]

@@tentative_flora2690 An interesting property of printing TPU is by varying infill and flow rate you can vary its stiffness, in effect lowering, or maybe even stiffening slightly, its Shore hardness in the overall part. Mixing infill density within certain areas could produce a composite of soft and hard like modern composite gaskets. This is possible with modern slicers, though it can be difficult to set up in practice. I do it with my lathe stops to some degree. The centers have 7 perimeters(walls) while the top and bottom layer have only 2. This is done for aesthetic purposes on the outer shell while retaining the strength of the center and making the teeth solid. The process would be similar. One could also pause the print and change filament or perhaps more interestingly insert a stiff piece of some material to change the performance of the gasket in any number of ways like a composite head gasket. The possibilities are only limited by the thermal properties.

[@luckgrip252]

If you're interested, you can look up a channel called CNC Kitchen. There is a young pal who is doing a lot of 3D printing experiments including the 3D printer material annealing. Might be helpful in a way 🙌

[@theeddies]

I have been watching him for a while now. One of the inspirations to do some of these tests. he is certainly better at it than me. Younger too, lol.

[@luckgrip252]

@@theeddies Yeah! He is cool and pretty informative. I'm watching him for my little projects also 😄

[@TiagoTiagoT]

You might be interested in swapping some notes about testing procedures and results with that CNC Kitchen guy

[@theeddies]

I would love to talk with @CNC Kitchen about some of his procedures. The work he does is far and above what I am doing.

[@Fantaman900]

2 stoke feul has oil in it, can be the cause of it curling. Mill gasket comes in contact with oil and grease. Valve gasket comes in contact with 90c oil at operating temperature. You really need to dunk TPU in oil and see if it gets as nasty as modern tools with rubbery over mold.

[@theeddies]

That's a good point. The valve cover gasket will answer a lot of that. Thanks!

[@danharold3087]

The Briggs OHV engines use 2 or 3 square section o-ring like gaskets to seal the intake in places. These get brittle with age. I would like to see you make these.

[@theeddies]

Hello Dan. Do you mean the intake manifold to cylinder head o-ring for instance? The one on this Craftsman is a square cut I believe.

[@danharold3087]

@@theeddies Yes the profile is square. Briggs & Stratton Part# 691917 SEAL, O-Ring Note: (Intake Elbow) On the 31P777 there are 2 on duct between the air cleaner and carb and one on the other side. Not 100% sure on the 3rd but I recall seeing ones that were cooked. It would be great if we could print these and replace them while we have the carb off. Clean air longer life.

[@theeddies]

@@danharold3087 it might not be the next video but I am on it, lol. I want to know as well

[@amtechprinters3339]

Two thick class sheets, some spacers what are e.g. 2mm thick or what ever needed to be Slightly over sized height but inward scaled in XY prints, place them between sheets, add some bricks to weight and thorw it to oven? Test slowly temp what needed so it will settle nice and flat as that glass sheet

[@theeddies]

Sounds like you have done it before, lol.

[@amtechprinters3339]

@@theeddies I have seen similar method some other applications and see it would work great to flatten sheet prints :P

[@theeddies]

@@amtechprinters3339 That is a great idea. I print TPU on plain glass and the bottom of the prints are shiny glass smooth and completely sealed, Your method would likely produce that on the top as well. You could even flip it a few times if necessary to equalize the effect of any gravity sag. I might test this. I would need better temp control for the oven (or a better oven). The reason that oven is in my shop is that it was not holding consistent enough temp in the kitchen. But yeah, that is something to try for sure. Thanks!

[@amtechprinters3339]

@@theeddies Id like to see resoults as well, I have only kitchen oven, would test if seal that into heat resist bag / container even there would not be thst bad fumes.. but never know

[@vanishingfox1339]

Tradeoff some length for girth. lol couldn't help it.

[@stevenhitchcock4278]

What about extreme cold???

[@theeddies]

According to what I have read, it does not freeze or harden until around -32C. But that remains to be tested in the real world.

[@nsmith0723]

i think the obvious use is colored gaskets in custom projects. IDK how many times I've seen a slick look get ruined my an ugly gasket.

[@redrob2230]

So a little bit of shrinkage, and a gain in girth. Not a bad trade off

[@redrob2230]

😉

[@theeddies]

Never gets old, lol

[@andyruse4670]

I think that so long as where it’s used, doesn’t get so hot that it liquifies the plastic. I’d take that any day of the week over RTV. I’ve worked on stuff where the gaskets aren’t unobtanium, just where the last guy decided to save a few bucks by using a tube of RTV. Screw people who use that stuff, it works perfectly fine, but the next guy is gonna spend a half hour with a razor blade if you go nuts.

[@theeddies]

I took apart an old Triumph engine on video a few years ago that was sealed with white silicone bath caulk. Still easier than removing RTV, lol.

[@WhenDoesTheVideoActuallyStart]

Technically, amorphous thermoplastics such as TPU are like glass, they're always "running" like a liquid, just very very slowly at room temperatures/pressures. Think of a spaghetting bowl with a congealed sauce. Add some heat and pressure and it'll eventually creep into a thin sheet.

[@ZED-PV]

I'm guessing they won't do for cylinder head gaskets? I couldn't imagine 3d printing gaskets for 30ton trucks 😂😂

[@theeddies]

No, I would not try them on cylinder heads or any critical components of large vehicles. Lots of other uses though.

[@Rippthrough]

15 minutes is nowhere near enough to form microstructures between the hard and soft phases in TPUs. I've been annealing printed TPU parts for production cars for years and it's very rare they'll get anything less than 24-48 hours at 100+c

[@theeddies]

Great info, thanks!

[@Rippthrough]

@@theeddies No problem, it's worth doing, the heat resistance generally rises by 10-15c before the stiffness drops off, and the resilance and tear strength change is huge - it can be a third better in softer TPU's

[@theeddies]

@@Rippthrough My biggest problem is temp control, really need a better device for annealling. I would have preferred to let the parts soak longer but maintaining consistent heat was a bear.

[@GoingtoHecq]

Those are some weird gaskets.

[@abcanimal]

Mam, that's a "hard" way of making a gasket! 🤣🤣🤣🤣

[@theeddies]

LOL

[@geist-2111]

these are some strange gaskets 😂

[@GoatZilla]

Kind of seems like you should be 3d printing molds for gaskets instead of the gaskets themselves...

[@theeddies]

Other than higher heat applications (over 100c), why does it seem like that to you?

[@GoatZilla]

​@@theeddies Quality of parts. It's probably easier to get a higher quality mold printed with ABS (and smooth it) than directly try to print the part in TPU. Ability to vary the properties of the gasket. TPU you're limited strictly to TPU filament offerings.

[@theeddies]

@@GoatZilla Surface quality does not matter and performance is on par with many rubber gaskets. This is not an industry solution. It is for home shops and speciality circumstances. Molding is certainly an option but for my purposes it is just an extra step. Plus TPU filament is available in different hardnesses, if you really need different properties. It is not meant to be a replacement for any other method just another tool.

[@GoatZilla]

@@theeddies Depends on the application. So making a mold is an extra step, but all this annealing stuff is not an extra step. I don't think I've seen 70 durometer TPU filament. Even if it exists, it would be a challenge to print with.

[@theeddies]

@@GoatZilla @GoatZilla Filaflex makes a 70A. I don't think it will be bad with my direct drive but I will find out eventually. And it is debatable to me whether annealing is even worth it. My tests really only showed a significant improvement above 120c and I would not run TPU that hot, so the test was a wash really. But I would not have known had I not tried. It does seal and smooth the print but again not necessary in most cases. Like you say just depends on use and what you want. Making molded silicone gaskets is another whole art really. I am just testing the limits of this stuff. So far I think it is faster and easier for a range of applications. Even at 85A or 90A it is still soft enough to seal a carburetor. And by making the gasket maybe 1.5 or 2 mm thick you can vary the measured Shore hardness by using a lower percentage infill. At 50-75% infill I bet could get the measured hardness below 70 and still have enough top layers to seal...and that just gave me a whole new video idea. Thanks!

[@jkrules4161]

Bruh

[@WolfgerSilberbaer]

He calls it stupid and juvenile, but he keeps playing with it. Can't stop touching it, really.

[@jkrules4161]

Bruh

[@jkrules4161]

I like your channel tho