Perhaps your results will be improved further if you used a polymerizing oil such as tung oil or linseed oil. After your print absorbs the oil it would harden and seal up the print preventing moisture from being absorbed into the print.

I didn't skip a second of this. This research is great. I've always took my nylon out of the vacuum seal and went straight into a 170 degree dryer for 4-6 hours and then right into a spool dryer and print through a bowden tube all the way to the nozzle. If you have a heated enclosure and your printers electronics are outside of it I recommend annealing inside the enclosure with the supports. From that point I'm thinking I should immediately cerakote and bake the nylon part right away. If I let the nylon filament sit for any amount of time in the atmosphere the layer strength went bad fast. Thanks for all the hard work. Increase the oil temperature to 212f or higher??

You're doing so much good in furthering everyone's understanding of material science and how it relates to filaments. The technical side to filaments is so fun to nerd out on. Keep it up!

In wood working they use a heat activated resin. A popular brand in Cactusjuice. The wood is submerged in the resin then placed in a vacuum chamber. Sometimes it is cycled between vac and pressure. Once the wood stops bubbling it is removed and wrapped in foil. It is then heated to about 250F until the resin is cured. I wonder if a good wipe down of the exterior of a 3d printed part would maintain it's measurements. Another process is with Boiled Linseed Oil instead of resin. I allow BLO wood to air cure. I've never used heat cured resin.

That was a really good simple explanation of young's modulus and the yield point.

Would be super interested to see this test repeated with the parts soaked in a hydrophobic liquid like what can be applied to tents, outdoor furniture, etc. Great work, as always!

That’s a clever idea…

Fantastic tests and results, looking forward to the continuation

Have you heard of stabilizing resin? I've seen it used to do basically the same thing for woodworking or arts & crafts. They use a pressure pot or vacuum chamber to remove air and replace with resin and then they cure the parts in an oven to harden it.

Very interesting information! I really hope, YT doesn't nuke this channel. There's so much knowledge on here. Have you ever really tried ASA? I overlooked this material, because of needing a heated chamber to not warp too much. However it has very good mechanical properties. Impact resistence seems to be good, heat resistence is great, it has almost no creeping and is UV resistent.

Great video! We absolutely need more of this in the community please keep doing more testing like this!

excellent information as usual. always the most interesting research from this channel.

Really cool primary data. Keep up the good work!

I would love to see a clear lower using something like clear pctg / pc /xt, cnc kitchen has recently uploaded a video on how to get glass like quality from a fdm printer with thick walls. I think it would be a good idea to be able to show people where the wear spots are and you can even see internal stresses.

Excellent video! As always!

Fantastic testing, thanks!

Love the video. Looking forward to the next. Would love to see if there is some other substances which would impregnate the nylon (or at least provide a durable coating) to prevent moisture absorption.

You should consider doing this in the microwave with carbon fiber filling. Carbon fiber filled materials can convert microwaves into heat, thus providing a convenient avenue for controlled heating.

Fantastic research!!

Got a great science lesson in materials today. Most excellent!!!

nice descriptions of youngs modulus, this is as good as a colledge course :)

Makes sense. Maybe try using a drying oil like linseed to seal any pores or gaps in the material?

Consider a alcohol bath baseline for testing. Ethyl Alcohol will quickly repel any moisture content...

The pressured/forced impregnation is a great variable. My brain is in search mode for additional materials to test. Fundamental advancements in the materials first though, then incremental.

You should try linseed oil, it’s a drying oil and used to season cast iron cookware to make a non-stick coating. The oil molecules dry to form a polymer. Extremely tough and slick. Maybe anneal in linseed oil, wipe “dry”, and let sit for a week or two before testing.

You should try nylon 12 instead. Has far lower moisture absorption. Would be interesting to compare.

Damn good work! Yes, I'm a nerd, because I want testing and facts, especially when coupled with thinking outside the box.

Vacuum drying may help. Vacuum annealing may help too. You can use a pressure cooker and a cheap vacuum pump. Vacuum may also allow more oil to be drawn in on those samples

here in dry colorado brittle zip ties are a real problem.... that i never had on the east coast..... Since the most strain occures during installation I soak them in warm water for a few minutes before installation. I'll go set up a storage test now... oil treated vs not, and check in a few months

Cool. Very interesting to see these results. Thx for the vid! BTW, what’s the best way to support your channel? Utreon?

What do you think of using a hard watery paint or varnish that acts similarly to tung oil or boiled linseed oil? I think that the penetrating action would keep water out even with scratches and gauges, and the hardening action would maybe either increase wear resistance or strength/rigidity. There's this stuff called cactus juice which is used to stabilize wood and other natural materials, and has a curing temperature of 175-205, within the range of Nylons.

15:16 Your explanation about oil being a competitive plasticizer (displacing water) makes sense, but I suspect that this trend could otherwise be due to differences in crystallinity (i.e. annealing degree-of-completion). Oil has higher thermal conductivity and higher specific heat than air, so it's possible that the samples in oil were slightly more crystalline, due to somewhat more effective annealing.

Good video 👍

Some type of sealer, like a dip in thin cyanoacrylate might work but it'll mess up all the tolerances between parts.

This has me wondering how the parts would hold up if coated in spray on silicone lubricant. Although slippery, it is remarkable in terms of waterproofing. For something like an AR lower where friction is largely irrelevant it could be a viable means of prolonging the effect of the aneeling.

I suspect the oil is only surface treating the nylon to create a water barrier. the heat and pressure annealing might force it in deeper but I dont see it working any better and might even make it weaker. it might be interesting to try the high temp and pressure annealing with light weight hydrocarbon gasses to see if new polymers are formed.

@Hoffman Tactical 👉 It would be interesting to test coating test pieces with (a) Renaissance Wax; and (b) Turtle Wax 53409 Hybrid Solutions Ceramic Spray Coating.

In addition to adding pressure, it would be interesting to see what "penetrating oils" like kroil oil would do. It may be possible to force something that dries/cures to be water resistant into the nylon, like certain wood finishes, after diluting with a solvent. .

Couldn't you theoretically do the same thing in a vacuum chamber? Wouldn't the moisture vaporize under vacuum and then the oil would absorb back into the pores once it returns to atmospheric pressure?

Can you do a video on your modified dehydrator that you dry filaments in? Specifically how you modified it to run continuously?

Thanks for the tests! Some thoughts, Please test the PA12-CF with PA6-CF directly from Polymaker as well. It'll be a good and more direct 1:1 comparison and will help compound the fact that moisture affects nylon. Also, perhaps test a super strong nylon filament, such as atomic nuclear nylon with moisture as well. I know it hasn't the best layer adhesion, but it will be interesting to see how moisture affects a super stiff/strong nylon to begin with.

Polymaker pla pro in terms of ease of use, mechanical properties, and price is a damn powerhouse. Yeah heat resistance is a problem but there are some remedies for that.

So basically what you're saying is this nylon blend with 8-10% CF rather than GF would be superior due to the added rigidity, better bridging, and better surface finish :P Some form of a thin clear coat of paint/epoxy seems to be the answer since from this baseline testing oil just isn't enough to get the rigidity of PLA+. I am curious to see the results of the PA12 CF nylon. Hopefully it's impact resistance isn't too low compared to pla+ or nylon 6 or 6/6 to be unusable. Impact resistance and layer adhesion are usually the points of failure with FDM printing in general.

Have you tested resin impreganted prints? I've been impregnating receivers but haven't been able to test how much strength it might add.

Try using a pressure cooker as a vessel. Warm up the pan of the cooker with oil in it, then drop the parts in. Cap and hook up to an AC Vacuum pump. Vacuum down to .500 microns. then allow to go to atmospheric. Attach nitrogen source and pressure to cooker max. Leave for the time you want. Pressure cookers are handy for industrial uses.

try annealing in Argon Atmosphere this is the proper gas for annealing Nylon.. do you have the temp increase Data and max temp hold times with decrease temp data?? first time seen some one trying to anneal Nylon correctly also sand support for complex shapes to help hold it's form works nice :) doing it in Argon rather then the oil preventing those pores and valleys from filling in, this is why the air one will be stronger at first these are getting filled in but there is still water in the air effecting the material as it exits those pores as well, also a lot of oils still absorb trace amounts of water soooo you might want to be aware of that (hygroscopic to a point before they start separating) any who if you don't have that data I should have it around here some whare

Could you anneal and soak in one of those hydrophobic materials for nylon fabrics?

Commenting mainly to sacrifice to the algorithm gods. Very interesting. Thanks, Tim.

Have you looked into salt annelling(remelting) ? It's said to improve a part drastically. Would love to see if it would be better or worse than air or oil annelling.

you beat me too it, I was going to suggest trying the PA12. it would also be interesting to see polymaker CO PA. a couple thoughts on this setup....I'm no expert on nylons and moisture absorbsion, but I thought I read that the water that is absorbed forms a chemical bond with the nylon which acts as a plasticizer which is why the toughness seems to increase as moisture is absorbed. so when the term "absorbed" is used I guess the water is being chemically absorbed. I wonder how the oil is "absorbed" in the nylon. my guess is that it's mechanically coating the nylon and preventing water from being chemically absorbed of that makes any sense.... just hypothesizing here. another though is.... does the sample size (physical size of the sample) here matter? if you have a 1" thick slab of printed nylon, is the inside of that slab absorbing moistire? or are the few mm outside layers absorbing and protecting what is inside. maybe print a 1-2 mm sidewall thickness container, print and dry a sample, put inside the nylon box for a few weeks, see if moisture works it's way through the box or not? I would imagine a lot of cross sections of reviewers are thicker than your test sample, maybe the inner portions of thick members stay dry and stronger

Hoffman, a question for you: One of the key benefits on annealing is the layer adhesion increases dramatically. Have you seen or done any studies on that? I think post-anneal strength would be a big factor for print orientation.

We’re gonna need a chemist to figure out what kind of oil might actually improve things. I have a feeling the stuff is not likely to be safe to handle.

Do you have a pdf or doc of this data and graphs for us to do some experiments ourselves and compare data? What was the humidity of the day? I live in a similar state and the humidity is similar. Would a dry room make a difference? Would you say your prints were exposed to sunlight while drying/absorbing? Would a different weight of oil make a difference you think?

13:16 Having a small plastic deformation limit is not particularly a good thing because that means when it fails, it fails quickly. This means there is little to no warning before a catastrophic failure where as a material that has a greater ultimate to yield ratio will fail more safely.

Oil can degrade some plastics. I used to work in injection molding. One of the major quality concerns was lubricating oil, grease, or hydraulic oil leaking onto the chutes or conveyors that carried the molded parts out of the machines.

I like how he printed this out on a 4x6 shipping label printer :)

Possibly dumb question, but would you be able to slow down the moisture absorption through a coating of some kind?

Tim, are you using a dryer set up for the Nylon like the Sunlu S2?

Has anyone tried using something like Cactus Juice (polymer) to eliminate water absorption? It's normally used to stabilize wood. Normally you put the dried material in a vacuum chamber with the cactus juice and then cure it in an oven at 220F.

Thank you. Exceptional. Is the a place to donate? This work is more than a couple hardware kits worth. Confirmed my own informal observations without having to do do my own testing. I really feel I'm not going to get the properties I want, until I liquid cool my steppers, move most electronics outside the cabinet and go with PEEK printing. There just isn't anything in the lower heat ranges with the intersection of heat rejection, strength and toughness.

thinking about linseed oil but then though what would be better than an oxygen activated resin would be a 2 part epoxy. put finished prints in the more liquidy/less viscus 2 part epoxy for an hour or two, then paint on the freshly mixxed 2 part expoxy, maybe with a drop of extra hardener if u have one of those types with the hardener catalyst seperate. just thinking, very good research and presentation.

would be interesting to see what happens when you use a Heated Vacuum chamber to anneel the nylon in oil. i dont think pressure helps a lot to impregnate it. i would rather use a vacuum Nontheless, thanks for your tests :) great video!

I wonder if the oil being impregnated into the nylon also makes it slipperier, kinda like how adding graphite into bushing makes better bushings

Maybe I missed the detail, but did you do anything to the PLA pro with humidity or not? I don't think PLA is a sponge the way nylon is but I wonder if it would have a measurable effect.

My main issue with these types of test (and well most studies in general) is the lack of ability to eliminate or properly account for possible causes like UV light or the extra heat cycle degrading the material.

Okay I’m actually incredibly stupid and can’t seem to follow anything in any video that Tim explains the technicals. He’s probably doing a fine job but like I said my brain can never keep up with graphs and such. I have multiple of Tim’s lowers printed out of Push Plastic CF Nylons. I’ve never annealed them. They have been sitting inside and rarely put any rounds through so far. #1 Would annealing them now do anything helpful or is it something you have to do immediately after printing? #2 is it bad if my nylon isn’t stored in a dry box but I always dry it hours before printing and seems to print beautifully if done that way. #3 is annealing 100% needed for my lowers.

Want to test, do non polar solvents dissolve plastic, how much each plastic dissolves, is there a non polar solvent designed for and effective at not dissolving plastic? Thanks

Have you tryed Nylon 12? It absorbs less than half of moisture compared to Nylon 6

is polymaker pla pro better than the esun pla+? wondering what the meta is at the moment.

There is a general misconception how the water absorption of nylon/polyamides works, that's why the oil idea failed. Nylon does not have "pores" that trap water, nylon chemically bonds with the hydrogen atoms of water molecules. So we look at many many magnitudes of size difference than what was expected to happen. The "oil annealing" likely only showed a wet-difference because the oil was still coating it partly, reducing water uptake so the "oil samples" were just more dry than their competitors at the time of testing. For the best strength of mechnical parts, you could try a laminating approach. Print nylon and another hydrophobic material in alternating layers. This sandwitches the nylon into the print making it almost impossible to absorb water in the projected lifetime of that part. The delay in printing should be acceptable, as the whole layer can be printed with one nozzle each time.

These FDM fiber composites appear to me to put additional shear on the layer interface. Lots of tests on KZfaq verify tensile strength across layers, but what about bending loads? If you make a beam with the layers stacked vertically, each layer is inelastic and they'll try to slip against each other in shear. Like an indoor plywood left outdoors so the glue becomes weaker than the layers, bending the sheet will cause the layers to delaminate. A bent-till-broken Nylon-CF piece can actually look like broken plywood. The strong layers actually concentrate this shear into the layer interface. So I'm curious how a bending test would go for wet and dry nylon.

You need to write a thesis on 3D printing and get the PhD you deserve.

Giving the nylon some sort of coating to protect it from moisture might be worth trying.

What machine are you using to dry your filament?

Can you clear this up for me? Is moisture intrusion a problem with all plastics or just non homogeneous 3d printed parts? Furthermore, once a part is annealed, is it still susceptible to moisture? Lastly, would a simple coat of paint help this issue?

Something to keep in mind is that the water absorption of nylon is on a molecular level - we're not talking about (even microscopic) 'drops' of water - we're talking about H₂O MOLECULES. Which are up to hundreds of time smaller than a typical long chain hydrocarbon oil. Oil isn't 'taking the place' of water, but it may be physically blocking it from entering molecule sized imperfections in the nylon polymer chains. Also, water is a highly polar molecule. It has strong (+) and (-) ends, which allow it to 'stick' (but not make a molecular bond) to things. Oil is a highly **NON** polar molecule. This is why water and oil don't mix and dissolve in each other. So... oil isn't going to "take the place of" potentially absorbed water. It may perhaps only minimally physically block it. This can also be bad if you use solvents for cleaning, you may also be washing away the oil that was physically blocking the areas where water could be absorbed. So (2)... a 'thinner' oil may in fact be better. WD-40, originally named for it's "Water Displacement" properties is nearly as thin and runny as water. Might be worth a try. Something like kerosene or naphtha may work similarly, too Also (2)... Even though (plain) annealed nylon is 'weaker' and more elastic than PLA Pro it may still be "good enough" to function safely in a firearm. Wet, but previously annealed, nylon may have a high enough impact resistance (due to it's increased elasticity) to make up for it's lower tensile strength. I can't help but think of brand name commercial polymer framed firearms - they use glass filled nylon almost exclusively. There has to be a reason for that. Granted, injection molding produces a far different final product than additive manufactured, 3D printed plastic and most of the injection molded firearm frames use something closer to nylon 12 rather than nylon 6. Nylon 6 is much more effected by moisture than nylon 12.

i wander what oil + vaccumm chamber would do

Okay, but does oil annealing actually improve the longevity of 3d printed parts? You should do a test where you take an already nylon printed oil annealed part and expose it to the Tennessee humidity over a week or so.

Have you tried annealing the PLA+ to see if it increases the heat resistance?

Are you gonna try “Liquid-Glass” Sodium Silicate?

Kind of makes me wonder what the results would be if you Treated printed nylon part with penetrating epoxy rather than oil? I am thinking about printing some parts for my boat, but worried about UV for PLA+ and moisure for Nylon.

Aye u forgot to say the area under the stress-strain curve is equal to the toughness, or energy required to break the material. I wonder if the wet nylons are actualy tougher somehow (the areas in ur graphs looked slightly larger).

I would doubt that the nylon is absorbing the oil like it does water. I think nylon absorbs water on a molecular level and if that’s true then the oil molecule would be to large to absorb into the nylon. I think that oil annealing in is just drying the nylon out a little and then coating it. If you could find a way to completely seal the nylon from water absorbing into it then I feel it would be a good material.

I have idé about anealing nylon for stronger parts i believe you will find highly interesting. On what platform can i get in touch with you to discuss it further?

Humidity is realitive to temperature so a hot day at 30% might be more water than a cooler day at a lower temp. Also you need about twice as many samples before your stats really hold any actual weight. The smallest set should contain no less than 6. I know it's a pain but you'll actually get far clearer data. So the oil doesn't seem to actually degrade the plastic. Instead just isn't as strong an increase as much as letting it be dry. Those close numbers would be better if you used many more samples. However, it is still understandable why you wouldn't you've getting what it is. Send me a message if you need a statistical experiment designed is be more than happy to help you if that's something you need.

Try linseed oil. It hardens as it is exposed to air. Be carfull though if you do. It generates heat as it reacts and hardens and might get hot enough to melt the part. also where the spontaneously combustion oily rag myth comes from.

Can you use a tabletop resin to seal nylon against moisture?

Have you tried Polymaker PA6-CF? It seems to be one of the better Nylon blends on the market.

I have considered polypropylene carbon fiber but it might have too much plastic deformation.

I was just reminded why I did math in school 😅

While injection molded nylon is “annealed by steam” to improve strength, 3dp community is trying to dry it in order to keep it brittle is interesting. Usage? Or layer adhesion issue?

Tell me you're an engineer without telling me you're an engineer.....

Wondering how much of a difference in test results there'd be for PA12CF? I sell brackets for the land surveying industry and have a current order for Puerto Rico, was wondering if annealing would help with the longevity of my parts, or just be a waste of valuable material testing things out.

WHy wouldn't you use PA12 nylon? It's better in every single way.

does the pla pro absorb moisture and become weaker as well?

so if i watched this correct, nylon printed parts will weaken when exposed to open air to the point of being less strong than PLA+?

At the cut around the 10.5 minute mark he goes full nerd mouth breather mode.. I like that better than the try-hard before then

Could have used WD40. Water Displacement, 40th formula.

What temperature did you anneal the nylon in the oil bath at?