Resin Casting: Pressure vs Vacuum

[@JimsonMakes]

I’ve given up trying to de-gas resin in a vacuum chamber, I just use the pressure pot now for getting rid of the bubbles. The vacuum chamber is great for degassing silicone and of course stabilisation. Cheers Jim

[@peterbrownwastaken]

I agree with you. It's so much more reliable.

[@xzendon]

What would the effect of pressurizing the champlber with pure oxygen be? Especially if you had some kind of agitator in there to mix in as much gas as possible. Would you get a hypercombustible brick of death? Or just a block of plastic that slowly seeps O2?

[@ExaltedDuck]

One advantage of vacuum degassing is that the material can be degassed and then poured in molds that might not fit in a chamber of either variety. Having vacuumed degassed stuff like this more than a few times, I'd recommend a container wide enough so that the resin doesn't fill it more than 10-20%. I just leave the release valve open and cover it with my thumb until the material almost overflows, then pop my thumb off until the pressure goes about halfway back to normal (without a gauge, just let the material settle down to about it's original level). But given the results of this video, it does appear than pressurization might be the easier way to go if the mold does fit in the chamber.

[@JimsonMakes]

Yes degassing resin certainly has a place but for the sort of work I do the pressure pot works better. The temperature has to be right for degassing to work and it needs to be done quickly. There is a danger of boiling the resin under a strong vacuum, which I think is what happened to Peter in this video.

[@Oomuu]

Looking at it from an electrical engineer point of view, you could have a cheap 4 dollar ebay IR light (or a simple laser/receiver pair) shine on a receiver and position them right above your inner bowl, when the stuff foams above the bowls height it will interrupt the lights ability to shine on the receiver and have that communicate with a pressure switch (solenoid?) of some sort to let some pressure back in so you can just run it continuously without having to worry about it. You could make something like that with audrino for around 20-30 bucks and I dont see why it wouldn't work for everything including resin. The constant cycling of pressure>vacuum>Pressure>vacuum would work perfectly to remove all the air if done constantly by allowing the bubbles to collapse and pop instead of a constant vaccuum/foam mess, then follow it up with the pressure chamber thing should smooth it back out quickly before it drys....and should make your resin almost perfectly transparent.... or a strong pump paired with the smallest possible chamber with the pump and pressure timed in short intervals to keep repeating high>low>high>low pressure to pop and draw out the bubbles a least 3 times faster then in the video....and the short intervals will stop it from foaming over if timed correctly.......then the sudden pressure when then after, it is put in a pressure chamber...should make it even more clear than your clearest result in this video..

[@johanneshalttu9047]

Dental technology student here! We use best of both worlds for gypsum and silicone, first vacum mixer for 30sec to 1min and after that we pour the cast on a vibrating table and put the cast in the pressure pot for curing :) Thanks for your awesome channel, i love it!

[@SeraphimKnight]

Under pressure... dun dun dun du-du- dundun...

[@bunkertons]

👏👏👏

[@peterbrownwastaken]

this makes me happy. You know I long I searched for a font where the R had that swoopy bit?

[@TripleGatan]

@@peterbrownwastaken worth it

[@SeraphimKnight]

@@peterbrownwastaken It worked, I only glanced at the thumbnail and had the song in my head.

[@josuelservin2409]

@@peterbrownwastaken, We appreciate the effort.

[@nessagirl1911]

It would be awesome if the resin would set as the foam, or solid on the bottom and with foam on top. It would look like blue beer.

[@peterbrownwastaken]

We were both hoping for that. I MIGHT have to try that in the future, but I sort of can already do that with the lava effect.

[@rastas000]

OR, add a little moisture to a polyurethane casting resin... Makes a great foamy top for a beer art piece.. Such are the things one learns from ones mistakes!! (I used a moisture sodden stirring stick to mix my resin)

[@smash5967]

I wonder if using a faster setting resin might allow for that.

[@minecdiamondcrafters]

You should try getting it all foamy and then turning off the pump to hold the foam where its at and the letting it cure

[@SixKoi]

He's done that with the resin that boils when certain dyes are mixed with them, if I remember.

[@Sorarse]

The problem with a vacuum is that the boiling point of any liquid falls with a drop in pressure. I don't know what the normal boiling point of the resin you were using is, but it's conceivable that it is at room temperature when you drop the pressure that much, and the resin was actually boiling, which is why you got so many bubbles. It's the same principle that creates cavitation behind a boat's propeller.

[@HarnealMedia]

That's a dramatic way to prove a point that resin casters have spoke of for years. Very good job Peter. It made for an interesting result

[@peterbrownwastaken]

Thanks!

[@AaronTheBlackDragon]

I really would love to see if you could make a resin foam cast from your vacuum.

[@ShineHatfield]

He can, he just needs to use a fast-cure resin. Edit: resin, not reason lol

[@MusicFurler]

AaronTheBlackDragon he's already found that he can make a foam looking resin. He calls it Lava.

[@bushwoogie]

@@MusicFurler that's a little more sponge looking I can see the value In a foam like casting that looks like the resin in the vacuum chamber.

[@Karasuraven0395]

I dont know why but seeing the resin foam up like that was kind of satisfying. I could honestly watch hours of just that lol

[@JLK89]

Vacuum is below the alcohol dye's vapour pressure. Don't add it if you want to use vacuum.

[@JLK89]

@@LoganDark4357 only in the US

[@himynameishelen]

@@LoganDark4357 But it's literally called "English" so maybe respect that English people spell things differently to you and don't be rude.

[@JGnLAU8OAWF6]

@@LoganDark4357 are you sure? More than a billion people in the world speak english...

[@JGnLAU8OAWF6]

@@LoganDark4357 en.wikipedia.org/wiki/List_of_countries_by_English-speaking_population

[@JGnLAU8OAWF6]

@@LoganDark4357 not only UK speaks british english -_-

[@RebeccaFyre]

This is exactly how Games Workshop make their ForgeWorld models. Using silicone moulds and black resin, it gets degassed twice, 45 seconds each time then left to set for an hour before being removed, I did the job for 2 years :)

[@nohowahay4179]

Hi Atomfire, how did they degas it?

[@RebeccaFyre]

@@nohowahay4179 with a large vacuum chamber, the size of a school dinner tray(ish). Suck the air out leave it for a min and degas, then do it again, degas then send it off to the other guys to take the parts out the moulds

[@nohowahay4179]

@@RebeccaFyre Thanks for the quick reply. So they used a vacuum chamber instead of a preassure pot.

[@RebeccaFyre]

@@nohowahay4179 yeah just because the moulds are big, as you can imagine with some of the figures.

[@nohowahay4179]

@UCdW-U0aqDxAknXcxnVMPY_g Thanks again. Just wanted to know. So if you do it right you can indeed manage to degas with a vaccum chamber and the test above is just somehow not done correctly.

[@stephss]

Art resin is by far the most bubbly resin I've used... so good choice on resin for the demo. #artresin

[@rastas000]

Depending on the thing I am casting I have used the vacuum pot to degas the silicone and then cured under pressure to reduce deformation if I am casting a clear part (lens covers) that I want to have crystal clear by curing under pressure... An understanding of Boyle’s Law helped me work out what was happening.. Loved the demo..

[@seriouslyintolife]

Peter could you try a small amount of fast setting resin in the vacuum chamber and see if you can get it to set as foam?

[@rallekralle11]

i wonder if it'd implode when the vaccuum is removed

[@fishsticks2965]

@@rallekralle11 it would not ^^

[@Fitz1993]

Would it even set in the chamber? What with the constant movement and lack of oxygen? I might be comparing resin to concrete a little to much here...

[@noname_atall]

@@Fitz1993 resins, generally, don't react with oxygen to solidify, they either react with themselves thanks to a catalyst or one part reacts with the other. so at to the constant movement, it will slow down as the resin get thicker. things like gelatin don't set while moving because they rely on reversible interaction between molecules, resins rely on permanent and not normally reversible chemical reactions.

[@Fitz1993]

Oh wow, thanks for that response, thats pretty fucking sick. So what will happen / potentially happen to the cavities left if you were to set resin in a vacume chamber? I guess nothing if the cavities are sealed in resin?

[@sinphony9835]

Peter's videos are the highlight of my week. They just make me happy.

[@SparkieNeisti]

I wanna see that resin foam set like that! Looks awesome.

[@BitchyBoxxy]

Sparkie3222 I think a similar one is when he made it go into thermal runaway and it made a very bubbly cast. It was set in I think under 5 mins. I’ve worked with resin for epoxy floors that have gone wrong in very hot days. By the time you mixed it to walking down hallway it was boiling over and setting up.

[@RK4000]

It would resemble expanding foam used in insulation.

[@AaaaNinja]

Go to The Kind of Random's channel he has a video.

[@lucjhaina8372]

A ninknnjjniooojojlnknjioojmiknnn

[@f4z0]

After seeing that clear casting in the pressure chamber i wonder of you could make one of those crystal skulls from indiana jones they should look amazing

[@doveoo5]

Just this week I was looking at the Crystal Skull vodka bottle on my shelf and thinking about a silicone mold....

[@f4z0]

doveoo5 if you try it post the results, my inner child would geek the hell out of anything related to indy

[@JimsonMakes]

I cast a clear skull on my channel.

[@charlesbonkley]

Cast a full-size replica of the lead-lined fridge to commemorate such an awful scene.

[@timberdish]

Very interesting and somewhat ridiculously well timed - I was just starting to look into getting one or the other for resin turning projects. So thank you very much :)

[@TupmaniaTurning]

Matt Jones - Me too! Now we know!

[@yumek06]

Thank you so much for explaining the pressure pot method of curing resin! It makes so much sense now! I'd see other makers like Nick Zammeti use it and never understood why. Also, I always love seeing makers add new tools to their arsenal and experimenting with them. I love watching your videos and can't wait to see your new creations!

[@TacticalKiwi4862]

I was just thinking today when your next video was going to be put up. And here it is!

[@serendipitousdudaday68]

Same, I had that thought 30 mins prior to this upload. I'm putting the Alexa in the cupboard for a while.

[@doveoo5]

@@serendipitousdudaday68 Positive thoughts, dear. Positive thoughts. Thank you. ( made my day, ty)

[@MohamedAhmed-zi1ru]

I can't believe that the king of epoxy didn't have a pressure pot for all of these years .. while everyone else was using it u were just talently bublle-freeing ur cast with a blow torch .. now that u got one i will still call u the king of epoxy and i know how hard it is to bubble-free complicated casts hope we all have fun with it

[@Waterflame]

I've been watching a lot of videos by Nick Zammeti lately, so I was hoping you'd also get into the pressure pot game! Can't wait to see what awesome creations you make now!!

[@xSaucySirenx]

Waterflame I was thinking the same thing. He’s been in the pressure pot game for awhile lol

[@TheRuko15]

I'm so glad you did this video! I've been wondering for so long why people use pressure pots to "remove" bubbles, instead of using of a vacuum chamber.

[@DaveDodd]

Gotta say...I'm subscribed to a lot of channels...but i get the most excited when i see a new Peter Brown vid :P

[@kbosell3812]

Me too

[@This1unbox]

Yaaaas!

[@sum1liteamatch]

Another off the wall, over the top, and educational video as usual. I always look forward to your videos.

[@Deneb626]

Obligatory "you should turn that pressure pot resin on the lathe" comment

[@Scott_C]

Second!

[@twilightsparkle75]

what an awesome eevee avatar

[@coldstub]

I've been wondering for ages what the difference between a pressure pot and a vacuum chamber were in terms of resin quality, thank you so much for this video it was incredibly helpful to me.

[@MysticalRhythms]

I think the alcohol dye was just boiling off in the vacuum chamber. I'd like to see this again without the dye.

[@markf.4063]

It would be the same. When you put any liquid in a vacuum you lower it's boiling point and it turns to vapor. Those bubbles you see in the resin are just that, vapor.

[@StoneAndersonStudio]

But the alcohol is boiling off, which may have a difference in the amount of off gassing that occurs as opposed to just the resin. I agree with MysticalRhythms- it would be super interesting to see one in the vacuum chamber without the alcohol dye.

[@1972Russianwolf]

@@StoneAndersonStudio Epoxy resin will boil at room temp when under vac. Art Resin is an epoxy.

[@KristenK78]

Also, I’d want him to take more normal care to not stir air into it before putting it into the vacuum chamber. The extra bubbles proved the capability of the pressure chamber to correct for that, but it seems unfair to compare it directly with the vacuum under less than ideal circumstances.

[@sammartin2725]

With out the dye you get the same results made a mess of my vac chamber I did not have a clear top but part of the side was clear and it filled full of foam verry quickly with nothing but ENVIROTEX LIGHT ,.

[@AlBarathur]

You can use both, if the resin gives you time, you put on vacuum chamber to take out the worst of it as you manage to have it not to overflow with foam, and then after these minutes of vacuum shock, you put it in the pressure chamber. BTW on the vacuum chamber, you don't need full vacuum, the goal is just to make the small bubbles to grow large enough that the equivalent weight of resin will dislodge them and make them defeat the resin viscosity and float to the top. Great vid, love it.

[@almagill]

OK, so, quick back of a beermat calculation.... pressure increases by about one atmosphere (15psi) with every 10m deep you go under water.. 50 psi would be what, about 35m down? Maybe 40 ish? Right, whose got an atmospheric diving suit we can put Peter in and is there a resin that'd set under water... Y'know, for science and stuff...

[@karol30660]

You can easily do 40m in a wetsuit or drysuit and you won't feel a thing

[@echoedinnocence]

FOR SCIENCE!!!! 🧐👩‍💻👩‍🔬🕵️

[@Shardok42]

Or... we put the resin in the pressure pot before sending Peter down into the water with diving gear and then he pressurizes it while underwater!

[@SBVCP]

@@karol30660 i ventured into the 4 meters...once.

[@SBVCP]

wouldnt the pressure be held OUTSIDE the container, or you are suggesting water-pressure? or some kind of flexible thing? i wonder if a plastic bag would work... Can you imagine? "pressure casting resin with a ziploc bag under the sea"

[@jeffs.6488]

I have found one way to prevent the over abundance of bubbles when vacing resin, it is to mix part A of the resin with the color you want, vac the bubbles out and then mix in part B to the already tinted/colored part A and vac once again. You won't get the bubbling over like you did with the way you did it in the video. This I have learnt from trial and error, casting this way greatly reduces the likelihood of bubbles, however when you pour resin on to or into wood it is better to pressure pot it. Also as a side note, not all resin colorants are alcohol based, these non-alcohol based tints greatly reduce the bubbling over due to boiling off of the alcohol in the alcohol based tints in a vacuum.

[@csis8460]

What you gotta do is let the resin foam up, then you break the bubbles (let air in) and re do until it's only pulling air out without foaming up

[@MyBallzGotShocked]

I would just reduce the pressure in the vacuum slowly. Instead of allowing air into the vacuum to raise the pressure, use a needle valve on the pump side to reduce the flow out.

[@kevinburrows1705]

Thank you very much. I was a vacuum technician. Melting metal and now retired. I’ve started turning wood and resin and thought about getting a vacuum chamber for casting. Now I’m getting a pressure pot 👍

[@TheTacticalPainter]

By chance could some of the foam been caused by the alcohol boiling while in the lower pressure? Just like boiling water at room temperature in a vacuum chamber?

[@jamesgrimwood1285]

I was also wondering if the bubbles were partly caused by things in the resin boiling, rather than air being pulled out.

[@TheTacticalPainter]

@@jamesgrimwood1285 I think you said it right, "partly," the resin will bubble like this anyway, but I think it was this violent because of the alcohol.

[@markf.4063]

Not just the alcohol. ANY liquid in a vacuum will boil off.

[@MakeThings]

Peter, I’m glad you did this. I’ve been trying to explain for a while that you cannot vacuum out air bubbles when casting. It explodes!!! You have to compress it.

[@davidgreen5099]

When i debubble in vacuum, i wait til the resin almost crests, relase vacuum, let bubbles pop, and repeat. Over and over until it stops rising.

[@stefanl5183]

Yes, I think you're very much correct here and this would be the technique that would be preferred and not the way it's done in this video. With vacuum, you wouldn't absolutely need to maintain the vacuum constantly until the resin hardens the way you do with pressure. That's because with vacuum, you are sucking the air out. Once you successfully get the bubble to the surface and they pop, you'd be done. Therefore cycling it on and off would make more sense. The cycling might also help move the bubbles to the surface because of the agitation it would also produce.

[@LadyTea]

@@stefanl5183 Wouldnt you want to degas, aka boil out the air of each of the base and the hardener separately? Then mix them together and then degas one last time. then poor.

[@flyingwoodshop1545]

@@LadyTea I THINK (not sure) most of the air is introduced during the mixing process. At least that's how it looks when I do it. But I'm using the resin as a filler for knots and splits, not for casting. This video was interesting to me, but the pressure method really only works for casting. If you want to degas the resin and then pour or spread it onto the wood, the vacuum method is the only one that will actually work. Good thing that I only have a vacuum chamber and not a pressure pot!

[@markbeiser]

Use both! After mixing the resin, degas it with the vacuum chamber. It happens fairly quickly, the foaming you were getting after the first minute or so were components of the resin boiling off. Then pour the resin in the mold and put it in the pressure pot. You can also vacuum degas it after pouring the resin in the mold to help get air trapped in the wood out before going to pressure. I do resin casting of miniatures for tabletop war games, so have to get air out of and resin into some intricate fine detailed molds. I have the same HF pressure pot and found that the top for my vacuum chamber also fits on the pressure pot, and seals fine, so I started doing my vacuum degassing and pressure casting in one pot.

[@TheRyanjMain]

pressure pots remind me of the movie flubber

[@Guru_1092]

They remind me of a marathon that occurred on the East coast. Oh... wait.

[@MsCherade9]

@@Guru_1092 Can we not?

[@Guru_1092]

@@MsCherade9 :D

[@bradgeary3467]

couple things. i use vacuum at work almost daily for evacuation of air/gas in perfectly sealed refrigerant systems to remove air obviously but also we are boiling any moisture in either gas or possibly liquid form to creat a as perfect dry environment as possible. It looks to me like your boiling that epoxy mix to me. place a class of water and same thing will happen as the water turns to vapor then gets extracted by the pump. If your vacuum level is taking too long to build as I believe you commented i’d be willing to bet it’s the size of your hose and possibly even leaks in your vacuum setup you would not even consider. also if the condition of your pump oil is anything but new and clean your killing the pumps ability to pump efficiently. I test my oil before use and find I need to change it every few uses on systems not much larger than your vacuum vessel. Have a look at it. any milkshake color to it? if so change it as it will take its toll on pump internally. regardless of you pumps current hose fitting size try running a actual vacuum rated hose (often 20-50 microns) at least 2x larger in diameter if not x3, run fittings with non obstructed paths (you may be already) use a none drying smear of sealer on the vessel cap seal and around where any valve shafts penetrate fittings under levers by removing lever to apply, run clean oil and that system will pull down so fast and so hard your head will spin. It would suck a golf ball through a garden hose :).

[@MikeWaldt]

Great video Peter ... I don't "do" resin, but still watched every foamy second. Take care Mike

[@CFGossettAbbasHealingArts]

Peter, You have some of the coolest videos I have ever seen. I've also learned stuff from your videos. Keep on keeping on. You and Nick Zametti are my favorites on KZbin.

[@acroque]

I was waiting for the polish part :(

[@peterbrownwastaken]

next video! :)

[@kbosell3812]

Woohoo!!!

[@Shardok42]

@@peterbrownwastaken Do I sense a translucent blue bracelet in the future?

[@WaifuTrashWeeb]

No need to polish, that thing came out crystal clear.

[@heavystalin2419]

For all i know, it got split in 2

[@mancraft18]

I'm just glad you're back to making videos on the regular I missed you. You and a few others are the very inspiration for the channel I'm trying to create now thanks Peter... Everyone should have a little pet... A little brown... You in they're life

[@nexus01gr]

No control piece?

[@peterbrownwastaken]

I suppose my whole channel is a control piece. Even at my best, I still normally get one or two bubbles in a casting.

[@MohamedAhmed-zi1ru]

😂😂😂 What an answer

[@robinsonvargas1467]

Thank you I have ask many woodworkers about the difference between the two and you just gave me the answer plus an excellent demonstration.

[@Thingsthatgopew22]

It is NOT air going off in the vacuum, it is some of the solvent boiling off. And not a single youtuber understands this. Amazing.

[@MrEfarmer]

Agree!

[@TwoScoopsOfTubert]

Interesting - are there actually volatile solvents in the components? Would those not spontaneously form bubbles even in a regular atmospheric cast?

[@RobertSzasz]

@@TwoScoopsOfTubert it depends on the resin, material being cast or used as reinforcement, and any additives Degassing resins with vacuum and then pressure casting is pretty common and really effective

[@MakeThings]

WGwireless that’s really besides the point. If we were working with resin and non stabilized wood you would have problems with air bubbles from the wood. Pressure casting is the only method that makes sense unless you find a different method that doesn’t create the solvent bleed off and you’re using wood (or any other material) that had absolutely no air in it.

[@peterbrownwastaken]

OK. I now alone understand it. I'M A VESSEL FOR YOUR WISDOM.

[@phantom715]

You are the highlight of my KZbin playlist. Keep it up!

[@reeepingk]

I think what you want to do with the vacuum chamber is let the air back in FAST when it almost overflows. Then it'll actually pop the bubbles. (At least that's what I understand from watching the king of random.)

[@cameronpolite8514]

Kyle R no it’s just they don’t think about it bubbling up. The vacuum will pull it out if it’s left.

[@RobertSzasz]

Cycling the vacuum can pop bubbles, You want to pull the vacuum, then release it while the resin is still liquid.

[@MakeThings]

This is all well and good but this is argument you make is an argument that focuses solely on casting a pool of resin. Add wood that has not been stabilized and you have to deal with the bubbles from the wood too.

[@markf.4063]

Also of note, not all vacuum pumps are the same. I have no clue as to which he uses but it would be interesting to see how a better pump fairs in this regard. Perhaps a 2 stage pump would pull faster in this material.

[@nifty1a]

That's what I had to do when I worked potting sensor electronics for aerospace sensors, vacuum each component before mixing, mix and degass again the pour into mould and degass again. Degassing is done by vacuuming until foam nearly crests container, then rapidly bring up to atmosphere, then repeat until no foaming occurs. Did it for about 2 years... For actual space use, they use vacuum degassing, and then cure under pressure as well. you don't want air trapped in cured resin in a hard vacuum as it will explode and crack....

[@danstark3341]

Thank you so much for this video. I am just getting into turning. Just set up my lathe about two weeks ago. I have been trying to take my knowledge from metal casting and use it here. I used vacuum chambers for removing the air in small mold making, for casting. But everyone I watch says, "Into the pressure pot it goes." and I wondered why not a vacuum.

[@seigeengine]

Would the alcohol dye be vaporized in a vacuum?

[@hanelyp1]

Or some other solvent in the liquid resin? Would chilling the resin before mixing make a difference?

[@markf.4063]

@@hanelyp1 The alcohol would be vaporized and the pigments left behind but that would happen at atmospheric pressures as well.

[@crashandburn22501]

Wishing you the best for the future with the pressure pot. Can't wait to see what you come up with.

[@JPKenneys]

I feel like every time I've seen someone use a vacuum with resin they've had to cycle the vacuum to avoid the boil over

[@bigfootandbananaman4746]

I didn't think the pressure pot would work that well. I can't wait for the next video

[@Typersx1]

Wonder if mrs. brown thinks you cray cray. 🤔🤔🤔

[@peterbrownwastaken]

undoubtedly

[@daisyrushton1574]

To be fair she’s pretty cray cray too, she handles a blowtorch like blam

[@Telemachus2814]

Mrs. Brown likes to burn the things Peter creates... or anything really. Check out their "Burn it" series. I'm sure she thinks he's crazy, but she probably also likes it. His crazy probably works with her crazy.

[@MsCherade9]

@@peterbrownwastaken I'm sure that's why she loves you, we all secretly love a batshit lunatic from time to time. In moderation...

[@ristube3319]

Typersx1 She doesn’t complain at all anymore, FYI, don’t go digging around in his backyard.

[@bearthompson6506]

Excellent vid! I’ve done some small mold making and casting as a hobby and knew about degassing latex, urethane and silicone, but wondered why people pressurized resin. Now I know . Thanks!

[@VideoGameCathedral]

Asking for for years? He's finally making a cereal bowl out of cereal!

[@raybone3]

For some applications like casting insects in resin, or anything else that may implode under pressure, I use the vacuum chamber. I will pour resin just to the bottom of where I will have my fragile item and use the pressure pot. Then, I will mix a small amount of resin to cover my insect, or whatever. I put the resin in a container that is at least 4 times larger than my volume of resin. Vacuum it down until the bubbles almost crest my container and let it hold there for a few minutes. The bubbles underneath the surface cannot pop until they reach the surface. On their way to the surface, they join with other bubbles and grow larger. Once these larger bubbles are able to reach the surface they will pop and allow more room in the container. Pressure back up until bubbles reach the top and repeat if necessary. I use small pours in layers until I cover my fragile content to avoid heat buildup. Once covered and cured, I can finish the pour and use the pressure pot for the remainder now that my fragile pieces are encased in cured resin. Thanks for the video.

[@regstarr3430]

Agreed, you are not pulling out the air, you are actually “boiling” the liquid as a result of the low pressure.

[@kittycobbs3501]

Yes! Super excited for this after a very anxiety filled day today

[@cosmicrdt]

Black beard projects did a video on this exact same topic yesterday

[@peterbrownwastaken]

who? That's hilarious... :)

[@davidgagnon1961]

this answered so many questions I have had about which to get for casting.. I have watched A LOT of videoes and none really explained the purpose of each. Thanks.

[@kst357]

There's no way the resin had that much air in it. I think that the vacuum's negative pressure was vaporizing the chemicals/solvents in the catalyst. Maybe using less vacuum would draw the air bubbles out without causing vaporization of the casting resin. I'd try slowly raising the vacuum until the resin starts to vaporize, note the PSIV, & then set your vacuum below that level. I've seen epoxy resins that didn't foam at all under vacuum. Maybe the foaming has to do with the type of chemicals used in the resin, meaning that some resins will work under vacuum & others won't.

[@susantipsyhealy7655]

i agree, cactus juice will boil over , feathering the vacuum will control that unitl it is pulling the gasses etc out without foaming over. granted, it takes time but get good results.

[@krystalboudreaux9405]

Thank you!!!! I've been searching all morning for a definite answer and a video that explains it clearly. This helped alot.

[@RamosLuis2550]

the pressure pot is best for resin impregnating wood or other porous materials

[@galatician8063]

Thankyou!!! Just found your channel today to answer this very question!!! That was fun to watch, and I didn't have to clean anything up!!! So I won't bother trying this in my vacuum chamber, and will learn more about a pressure pot. Not sure I can justify getting one as I am just trying some small casts to repair minis. I have a 2 minute resin which probably isn't long enough working time even for a pressure pot. I may try using a needle next and see if that can inject the resin into the recesses enough to force the bubbles out of the thin sections.

[@davespeedee]

4 hours rock hard? o_O

[@peterbrownwastaken]

*giggle*

[@LittleTas12]

@@peterbrownwastaken Contact your doctor if your resin stays hard after only four hours.

[@almagill]

Oh. My!

[@KubedPixel]

I've never used resin but during the curing process there is an exothermic reaction. In a vacuum water boils at a much lower temperature. What you see happening in the vacuum chamber is an already hot liquid boiling at an even lower temperature. You're not seeing the vacuum taking the existing bubbles out of the resin but you're watching the resin boil. That's why there are a lot more bubbles/foam than you'd expect.

[@xTheDeerLordx]

It's likely the alcohol based dye boiling. The boiling point of resin is ~176C at full vacuum

[@davidernesto6258]

First, yes. Harbor freight is good.

[@davidernesto6258]

Literally the view count says one

[@davidernesto6258]

No one cares I know but I was amazingly bemused

[@peterbrownwastaken]

I've got a Harbor Freight benchtop grinder that I've been using for 10 years as my lathe sharpening setup. Love it. I've also bought loads of junk that I've just pitched out. You just never know. This pot is decent for the price and can be quite useful for getting into casting with a pressure pot.

[@davidernesto6258]

@@peterbrownwastaken we largely use harbor freight for workshop consumables. Sand paper, shop towels, vinyl gloves, etc. Not so much for foundational shop tools. I think we have a router and table we got from there as well as some palm sanders some drill bits. If you need a one off tool it's good to check there

[@This1unbox]

All these other channels and i get my jollies up when Peter Brown uploads a video!

[@eurobum2012]

That's not air. That's substances in the resin boiling off.

[@yl7108]

I agree. He is getting rid of some volatile ingradient, which is not good.

[@SilvaDreams]

@@yl7108 Actually it's just speeding up the process of it releasing the volatiles due to the lowered boiling point. The process works perfectly fine but you have to user slow curing resins and you just do short cycles as not to cause it to violently bubble.

[@Doazic]

SilvaDreams If those chemicals weren’t needed in the resin, the manufacturer wouldn’t have added them in. You’re clearly not meant to boil them off.

[@mel7953]

Under pressure! one of my favorite all time songs. Also, yep...pressure pots, terrifyingly inexpensive. Love the clear, looks great.

[@RangaBonsai]

Amazing! Love watching and learning about new maker strategies I’ve never heard of before

[@bradleypackard8828]

I don’t comment often. Have to say my fiancé and I LOVE to watch you and you have a great sense of humor!! I recently started wood turning. I noticed you don’t have any STICKERS for sale on ur website. Have a fantastic day!

[@holly-anne680]

How timely was this video for me...….I got "god struck" with an idea this afternoon about how I wanted to spend the rest of my resin life...…..and I knew I was going to have to have a pressure pot, I'm terrified with anything under pressure, a pressure cooker once exploded on my stove......overcoming that, I will need a pot nearly 20 inches in diameter…..or I'll have to layer and torch layer and torch, hoping for a bubble free outcome......any and all vids you have on using the pressure pot will be appreciated...….thank you so much for your time and talent!

[@dobokaydani]

Vacuum chamber is great too for degassing resin. Just many people dont know how to use it. Never set it on -1 bar at the first step. You have to start degassing between -0.6/-0.8 bar. DON'T let foam up the resin! After several minutes (when most of the bubbles gone-depend how much resin you mixed) at the very and you can close the inlet air and finish your degassing on -1 bar. Welcome!

[@themajesticwierdo2193]

This was so neat to watch! I'm glad you showed us how both acted. Love it!

[@rastas000]

I poured some polyurethane resin into the base as a self levelling base internally to the pressure pot. It worked a treat and has (so far) stayed in place.

[@peterbrownwastaken]

that's a good idea!

[@KelseeBeth]

I knew what was going to happen, and I enjoyed watching it immensely!!!

[@GeekyAsItGets]

Congrats on discovering a better way to prevent bubbles in resin!

[@kellyfoster6983]

wow. As a newbie to resin I have been really struggling with the bubble issue and bought myself a vacuum chamber. I normally put my resin in, turn it on to full and then switch off the motor and walk away. I have had some really REALLY weird looking stuff come out of it. I'm guessing the guys I see using what I thought were vacuum chambers may well be using pressure pots. Thanks for the demo. Much appreciated.

[@spicesfunny]

That is nuts!!!! I was wondering the difference and pressure pot is the way to go. Now i know why Nick Zimmetti uses one all the time.

[@ZacHiggins]

Great video Peter!! Thanks for the shout out and link to my channel, I appreciate it =D I got the same results when I tried it too, foamy mess LOL One cool trick is to use a fast setting resin under vacuum and create a resin sponge looking blank, almost like your resin lava bowls

[@christopherdunn6464]

Thank you very much for this video. As a newbie (uninformed) resin user I purchased a small vacuum chamber. The results were disastrous. I watched over a dozen tutorial videos on 'resin mistakes', and nothing worked. Duh, it was the vacuum chamber. I had no idea. Thanks, again.

[@dougalexander7204]

Peter, good to know. Thank you for your comparison and sharing it with us.

[@RyuRaeArashi]

I've actually always been really curious about this with resin, since I know silicone molding usually uses a vacuum chamber to remove bubbles. Nice to see a video up about it.

[@peterbrownwastaken]

I think a lot of people were right there with you. I get that comment a lot in my casting videos. I hope this helps to clear up some confusion.

[@RyuRaeArashi]

@@peterbrownwastaken Definitely, I watch Nick a lot these days and I was always curious about why he used pressure but never really dug into it very much eh. This explains it in a much more amusing way though I imagine.

[@KiKiJahDore]

I like the pressure pot results wayyy better. Right now I’m making small projects but this will be helpful when I start making my paperweights.

[@Themaverickdetector]

Have you ever tried pulling a vacuum then quickly release the vacuum to put pressure on the bubbles so they pop then repeat the proses to more quickly reach an equilibrium?

[@DadeDreamer]

I would recommend Crystal Clear resin from Smooth-on. It is a thinner liquid and will degas much easer. I have used this product with great success. They have several kinds however, make sure you get one with a pot life that works for your time constraints. The art resin is likely to thick to be degassed. Thicker resin has bubbles that don't pop as easily as thin resin. For Thick resin, you would want to jar the chamber to help the bubbles pop. Also letting the resin rise and release the pressure as many times as you need will help remove bubbles.

[@stumask]

Great video showing the effects of Degassing a thick material, a material of this viscosity will expand 5 to 8 times its volume depending on the material so with that in mind if you know the viscosity of the material this is called its Centipoise ( this should be on the materials container or COSH data sheets ) or cP, water has a value of 1cP and honey/corn syrup has a value of 2,000 to 3,000, looking at the resin used its going to be around latter value so the thing we now know that this material expanded 4 maybe 5 times its volume at this cP so that would mean you will only be able to Degas 1/4 of the total volume in that pot to stop it over flowing or just use a wider deeper pot, also giving the Degaser a little shake while you are Degassing will break the surface tension and collapse the bubbles, being carfull not to knock you pot over inside the degasser, I put a vibrating pad on the inside of my degasser to do this for me, the thinner the viscosity the less foaming the thicker the viscosity the more foaming, you can make your own chart up giving the materials you use the cP value and expansion rate, hope this helps, love your work

[@metalheadmalpass3939]

I work with resin and use both vacuum and pressure chambers. I used vacuum when moulding small figures as we can never seem to get the bubbles out under pressure. Each figure has a plinth which allows for expansion in the vacuum. Once the vacuum has sucked the air out the resin will colapase like a bad soufflé. I then let the air back in, which cause it to sink further, then repeat the process. Each mould of three figures takes about 1 minute to process. If I was able to use the pressure chamber, they'd be in there for at least 15 minutes. I used 228, 2 part resin.

[@arta2870]

good info. ended up being messy. I was skeptical about harbor freight pressure tank but now I see it works. thanks. gonna by one

[@L0STinNARNIA]

Shop time on a Saturday? We are truly blessed :D

[@andy-in-indy]

The question is not "Pressure pot OR Vacuum chamber" but which to get first. Use the vacuum chamber to stabilize wood and degass silicone rubber or 2 part resins (see videos about how and why to do that) and then cast the silicone molds or resin in the pressure pot. The combination of the two makes for some very clear and strong parts. If you are going to stabilize wood, get the vacuum chamber first. If you are making silicone molds get the pressure pot first (then make a lid to turn it into a basic vacuum chamber.)

[@smash5967]

I think it's worth mentioning how you can usefully use a vacuum for resin. For a regular casting, you can put the resin in the vac chamber to pull some air out of it, then pour it as normal. You can also use a vacuum bag, which works more like the pressure pot. That's usually used for fiberglass/carbon/whatever other fiber work, though I think it might work for casting with clever mould design.

[@SardiPax]

I agree with other comments that the foam in the vacuum chamber was 'boiling' of the solvent (or even the uncured resin, styrene?, itself) in the resin. My understanding of how to use a vacuum chamber for resin casting is that you take it down low enough that real air bubbles expand and float to the surface, then allow the air back in while the resin is still very fluid. It isn't used in the same way as a pressure chamber. I guess if you wanted to be extra certain, with a complex mould for example, you could give it a couple of minutes in the vacuum chamber before transferring it to the pressure chamber for the final cure.

[@doreenwatson-read]

Looks like a teacup and saucer, ide like to see you make that. Maybe you could place some tiny flowers in it and give it to your mum or wife for mothers day as a show piece. I would adore something like that. You could even place her name in the resin too. Nice!

[@chillaxter13]

Thanks for the comparison! This answered a question I've had for a long time... I wonder about the density of each method though... I'd love to see a chunk of each, cut to the same size, then weighed...

[@ianthomas3653]

First of all 3:55 ... Thats what she said. Seriously though I would agree that a pressure pot is the way to go for casting. However adding a silane or any other antifoaming agent to reduce the surface tension of the epoxy would help alleviate the foaming you were getting with the vacuum chamber. I personally would vacuum degas each side "A" and "B" prior to mixing, then add in a silane during the mix. Next vacuum degas in a separate vessel as you did and then pour it into your cast. That is probably going overboard if you have a pressure pot, but those things scare the hell out of me. Can't wait to see what you have cooking... Also forgot to add around the 7:30 mark when its bubbling like that with certain epoxies that have volatiles you can actually over degas and start to pull out parts of the hardener. This will affect cures in some situations.

[@sudhirpatil2870]

Wow! I never thought of using pressure pot- until i saw your video! Thx

[@RB-ck3xr]

We degas resins as SOP. First vacuum degas the resin and hardener seperately without allowing either component to "foam up" once the two components have degassed they are mixed well and degassed again to remoce any entrained air. Because both components have been fully degassed any air is entrained from the mixing (visable bubbles) which will come off very quickly. The activated resin should not "foam" at this stage. The resin can now be poured into the mould, given one more vacuum treatment to clear any air pockets in the mould and finally the mould can be pressurised to 75psi. This process has worked for us giving lear, bubble free, high integrity castings in either polyester, polyurathane or epoxy resins. The first vacuum degassing removes both entrained gasses and dissolved gasses after mixing the second vacuum treatment only has to remove entrained gasses from the mixing (no time for the resin to absorb / dissolve any gasses) which will come off very quickly as largish bubbles, not foam.

[@214SmileyFace]

That pressure pot resin so beautiful!