I've finally made the decision, I'll be looking into buying a pressure pot NEXT WEEK.  I've been doing a lot of research on them.  It's been on my want list for quite a while, well while I am able to do so I probably should just go ahead and do it while I can before I cant get one.  Either way I know folks are saying harbor freight is the way to go.  Some youtube videos that I've come across are saying DONT GO WITH HARBOR FREIGHT.  If I wanted it now Id go with them and cheap.  But I want to be able to leave it in my shed over night and pressurized with out having to worry that the thing is going to explode because of the pressure.  I'm also not wanting to spend over 200 dollars on one either.  Knowing what i know now about them and that you run them with an air compressor instead of a vacuum pump which should be easy for me I already have the air compressor a little 6 gallon tank with compressor and 25 foot hose plus all the connections.  The only really money I need to spend is on the pot.  Just un sure of which one to get.  So many to choose from.

My HF pot will hold 65lb over night. But, an hour is really all that's needed. 

I haven't had very good luck with HF lately unfortunately I'm not too sold on them at all at the moment.  Unless its for cheap clamps.

Id only purchase the HF pot if I knew I only had to pressurize the resin to a certain PSI rating say like 40 PSI.... Then I may consider the 100 dollar pot.

I use it @ 50 psi. 40 might work. It's rated for 65. I only took it to 65 once to test my seals, gauges etc. 

Its just really hard for me to trust cheaply made things like that just my thing.

I think TCP Global is going to be the closest in price to Harbor Freight. California Air is a bit more pricey. You'll probably need only a 2.5 gallon model unless you are thinking of doing really large objects or lots of small objects at the same time.

 

Just a personal note, in my younger days I owned and operated a Scuba diving shop. To test depth gauges, I had a pressure box made that had a 3/8" lexan window. For "safety", I would fill the box with water, place the gauge inside, and pressurize the box to a depth of 100 feet (about 50 psi). When the lexan window blew out, it shot a column of water about 15 feet. Luckily I wasn't looking in the window at the time. 50 psi may not see like much but it can kill or maim. DO NOT skimp on the cost of the pressure pot. Spend the bucks. Get one that is safe.

 

Alumilite recommends 40 to 50 psi for casting. Unless it is cold, the resin should be set in an hour or so. You really don't need it to hold pressure overnight. 

Nope I've been planning at some point making pen spindles and possibly some bowls.  How ever still working with wood but I wanted to get set up and ready to go if and when I decide to start on that aspect.  ANd @lew that was my main thing was safety

Edited August 8, 20205 yr by AndrewB

Just looked up TCP Global on Amazon sadly I wont be able to get one until Wensday but I think this one should possibly work no problem

https://www.amazon.com/TCP-Global-Pressure-Paint-Nozzle/dp/B002ABWVRM/ref=sr_1_7?dchild=1&keywords=TCP+Global+paint+pressure+pot&qid=1596848874&sr=8-7

 

I doube I will need the paint sprayer hose.  I'll still have to read up on how to operate the things, this one I will be reading a manual and watching videos LOL.  When it comes to something that has to be pressurized I can't afford NOT to read a manual.

How long you intend on leaving products inside the pressure pot?

I've got a buddy who makes knives, and he uses a specially formulated resin made for this type of work, into his knife handle blanks, I believe he stated the blanks are only left in for several hours, he calls the process "stabilizing the wood". Then he bakes the blanks in his oven for an hour at low temps. He uses a pressure pot and vacuum pump he purchased from Amazon. I believe the pump and pot together ran around 200 bucks.

I remember him saying after the pot and pump investment, the resin is the most costly material. But his knives are beautiful, the handles are incredible.

I may be able to get him to come aboard here and chime in, let's call him @Rich Carleton.

 

I believe the idea is to not pressurize the pot, but to vacuum all the air out, sucking out all the air from the wood, and sucking in all the resin to fill those air gaps.

Well from seeing @lew comment earlier about an hour at most.  I was contemplating on vacuum chambers but then again it wouldn't be for stabilizing wood.  I've seen some of those stablized wood / resin knife scales all finished up and fixed to the tang of a blade and they look extremely nice.  I dabbled in that area for a while but never got that far into it as I was told to quit.  How ever with the resin casting Id eventually like to give it a shot and see how well it works out.  So I probably wont be going as far as a vacuum chamber at this point.  Those can get spendy.

5 minutes ago, AndrewB said:

How ever with the resin casting Id eventually like to give it a shot and see how well it works out.

I missed that part, didn't know you were going for resin casting.

Never mind @Rich Carleton !!

Yep LOL gonna give it a try out at some point in the near future.  I have a bit of resin still in the shed but not a huge amount its just enough to give it a try.  All I've gotta do is aquire the pressure pot LOL.  Stabalized wood how ever is probably far too advanced for me at this point.

1 minute ago, AndrewB said:

Stabalized wood how ever is probably far too advanced for me at this point.

I doubt it Andrew, from the way my friend described the process, it was pretty straight forward and simple, plus finishing stabilized wood is just sand it fine and rub it out with tung oil, because the finish is more or less already in the wood itself from the process, it doesn't take much to get it beautiful.

Hey man, don't sell yourself short, you already done more than many of us this entire year in your own work, you are hitting it with all 8 and dove into the deep end, and in an admirable way I may add. Keep it up Andrew!

I learn quick with nothing but free time on my hands I'm able to do a lot of things.  Matter of fact I've got two more sets of pen barrels to turn today too LOL.  The pressure pot is an item on my list that I've been wanting to get.   When you don't have to work you can get bored rather quickly and you start looking for stuff to do LOL.

Pressurizing and vacuuming are used for different purposes, but to a similar end result- getting rid of air bubbles. A friend started a cold casting business many years ago and had me help him get up and running.

 

For resin casting, pressurizing is typically the only process needed. It squishes any bubbles down to almost nothing while the resin hardens. Then the pieces are machined.

 

Some materials are so porous that the resins don't penetrate complete, or are so soft that they can't be machined well. Those materials are Stabilized by a vacuum process. Vacuuming creates almost a zero atmospheric pressure around the piece and any air contained within the piece escapes. This process use a liquid that fills the voids where the air was trapped/released. Once this is accomplished, the wood is baked to harden/dry the stabilizing liquid. The stabilizing liquid most commonly use is something called "Cactus Juice".

 

Mixing 2 part resins can benefit from both processes, depending on the curing time. Mixing resins introduces air into the mixture (Alumilite has a great video on this). If the cure time is fairly long, the mixed resin parts can be briefly vacuumed to pull out the trapped air before the pour. Then the poured blank can be pressurized to further reduce the trapped air. This is the process we used in casting "one of" artist work for reproduction. 

 

For woodworking applications, what I've seen is vacuuming for stabilizing and pressurizing for casting. Although some may use both.

 

Pressurizing requires a reliable pressure pot with pressure gauge, a compressor capable of obtaining the desired pressure, a pressure regulator and an air dryer/moisture separator (some casting resins are moisture sensitive).

 

Vacuuming requires a vacuum pump, vacuum chamber with vacuum gauge, inline filter to prevent contaminants from getting into the vacuum pump (two stage is prefered) and oversized containers to catch overflows- vacuum liquids "boil" and can end up all over the bottom of the chamber.  

A pressure pot can be used as a vacuum chamber too.  You would have to change the pressure gauges to vacuum gauges.  You can curb shop for a vacuum pump.  The pumps for dehumidifiers can be used as vacuum pumps. Usually when a dehumidifier goes bad it is not a faulty pump.

I have to plead ignorance.  Just what does one use a pressure pot for?

(asking for a friend)

15 minutes ago, kmealy said:

I have to plead ignorance.  Just what does one use a pressure pot for?

(asking for a friend)

Tell your friend that it's used to squeeze the bubbles down in a resin casting....in this instance. Or, you can spray paint with it.