# Using a pressure pot



## Bobostro61

My wife got me Shop Fox pressure pot off of Amazon for my birthday.  This pot will take up to 45 psi.  This will be sufficient for making blanks?  I believe the harbor freight pressure pot will hold up to 80 psi.  I'm just wondering if I should have her return it and go for the HF model?


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## MesquiteMan

The HF pot may be stamped that it is rated to 80 psi but no way in hell would I use one past 45.


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## paintspill

i just started casting and through my research looks like 30-40 psi is plenty. i cast my first around 30 and it looks fantastic


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## healeydays

I would be careful around too much pressure in your pot if not rated very high.  I have a Binks and a Devilbiss which are rated at 110 PSI and I don't take them over 60 and those manufacturers are rated some of the best out there.


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## Russianwolf

I have 2 Grizzly pots which should be identical to the Shop Fox pots. Much better built than the HF pots, but are actually realistic in what they say is max pressure. I tested mine to 60 PSI without an issue but cast at 45.


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## cwolfs69

MesquiteMan said:


> The HF pot may be stamped that it is rated to 80 psi but no way in hell would I use one past 45.



use mine at 60 PSI all the time with no problem. actually pressure tested myself to 110 PSI (using safe conditions of course) and now feel safe at 60 PSI all of the time.


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## Russianwolf

I take it back, that pot looks identical to the HF pot.

Shop Fox W1799 2-1/4 Gallon Paint Tank - Amazon.com

Here is the Grizzly that I think is a better design

Grizzly H6329 Paint Tank with-Gauges, 37288-Gallon - Amazon.com

No way for the clamps to slip, you have to break a weld for the lid to come off as has happened to some of our members.


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## cwolfs69

i do like the clamp style on the grizzly but it only states allowable pressure of 45 PSI.


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## Kenny Durrant

First off I'm not an engineer but when you exceed the recommended pressure your making a bomb. It's been my understanding that most products can withstand the recommended pressures but for safety they back off that amount. The max pressure rating is for repeated use and still be safe. It may be able to go above that rating but the material and parts start to fatigue. Don't push your luck and stay safe.


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## Sabaharr

I work with many items involving really high pressure (upwards of 6000 PSI). I can tell you that for safety reasons and pressure vessel MUST be pressure rated at minimum to actually handle 1.5 to 2.5 times what its rating is. It's a built in safety measure. The vessels we test only need to hold 1500 PSI but at NASA we have a reputation for pushing the envelope. Now with that said who's to know how well the production quality of anything is. Each item may not be tested at such low pressures (under 1000 PSI). But it has to have a certain number tested at random from production to support the rating it has.


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## Bobostro61

So I guess my real question is, if the pot I have is rated for 45 psi, will pressurizing it to at least 30 be enough for making blanks?  Or should I push it to 35 to 40?


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## PenMan1

MesquiteMan said:


> The HF pot may be stamped that it is rated to 80 psi but no way in hell would I use one past 45.



My HF pot lists 60 PSI.....BUT it DOESN'T list a "working" pressure. 60 PSI is the MAXIMUM pressure.

If you observe a rule of thumb of "Maximum pressure minus 10 percent", that's 60-6=54 PSI WORKING PRESSURE.

I'm with Curtis! I wouldn't DARE take my HF pot above 45 PSI.


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## PenMan1

Bobostro61 said:


> So I guess my real question is, if the pot I have is rated for 45 psi, will pressurizing it to at least 30 be enough for making blanks?  Or should I push it to 35 to 40?



30-35 PSI is plenty for MOST PR casting, but completely inadequate for Alumilite.

Most alumilite applications like at least 60 PSI or better.


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## ironman123

I have the HF pot and use it at 55-60 PSI.  Took 3 back before I got one that didn't leak.

Ray


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## Russianwolf

I use my 45 PSI max pot at 45 PSI. 

No issues to date.


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## MesquiteMan

Do you guys really want to trust Chinese quality and engineering to adhere to the 1.5-2.5 times mentioned above?  Heck, they just poisoned 600 or so dogs with Jerky treats.  Do you really think they care if your pot is going to blow or not.  Sorry, but I am NOT trusting my life under any circumstances to the Chinese.  I will stick with American made on this one.  the money saved will not even cover my insurance deductible.


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## PenMan1

MesquiteMan said:


> Do you guys really want to trust Chinese quality and engineering to adhere to the 1.5-2.5 times mentioned above?  Heck, they just poisoned 600 or so dogs with Jerky treats.  Do you really think they care if your pot is going to blow or not.  Sorry, but I am NOT trusting my life under any circumstances to the Chinese.  I will stick with American made on this one.  the money saved will not even cover my insurance deductible.



And Curtis, that's 600 or so dogs THAT WE CAN CONFIRM! The truth is likely THOUSANDS!


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## Bobostro61

PenMan1 said:


> Bobostro61 said:
> 
> 
> 
> So I guess my real question is, if the pot I have is rated for 45 psi, will pressurizing it to at least 30 be enough for making blanks?  Or should I push it to 35 to 40?
> 
> 
> 
> 
> 30-35 PSI is plenty for MOST PR casting, but completely inadequate for Alumilite.
> 
> Most alumilite applications like at least 60 PSI or better.
Click to expand...


Sounds good!  All I do is PR so I guess this little pot will work for me (for now).


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