Using a pressure pot

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Bobostro61

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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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healeydays

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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.
 

Russianwolf

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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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Kenny Durrant

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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.
 

Sabaharr

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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.
 

Bobostro61

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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?
 

PenMan1

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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.
 

PenMan1

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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.
 

MesquiteMan

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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.
 

PenMan1

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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!
 

Bobostro61

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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.

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