How big is the compressor are you using?

[healeydays]

Hi folks,

Might be replacing my old workhorse of a Curtis air compressor for a multitude of reasons and one is casting. While looking around, a thought came to me, what are folks using to get the pressure up as quickly as possible?

How many of you are using the small pancake compressor vs a large one that could sandblast, paint a car and build 3 houses at the same time?

Mike B

 

[HamTurns]

I use a 3hp compressor with a 30 gallon air tank on it set to shut off at about 120PSI. My compressor is out in my detached garage/shop. It takes about 4 to 6 minutes to get up to pressure.

Although I do my Alumilite casting in my basement because I live in Wisconsin and it's too cold now for casting out in the garage.

When I'm going to do a casting I take my 7 gallon portable air tank out to the garage and fill it with air up to the 120psi my compressor is set to. My portable tank is rated to 180psi.

So when it's "pressurize that BINKS" time I don't have any lag time to get the tank up to the 60PSI I use. I screw down the lid, hook up the hose and immediatly bring it up to 60PSI in about 3 or 4 seconds. I can get two castings from one fill up very easily, 3 may be pushing it.

Using Alumilite I wouldn't have enough time to wait for the compressor to come up to pressure, so I get it "in the can" and ready to go.

I don't think you need a very big compressor for casting, but you'll want to have it up to pressure before you need it. It shouldn't need much volume either, a pressure tank at usually 2.5 gallons, and pressurizes quickly.

Tom

 

[BSea]

I agree with Tom above. You don't need a big compressor for casting. But as long as you are getting one, you might as well get one big enough for other things too. Mine is a 30 gallon from sears. I've used it for lots of projects. It's big enough for light automotive work, I've used an air hammer to take up tile, and run a finishing nailer for trim work. And being just a 30 gallon, it's small enough to load into my truck. I used it at my son's house to help him put up some crown molding. I'm guessing it's about 75 pounds.

 

[MarkD]

I have a 5hp Ingersoll Rand compressor with a 60 gallon vertical tank. The compressor is located in the garage, away from my workshop so I don't have have compressor noise, although it doesn't run very often unless I'm running an air tool for an extended period of time.
It takes no time to fill my pressure pot although I usually use the value to "gently" fill the pressure pot rather than "blasting" it.

 

[Justturnin]

I have a little Pancake and I hate it. It is loud as all get out. Last thing I need when filling a pressure pot to 80psi is a load bang when the compressor kicks in. Looking for a larger Oiled compressor that will be much quieter.

 

[MesquiteMan]

I have been running a 60 gallon compressor for a number of years now. I recently got a heck of a deal on a much better quality 60 gallon 2 stage compressor. My shop is plumbed for air in various locations so while I was installing the new compressor, I updated my air lines. Previously, I was simply running 3/8" air hose as my supply lines and my casting area was towards the end of the line. When I did the new system, I changed everything out to 1/2" ID Pex piping. The larger lines made a heck of a difference! With the old setup, it would fill the pots fairly quickly but with the first time I used the new lines, I blew the relief valve at 80 psi before I could blink! It was about 1/4 the time to get to 80 psi.

So, the moral of the story is if you are using your compressor without piping, use the largest and shortest air hose you can and you will get there faster. While I was changing everything out, I had to use one of my 2 pancake compressors and it worked just fine. When I used my little 1/4" air hoses that I prefer for trim work, it took much longer than using my 3/8" air hose. There is plenty of volume in a pancake compressor to fill a pressure pot but the bigger the hose, the quicker you can get it out and into the pot.

 

[PenMan1]

I have a big compressor with air hose reels all over the shop. BUT when filling the pressure pot, I have a pancake compressor hose permanently attached to the "little" pot which never gets detached from the lid.

This pot is exclusively dedicated to embedded PR casting. This pot never gets filled past 50 PSI (and usually 35 PSI). The little pancake will fill the pot PLENTY fast enough, and it gives me a little more time to help with the lifespan of my molds. In my shop, anyway, higher pressures mean shorter silicone mold life.

How much pressure you need and how quickly you need to fill the pot can change you plan significantly. For example, trying to fill a 5 gallon pot quickly enough for a 80 PSI alumalite pour, would be difficult, if not impossible to achieve in the time constraints necessary.

Respectfully submitted.

 

[Haynie]

If you aren't going to dedicate the compressor to to casting but are going to use it for other things as well then forget thinking about casting and its requirements. Instead decide on the requirements for the biggest job you MIGHT do with it. Everything else can be done with the help of valves.

 

[Hendu3270]

I have a 2.5 hp 21 gallon that works great for my shops. Been using to replace siding, eaves, fascia board around the house with my nailguns for the past few weekends. bringing up a small pressure pot is not a very difficult task. Get the biggest compressor you can afford is my advice.