Vacuum pump

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No brand name mentioned anywhere, so it's probably an import knockoff from who knows where (unless maybe it fell off the back of a truck). At 1.8cfm, it's pretty low capacity.

If it were my money, I would spend a few bucks more buying a robinair or mastercool (3cfm+ / 75 micron) at amazon. I would even buy the HF 2.5cfm before the one you linked.

But that's just me.

Ed

Edit: I've been using this one for more than a year with pretty heavy use. It's worked great.

http://www.amazon.com/Mastercool-90...2&sr=8-6&keywords=mastercool+6cfm+vacuum+pump
 
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Like Ed said, you can buy them at HF for about $90-$120 last time I checked. They are not top of the line but they will serve your purpose.
 
What Don failed to mention is that you need a pretty good air compressor to make his suggested $15 solution work. When I've played with the venturi vacuum pumps in the past I decided I didn't have enough time to wait for the thing to evacuate my vacuum chamber. If you have the compressor and you have the time, then maybe it's something to consider.

My vacuum chamber is about a cubic foot. The higher the cfm rating, the faster you will get to your target vacuum. My pump claims 6cfm, but that rate slows down as the vacuum increases (and the air runs out). It takes it about 45 seconds to bring my cubic foot chamber to 75 microns. That's fast enough for me to do what I need.

I would get one that pulled to 75 microns. That's about 29.9+" mercury. That's almost complete vacuum and a huge difference (better) over a venturi that only gets to 25". Tie off a latex glove (don't even inflate it) and toss it in the chamber. At 25" it's still laying pretty flat. At 29.9" it's fully expanded. Bigger bubbles rise faster than smaller bubbles.

Ed
 
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One other thing I should mention. Rotary vane oil sealed vacuum pumps like the ones above will put out a very fine oil mist when they are running. I would not recommend using one inside unless you have a way to exhaust that mist. The oil mist settling out on your tools may help prevent rust, but it's not likely to do much good anywhere else.

Ed
 
Don - Here's an example of the difference between 25" and 29". If 25" works for you, then great. For me, I wouldn't even bother with vacuum if I could only get to 25". Using heat and vibration (as advocated by some successful casters here) would be more practical than a venturi fo rme.

But to each their own.

Ed
 

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I'm getting my wood stabilisation system put together as we speak and I can understand all the questions raised about the used however, would make thinks a lot simpler if we keep the issues of stabilisation and casting separate, as they are a completely different issue that requires totally different equipment and principals...!

Pressure pots for casting, is in my view a much easier issue to deal with, as there are not a lot of choices, really. You either by a cheap pot or you by an expensive one, the differences have more to do with the safety aspect than anything else, and while cheap pots can do the job for most casting needs, better quality ones will have less leaking problems and are capable of safely be pressurised at higher pressures (over 50PSI to about 100PSI).

Compressors, well...! it all depends of how fast you want the pressure to be reached, and any cheap compressor will do for a pot that will not exceed 50PSI, if higher pressures are required any mid range compressors are capable to do the job.

There are off-course, many other small details about casting, with one that can cost a bit and keep you making some more, as the molds..!

With the vacuum systems, the principle couldn't any simpler but, the most confusing aspect of building your own "proper" stabilising system, is the pumps issue. There are a ridiculous amount of different operating systems in these things, single/double stage, oil, dry, vane, diaphragm, etc, etc, etc, etc...!:eek::hypnotized: which one is the best and most durable...???

Then we have the damn chambers...!, glass, acrylic, aluminium, stainless, square, round, odd shape, all clear, partial visibility, top opening, both ends opening, double container systems, etc, etc, etc....!

I tell you this, if you only need a small to medium stabilising system, talk to Curtis, the Cactus Juice man from IAP and ask him to put a complete system together for you, he will supply you with everything you need except the pump that you will by yourself but under his recommendation, that way, you will save yourself a lot a dead brain cells from trying to sort it all out, by yourself...!

It has been proven, time and time again that, and with the exception of a few situations that, the great savings we all think we have by doing it all ourselves, improvising as we go, to save all those "bucks", is in fact, a big mistake and certainly not as a money saver as we all think, the truth is, will endup costing us more in the end and me "may" for ever being "patching holes" with something that was either made to fail, preform poorly, or be simply to damn dangerous/unsafe...!

How do I know that...??? been there, done that...! and I'm still falling in the same mistake today, why is that...???

This new stabilising system that I have been spending money on for about 1 month, have already ate in excess to $750.00, and I'm far from over yet...! I still have to do a lot of work to install the gauge, hoses, filters, work on sealing the lid with liquid silicone or something that will do the job, and find a way to glue this special O'ring to the lid that has cost me a fortune in phone calls, 150 miles of driving just to make sure it will fit, nearly the hole day on the damn road due to the road works everywhere and still, I have no guarantee that the lid will work and the O'ring will do what its needed, as "again" I decided to save a few bucks and do something that looked simple enough, myself...!

Has been a month working on get all the bits and pieces and spending money, I'm still waiting for stuff that comes from overseas, I'm still trying to find bits and pieces that, I have to wait for something to arrive before I know what to look for next so, lots of wasted time, for sure...!

I doubt that, I will be having the system going in the next month as I still not know if everything is going to work as intended, when, if I had accepted to spend $1.300 to start with and by a factory system that is supplied with everything, apart from the "Juice", I could have been stabilising within 2 weeks from when I decided to get this "thing" going so, my piece of advice to you is, think hard and think twice, being "handy" in making things up, is not always all its needed and after all, surely your time has got to worth something, huh...???

PS: Your blood pressure could also benefit greatelly by voiding to get all worked out and annoyed, as I have been with this damn idea of mine...!

Good luck tough...!

Cheers
George
 
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You might get this one a little cheaper: 2.5 CFM VACUUM PUMP 115 VOLTS 60 Hz, 1/6 HP, 1720 RPM | eBay.

Or this one: Emerson 93100 High Vacuum Sevrice Pump NO RESERVE | eBay.

If you are handy, you could put new diaphrams in this one and have a great little pump: DeVilbiss GSE ZW370D14 Model Vacuum / Compressor AS-IS | eBay.

This isn't a bad little pump, but i t won't be real fast: SPEEDAIRE 4Z792 Diaphragm Vacuum Pump | eBay.

For the money, this is proabably the best of the bunch: Thomas Compressor Vacuum Pump 2619 2639 Aerate Pond | eBay. Looks to be a Gast type.

FWIW, my first vac pump was one of the $15 HF types. Works, but requires a good air compressor with constant flow if you intend to draw a lenghty vacuum. I later bought a good used Gast.

Then there is this Gast: Gast Vacuum Pump, saa-v109-nx, rebuilt | eBay.
 
The pump you linked to in the original post is your typical Asian import pump. It is not any better or worse than the HF pumps or even the cheap Robinaire pumps. I did a lot of research last year about acquiring a line of vac pumps. I found out that there are only 3 or 4 vacuum pump manufacturers in China and the cheap pumps you see over here are just different names on the same pumps.

I was especially disappointed when I found out that Robinaire, who I thought was American Made, had Asian import pumps. I called them and spoke to their technician and found out that all of the Vacumaster pumps are imports. The blue handled pumps are still US made but that is it.

For stabilizing (which is what the question was about), forget the CFM rating. Higher CFM pumps will not generate a deeper vacuum, it will just get it there quicker. If you have one pump rated at 50 microns and 1.5 CFM vs another rated at 50 microns and 6 CFM, they will both do just as good of a job.

The main reason for the higher CFM pumps is for the HVAC industry. If I am an HVAC tech and I go out to pull down a small house system, I may only need a small CFM pump. But, if I go pull down a large hospital system, I need a high CFM pump to make the job go quicker, otherwise I may be pulling vacuum for a few days.

For the money, I would look at this pump. I have used this pump in a demo I did and it did a fine job. It is $74.99 and is the same Asian import as all the others. Sure, it is not serviceable or rebuildable like an American made pump but for the cost, you could afford to replace it every few years if necessary.
Amazon.com: FJC 6905 Vacuum Pump 1.5 cfm: Automotive
 
Don_Hart said:
My opinion is that an actual vacuum pump like the ones mentioned is overkill. I cast on an almost daily basis and I use a venturi vacuum pump. I am able to pull 25" of vacuum without a problem.

These units are commonly used to evacuate cooling systems and you can usually get one for under $20. The unit here will do you fine Vacuum Pump - AC Vacuum Pump w/ R134A & R12 Connectors
Click to expand...

You are talking about casting whereas the original poster was asking about stabilizing. For stabilizing, you want the deepest vacuum you can get. The definition of a perfect vacuum is the absence of all air. Since the idea behind vacuum impregnation (stabilizing) is to remove as much of the air inside the blank as possible to allow for the stabilizing resin to enter, the higher the vacuum, the more air you will remove. If you are getting 25" Hg at sea level, you are only pulling a 83.5% vacuum or a maximum of 83.5% of the air out of the blank. With a higher vac pump, you will be pulling much closer to a perfect vacuum. If you are pulling 29" Hg at sea level, you are generating a 96.9% vacuum or a maximum of 96.9% removal of the air in the blank.

Of course, if you are in Denver and pulling 25" Hg, then you are about as close to a perfect vacuum as you can get (and you gauge is most likely off!). There is less air the higher you go so there is less air in the blank to begin with, thus less to remove. You loose aprox. 1" Hg for every 1,000 above sea level. Therefore, in Denver at 5,000' ASL +/-, the perfect vacuum is 25.175" Hg so a 25" Hg vacuum is a 99.3% vacuum!
 
Curtis,
I know, and you have stated many times of the amount of time and tests you have done about the stabilisation issues and what works, etc..!

I wonder, if you could explain, what's the difference in between all the vacuum pumps working system, we see for sale, such as the single and double stage pumps, and another hand full of different working systems factory produced.

I can admit that was the most irritating point I found when I was looking to purchase a vacuum pump, I endup with this one, as a recommendation from a engineer friend that makes knifes using my woods for handles and is very pleased that I'm starting to stabilise soon.

By the way, I got your "stuff" this morning, thank you...!

Cheers
George
 
For my money, used so far on 6 batches of stabilizing stuff in on of Curtiss' tanks...my $40 refridgerator compressor is fantastic!! 2 CFM, but as mentioned, it just takes a little longer, but gets to -28 in about 2 minutes.
 
tool-man said:
I'm not Curtis, but here is a pdf file by Gast that has a pretty detailed explanation of the various types of vacuum pumps, how they work, etc.
http://www.gastmfg.com/vphb/vphb_s4.pdf
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G'day Andy,

Thank you very much for the link, it is exactly what I needed and will certainly save a lot of time to Curtis, if he had decided to explain it all here so, and for anyone that is intrigued about the various vaccum pumps system on sale out there, this is a great document, thank you...!

Cheers
George
 
Jim Burr said:
For my money, used so far on 6 batches of stabilizing stuff in on of Curtiss' tanks...my $40 refridgerator compressor is fantastic!! 2 CFM, but as mentioned, it just takes a little longer, but gets to -28 in about 2 minutes.
Click to expand...

Yes, I've heard good things about those fridge motors and I though going that way in the beginning but, I have thousands of blanks to stabilise, some a lot bigger than pen blanks, some actually round bowl blanks up to 12" diameter so, I knew that I needed a chamber that is a lot bigger than the biggest Curtis make and a few times the volume of the small ones, most people need and are using.

There was the combination of the speed reaching the ideal vacuum, as the lid as a large are to seal and a small amount of vacuum at the time would probably not be sufficient to get the suction required to seal, as I will compare this to inflating a tubeless tyre, unless you have a certain amount of pressure to make the tyre move towards the rim, you would be there forever and you not inflate...!

Other factors are the durability of pump in constant and prolonged working ours, and the most critical point, the capability of reaching maximum vacuum possible in the sea-level altitude, I'm at...!

I may be disappointed with my system, or it may fail all together, particularly due to the large stainless round pot and glass lid that come with it. I was told several times that will explode/shatter/fail and while I have some reservations of its performance/suitability, I will not be a bit surprised if it will stay in one piece and do the job I need it to do...!

I'm nearly ready to put it all together, and a safe test will be performed to verify the glass 4mm curved glass lid strength/suitability. It if fails, a replacement will be made with a flat piece of 3/4" clear acrylic and a flat O'ring/gasket glued to the inner surface of the acrylic but, I want to see what the lid does, regardless. No guts, no gain...!:wink::biggrin:

Cheers
George
 
I ordered on of the vacuum pumps that Curtis recommended and it was at my house within 2 days. They are very fast shipping. Now I am all dressed up with no place to go. I got on the waiting list last weekend and can't wait to join in the fun. I have some really nice spalted maple here that is begging for some cactus juice.
 
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I just used my pump to hold about 27" for an hour I have the blanks in an oven now I hope they came out good but they were pretty light still? The wanted to float. I will try it on another set tomorrow and take longer this time..
 
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