Help building vacuum frame (need pump suggestions)

[menglert]

I'm going to build a contact printing frame because I can't find one at a resonable price. I found instructions on B&S , but can't find information on what type of pump I need. I'm only working with 8x10 at the moment, but in the future would like to work up to larger prints of 20x24. So I will build the frame to accomidate that.

What type of pump should I get? What should I look for in the pump as far as features? There seem to be a lot of different options, and I have no idea how much power I need.

Any other suggestions from those who have built a vacuum frame in the past or have expeniece with them is welcomed.

Thanks,
Martin

 

[Donald Miller]

I'm going to build a contact printing frame because I can't find one at a resonable price. I found instructions on B&S , but can't find information on what type of pump I need. I'm only working with 8x10 at the moment, but in the future would like to work up to larger prints of 20x24. So I will build the frame to accomidate that.

What type of pump should I get? What should I look for in the pump as far as features? There seem to be a lot of different options, and I have no idea how much power I need.

Any other suggestions from those who have built a vacuum frame in the past or have expeniece with them is welcomed.

Thanks,
Martin

Martin,

I am assuming here that you are speaking of a vacuum easel that has perforations through which air is evacuated to hold the paper flat. If I am mistaken, then what I am about to relate will probably not apply.

Once the openings in the easel are obstructed by the paper then you will not need a vacuum pump to pull a deep vacuum. An example of a deep vacuum pump would be a two stage pump that evacuates refrigeration systems.

The higher the CFM vacuum pump that you can obtain will serve to hold the paper down quicker. The thing that makes the most sense...the most bang for the buck, so to speak, would be a used tank vacuum cleaner...if you provide a large enough opening into the easel to accept the vacuum cleaner hose you can probably get this done for very little money. Pawn shops usually have a ton of these things laying around for less then $20 bucks.

The downside is that they are fairly noisy...but you could remotely position it.

 

[BradS]

shop vac.

 

[Allen Friday]

I use a shop vac with my frame.

 

[menglert]

Thanks for all the quick advice.

So as I understand, I don't need a powerful vacuum, because the power will only determine how fast the contact is made, right?

Shop vacs seem to be a good idea. Do you use anything to make the hose opening more narrow?

-Martin

 

[edz]

Shop vacs seem to be a good idea.

No. They are not. Vacuum cleaners are a cheap but not good idea. They are designed and intended to suck but not to suck hard (closed intake) for longer than a few seconds. They will get very hot. They are also not terribly constant so no only unreliable (if one is sitting on a bunch of old vacuums perhaps not that much of an issue) but inferior. In a frame you want a reasonable (relatively low underpressure but with moderate volume capacity) a vacuum and you want to hold it, typically, for longer than just a few seconds. If you hunt around, however, and with a bit of luck one can find a surplus rotary vane industrial pump (costing new many 100s of USD) for less than the price of 10g, maybe as much as 25g, of silver nitrate.

 

[Joe Lipka]

Gast makes the vacuum pump used in the NuArc vacuum frames. They are almost bullet and fool proof. Google Gast and see what they have. You should be able to purchase through a local industrial distributor.

Don't forget you need a vacuum gauge to measure how much your apparatus sucks. No, seriously, sucking for a vacuum frame is a good thing. Vacuum gauge is important because you need to maintain a specific vacuurm level as part of your printing routine. The level of vacuum, or how tight the negative is pressed against the paper is key in maintaining consistent highlight exposures.

At least that's been my observation. Your mileage may vary.

 

[TimVermont]

I have a very small Gast pump. Noise and vibration are issues you'll need to solve. I used rubber washers, nylon sleeves around the mounting bolts, cork and felt. Use only a small section of soft flexible tube to avoid loss of suction. I use hard fiber reinforced tubing for the long run.

 

[Richard Wasserman]

I bought a small vacuum pump and gauge from McMaster Carr. It's a bit slower than a larger pump, but a lot quieter. I also installed it outside the darkroom on a styrofoam pad.

Richard Wasserman

 

[menglert]

Thanks for all your advice so far...

I'm looking through some different pages, and at the Gast pumps. There are a lot to choose from with different specs. What is the minimum vacuum "psi" rating I should use for contact printing? Are there any other specs I should be concerned with while choosing one?

-Martin

 

[menglert]

Richard,

What were the items you ordered from McMaster-Carr? I'm looking through their site, and they have vacuum pumps priced from $50-up.

Thanks,
Martin

 

[Richard Wasserman]

Martin,

I bought the pump item number 41675K31 at $183.47.

Richard Wasserman

 

[michael9793]

I bought a 28x36 Vacuum frame on E-bay for $75.00. you can buy a whole flip top plate burner of $200.00. Hell I'll sell the one in my gararge for $100.00 if you will pick it up. It has a light tube, vaccum pump and the whole 9 yards. the last time I used it was for Pt/Pl. But I'm into Azo now. P.S. I live in Fort Myers Fl.

 

[Jeremy]

ROTARY VANE COMPRESSOR GAST, #1532-P104-G597X. Oil-less rotary vane compressor. Rated at 1.5 cfm. This pump can also be used for vacuum service and is rated 20" Hg max vacuum. Motor input: 115 VAC 60 Hz 0.55 amp, 0.025 hp, 1075 rpm. Single phase. Ball bearing motor. Input and output ports ar 1/8" female NPT. The unit is supplied with a noise suppressing filter screwed into one port and an output filter unit is supplied connected to the other port. The mounting base has 4 flexible shock suppressors installed in the base mounting holes. The suppressor mounting holes ar 3/16" in dia. The centers of the mounting holes ar 3-7/16" apart along the width axis and 2-3/4" apart along the length axis. Capacitor supplied. Dimensions: 5-5/8" long x 4-3/16" wide x 4" high. Stock #PC2050 $39.95

http://www.aaaim.com/u/web/aaaimc/cgi-local/shop991/shop.pl/SID=490815316/page=REGS.htm#PC2050

This is the pump that Sandy King recommended on the alt process list for a 22x28 Nu-Arc Vacuum Frame.

Recommendation came from this thread:
Dead Link Removed

I'm searching myself for a vacuum pump myself as I just came into a 22"x29" NuArc frame w/ everything but the pump (thanks, Clay!) and I think this will suffice for my needs.

 

[glbeas]

Jeremy I've got a spare pump if you ever go near the Atlanta area.

 

[Jeremy]

Jeremy I've got a spare pump if you ever go near the Atlanta area.

Gary, I'll be in Atlanta the end of May

 

[menglert]

Will the "ROTARY VANE COMPRESSOR GAST, #1532-P104-G597X." work fine for a homemade vacuum frame? I'm working off the design on B&S. I plan to make it about 24x24.

-Martin

 

[glbeas]

What kind of design is your vacuum frame? The so called vacuum easel needs a high flow at just a few pounds pressure drop, whereas the contact printing frame that seals well when closed works best with the higher pressure drop that the vane pump is capable of.
In truth it may be way easier to find a used vacuum frame from a print shop than it would be to build one yourself.

 

[menglert]

This is the design I was working with (LINK) .

Any other ideas on how to construct one is welcomed, but today I bought most of the materials to build this.

Thanks,
Martin

 

[glbeas]

Thats a really nice design! Yes this is what the Gast pumps are for, they are perfectly okay with almost no airflow when the frame seals up and can be run for very long periods of time on high vacuum. Good luck!

 

[menglert]

Thanks for all the excellent advice. I'll go on and order the Gast that was suggested above for $39.99. Are there any other supplies I will need with the pump?

Thanks again,
Martin

 

[Claire Senft]

If you deal with an industrial supply house do not ask for a vacumm pump..ask for a vacuum motor. Vacum pomps are designed to move liquids, vacuum motors to move air. I realize that it is common to use the term vacuum pump but it is incorrect and can cause confusion as I found out at an industrial supply house.

There is available a vacuum motor made by Daytom electric for approx $120.00 from Grainger that should work nicely bu will need you to construct a housing.

Good luck with your project.

 

[menglert]

I placed an order for the Gast motor suggested earlier. I think it will provide me with everything I need at the moment and was a good price. Any other suggestions are welcomed. I'll keep everyone updated on the progress.

Regards,
Martin

 

[menglert]

OK, so now I've recieved the Gast pump I ordered. I wasn't aware these needed a power supply. Is it possible to just splice the wires and connect it to a plug for the wall? If not, what type of power supply would work (PC power supply?)?

Thanks,
Martin

 

[glbeas]

There should be a wiring diagram on the cover plate at the end of the pump to show where the power should be applied. It should be 110 or 220 volts depending on the motor you ordered. Some motors have connections to run either voltage.