Veneer pump question

[Dan Forman]

I have been thinking about building a veneer pump using supplies from Joe Woodworker. Wondering about the relative merits of the compressor vs vacuum pump approach. I have a 6 gal compressor now, but he recommends a 20 gal, so if I went that route I would have to upgrade, but would then have a unit that would be better for spraying finishes as well. I'm not very mehcanically inclined, so don't rally feel very comfortable adapting such things a refrigerator compressors, unless it is truly a no-brainer. I would appreciate any feedback you could offer.

Dan

[tod evans]

dan, the most inexpensive route is to go with an electric pump. i think venturi pumps are much faster and will out live the electric but they love air. as a rule of thumb if your compressor sounds like an angry 100# hornet it`s not suitable for a venturi pump, whereas if it goes thunka-thunka, as in oil-bath cast iron, the venturi might be a good choice for you. hope this helps? tod

[Steve Cox]

I built the venturi pump from JoeWoodworker a couple of years ago. I believe he has updated the design since then so all this may not apply. Construction was very straight forward. I had the whole thing made in far less than a day. It works very well but it is loud and uses LOTS of air. I have a 60gal single stage compressor (Lowes) and it runs frequently. However, I have not used the press very much and don't have the pump dialed in yet. I think it will use less when all is said and done. I built this system for the same reason you're thinking about it. I was equiping the shop and it was a less expensive option to buy a compressor that could be used for spraying or sanding and then use that same power for veneering than it was to buy a seperate vacuum pump. I'd probably do it the same way again but I wouldn't buy a smaller compressor and I might very well look at a two-stage pump for my 60 gal tank. If your compressor is adequate for the tasks you need air for it will be cheaper to get a dedicated pump. Dedicated pumps are usually faster than venturi units and are much quieter.

[Chris Barton]

I use an electric pump and it works great. The vacuum pumps can be easily found on auction websites for under $100 and then all you really need is a bag and a vacuum board which is nothing more than a piece of wood with groves cut into it so a vacuum can be drawn. I bought mine as a kit for around $300 but, you can build one for less...

[Dennis Peacock]

Get you a used vac pump and get'r going. It's the best way I've found for vacuum pressing and for vacuum chucking on the lathe. you can find a good used Gast pump for around $80 and will serve you well.

[Cecil Arnold]

What Dennis said. The JWW route is easy for anyone who can pound a nail. (it doesn't even have to be a straight nail)

[Charlie Plesums]

I'm about ready to order one, but have divided the field into three, not two options.

The venturi vacuum, driven by compressed air. Everyone says (including here) that it takes LOTS of air, so I ruled this out... noisy plus why beat a compressor to death (or wear out the one I already have).

The vacuum pumps with tank and control system, such as the ones advocated by Joe Woodworker. Looks like a good way to go, but I have no desire to spend a day or more running around looking for the right kind of PVC and building it. You can buy this type of system factory assembled, but they aren't cheap.

The third option is a continuous duty vacuum pump. Once the bag is empty, it only takes a small pump to keep the pressure up (or for vacuum, is it down?). I didn't appreciate this option until I took a veneering class from a woodworker who does a lot... and that is what he used. He had plumbed a "T" into the vacuum line, so his shop vac could remove the bulk air, then he shut the valve to the shop vac, and the little pump did it's thing in no time, and quietly ran all night (not drawing a lot of power, not taking a lot of space, not creating large amounts of noise or heat). At this moment, I am about to order a small continuous duty pump for veneering and for vacuum chucking.

With a minor hijack of this thread, any comments on the continuous duty pump, compared to the other approaches?

[Cecil Arnold]

Charlie, I think if you can find a good continous duty pump for a good price that may be the a good way to go. One point. You don't need to let it run all night. Most of the glues will set in an hour, and my bag (the JWW design) is sealed well enough that you can take th epump off and still hold a vacuum for another hour.

[Dan Forman]

Thanks to all for your comments. I think perhaps the continuous duty pump is the way to go.

Charley---What are you going to order, and from where? Not rally a hijack, I would be interested in any additional info as well.

Dan

[lou sansone]

Get you a used vac pump and get'r going. It's the best way I've found for vacuum pressing and for vacuum chucking on the lathe. you can find a good used Gast pump for around $80 and will serve you well.

yep what dennis said... I did the same and it works fine for what I needed

lou

[Steve Roxberg]

I bought a Gast 1/4 horse Continous duty from Surplus supply for $89. It was under $100 with shipping.

The only down side, if there is one, is that it will only run on 220.

I've heard of some folks buying a converter from them for about 30 dollars that converts 110 to 220.

These are excellent pumps.

I can provide the link if anyone needs it.

[Mark Singer]

I bought a Gast 1/4 horse Continous duty from Surplus supply for $89. It was under $100 with shipping.

The only down side, if there is one, is that it will only run on 220.

I've heard of some folks buying a converter from them for about 30 dollars that converts 110 to 220.

These are excellent pumps.

I can provide the link if anyone needs it.

Steve,
I got the same pump....don't we need a relay and some tanks, a valve or 2 mine is just sitting waiting for me to figure it out. I noticed that Joe Woodworker has the mac valve in 220 volt

<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0><TBODY><TR><TD><TABLE cellSpacing=0 cellPadding=2 width="100%" border=0><TBODY><TR height=40><TD class=pageHeading></TD><TD class=pageHeading align=right>$25.20</TD></TR></TBODY></TABLE></TD></TR><TR><TD>http://www.joewoodworker.com/catalog/images/pixel_trans.gif</TD></TR><TR><TD class=main><TABLE borderColor=#ffffff cellSpacing=0 cellPadding=2 align=right border=0><TBODY><TR><TD class=smallText borderColor=#ffffff align=middle><SCRIPT language=javascript><!--document.write('images/macnew.gif3-Way" title=" Mac Valve
3-Way " width="113" height="85" hspace="5" vspace="5">
/catalog/images/image_enlarge.gif (http://javascript<b></b>:popupWindow(\'http://www.joewoodworker.com/catalog/popup_image.php?pID=57\'))');//--></SCRIPT><IMG title=" Mac Valve
3-Way " height=85 alt="Mac Valve
3-Way" hspace=5 src="http://www.joewoodworker.com/catalog/images/macnew.gif" width=113 vspace=5 border=0>
http://www.joewoodworker.com/catalog/images/image_enlarge.gif (http://javascript<b></b>:popupWindow('http://www.joewoodworker.com/catalog/popup_image.php?pID=57')) <NOSCRIPT>images/macnew.gif3-Way" title=" Mac Valve
3-Way " width="113" height="85" hspace="5" vspace="5">
/catalog/images/image_enlarge.gif (http://www.joewoodworker.com/catalog/images/macnew.gif)</NOSCRIPT>

</TD></TR></TBODY></TABLE>This 3-way Mac valve controls the air flow from your compressor into the venturi unit. It has the recommended 1/4" pipe threads and meets the CFM requirements for the venturi press (if that is the style press you are building).

This unit is also suitable for use on motorized vacuum pumps to release the back pressure when the unit shuts off during each cycle.
Available Options:
<TABLE border=0 cellspacing?0? cellpading="0"><TBODY><TR><TD class=main>Voltage Option:</TD><TD><SELECT name=id[18]><OPTION value=62>110 VAC - Standard Voltage</OPTION><OPTION value=61>24 VDC - Low Voltage</OPTION><OPTION value=63 selected>220 VAC - High Voltage</OPTION></SELECT></TD></TR></TBODY></TABLE>

</TD></TR></TBODY></TABLE>


Hre is the link and the transformer is also there...

http://www.surpluscenter.com/item.asp?UID=2004111114162930&item=4-1540&catname=air

[tod evans]

i`ll adlib on what charlie said, in my system i use a tripple venturi pump to evacuate the bag, this unit draws about 24cfm@100psi. once the bag is sucked down i switch to a small 3.5amp diaphram pump to hold the pressure. the last thing i want to do is run my compressors to maintain the vacuum, but afterall i`m cheap and don`t much care to write big checks to our electric co-op. hope this helps? tod

[jerry cousins]

here's my .02.
i started with a venturi system and it really did beat the compressor pretty hard - and barely made the vacuum. then bought a continuous duty pump (110 volt) - which is rated for 40000 running hours. has worked wonderfully - not very noisy at all - just a small "puttering" - i usually keep the piece in the bag for 2 hours - that seems to be enough to make a successful press. so if the pump rating is good that's 20,000 pressings - likely more than i'll need.
but the other day i did a piece and the shop was pretty cold - probably high 50"s - took the piece out after 2 hours and then had to manually press it cause it hadn't set enough. going to get an elelctric blanket to cover it while pressing.
other than this one all others have been successful.

jerry

[Steve Roxberg]

Mark,

I just hook mine up directly to the bag I got from Joe.

The pump runs 100% of the time, but it's rated for that and it's not too noisy.

The only advantage with the tanks would be that the pump would cycle on and off as needed. Not worth the bother for me at this time.

It would be nice, but I'm still learning.

[Mark Singer]

Steve,
Thanks....I am not a scientist and just want to get started...I have 220v so i am good!

[Aaron Montgomery]

This is the vacuum press that I built last Christmas using the Surplus Supply 220V Gast pump. I haven't actually used it yet to make anything, but it seems to work just fine. (it holds vacuum) If I were doing it again, I'm not sure I'd go to the trouble and expense of building the JWW rig. It's cool, but other than the noise, I don't see any reason to build the JWW rig. I was surprised at how much additional cost was involved in building it. (Considering the pump itself was only $90) The rig I built is heavy and somewhat awkward to move. I'm not real excited about having a 220V and a 110V cords to plug in to use it. I think I'd recommend starting with the pump and building the JWW rig down the road if you were so inclined.

http://home.insightbb.com/~apmonte/Graphics/WoodShop_37.jpg

[Ben Abate]

Aaron,

Could you elaborate about the Joe Woodworker rig. What are the problems that bother you. The reason I ask is, I have been looking to buy or build a vaccum pump. I have been putting off quite a few projects because of not having the time to put a system together. I was thinking of building one of Joe's setups after the Holidays. My intentions are to build one that I would not say oh, I should have built a larger system. So if you could tell us why this is not the answer.

Regards

[Mark Singer]

Aaron,
Very usefull info...It sounds like the 220v Gast can easily run for 3 hour periods and at that point no cyclying system to releive the pump is required...I will spend the money on a bag instead.

[tod evans]

mark, i regularly leave my small pump running overnight. i too don`t see a need for the switch. the only reason to consider a reservoir is to pull the bag down faster. if you`re doing large "form in bag" bent laminations it can be a real plus to pull a vacuum quickly (picture me on top of the veneer table trying to force a piece down to the form so the bag doesn`t get sucked together between the workpiece and form,using my arms,legs and nose to restrain this eel-like mass of glue and wood while the pump sloooowly pulls a vacuum.) but if you`re just using the press for flat work there is really no need for a method of quickly applying vacuum. just food for thought, tod

[Aaron Montgomery]

Ben,

I'm not sure that I have any problems at all with the JWW setup. I'm really just nit picking. I was only suggesting that it may not be necessary. I enjoyed putting it together because I like tinkering with stuff like this - it's cool. It's more that on hindsight I'm wondering if it was money and time well spent. The JWW rig that I built is heavy and somewhat awkward - the pump alone would have been easier to move around and to store. It's not a big deal, but for some reason I really wasn't thrilled with having two cords (220V & 110V) on a single tool.

I don't think there's a right or wrong answer here, but I'd suggest that if the pump is capable, that you use it as is and see how it goes. Nothing is stopping you from building the JWW setup at any point in the future.

Mark - Surplus Supply lists this Gast pump as continuous duty, so I don't see why you couldn't run it for extended periods.

[John Gregory]

Aaron,
Very usefull info...It sounds like the 220v Gast can easily run for 3 hour periods and at that point no cyclying system to releive the pump is required...I will spend the money on a bag instead.

Here is the link (http://www.joewoodworker.com/catalog/product_info.php?products_id=704&osCsid=feeb447e407caa49fe1676f29600f427)for the kit Joe Woodworker has for continous operation.
I am hoping to get the surplus pump and do this one day. I have no experience with vacuum hardware or use but I am very interested in this thread.

[Charlie Plesums]

The pump I have been looking at is this one (http://www.joewoodworker.com/catalog/product_info.php?cPath=46&products_id=248&osCsid=feeb447e407caa49fe1676f29600f427) from Joe Woodworker. It includes the "add on parts" that seem to sell for $75 or so, plus a pump that I might be able to get for just under $100 if I looked, but for roughly $275 I have a complete system with someone I can lean on if it doesn't work right.

Plus another $22 for vacuum clamping (why not)

Another $50 to $150 for a bag

Another ??? for a sheet of melamine to use inside the bag

The $225 I already spent on a veneering course

The few bucks I already spent on tape, softener, blades, glue...

The results... priceless... well maybe not quite.

http://www.plesums.com/wood/4WayPanel3006.jpg
But this is my first 4 way bookmatch panel, that will soon become an end-table with a walnut border. (I used the instructor's vacuum system).

Incidentally, Jerry, my instructor admitted that under ideal conditions the glue would set up in an hour or two, but he always left it in the bag at least 5 hours (normally overnight) to be safe.

[Mark Singer]

Here is the link (http://www.joewoodworker.com/catalog/product_info.php?products_id=704&osCsid=feeb447e407caa49fe1676f29600f427)for the kit Joe Woodworker has for continous operation.
I am hoping to get the surplus pump and do this one day. I have no experience with vacuum hardware or use but I am very interested in this thread.

John,
That seems lot a lot of $$$ for a few pieces of hardware...

[Mark Singer]

Do you need a gauge, valve or other stuff or just a direct conection to the pump? Will that create too much vacuum pressure? Should it be regulated?

[Steve Roxberg]

Mark,

Yes, I have a gage, T and ball valve. I purchased them at the local HD for about $20.

The gage allows me to see how much vacuum I'm pulling and the valve allows me to cut the vacuum or control how much I apply.

I'll try and get a photo later today.

[Dave Tinley]

I use a continous duty pump and it works great for me.
As a side bar- JWW sometimes lists his pumps on a particularly popular auction site and can be had at a good price.

Also-those that are interested in making your own vac press bags, contact a local auto upholstry repair shop.
I picked up some of the thicker clear plastic real cheap. It was left over from a job they had done, but the owner of the shop can order more. I have made 2 bags of different sizes and plan on making 2 more. Makes it very nice when doing a small jewelry box top to use the small bag.
I believe there is an article on JWW site on how to make bags.

And lastly, continious duty pumps work great for vacuum clamping.







Dave

[tod evans]

here are some pics of what i have done, the fittings are common hardware store items, the manifold is a piece of brass bar stock and the hose is 1/2" id heavy wall clear plastic tubing.i use plastic window screen to help the vacuum travel as well as kerfing the platten. hope this helps, tod26185

26186

26187

26188

[John Gregory]

John,
That seems lot a lot of $$$ for a few pieces of hardware...

I agree Mark, but it does provide a list of the parts needed. One could round up the parts locally.

[Dan Forman]

Charlie---That is one stunning panel. Kind of looks like a Tibetan painting, some wrathful diety. Like the two distinct eyes in the upper half. Will make an outstanding table top.

Dan

[Matthew Poeller]

Ok so I have been in contact with Tod Evans and Aaron Montgomery on this issue but I think that I am confused a little still. (They were very helpful. I think that sometimes I am just not smart:D )

I was thinking that they venturi system was the way to go for me. Mainly because of cost. My compressor is not at big as the ones that people have said they beat up throughout this post though, so now I am concerned.

So here is my question and I will explain my rational behind the reason.

Why does the compressor cycle so much?

I understand that there will be leaks in the system but I cannot figure why, after the initial pull on the bag, would the compressor cycle so much.

The venturi that JWW sells will consume 4.8 CFM at 80 PSI and my compressor can do that.

So here is my rational behind my question. The first pull will consume a lot of air and that is fine. (Have to evacuate that bag and all the good stuff) After the proper vacuum is reached though the vacuum controller will send a signal to the MAC valve and shut down the air, the compressor will recharge and be set with a full tank of air. The bag will leak a little and eventually the vacuum controller will send the signal to the MAC valve to open up again. Upon opening the venturi will draw the air out of the system until it reaches pressure again and the vacuum controller will tell the MAC valve to close. This should not be that much and not happen that often (depending on the integrity of the system), I would think. Am I wrong?

Being an engineer I have been racking my brain while writing this and thinking why this would be and went back to the way the venturi works and I think I may have answered my own question. Let me run it by you:

As the vacuum increases more air is required to pull an even higher vacuum(inversely proportional). So at 24" of Hg where the vac controller would be set to open the MAC valve at to get back to the required 25" would take a LOT more air that if you were making the same 1" of Hg increment at 10" of Hg.

SO DID I GET IT RIGHT TEACH?

[tod evans]

matt, you got the therory correct. just as a compressor must work harder to go from 90psi to 125psi so must a venturi move more air in order to achieve 27"hg from 20"hg (which by the way is only attainable with these smaller units at sea level) as i stated earlier in this post the reason i went with the venturi system i use is so i can evacuate the bag quicker. i don`t even know the specs of the unit you`re refering to in the "joe" site but as a rule if you`re only going to do flat work a small electric pump is the most cost effective option. in my case to use an electric pump for evacuation would have required either a very large storage tank or a screw type pump. so i made the most cost effective choice for me. tod

[Matthew Poeller]

Well that is what I thought. Thank you. I saw your post definitely and the prior PMs but I was still just a little bit confused.

I think that I will have to go to the continuous duty pump route.

The venturi that I was refering to was the one on Joe Wood Workers site and can be found here http://www.joewoodworker.com/catalog/product_info.php?products_id=1682

Thank you for you response.

[tod evans]

matt, checked out the "joe" site and i believe you have made a good choice. and you`re welcome, tod