Thread: Vacuum Press

Vacuum cleaner won't work. High throughput, low vacuum.

I don't know about the vac. bags.

So far as I can tell, the handpump is just as good as anything EXCEPT - that it must be manually operated and may (if you are unlucky) lose vacuum. A machine can be left running to keep the vacuum supplied even if a seal leaks slightly.

Cam

Thanks for that Cam, I think that I may as well try the storage bag on a non-critical job and see what happens. If it fails, then at least I can still get some use out of it as storage, and then go to the next step with a Carbatec cheapy. If, as you say, I get leakage, then the only thing left is to get a mechanical pump rather than the hand pump.

Yeah,

I haven't had a problem with leakage (but I use mine for stabilising instead of veneering). It is pretty much the same set-up.

A lot of people here have said that basically any sealable bag should do. But the Roarockit site (the cheapy from Carbatec) is really worth a look.

Cam

Hi,

I have a cloudmaker vacum press setup and its works a treat. I tried building my own vacum press from a Fridge compressor but after blowing up 3 of them I gave up .


as far as your questions goes:

1. Is it feasible to use the ~$25 space saving storage plastic bags sold at homewares

Space Saving bags are a lot thinner than the proper vacum bags used, it might be ok for flat work but they'd probably tear in higher/thicker work or jigs. The plastic used in vacum bags is resistant to most glues, you might want to see how space saver bags hold up with the glue your trying to use. (you will get some squeeze out).

As it was said before a vacuum cleaner wont have enough suction.


2. Does the simple Carbatec hand vacuum pump do the same job as an expensive compressed air venturi pump or an electric vacuum pump, and if so, then what extra benefits do the costly options offer?


This is probably a good starting point, the final results would be the same as long and you create the same kind of vacum. Just be aware that if there is a small leak you'd need to keep your eyes on the job to keep re-vacuming the bag as it loses pressure (some glues can take 8+ hours to dry!). Another possible issue might be with things moving around as you suck all the air out. Normally your using your hands to make sure everything stays flat (creases etc) and doesnt move while the vacuum is building. If your pumping away you cant hold things down and all the hand pumping might cause even more movement.

Electric vacum pumps make it a lot easier, your hands are free to ensure everything is where its supposed to be. You wont have any issues with pressure loss, you can setup the glue up and walk away. Sometimes things might move or you get excess glue squeeze out ,when vacum pressing with an electric setup you just break the seal reposition/clean up and re-seal, if it was a manual setup you'd have a lot of hand pumping to do.:eek:


3. I have seen printed claims in advertisements for the expensive presses that the clothes-flattening plastic storage bags will leave marks or creases on the finish if used as a vacuum press. True of false?

Might happen if the bag reacts with the glue etc, creases can happen either way you just need to watch the job as the pressure builds.


I'd say it your choice depends on the size of the projects your using it for, for flat picture frame type jobs give hand pumping a go, if its larger jobs or bent laminations using jigs etc... go electric.



Hope this helps

Joez

Don't many of the manufactured vacuum bag kits come with some sort of mesh to overlay the workpiece with before inserting them into the bag to avoid the creasing issues?

I haven't investigated this myself (yet) but someone here (Lignum, possibly?) suggested going to a tarp manufacturer and have them seam weld up some suitable plastic into a bag of the desired shape. Seems plausible (and likely rather cheaper). The only issue I can see would be finding a connector between the bag and the vacuvin (handpump) or whatever.

Have used and own both the carbatec and cloudmaker vacc bags, both work well. For small stuff the carbatec one is great- the seals work well(directions are good) and for ease of use the compressor-venturi valve cloudmaker is fast . Depends on what you want to compress and how much you want to spend.
cheers rosethorn

The only issue I can see would be finding a connector between the bag and the vacuvin (handpump) or whatever.

I've been watching this in the hope that a cheap and reliable solution is arrived at, so I can thieve it.
Some of the prices for the vacuum bag presses are really scary, considering the amount of use it'll get at my place!

I'm hoping that the hand pump bags like the carbatec Roarockit one can be plastic welded. That way I can use one for the valve and pump connector and get it welded into a bigger bag.

Unfortunately I don't want it for small items, for which the off-the-shelf bags are ideal.

From the sounds of it using the hand pump makes it a 3 or 4 hand job, I might have to get the missus on the job as well?

Clinton,

Here's a link I posted recently on another thread: http://joewoodworker.com/

I'm still contemplating building a small venturi version using my existing compressor. How cheap is cheap?

I think it's that site that also has instructions for building bags out of heavy "curtain" vinyl, and they also sell valves for same at reasonably modest cost. They may be available elsewhere, I just don't know where to look!

Cheers,

P

Midge doesn't understand real cheap...

The windpump plugs are rubber - they can be glued, but not welded so far as I can tell... HOWEVER, if you make a connection that sits inside the bag and outside the bag (can't remember the name of that now - idiot). Anyway, then you should be able to use any size bag. Also, if you were REALLY clever in making your own bag, you could make it too large, and put the pump connection off to the side. Then put some rigid porous material under the pump bit and pump away. That way you aren't putting any pressure on the piece, so the glue-up shouldn't slip and it then becomes a one person job again...

Cam

I spent some time a while back talking to the fella who made the Cloudmaker Vacsac and he said that he spent years getting it right. Sourcing a successful venturi was his biggest challenge and it took lots of false startsto get it right. I have held vacuum in a Vacsac for over 24hrs, so he must have got it right in the end. The low tech vacuum press from C/T seems to be on the money IMHO.

Originally Posted by CameronPotter

Midge doesn't understand real cheap...

Hmmm... If I can't copy it from entirely scrounged materials, I don't consider it to be cheap!

Does Cloudmaker have a website anymore? I tried to find them but failed.

P

I guess it depends on the efficiency of your scrounging... I looked at the JoeWoodWorker site at his vac pump - and decided that other options would be much cheaper (and less effort).

Cam

Originally Posted by CameronPotter

I guess it depends on the efficiency of your scrounging... I looked at the JoeWoodWorker site at his vac pump - and decided that other options would be much cheaper (and less effort).

I guess it also depends on one's ambitions with regard to size of project.

Apart from the venturi in the case of the compressor driven units, or the pumps in the case of the others, all the other bits are standard fittings.

I have been harbouring a few options:

1) Find a fridge and use the bits, but I like the valves and auto maintenance of pressure that the plans provide. Initially almost free.

2) Go the venturi, and run it off my el-cheapo compressor, manually at first, but all the bits necessary can be got from old commercial fridges or AC scrapheaps. Venturi around $70 I think.

3) The most interesting...... how about buying an el-cheapo compressor and plumbing it backwards? They come with all the dials, gauges and auto cut-off things.

All you'd need to do was create a vacuum in the tank rather than fill it with compressed air.

So you'd have a new MickeyMouse setup with auto cut-off for $70 - $90.

Would that work??

Cheers,

P

If it would work that would be awesome...

I know some compressors can be run backwards, but I think that they are pretty expensive...

As for the venturi, well $70 is more than $30 for the win pump - but probably a lot better too.

Also, my scavenging tends to be limited to non-mechanical components. I really must graduate to the "flashy" end of scavenging some day.