Homemade vacuum veneer press (with pump from freecycle)

[oddsocks]

After a busy week gaining info via another thread I was fortunate enough to get a response to my 'Wanted' post in freecycle for a vacuum pump. I collected that on Thursday and have today made my first successful bag. The photos hopefully show it all, I tested it with two pieces of wood and they cannot be budged once the vacuum is applied. Total specific cost £4 so far.....

Pump - free from freecycle
Hose - from leftover stock after building a whirlpool bath some years ago
hose connector - from stock (salvaged from an old broken compressor).

Bag connector made up from:
- matching air hose PCL (i think) connector - salvaged from unwanted air spray gun
-Reducing coupler - I had to buy these and the washers, total cost for 3 sets £4. The air fittings are BSP and the reducer allowed the fitting to be bolted through the bag.
-O ring from stock.

Breather fabric - spare length of frost protection fleece (even in many layers you can breath through this)

Bag sealer - length of 25mm plastic conduit cut as in photo. The inner diameter is 20mm so I turned a length of broom handle down to approx 19mm to be a good fit inside the pipe.

Bag (for this one) an axminster bag with the hole for the connector cut with a 12mm punch (make sure you cut against a block of wood!)

I have found an online suppler of 250micron plastic sheeting so will make up some bigger bags (for a project I have) hopefully in the next week. I will follow joewoodworker's method of making the bags.

EDIT 17 May- homemade bag details and pics added in page 2

Photos....


the unit in use:

the bag connector components:

and connected:

and finally the open end sealer, just wrap the bag around the dowel and slide the clip on (note the bevelled lead in). The black pipe edges were sanded smooth.

 

[Calpol]

That's very trick Socks, love that! Veneer kits seem to be really quite expensive and I'd like one, might give this a go myself

Let us know how it works...

 

[OPJ]

Nice to see you've saved one item of 'junk' from going to landfill while saving a fortune in what would have otherwise cost you hundreds of pounds!

I'm sure people would also find it interesting if you could show how you 'make' your bags next time. :wink:

 

[wizer]

:shock: :shock: I can't believe you got a vacuum pump off freecycle!!

What was it's original purpose? Is it for veneering or something else?

Guess who's off to put a wanted add on FreeCycle.....

 

[MikeG.]

Now, that is my sort of workshop kit!! Excellent!

Can someone tell me why a vacuum cleaner wouldn't work as the pump?

Mike

 

[custard]

Great stuff Dave!

I've spent the weekend veneering a piece with the most fantastic Macassar Ebony. That's the thing with veneer, you can use such incredible timbers, the type of stuff you'd normally only find in a musical instrument or in an exhibition at West Dean, that it kind of spoils you for anything else!

 

[oddsocks]

I'm sure people would also find it interesting if you could show how you 'make' your bags next time. :wink:

Will do Olly - the bag i used this time was an axminster dust extractor bag (all I did was cut the hole for the air inlet). Search in axminster for 'dust extractor waste sacks' - mine is the smallest at 560x915mm flat dimension and cost £10.45 for 10. The biggest 1065x1370mm cost £19.85 (for 10).

I have got 250micron PVC sheeting on order from www.allplas.co.uk and will post my efforts in making the bags.

Shocked Shocked I can't believe you got a vacuum pump off freecycle!!

What was it's original purpose? Is it for veneering or something else?

Guess who's off to put a wanted add on FreeCycle.....

I was amazed as well - and I only posted on the local one that has just a few hundred registered members. It was from a very expensive parker print down frame now obselete with the advent of laser plate setters. The giver had intended to use the pump for an aquarium but never got around to it.

I bought a euromillions ticket the same day but didnt have such luck with that :-(

Can someone tell me why a vacuum cleaner wouldn't work as the pump?

Mike - not sure (seeing as other posts use the clothes vacuum bags) but the pump I have is very very quiet and is left running - not sure the household cleaner is up to that

 

[wizer]

Thanks Dave

Mike a house hold vacuum will do it but it won't last for long. They are not designed for constant load.

 

[rileytoolworks]

Wow. I'm gobsmacked. I've been gathering the bits together for ages to make my press. Then you go and bloody well get the parts and make one, and USE it, in less than a week. I applaud your ingenuity.
Adam.
P.S. Let us know how you get on with the new bag once it's up and running. I may pick your brains about this subject.............

 

[Steve Maskery]

Excellent. You'll wonder how you ever managerd without it.

Mike
A vacuum cleaner is a turbine rather than a pump. It will create a much smaller pressure difference. It's probably enough for flat veneering, but not for, say, former work.

A vacuum pump actively pumps the air. Mine has carbon vanes in it - it's quite a clever design really - and can reach much lower pressures, so more demanding work can be tackled.
S

 

[Night Train]

That is a nice cheap bity of kit you've got yourself. I like the bag seal idea, I'll steel that for college is you don't mind. Ours has split so we rely on the vacuum closing the other end of the rolled up bag.

Has any one any thoughts on using a compressor, with valves reversed, as a vacuum pump?

I also read somwhere of using two clear plastic shower curtains with double sided tape as as a cheap bag.

 

[oddsocks]

I'm not intending to divert this thread too much, but have been googling to try and understand how vacuum pumps work. Among the many normal items, I found this DIY vacuum pump version that is made out of normal plastic pipes and one way valves. The article says it pulls up to 25" Hg. It's very americanised, but providing the one way valve can be bought in UK it looks easy enough to build (it would presumably need a good stop valve to keep the vacuum)

http://blog.makezine.com/archive/2008/06/diy_vacuum_pump.html

anyone up for the challenge of building one? .

Dave

 

[oddsocks]

That is a nice cheap bity of kit you've got yourself. I like the bag seal idea, I'll steel that for college is you don't mind. Ours has split so we rely on the vacuum closing the other end of the rolled up bag.
...

I also read somwhere of using two clear plastic shower curtains with double sided tape as as a cheap bag.

Feel free to steal any idea I ever post! I'm fairly sure that isn't an original but an idea that came to me because Ive read or seen something similar!

I never thought of shower curtain but it would make sense as it's tough enough. In my browsing around the net tonight one post mentioned using silicon to seal joins (I intend to use PVC cement but silicon sounds a good less noxious option)

 

[Night Train]

Feel free to steal any idea I ever post! I'm fairly sure that isn't an original but an idea that came to me because Ive read or seen something similar!

Thanks, thought it best to ask first.

I never thought of shower curtain but it would make sense as it's tough enough. In my browsing around the net tonight one post mentioned using silicon to seal joins (I intend to use PVC cement but silicon sounds a good less noxious option)

The idea behind shower curtain is that it is cheap and available from any DIY shed. It can be joined to any size or shape with carpet double sided tape, also cheap and from the sheds.

I think the article I read just said that he place tape around three edges of one curtain and then overlaid the second curtain on it and pulled out the waxed paper strip, sealing the tape as he went.
If you needed a longer bag then you can join two lengths of curtain together in the same way by overlapping the taped edges. Likewise you can make little bags with just one curtain folded in half.

 

[herdsman]

I use a home made screw press for veneering and a vacuum system using Vacuvin wine saver hand pumps. A hand pump and two non return stoppers cost £8 from Amazon.

This system is suitable for veneering and laminate forming, a very cheap solution for the hobbyist.

 

[ivan]

A proper vacuum pump gets closest to a true vacuum, and this gives about 15 lbs of clamping pressure per sq inch. A hand pump might do for a very small bag press - I think one was available in a kit to laminate a skateboard; but otherwise far too slow to build the vacuum.

Vac cleaner motors can operate continuously if the motor has separate cooling (bypass motor). However the average cleaner will only give 3 or 4 lbs per sq in clamping force; a 3 stage sprayer turbine might manage 6 or 7 lbs per sq inch. Even the full 15 psi looks a bit feeble in comparison to the optimum (Hoadley, Understanding Wood), 200psi for invisible glueline. Not surprising laminators like epoxy with its gapfilling ability and long open time.

 

[oddsocks]

I thought my freecycle 'win' was going to be shortlived as when I switched the pump on yesterday nothing happened (other than the hum of the motor trying to work). The problem turned out to be the pump being bolted too tight- but to get to this I had to do a bit of dismantling and now know how it works

In this image the rotation is anticlockwise and the 4 vanes slide in the slots, so centifugal force does it's job re sealing (two are partially in because I had moved them.

on top of this is the inlet /outlet chamber (it was this that needed to be undone a bit). The outlet is at the top and you can see where the rotor was rubbing against this.

The only other piece I needed to add back on was the end cap silencer - it's amazing what a good job that does!

So looking at the photos the mechanics look simple bt to very close tolerances!

 

[rileytoolworks]

Hello mate. Have you received your vinyl yet? What's the quality like and is the delivery o.k?
Looking to order some myself, but thought I'd wait to see how you get on......

 

[oddsocks]

Hello mate. Have you received your vinyl yet? What's the quality like and is the delivery o.k?
Looking to order some myself, but thought I'd wait to see how you get on......

Hi Riley,

Yes - got it mid week and have almost completed making a bag 2.5m x 1m - will post photos hopefully tomorrow (camera battery ran out!).

The pvc is about the same thickness as the axminster bag I used. After trying pvc weld (plumbing waste pipe glue) and bostik soft plastic glue (neither of which worked) I settled on double sided tape (as per an earlier suggestion). it seems to be the way to do it, but I haven't applied a vacuum yet - relatives visits etc hindered progress today.

I still have plenty of plastic left to make a few more bags

re allplas. no issues with the quality or delivery (the parcel with 8m x 4m arrived 3 days after ordering). Wait for my WIP photos, as making a large bag is more about organization than anything else. You could probably get similar plastic from a big garden centre, but for me the P&P was the cheaper option.

 

[oddsocks]

Finished and tested the bag (2.5m x 1m) successfully this morning (discovered that when I need to use it for real the kitchen floor is the best place!). Photos after the 'how to' text...

The final version was built using the following (I have given links and approx costs where known)

• 
  Bag material - 250micron (1000 gauge) polythene from http://www.allplas.co.uk/acatalog/4mtr_x_25mtr_x_250mu__1000gauge.html cost per running meter (4m wide) is £3.39 incl VAT. I ordered 8 running mtrs and with P&P £34.62 (the bag shown here used just over 2 running metres of plastic)
  
  fixing - After failing on test pieces with PVC pipe weld and bostik soft plastic glue I went with the suggestion in an earlier post and used 'Duct General Purpose double sided tape for internal use' 38mm wide, 5m role £3.16 incl VAT. Basically good carpet floor tape that is not repositionable
  
  Open end sealing system - length of 18mm pine dowel - 2.4m, £5.99 focus & length of plastic conduit with 20mm internal bore - from stock.
  
  Air connector - see earlier pics at start of thread. Looking in Axminster catalogue I think the same could be made from 100314 (1/4" female bayonet £1.04) and 500083 (1/4"male-female coupler £1.23) plus washers and O rings.

So onto the actual making....(If a smaller bag is needed it is a lot easier - with a bag this size (2.5m x 1m) initially the amount of plastic makes it harder). All the techniques I used were gleaned from other posts and 'Joes woodworker. site.

The first task is to form the long side join (2.5m). I had a suitable length of timber and put this on top of the plastic, wrapped the plastic around the wood, clamped it to the wood and with sharp knife and straight edge trimmed the length. The double sided tape was then laid (using a seam roller) so that it was right to the edge of the polythene. I then used a blue marker pen to define the edge of the tape (otherwise when the brown tape is lifted you cannot see where to align the other part of the join).

Next, bring the other end of the polythene up so that you are forming an open ended cylinder (not a teardrop type of join - when finished this side seam is not at the edge of the bag). Ensure that this edge is also straight and temporarily clamp and take the weight off the rest of the plastic. This photo shows that stage, ready to start pulling back the brown tape (6" at a time) and aligning the plastic seam against the blue line, seam rollering as you go.....roll to avoid air bubbles...

Once completed, remove the wood from the inside of the tube (the wood has acted as the surfce to roll down onto).

Next is the closed end of the bag. With a large bag two pairs of hands make this easier, but smooth out the tube so that the long seam is about 4" from the 'flat edge' of the bag (so it is not on the side where it would get stressed). Before sealing the end of the bag, now is a good time to fit the air intake (I didnt so had to fight with 2.5m of plastic to get the spanner in).

The end is sealed using double sided tape, but in a tear drop fitting (it is easy enough to get the tape right into the corner -use the blue line marker again). Once that was done, I then laid another run of tape on the outside of the bag, following the blue line, then folded the already sealed end over and onto that second tape.

Finally, make the open end seal as shown at the start of the thread. This time I used 18mm dowel and it gave an easier fit and still sealed perfectly.

Here is the first test of it in my kitchen with just a piece of iroko that was suitably long. The vac gauge showed it was pulling 24" Hg. You can see the blue line of the long seam -that is where the edge of the joined plastic is, so not on the bag corner