Thread: Vacuum Bag Press/ Pump?

You may want to consider a vacuum pump from an auto parts store. They are normally used to service the air conditioning in vehicles.

Hi rrich, Thanks for that, I'm not very technical minded, so I was thinking of something I could just hook up to the bag & not have to do anything. Would a Vac pump for a car be powerful enough?

I was talking to a group in the US. One dude pointed me to the under-bed storage bags.

The plastic is thick, the bags are very big (commercial veneer bags are so damned small!) and for the decent quality ones don't cost too much.

He runs a small commercial shop. The name eludes me. He wrote the white covered marquetry book I'm reading ATM (it comes recommended on amazon)

The tips were:

-- use the mesh that's on the outside of swap-and-go gas bottles as the "mat" inside the bag
-- good quality clothing vacuum bags hold a high vacuum for 24 to 48 hours without hassle
-- he mentioned 30 minutes was heaps, but longer won't harm
-- the hand vacuum was exceptional. It was quick and drew an intense vacuum.

The one I saw was EXACTLY the same as the wine bottle hand pumps I see in bottle shops. The kind where you put the plastic cork in the bottle and pump until it goes pop-pop-pop.

Btw, yes, I've been thinking a lot about marquetry and veneering recently.

A standard vacuum cleaner also makes a handy "pump the bag down fast" tool.

Until recently I had been using the hand pumped "Roarockit" vacuum veneering system (http://www.carbatec.com.au/roarockit...ss-kits_c19154) but the bag sizes are limited, and the Roarockit hand operated vacuum pump can be tiresomely slow to establish a decent vacuum.

So, I've recently purchased a Vacuum Pump off Ebay. The type of Vacuum Pump that I bought is designed to be used by Air Conditioner Service Technicians. hey use them on Automotive and small Household Air Conditioners. I bought this one, (http://www.carbatec.com.au/roarockit...ss-kits_c19154) but there are numerous similar ones available. The one I bought is rated at 3 CFM (Cubic Feet Per Minute), and is plenty quick enough to establish the vacuum.

With the benefit of hindsight, I think a 1 CFM pump would have probably been adequate. I run the pump for about 20 minutes and then close off a vacuum valve to seal the bag, and shut the pump down So far no leaks and my bag held vacuum for 18 hours on the one epoxy bent lamination glue-up that I tried. The pump I bought is supposedly rated for continuous running. Note that some pump designs are not designed to run continuously - you'll probably need to ask the supplier to provide you detailed specifications, as some were designed to run continuously only up to about 75% vacuum, whilst others will pull and maintain a near perfect vacuum and are rated to run continuously.

I don't know what electricity supply voltage is used in Thailand (115 volts, 220 volts, 240 volts, or something else), so if you buy one of these just make sure that you buy one that suits your electricity supply voltage. I made an adaptor so that on large vacuum bags, I can do a rapid air evacuation using a vacuum cleaner, and then switch over to the vacuum pump to finish pulling a good vacuum, well before the glue starts to go off.

I notice that someone earlier in this thread suggested using a vacuum vacuum cleaner to create the vacuum for vacuum bagging. I use a vacuum cleaner to quickly remove most of the air in the vacuum bag, and then switch to the vacuum pump. The clamping pressure created by using just a vacuum cleaner is inadequate - I've tried it and you'll sometimes end up with gaps between the veneer and the substrate on a flat panel, and on a bent lamination, you haven't got a chance using just a vacuum cleaner. Once you pull a decent vacuum with a vacuum pump, you see heaps more glue squeeze-out, and when you look at the glue-up after you remove it from the bag, there will be no glue line gaps, which do often occur when only using a Vacuum Cleaner.

I also tried a few different "Under Bed Vacuum Storage Bags". On the ones that I've tried, the bags are not thick enough or strong enough, and tear easily on any sharp corners on your workpiece. Plus, you'll still need to use a vacuum pump (hand operated or electric) as the vacuum cleaners that they are designed to be used with don't create enough clamping force.

Regards,

Roy

Thanks everyone for your helpful advice & tips.
It's so hard getting things here in Thailand, most shops don't speak English. Went to the local shop today for 4 bottles of cokes, 1st she gave me a beer, then candles, & when I pointed to the cokes, she said, oh coke, exactly as I had said it.
So what I'm saying is I can't go down to the local hardware store like you guys can & explain what I want. I'm sure there are pumps here in Thailand, but trying to get one is another matter.
Electric is 220 volts with a 2 pin plug. What did you pay for your pump off Ebay Roy?
I had seen the kits from Carbatec, but they are to small for what I want,
I've sent Emails to a couple of companies on Alibaba, but still waiting for their reply
Thanks again Everyone

Originally Posted by sprog1

Thanks everyone for your helpful advice & tips.
It's so hard getting things here in Thailand, most shops don't speak English. Went to the local shop today for 4 bottles of cokes, 1st she gave me a beer, then candles, & when I pointed to the cokes, she said, oh coke, exactly as I had said it.
So what I'm saying is I can't go down to the local hardware store like you guys can & explain what I want. I'm sure there are pumps here in Thailand, but trying to get one is another matter.
Electric is 220 volts with a 2 pin plug. What did you pay for your pump off Ebay Roy?
I had seen the kits from Carbatec, but they are to small for what I want,
I've sent Emails to a couple of companies on Alibaba, but still waiting for their reply
Thanks again Everyone

Greetings,

I just realised that I'd put yhe wrong link in my reply to your question. The vacuum pump that I bought is on Ebay and cost me AUD $144 + freight. The data plate on mine say 220 to 250 volts, so would probably work OK for you.

http://www.ebay.com.au/bhp/refrigeration-vacuum-pump

The above link points to a whole heap of them on Ebay that range upwards in price from less than $100.

Regards,

Roy

I bought a pump very similar to this a couple of years ago, used it for the first time last weekend, successful glue up
http://www.ebay.com.au/itm/3CFM-1-Stage-Refrigerant-Vacuum-Pump-Refrigeration-Gauges-Tools-Air-Condition-/271634529169?pt=LH_DefaultDomain_15&hash=item3f3eadfb91Hi

I used plastic sheet from Spotlight similar to this
http://www.spotlightstores.com/kitch.../BP80030583001
double sided butyl tape from Bunnings to seal the bag
http://www.bunnings.com.au/consolida...10266_p1090837

vacuum controller: distributer vacuum advance from wreckers, microswitch bought online, cheap car vacuum gauge Ebay, T's from Enzed
reservoir: 1m plastic drainage pipe 100mm diameter with a couple of caps, barb tapped into cap with drill press
Vacuum hose: old acetyline hose from garage sale
One way valve: bunnings plumbing fitting
breather fabric: shadecloth
release fabric: kithcen tidy bags

Hope this helps


20150412_105947.jpgP1030928.JPG20150412_110057.jpgstrappedForm.jpg

AussieRoy, good link for pumps. I might grab a 1hp 2 stage.

I'm wondering about the lines and bags. Can I ask what you'd suggest for bigger bags and how you connect them up?

Originally Posted by Evanism

AussieRoy, good link for pumps. I might grab a 1hp 2 stage.

I'm wondering about the lines and bags. Can I ask what you'd suggest for bigger bags and how you connect them up?

Evanism,

Have a look at Crankshim's post above, as he is using readily available items and re-purposing them to do the vacuum bagging - very interesting.

To date I've imported two shipments of Vacuum Bags, Veneer Tape, vacuum bag hose spigot fittings, etc from Rockler (using a Freight Forwarder) and from Highland Woodworking in the USA. The cost wasn't bad, especially seeing that these specialist items don't seem to be available in Aus. (Maybe one of our Sponsors will see a commercial opportunity here ... )

I've tried using nylon fly screen material as the breather fabric, and kitchen grease proof paper as release sheeting. The greaseproof paper worked OK with Titebond III glue. I haven't tried making my own bags yet - might give that a go next. I also use a few pieces of 19mm MDF that have 1/8" wide x 1/8" deep grooves cut across the surface in a cross hatch pattern (on 1/2" centres) - these work well as breathers as well as providing rigid clamping cauls.

I don't use a vacuum reservoir, simply based on the principle that the fewer components there are in the vacuum system, the less chance there is for a leak to develop. My pump is rated for continuous operation, so I plug it's hose directly into the spigot fitting on the vacuum bag via a valve, and leave the pump running for the glue's specified clamping time. The pump gets warm quickly, but never so hot you can't touch it. I don't worry about a vacuum gauge, because you can tell how good a vacuum you've pulled by looking at how closely the bag has conformed to the shape of the workpiece, and by looking at the glue squeeze-out. I figure that as I don't need to put a pressure gauge on an F Clamp to see if I've clamped a glue-up tight enough, then (as long as I'm using transparent vacuum bags) I don't need a vacuum gauge to tell whether the vacuum bag is applying sufficient clamping pressure.

I was originally plnning to rig up a vacuum switch to cycle the vacuum pump on and off to hold the vacuum over a long period of time, but seeing that the pump is rated for continuous operation, that seems to be an additional complication that isn't really needed.

Regards,

Roy

How weird was that! Crankshims post wasn't there for me last night. I saw it just then immediately above when I revisited and thought "bloody hell". Damned ISP must be cranking up the caching.

Thank you very much for answering. All excellent responses.

I would like to thank everyone again for your posts, especially Aussie Roy & Crankshim those posts were exactly what I was looking for.
Two other questions, one is when gluing Laminates {formica} to MDF using the press, what glue would you use, would PVA be OK. At the moment I use contact adhesive on flat doors, but there are always slight ripples & I don't know if that will be strong enough for curved doors. The other questions is, what is shadecloth ?
Regards Ron

Originally Posted by sprog1

I would like to thank everyone again .......... The other questions is, what is shadecloth ?
Regards Ron

Check out the link .....http://www.bunnings.com.au/our-range...ps/shade-cloth