Getting Into Vacuum Bagging

[Ken Krawford]

With a LONG history of a variety of woodworking projects spanning 50 years it seems that I now have a need for a vacuum bag press to do some veneering. My last project with clamps and cauls was a disaster. Can someone please suggest a fairly modest starter list of equipment to use? I will need a bag that is around 48" in the longest dimension.
Thanks.

[Kevin Jenness]

Here's a reliable source for parts if you want to put together your own system https://www.veneersupplies.com/categories/Vacuum__Press__Items/Vacuum__Press__Parts/. For a complete system https://www.vacupress.com/. I have two Gast 0522 rotary vane pumps bought from Ebay for <$150 each - one is over 30 years old and still working well. You can get a venturi device that generates vacuum from compressed air but it will use a lot of power.

A vinyl bag will work well, polyurethane is more flexible and longer-lasting. If you get serious about veneer a frame press is far easier to use than a bag. Vacuum is also very useful for obstruction free clamping of workpieces for routing, reverse turning bowls and the like. Have fun.

[John Jardin]

Ken,
This is one of many sites that offer everything you need to get started in vacuum bags. I built a vacuum pump with their kit and it works just fine.

https://www.joewoodworker.com/veneering/welcome.htm

[Ken Krawford]

Thanks for the reply Kevin. I was aware of the venturi option but didn't know if it required the compressor to run constantly in order to keep the required amount of vacuum. If so, the noise from the compressor will be a factor. I see that Harbor Freight has a 2.5CFM vacuum pump and wondered if it would be suitable for the infrequent use I will probably give it.

[Kevin Jenness]

Ken,

You should be able to set up a vacuum valve and sensor/switch to turn the compressor on and off automatically. You will have to source the parts and set it up.

I don't know anything about Harbor Fright pumps. I do know Gast pumps are ubiquitous.

[John TenEyck]

I make my own bags from 25 mil clear vinyl that I first bought from McMaster Carr and got the last time at my local boat cover fabricator. The first bag is 5' x 8' and is now more than 25 years old and has been used at least 100 times. Vinyl glues great with PVC pipe cement. I fabricated the hose penetration on the first bag but you can buy them from Joe Woodworker, too. Closure requires nothing more than rolling the open end of the bag around a wooden bar a couple of times; it seals to itself well enough to maintain a good vacuum.

I have two Gast pumps but I think the HF one you mentioned will work just fine. An air conditioning vacuum pump would work well, too, although it would be slow to evacuate the air initially. And I don't have a fancy control system; I just set the pump to cycle on/off using a cheap timer. In any case, I definitely would go with a vacuum pump and not a venturi system - much quieter and much lower energy cost.

John

[Jeff Roltgen]

Careful with the Harbor Freight unit. Tried one once, and discovered why you need to pay attention to how the pump is lubed. It was oil = room full of an oil haze before I realized what was going on.
Stick with Joe Woodworker/Veneer supplies if you want to dip your toe in on a budget, and little details like that are already dialed out of the equation. They care about you succeeding.
Just don't waste your money on Polyurethane bags. Highly over-priced and over-rated, and certainly not necessary if you're just getting started. Vinyl will last years longer, due to lower sensitivity to UV rays and oxidation. IME, the durability claims for polyurethane are complete hogwash.

[ChrisA Edwards]

You don't need massive CFM for vacuum bagging. Once the air is starting to be sucked out of the bag, atmospheric pressure, outside the bag is doing a lot to help get the rest out. If you have a bagging system with minimal, if any leaks, the pump is not having to work hard to counter these, that's why a small pump works just fine, even with a large bag.

Doing a veneer on a piece 2' x 3', my bag will be under full pressure in less than 30 seconds of the pump starting.

I have a Gast pump and a HVac pump, the Gast was about $80 from eBay and the HVAC from Amazon, but that one has oil that will leak a little and needs to be topped up periodically.

I prefer the Gast pump, it's almost silent in operation.

[Stewart Lang]

I'll put in my vote for Vacupress. I bought the Green Compact 300 and one of their 4'x8' bags. Came with everything I needed and it took like 10 minutes for me to get up and vacuuming. Excellent company and you certainly get what you pay for.

The green case for my Vacupress came slightly damaged by shipping. I sent them an email and immediately they had shipped out another to me for free. I'd recommend them very highly.

[John K Jordan]

Ken,
This is one of many sites that offer everything you need to get started in vacuum bags. I built a vacuum pump with their kit and it works just fine.

https://www.joewoodworker.com/veneering/welcome.htm

Joe's vacuum pump build has the reservoirs and sensors to only run when needed. The parts are not expensive and it's easy to build. He sells everything you need for veneer vacuum press. He also sells pumps. I bought one and it's excellent.

JKJ

[Richard Coers]

Careful with the Harbor Freight unit. Tried one once, and discovered why you need to pay attention to how the pump is lubed. It was oil = room full of an oil haze before I realized what was going on.
Stick with Joe Woodworker/Veneer supplies if you want to dip your toe in on a budget, and little details like that are already dialed out of the equation. They care about you succeeding.
Just don't waste your money on Polyurethane bags. Highly over-priced and over-rated, and certainly not necessary if you're just getting started. Vinyl will last years longer, due to lower sensitivity to UV rays and oxidation. IME, the durability claims for polyurethane are complete hogwash.
Very simple way to prevent the oil mist is to run a rubber hose into a bucket under some paper towels. I first used a generic cartridge gas filter, but it only lasted a half dozen times. Now I use the bucket.

[David Kenagy]

I'll put in my vote for Vacupress.

I thought long and hard about making my own, and studied a very good site called "Joe Woodworker". I'm sure their product would work well. But unless you've got a lot of the parts already lying around, when you're done making your own vacuum you have saved only a little money. I also bought the mid-sized vacuum from Vacupress. Darryl (the owner) has been doing vacuum pressing for years. He readily answers questions by phone or by e-mail, not only about his presses, but also tricky challenges once you've started. He made videos to answer a lot of common questions, and gives them to buyers of a vacuum.

I wanted to apply veneers to long, thin moldings, and he had a 'lightly used' vacuum bag that was of a perfect size at a very low cost. I also bought a cutter from him that was vastly more accurate than my "Exacto-knife and ruler" method, but a surprisingly reasonable cost. Shipping has been fast, both for the hardware and for later purchases of glue.

Vacupress is the kind of company any of us would run, if it were up to us.

[Don Stephan]

Years ago I purchased a Gast pump and components to fabricate a working system. Yes, it was less money up front than a system from Darryl Keil but I spent too much time working ON the vacuum pump system and not enough time WITH it.

[jerry cousins]

+1 for joewoodworker.com

[Robert L Stewart]

Another +1 for joewoodworker.com

[joe maday]

roarockit.com...skate board kits and veneering bag kits...hand pump. reasonable price.

[John TenEyck]

FWIW, if you buy a pump rated for continuous duty you don't have to turn it off. A small pump draws only a little power and is more than adequate to hold the vacuum on a well sealed bag. My setup is only a slight step up from this where I use a timer to cycle the pump on and off, usually so that it runs 1/3 to 1/2 the time.

The automatic vacuum control system is nice but completely unnecessary to achieving excellent results. You don't have to spend much money, or time, to have a low cost system that works as well as any. A bag, a pump, and a hose connecting the two are really all you need.

John

[Mike Henderson]

I went with the Joe Woodworker system. Works well.

There are veneers that don't behave well when they absorb water. When using one of those veneers, with a water based glue, you want to get the project into the bag and under press immediately. A very low CFM pump doesn't work for those veneers.

Mike

[Bubinga is an example of one of those veneers. It's a radial cut veneer. Many radial cut veneers can be a problem.]

[Ken Krawford]

Thanks everyone for your thoughts and feedback. I've been watching Craigslist for vacuum pumps but here in Atlanta they're few and far between. So far I've concentrated on the various pump options but lost a bit of enthusiasm when I saw the prices of the 3 different grades of bags. I may have to re-assess my thinking.It appears that an Excel 1 kit, the cheapest 4' x 4' bag and a few accessories will put me north of $450. For me, this is a bit hard to justify for something that may or may not get used much.

[Patrick Kane]

Ken,

Maybe try reaching out to woodworking clubs in Atlanta? That is a big metro market, and i guarantee someone has a vacuum setup locally. Id be surprised if someone on this forum didnt live in Atlanta with a vacuum bag. Buy the guy some booze, or lunch, use his bag for a glue up and then determine if its something you need to invest in or not.

[John TenEyck]

Thanks everyone for your thoughts and feedback. I've been watching Craigslist for vacuum pumps but here in Atlanta they're few and far between. So far I've concentrated on the various pump options but lost a bit of enthusiasm when I saw the prices of the 3 different grades of bags. I may have to re-assess my thinking.It appears that an Excel 1 kit, the cheapest 4' x 4' bag and a few accessories will put me north of $450. For me, this is a bit hard to justify for something that may or may not get used much.

You can make your own 5 x 5 ft bag for less than $50.

John