Bag Press

[lynx]

Looking at a bag press. Not much in the cost between the Airpress version and the bag press version. The latter does have a foot switch that i feel could be very helpfull.

Anyone had any bad expericance with either?

[cadas]

Forget the one with the vacuum system that runs off a water tap, I bought this to save money but after using the colleges one that had the vacuum pump the difference was amazing.

Bought a new pump the next day.

[jonnyd]

I have had the airpress pro pump for about 7 years and it has proved very reliable. Its not used everyday but has been used a fair bit. The bags have a tendency to split on the seams but can be mended easily with double sided tape. I have probably bought a new bag every couple of years other than that its fine.

jon

[nickw]

To prevent bags splitting at the sides you have to make sure that the work is places far enough away from them that they do not come under tension when the vacuum is applied.

I've had an Air Press for a good few years now with no problems (apart from when I broke the rule above) , however if I were buying again I would think seriously about the Bag Press offering as their bags are made of a more flexible material and so are less prone to damage. Llast time I looked though they were also a deal more expensive, so I guess you pays your money...

[jonnyd]

I mainly do flat pressing with the seams under no pressure and i think the seams just break down under general wear and tear after being used a few hundred times. I was also thinking of trying out a bagpress bag the next time i need a new one.

jon

[thebloke]

I've used the AirPress for several years now. The pump is excellent but the bags tend to split but as others have said they're quite easy to repair with a bit of tape. I use the brown parcel tape as it seems to stick to just about anything - Rob

[Scrit]

Fundamentally the pumps come from only a few sources, Gast oil-less rotary vane pumps being one of the favourites (take a look at their 23 series). Other manufacturers include Becker who have an outlet at Hull.

Apart from the pump the main things you need to make your own are pipe which won't collapse (that means the hard plastic push fit pipework sold by compressor suppliers in metric sizes 4 - 6 - 8 - 10 - 12mm o/d), manifold and push-fit fittings (same source), stop cocks, a vacuum gauge and possibly an automatic motor start-stop control (called a Mac valve) and bag connectors (which can be made by cutting a BSP thread into a nylon sheeting eyelets). names in the fittings world include IMI-Norgren (British), Camozzi (Italian) and Festo (German - and expensive). See the Joe Woodworker site for details of how to build your own and remember that most of the stuff you'll need can be sourced readily in the UK from the aforementioned compressed air people (up here I'd use someone like Thomas Wright - Thorite Group).

The bag material is sometimes an issue, although it is simple enough to make-up your own bags using vinyl and vinyl cement (the vinyl is used in the PoS, sign and banner trades - so signwriters or silk screen suppliers can sometimes supply a suitable material. For manufacturers try BXL at Brantham in Suffolk). Polyurethane sheeting (often from a rubber supplier) is more flexible and much more durable, but it cost more. Best bag material of all is silicone rubber sheet - very stretchy, extremely durable, will withstand higher vacuums and can be used with heated cauls/platens for thermoforming, fast production work, etc. Downsides are cost, the fact that it's probably better used on a frame type press and it's opaque. We have a couple of suppliers up here if you get that interested.

Scrit