Vacuum bags

[Steve Maskery]

I'm prepping the layons for my wardrobe doors, but I have discovered that my vac bag is barely big enough. The door will go in, but there is very little clearance on length and I'm not sure I shall be able to seal the bag. Another 6" would have made all the difference. Sigh. I did have a 3m bag, bought specifically for this job, but it was part of the Great Haul. If you've got it can I have it back please?

Anyway, I'm reluctant to pay £110 for a 3m bag and another £25 for a new pair of closures, just for one job, so I'm looking at alternatives.

I can get a big sheet of HD polythene on Amazon. Cheap and cheerful. It's 0.25mm thick, compared to the 0.5mm of my present bag. Can I make a bag out of it? I know it won't be as robust, but it only has to survive eight pressings.

I was hoping to find PVC tablecloth stuff on a roll, but the only place locally where I have seen that is closing down and everything useful from it has been sold off.

Anyone got any experience of using PE?

 

[Yojevol]

Have another look at my posting of 18months ago which you responded to Steve.
Just checked on Allplas website and it's still relevant.
The only update on my post that is worth mentioning is that the DS tape has not stood up well. It's gone all gooey and is no longer airtight. I'm going to have to reseal the seams with solvent.
Brian

 

[user22161]

Building film from local builder's merchants? Available on rolls usually either 500 or 1000 gauge.

 

[Trainee neophyte]

Greenhouse/poly tunnel plastic. I use it for all sorts of things that are not greenhouse, up to lining an Olympic swimming pool size pond. It will last for ever out of the sun,but sealing it may be interesting. Silicone? I would use some mastic adhesive, but I have no idea what the equivalent in UK would be.

 

[novocaine]

hold on a second, boyes is closing down? thats a sad day.

try the range at Alfraton or Sutton in Ashfield, they sell PVC table cloth.

 

[Steve Maskery]

Not Boyes, no, Chiltern Mills. Apparently the landlord wants his place back. Never thought of Boyes, I'll pop in.
Went to the Range yesterday, they've stopped selling it.

TN, where should I look for poly-tunnel film?

 

[novocaine]

thank goodness, panic averted.
Chiltern mills is gone, shame that, my mum will be gutted.
sorry for being 0 help.

you can make a bag from polyethelene, use heat to seal the edges. I'm aware you are unlikely to have a hot bar, so as an experiment you could try a heat gun to warm a ruler, or maybe 2 lengths of wood sat just wide enough for a wall paper roller, heat the plastic in the gap then press down with the roller.

 

[Tris]

Try Northern Polytunnels for film, they also sell polytunnel repair tape that sticks well.
Have dealt with them in the past and found them very helpful.
Hth
Tris

 

[Myfordman]

I use polythene sheet and silicone sealer for all my vacuum jobs. Works a treat.
The vacuum pipe goes in through the silicone seal.

 

[worn thumbs]

I use damp proof membrane from the builder's merchant a couple of hundred yards up the road.The usual problem is that the mastic tape won't release and the bag gets a little smaller with each job.If you use the interlocking plastic extrusions,this won't apply.I have used one bag for at least six jobs-glass sheathing centreboards and rudders-and its good for a few more yet.

 

[Steve Maskery]

What thickness do you use, please, Bob? My present bag is 0.5mm.

I've found a place that does polytunnel stuff for £7.50 per m at... 9.5m wide! The carriage will be more than the goods!

 

[Steve_Scott]

Might not be the cheapest way of doing it but composite suppliers will have everything you need to make a bag or vac down to a surface.

https://www.easycomposites.co.uk/#!/vac ... d-supplies

 

[Steve Maskery]

They are the people I bought my valve and hose from. Very pro. But I'm trying to do this on the cheap, the days of deep pockets are long gone.

 

[worn thumbs]

I have faced eight doors using ordinary polythene and just the one bag.It kept getting smaller with each one and I was using a piece of melamine faced chipboard as a base.If you don't normally use a breather cloth-it won't work as punctures are likely.With a breather cloth it may work well and I find old towels work well as breather material and of course you need release film to stop it sticking.The cheap way is to tape pieces of clingfilm over the edges where glue may ooze out and then lay the breather in place.

 

[Steve Maskery]

Yes, I learned that lesson the hard way. I once veneered a tabletop with some exotic burr, using epoxy. The breather strip was bonded rock hard and a couple of hundred quids worth of veneer went to the tip.
I shouldn't have done that.

 

[Lons]

Steve
I don't know anything about vac bags but I've used building film for many years as dust screens when working in peoples homes and it's remarkably strong and really cheap from any builders merchant, I still use it regularly under glue ups, dustsheets to cover up in the workshop if a lot of sanding etc.

As an alternative look at this from Scewfix, don't know the thickness but at a fiver for 50m x 2m it's not going to break the bank and is useful anyway.
https://www.screwfix.com/p/harris-taskm ... x-2m/19574
or this from toolstation
https://www.toolstation.com/search?q=polythene%20film

 

[Myfordman]

What thickness do you use, please, Bob? My present bag is 0.5mm.

I've found a place that does polytunnel stuff for £7.50 per m at... 9.5m wide! The carriage will be more than the goods!

Steve, I use screwfix 20738 620 gauge 3m x 4m for a tenner.
I certainly recommend using clear so you can see what is going on with the seal.
The vacuum does not lead to it creeping inwards but to be on the safe side I allow 6" on the three silicone sides just in case. I use the cheapest screwfix nononsense silicone. It does not set in use as the acetic acid cannot escape.
Once the job has been removed, the bulk of the silcone can be carefully scraped off and discarded, the remaining traces can be left to set over night and the sheeting reused, ideally for jobs smaller than the previous.
For a batch of jobs the same size, then just slather on some fresh silicone.

Bit of a write-up here http://www.thewoodhaven2.co.uk/viewtopi ... =19&t=2990

hth
Bob

 

[Steve Maskery]

Thank you all.
I've ordered the one from Amazon (before I read Bob's post) so I'll give it a whirl as see what happens.
I'm glad I've ordered something, as the more I think about it the more I'm sure I don't have the wiggle room I need.

 

[stuartpaul]

As an alternative look at this from Scewfix, don't know the thickness but at a fiver for 50m x 2m it's not going to break the bank and is useful anyway.
https://www.screwfix.com/p/harris-taskm ... x-2m/19574
or this from toolstation
https://www.toolstation.com/search?q=polythene%20film

Lons,

That stuff is ultra thin and OK as dust sheet but little else. Highly doubtful it would any use for vacuuming.

 

[Steve Maskery]

The polythene sheet has just arrived. Although it is not as thick as my existing bag, I think it is going to be just fine, provided I can seal it properly.