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Powerful food sealer, homemade - anyone interested building one? Answered

After finding out my favourite catch of a good fishing day won't fit into any normal foodsealer bag or tube I wasted a few hours thinking about the problem....
These normal food sealers are like an injet printer - you pay the real price through the consumables.
And with those I already noticed cheap only too often means bad quality unless you got the bargain price for ordering in bulk.
My favourite kebab shop has a big commercail sealer that is used for packing stuff for other stores and catering.
So I ordered a fresh and extra spicy kebab and asked if it would be possible to take a closer look on this sealer thing they use.
No problem for a good customer like me but of course I was asked to finnish my kebab first and to use the provided gloves if I want to touch anything - freshly sanitised and so on....
I was surprised by two facts:
a) the price of close to 5grand
b) the simplicity of the thing
Was not allowed to take pictures, so sorry for that as this time I really wanted some.
From what I could gather without taking it apart is that 3mm stainless steel is used for a big "pan".
About 80cm long, 50wide and 30 high.
On the outside several pieces of square tubing, most likely to prevent warping under a high vacuum, although 3mm stainless already takes a lot.
The lid was 5mm stainless with several thick viewing windows in it to check the correct placement and sealing action.
Of course I am not really planning to go that big, for now anyway.....
For the inside there were several frames available to cater for pots, bags, loose stuff and so on.
Purpose of these frames was to make sure the bag used will be held with the open end inside the sealing section.
The heating element or strip was on the floor of the pan and a push bar was mounted to the lid to give the desired pressure once the lid is locked in place.
Time for the actual heat sealing of the bag is started with two switches on the locking clamps.
The top bar is mounted with two springs, I assume to allow for just enough pressure for the air to be sucked out of the bag while still performing a good seal during the heating.

Getting suitable parts can be as easy as to salvage an old vacuum sealer and to use a frying pan or as "complicated" as building one from scratch with a powerful vacuum pump or old fridge compressor - I like the second better ;)
But after a few Instructables and still several in the making I thought the old thing of "group therapy" would be nice for this one.
We are from all over world and certainly not everything I can get around the corner is available for someone from the remote areas of India or South America.
And I am almost certain that someone might have a great idea on what common and easy to obtain stuff can be used for the vacuum chamber for example.
Another one might already have a heating wire solution for the sealing that is cheap and reliable.
You get the picture....

Why would I want to do this with several people from all over the world, maybe even fighting language problems?
The benefits are there is you look for them ;)
With a limited set of "rules" on certain areas of the project we get the benefit of:
a) Having an instant proove of concept with actually working devices for our readers.
b) A much greater chance that anyone can repeat the success at home and with already several working designs to choose from.
c) A chance of actually "working" together on something with some of the great people here!
d) Something new that is not a contest or challange.
e) Hopefully a lot of fun on the way :)

Of course and in the case this actually catches on, it would be great to somehow create a collection for this project.
Like when you add several Ibles to your collection but so everyone who made one can add it.
So anyone up for it?



2 years ago

Adding complexity what about letting in, low cost, nitrogen gas or liquid before sealing the bag... Would it help preserve food stuff ?

They rotate my car tires and refill them with N2...

Jack A Lopez

2 years ago

Homemade vacuum sealer: this sounds like a noble goal.

Although, I do not yet have a good mental picture of the commercial machine you describe, and how it is different from the uh, consumer-priced, white plastic, vacuum sealers, like the various models of FoodSaver(r) et al, name brand sealers that this forum occasionally gets questions about.

I don't quite see it yet, in spite of your detailed explanation.

If you can find, via Google(r) Images, a picture of the big, bad commercial sealer, and then post a link to those pictures, or discover the manufacturer's name, the model number. That might help me to, uh, "get the picture."

Anyway, I am kind of interested. I have been having fantasies about building a related project, which is a way to make homemade, gas-filled, plastic bags, like to make things like balloons, and beach balls, and stuff like that.

The problem of taking gases out of a plastic bag, and then heat sealing it shut, is not too different of a problem, I imagine.

Downunder35mJack A Lopez

Answer 2 years ago

Nothing much to imagine really....
Unlike consumer models that suck the air out of a bag, this one was a big box where you place your bag inside.
The entire unit, including the bag is evacuated and once done the bag is sealed.
So no matter if solid, liquid or mixed food - nothing will be sucked out of the bag as the vacuum is even all around the bag.
Once or let the air back in the bag is perfectly free from air.
If you look for restaurant grade sealer you get a pic on how they operate, although even these look tiny to the one my guy uses LOL
"Problems" as such at this stage is finding a suitable vaccum chamber or making one, the rest does not even require a microcontroller despite everyone needing one for something these days.

I think for certain people it might be interested for mold making as well.

Jack A LopezDownunder35m

Answer 2 years ago

I think I see it now. You are talking, writing, about the kind of vacuum sealer with a big chamber, big enough to contain the whole bag of food. I suppose it might also work with a glass jar with a lid.

So, while the chamber is being pumped down, there is low pressure surrounding the plastic bag, and higher pressure inside the bag.

The next thing I am wondering about, is the sealing action.

Is there a heating element, for to melt the plastic bag's opening shut?

Or does the seal happen, like naturally (mechanically?), from two perfectly flat things being pushed together by the pressure outside the bag?

By the way, you probably already considered cutting your fish, to make it smaller, for to fit the small bags for your vacuum sealer. Right. Make the fish smaller, or make the vacuum sealer machine bigger. I admit, it's kind of a tough question.

Downunder35mJack A Lopez

Answer 2 years ago

If you have a snpper of over 60cm in length and of over 5kg in weight then normal freezer bags just won't cut it LOL
And something like that is not what you cut down to filets or steaks - it goes on the BBQ or fire in full size.
The heating element on these units is inside the machine.
So all air is removed, this means inside the bag as well.
Once the vacuum is at the desired strength the bag is sealed with a push of a button - or automaticall, whatever one prefers.
This way it really does not matter what type of bag is used as long as it fits into the sealing strip.

Jack A LopezDownunder35m

Answer 2 years ago

That's a big fish. I think I heard this conversation before in a movie: something about needing a bigger boat. ;-P

Regarding "what type of bag is used", I am guessing that we are talking about roughly two types, specifically: (1) the expensive type with little plastic ribs or channels on the inside for to facilitate air flowing out of the bag, even when air pressure outside the bag, is pushing the walls of the bag against each other. (2) the inexpensive type, which is just smooth and flat, so that air pressure outside the bag can push two flat walls of the bag against each other, impeding air flow out of the bag.

Moreover, I am guessing the reason why "it really does not matter what type of bag is used" with the vacuum surrounding the whole bag, is because in that circumstance, the pressure inside the bag is greater than outside, and the air inside the bag is pushing the walls of the bag apart, as it escapes from the bag.

So that's the reason why you want to build an enormous vacuum chamber: so you can use bags made from, inexpensive, smooth plastic.

Also I guess there was another advantage, regarding liquids inside the bag. The big chamber design is less likely to pull liquids from the bag into its vacuum plumbing.

Of course the big disadvantage of the big chamber design, is that you have build this enormous vacuum chamber.

Another disadvantage of the big chamber design, is each pumping cycle requires more energy, and maybe more time, because you have to pump down the whole volume of the chamber, rather than just the volume of the plastic bag.

But, I dunno. Maybe there is enough money saved on special plastic bags, to pay for all this.

Another alternative, might be to just focus your hacking efforts on the plastic bag. By that I mean, construct a bag big enough for your fish, using cheap hardware store bought, polyethylene (PE) sheeting, and heat sealing that to make a bag. Then come up with some kind of hack for the air channels, like some plastic mesh, or string, or beads, preferably the same PE as the bag. Then pump the air out using an ordinary vacuum sealer, the kind with ambient air pressure surrounding the outside of the bag.

Jack A LopezJack A Lopez

Answer 2 years ago

Oh wait. Please ignore my question about the heating element. I just re-read your question, and you already described that part.


Answer 2 years ago

You could use commercial plastic tubing and then seal off as much as you need. Most plastic bags are made as a tube and later sealed off into bags. You can buy the tube on a roll.


2 years ago

I don't have a need for a vac sealer but when I sous vid things I do the following:

As a relatively simple solution to not having a vacuum sealer I put food into a suitable plastic bag, immerse the food and bag in water keep open end above water. Seal bag with zip lock or clip.

When removed there is very little air in the bag at all.


Answer 2 years ago

That is good for everything that will be cooked shortly after in the bag or only kept frozen for a few days.
Works great by the way and I use it often for marinating and pre-cooking steaks.
But for long term cold storage you really need to remove all air to preserve the best quality possible.
Fish for example is usually only frozen for a few weeks until you can expect quality loss, mainly because it dries out.
I had fish vacuum sealed and frozen at -20°C for over a year and it was still mothwatering good once it finally came out of the oven :)
Problem is always size and price of these special bags, so I would like something that seals whatever you put in there...