Vacuum Baging - The Cheap Way

[jase]

this is not my information. i found it off another web site (rcuniverse.com) if i remember correclty. but outlines a simple way to make a cheap and simple vacuum bag system.

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Here's how to vacuum bag on the cheap.

- Purchase some painting plastic and make your own bag. I'd use .014 mylar.
- Seal the bag with cord weatherstrip; www.thefind.com/garden/info-caulking-cord
- Purchase a Mityvac MV6203 hand held auto brake bleed pump. Less than $30. www.charlesriverrc.org/articles/foam_vac/scobiepuchtler_simplebaggingsys.htm
That's it!

Tips:
Fold the bag in half and seal two sides of the bag with the weather strip. Make sure you remove any small creases, it's amazing how small the crease is that will leak. I roll it out with a wood handle, this step really needs to be done well, once again make sure there are no creases or that you go back and apply more weatherstrip to seal those creases.

Take the hose from the vacuum pump and put some weatherstrip around the hose and lay this into the seal of the bag.

Place your layup in the bag using paper towels as a breather and waxed paper in between to keep the layup from sticking to the breather.

Seal the bag, then use a vacuum cleaner to draw out most of the air, crimp your line then attach the Mityvac pump and draw the rest of the air out.

It all depends on how well the bag is sealed but you'll have to come back every so often and give it a few pumps to hold the presure.

But if you're using Gorilla Glue it dries rapidly so this doesn't take long. Oh, make sure you mist if using Gorilla glue or it'll never cure.
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and if you've read all that, you can also read this. another good source of information on the subject.

www.charlesriverrc.org/articles/foam_vac/scobiepuchtler_simplebaggingsys.htm

[chamm37]

Sounds very simple Jase. I would like to try the electric pump idea as well. Just to see which one gives a better finish

I am pretty sure all they use is a old fridge pump and thats it really

[jase]

if you read through it, they talk about pressure. if you have too much you can crush the wing. so you would have to be careful with waht you use as a pump.

i'm going to give it a go this week. i get tuesday off so i can go get some materials then.

[Garth]

Hi all im not sure if this is the cheap way to build a vaccum pump, but i think its the only way to make a pump that will last. Im going of this pump so ill see how we go. Jeff if you could give me some feedback that would be great. Going to build a box this avo to put it all in. I found the fridge pump very hard to find for the price $25. so far the cost is at $35

pump info
www.dream-models.com/eco/vacuumpump.html

Jeff can you tell me what pipes are air and oil.

Thanks Mate

[jirvin4505]

I can't tell. Mostlikely find out when the motor is turned on...

Turning the motor on.... Has the unit got the relay plugged in



It's the box thing on the side of the compressor.


I try to get my compressor from an actual fridge and then i can trace the wires back to work out what is the power wires and what are the thermostat wires.

Will have to look at it in person ... shed visit??

Maybe Shane (plainginthepark) or Sean can identify the unit??

On my pump the oil lines come out lower than the gas lines - these have been crimped off by me so they don't spray everywhere

There should be a relay coil on the end of the motor.

Just had a look... 3 connections required. earth, black wire to top of relay and brown (???I'm color blind) wire went to a round plug on side of motor and then to the front of the relay.

cheers jeff

[jirvin4505]

Jul 20, 2009 14:26:47 GMT 10 Garth said:

...... I found the fridge pump very hard to find for the price $25.

Gone are the day of strolling around the local tip looking for goodies.

I usually stop on throwout days and pull the pumps out of fridges laying on the side of the road.

Shane got his by buying a used fridge of ebay IIRC

example.... Beer Fridge - An Oldy but a Goody
ebay.com.au item ..... 150360107270
cheers jeff

[Garth]

some more pics. The earth is on the right hand side.

[Garth]

will get it wired up in the morning and give it a go.........

[sean]

Looks good Garth. My fridge pump looks just the same, but I got it pre-wired and ready to go, I only had to hook it up to the bag and I was in business. If you run into trouble give us a yell, I can take a look at mine and see what goes where. I haven't made a vacuum regulator, just been running it continously. The blue foam I've been using can take all the vacuum my pump can provide without getting crushed.

[Garth]

Well i finished of the vacuum pump today and it pays to ring around be for you start a project like this as the pump i had bought yesterday did not work. So i rang around this morning to find another pump, got in contact with a fridge guy near my place and picked up a WORKING pump for $30 then took the old pump back and got my money back, all good. If anyone needs a fridge pump i know where to get them and the guy will show you that they work for $30. A few more things to get a bag. and some fittings for the bag but other than that its all good. a big learning curve for me. Thanks again to mikey100, sean and jeff for all the great tips on setting this thing up.

Next thing is now is to get some foam and start cut and bagging some wings. Will be doing a lot of tests firsts. Man do these things suck hard.

[chamm37]

Looks very interesting Garth. Was it hard to figure it all out and wire it up Whats the white coil thing next to the bottle

[Garth]

As im not using my rudder on my dlg anymore i have taken the servo out of the fuz and now using reverse differential. I have bagged up a new tail out of balsa and glass. This the first time i have painted the outer skins so when i pull it out it should be a painted tail..... I hope

[Garth]

Well 5 hours later im flying again. Happy days ;D On to the next project.....

[Garth]

On to my next project the stab. Went and got some yellow foam from Austec today, the foam comes in 2400x600x50 sheets for $40 cash and 2400x1200x100 not sure on the price. The computer power supply cuts it like butter with a 800mm bow. I cut some very small templets and i have made up my mind that im not very good at foam cutting .

With a little sanding to the foam all was ok, then cut some carbon to shape and away it goes.

[Garth]

Sanded this from foam, will be the plug for the new pod. Its only 23mm wide. Just enough room for one servo, rx and batt. It will be out of carbon when its finished.