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Vaccum bagging pump. - 6/17/2007 5:37:37 PM   
glueit


 

Posts: 38
Joined: 11/9/2006
From: Nagpur.Nagpur, Maharastra., INDIA
Status: offline 		Hi Everyone,
I am building a vaccum bagging setup & collected all items except pump. I got one but didn't sure that this pump suits well for vaccum bagging or not. Here is the link-

http://www.technicsindia.com/technical.htm

Please visit the link & suggest me which is suitable for my needs among them.
Manish.
India


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RE: Vaccum bagging pump. - 6/20/2007 4:16:18 PM   
j.duncker



Posts: 1220
Joined: 6/22/2004
From: Where I park the RV, AK, USA
Status: offline 		For a low tech and very cheap solution look for a discarded fridge or freezer and see if the compressor is running.

Remove it and use it as a vacuum pump.

If you need a regulator visit a car scrapyard and find a vacuum unit of a distributor on a car ignition system. One of these plus a microswitch and a spring plus a bit of suck it and see will get you a regulator. Mine worked fine.

Recycling is good There is info out there on how to do this.

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       Post #: 2

RE: Vaccum bagging pump. - 6/21/2007 12:34:06 AM   
XJet


 

Posts: 3596
Joined: 3/31/2003
From: Tokoroa, NEW ZEALAND
Status: offline 		Just buy one of those cheap direct-drive piston air compressors and modify it to suck instead of blow.

That's what we've done and it's great.

A fridge compressor will give you the necessary vacuum but it's *slow* to evacuate a large bag. The modified compressor is fast -- and because it has a tank, it will cycle far less often (because no bag/connector/hose setup is totally leak-free).

I posted pictures here a while back but since then it appears my image posting privileges have been revoked so I can't re-post them.

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RE: Vaccum bagging pump. - 6/21/2007 7:56:28 AM   
Magne


 

Posts: 333
Joined: 3/7/2004
From: Moss, NORWAY
Status: offline 		Manish.

Some things to consider when selecting vacuum pump:
1. Is it intended for continuous operation?
2. Does it have a vacuum regulator mechanism? (This will switch the compressor off at a pre-set level of vacuum, and start it again when the vacuum drops due to leakage etc.)
3. What level of vacuum do you require? (For molding in a female mold, use as much vacuum as you can get, (22-28 In Hg) but for laminating or gluing balsa skins on white foam, 0,2 bar (5-6 in Hg) vacuum is sufficient, anything more may damage your foam.
4. How large vacuum bags do you use? (Larger bags will leak more, and require a larger capacity pump)
5. Is this strictly for occasional hobby use, or regular "professional" use?
6. Is it noisy? (You may have to leave it on for up to 24 hours)


I am sure there are other points to consider as well, but this is what I could think of just now.

The pumps you are listing may very well be suitable for vacuum bagging as they come from the manufacturer, but I would guess that they are strictly on/off units, with no relulators, vacuum tanks etc.
You would need to add these items if you want to use it for foam.

Regards,
Magne

(in reply to XJet)
       Post #: 4

RE: Vaccum bagging pump. - 6/23/2007 5:31:31 AM   
Kevin Matney



Posts: 196
Joined: 11/29/2003
From: Erie, MI, USA
Status: offline 		try this
Found surplus pumps for vacuum forming

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RE: Vaccum bagging pump. - 6/23/2007 2:13:04 PM   
daven



Posts: 7013
Joined: 12/7/2001
From: Andover, MN, USA
Status: offline 		That looks like a great pump for the price, thanks Kevin!

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RE: Vaccum bagging pump. - 6/24/2007 1:57:00 PM   
glueit


 

Posts: 38
Joined: 11/9/2006
From: Nagpur.Nagpur, Maharastra., INDIA
Status: offline 		Hi Everyone,
I am some but busy last week & can't come online.
First of all thanks for giving such good suggestions.
XJET, can you please sent photos of your compressor vaccum bagging setup in detail.
Magne, If i purchase this pump what are the things/ spares i require to complete & where to get it. Is this vaccum regulator mechanism is used in compressor, or any other machines. It comes readymade or we have to built it. If we have to built it then, how?
Manish

< Message edited by glueit -- 6/24/2007 2:02:22 PM >


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RE: Vaccum bagging pump. - 6/25/2007 5:25:54 AM   
Kevin Matney



Posts: 196
Joined: 11/29/2003
From: Erie, MI, USA
Status: offline 		This is my set up for now. I have this pump on order and have a 5 gallon air tank to use for a holding tank and a stand with wheels

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RE: Vaccum bagging pump. - 6/25/2007 9:49:21 AM   
Magne


 

Posts: 333
Joined: 3/7/2004
From: Moss, NORWAY
Status: offline 		Manish.
Many (most?) airplane modellers make these systems up themselves. There have been several threads here on RCU with instructions, diagrams etc.
Kevin in post #8 above has one example.
I made my own using a refrigerator compressor, but any vacuum pump may do the job. I think the vacuum pumps you referred to in the first post are just the pumps, with no vacuum regulation, vacuum tanks etc. (These may be suitable for continuous work at full vacuum, but will damage foam cores because they are too powerful.)
Here is a link to one design, by Norwegian modeller Ola Fremming:
http://home.online.no/~ofremmi/HowTo/Vacuumbag/VacuumBag.htm
This design use a membrane from a car engine distributor to regulate the vacuum, but electronic switches (vacuum switches) may also be used.
I have previously purchased some carbon and fiber glass materials etc. from Aerospace Composite Products in USA. They list vacuum pumps and components, including vacuum switches, but I have not tried these systems.
http://www.acp-composites.com/acp-vbes.htm
(Their shipping costs may also be high to India, they certainly are to Norway.)

Regards,
Magne

(in reply to Kevin Matney)
       Post #: 9

RE: Vaccum bagging pump. - 6/25/2007 4:13:51 PM   
glueit


 

Posts: 38
Joined: 11/9/2006
From: Nagpur.Nagpur, Maharastra., INDIA
Status: offline 		Hi everyone,
I have everything now except vacuum switch. Now i have to search vaccum switch in India's market or i have to make vacuum regulator mechanism. Search for swithch is going on. But can anyone plese tell me how to make vacuum regulator mechanism & from where to purchase raw material for making it.
Manish.


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glueit@gmail.com

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RE: Vaccum bagging pump. - 6/25/2007 8:46:20 PM   
daven



Posts: 7013
Joined: 12/7/2001
From: Andover, MN, USA
Status: offline 		I prefer continuous operation pumps myself, as opposed to one that goes on and off all the time.

If your running continous, you don't need a regulator, but just a small adjustable air bleed. You just open it enough to let out air to maintain a certain vacumm pressure.

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RE: Vaccum bagging pump. - 6/26/2007 5:52:58 AM   
Kevin Matney



Posts: 196
Joined: 11/29/2003
From: Erie, MI, USA
Status: offline 		Hi Dave
I have lost a few wings from that way. I use a Vac switch all the time. If you look at the pic you can see it between the 2 tanks. And the light switch is set up to run all the time or with the vac switch. I still do glass bagging on blue foam.
I tryed the bleed off way and the bag fixed it self a few time and got more vac then I wanted. Have you ever seen a flat wing it is real ugly!!!!!!!!!!!!!!!!!!!

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RE: Vaccum bagging pump. - 6/26/2007 10:28:19 PM   
daven



Posts: 7013
Joined: 12/7/2001
From: Andover, MN, USA
Status: offline 		The air bleed screw I use is between the pump and the suction hose, and once the proper bleed is set, you tighten the second nut up to the first one freezing it in place.

Never had a problem with this.

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RE: Vaccum bagging pump. - 6/27/2007 5:09:38 AM   
Kevin Matney



Posts: 196
Joined: 11/29/2003
From: Erie, MI, USA
Status: offline 		Hi Dave
What has happen to me was , a small air leak in the bag thated fixed itself and to much Vacuum happen and a flat wing!!!!!

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Kevin Matney 2 wrongs don''t make a right But 2 Wrights make an Airplane
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       Post #: 14

RE: Vaccum bagging pump. - 6/27/2007 2:51:06 PM   
rwlewis


 

Posts: 306
Joined: 8/27/2002
From: Tomball, TX, USA
Status: offline 		We use the following McMaster Carr item (1/4" NPT) as an adjustable vacuum relief for bagging wings and running the pump continuously. It is a very simple item and works great, and will relieve the vacuum as required to maintain a set level even if the bag leaks more or less during the cure time.

*****************************************
Brass Adjustable Vacuum/Pressure Relief Valves

Adjust these brass valves to relieve vacuum pressure from 0 to 27" Hg. They can also be configured to work as pressure-relief valves for low-pressure compressed air applications. Pressure adjusts from 0 to 20 psi with the knurled adjustment screw. They are not factory set to a specific pressure. Valves have a Type 302 stainless steel spring. The 1/4" pipe size valve has a metal-to-metal seal with a Type 440C stainless steel disc; 3/8" and 3/4" pipe size valves have a Buna-N seal with a nylon disc. Temperature range is -40° to +250° F. Connections: NPT male bottom inlet and vented top outlet.
Pipe Size Ht. Each

1/4" 1 3/4" 48935K25 $7.70
**********************************************


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       Post #: 15

RE: Vaccum bagging pump. - 6/27/2007 4:19:05 PM   
daven



Posts: 7013
Joined: 12/7/2001
From: Andover, MN, USA
Status: offline 		I got mine from Aerospace Composites, here is the blurb from their site (unfortunately, no picture):

BLEEDER VALVE
An adjustible valve that allows the vacuum to be regulated to prevent crushing of light density foam. It's an inexpensive way to regulate vacuum pressure. However, the vacuum pump must run continuously until the epoxy resin cures.

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RE: Vaccum bagging pump. - 7/16/2