Vacuum cleaner for bagging use
#1
Moderator
Thread Starter

I'm sure it's been done, right? The idea is to make a PVC vacuum tank and use a ball valve (or something else that's better?) to seal it once the vacuum cleaner has done its thing. Does it work? Or is leakage too big an issue?
#6
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Thread Starter

That's what got me thinking about it. Yes, the plastic is pretty substantial. They hold vacuum for a year or longer. I don't know if it's enough vacuum though.
#8

Yea. they crush my shirts but the do hold for a long time. I guess just using the eyeball method for watching vacuum pull could be a problem using a vacuum cleaner anythime.
#9
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Thread Starter

Speed, do you have a link to plans for a vacuum system? I' know about the EZ vac. If I build more, it would make sense. But I'm a one plane a year guy at best.
#11

My Feedback: (29)

Jester, all you need to do is buy the vacuum switch on the link that Invert provided, find just about any vacuum pump at a surplus store. Make a tank out of 3" PVC pipe and caps. Install the vacuum switch to the tank and wire the switch to the pump. Plumb a line from the pump to the tank with an automotive check valve. Total cost shouldn't exceed $75.
#12
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Thread Starter

Pardon my stupidity, but there are a lot of vacuum pumps to choose from, and most are considerably more expensive than you're talking about. What kind of surplus store do you mean? I assume I'd be looking for a diaphram or piston type pump? For this application, CFM probably isn't a big concern?
#15

Jester, I splurged and bought a new vacuum pump from amazon for about $75 ish, the switch from Veneersupplies, and built a fairly large vacuum storage tank out of 15' of 4"ABS pipe, 2 T fittings and 4 caps in an H shape. Probably $125 or so in the whole thing and it has worked flawlessly for many years. I can turn it down to 5 inches for wings and up to 24 inches for carbon fiber components. Well worth the investment.
Scott
Scott
#16
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Thread Starter

I scored a free mini fridge today. It's leaking coolant, but the compressor still turns on. So I'm going to get started building my system. Thanks to all of you who chimed in to help me. I've been flying for a while, but am pretty new to real building.
#17
Moderator
Thread Starter

Looking at the veneersupplies website, I found the plans they have for the system which I've linked to below. They include the MAC valve and a few other items. The guide says that the pump won't restart if it's under vacuum already, which creates the need for the MAC valve. But it sounds like you guys are making it work without one? Their kit puts me at $171 without the pump.
ProjectEVS.pdf
Or I see this setup that's an air bleed/continuous run system that is a lot simpler.
https://www.joewoodworker.com/veneer...acuumpress.htm
ProjectEVS.pdf
Or I see this setup that's an air bleed/continuous run system that is a lot simpler.
https://www.joewoodworker.com/veneer...acuumpress.htm
Last edited by jester_s1; 08-15-2020 at 10:20 AM.
#18

Jester, all you need is the vacuum switch. Build a vacuum storage tank out of some ABS pipe, the bigger the better, but what space you have will dictate the size. The switch will operate up to a 10 Amp start up current, and I don't see a mini fridge pump exceeding that. No on the MAC valve, not necessary for our systems. Pick up a 2" vacuum gauge and screw it into your tank: kind of hard to adjust the switch when you do not know how much vacuum is in the tank. I bought mine from Grainger for about 20 bucks or so. My old version of the switch is good from 2" to 25", the new ones are a high and low. I would get the low switch, and wire in a DPDT toggle switch so you can have off in the center, switch regulated one way and continuous run the other. For carbon you will run the pump to 20" or so and shut it off, turning it on as necessary throughout the day to maintain vacuum. If you lay up early, by the end of the day the resin should gel off and the 10" of vacuum regulated by the switch will be fine until the resin fully cures.
Scott
Scott
Last edited by Pylonracr; 08-17-2020 at 08:20 PM.
#19

It seems to me it would be easier just to buy the EZ vac systems and get everything you need to start bagging. By the time you scavenge all the parts and buy a pump you would have spent a lot more than the cost of the EZ vac system. https://store.acpcomposites.com/ez-vac-systems It's a lot easier to just take it out of the box and plug it in and use it, than trying to put one together just to save a couple of bucks, (which probably wouldn't happen anyway)
#20

The problem is the EZ Vac system has a pump rated for Up to 8" of vacuum. Pretty much useless for composite work, but if it could be accurately controlled it would bag wings. You are still back to needing a vacuum switch to control the pump.
Scott
Scott
Last edited by Pylonracr; 01-01-2021 at 09:32 AM.
#21

The pump takes care of its self. Bags wings perfectly. Don't knock something if you've never used it. Seems like we've heard from another "self proclaimed expert".
#22
#23

My Feedback: (29)

The EZ vac system works for bagging/sheeting wings but that is about all its good for. Mine never gets used for a couple reasons. 1. It takes much longer to pull down a wing size bag then my pump/tank system. 2. One very small leak in the bag will reduce the bag's compression by half. The bag needs to be leak free, sounds easy in theory but sometimes you just have that tiny leak that you just can't find.
#24

The EZ vac system works for bagging/sheeting wings but that is about all its good for. Mine never gets used for a couple reasons. 1. It takes much longer to pull down a wing size bag then my pump/tank system. 2. One very small leak in the bag will reduce the bag's compression by half. The bag needs to be leak free, sounds easy in theory but sometimes you just have that tiny leak that you just can't find.
Scott
#25

My Feedback: (29)

I manage one maybe 50% of the time while doing wings and flat panels. When bagging fuselage molds I hook up both pumps and aim for 20". Of course the home jobs are much easier then bagging the aft end of an Atlas SRB. Since we only had 90 minutes working time it took a team of 5 to get the bag in place and reach 24" of vacuum without running out of time.