chelapa

Hey guys. Im back and i havnt posted in a VERY long time.

I have some questions b/c i want to get into vac. bagging. small exp first of course
I have a 80 gal compressor i always use for my shop, but i also have the vacuum pump they use for a/c system in cars. i saw a post while doing my search, BUT it has no details on how its hooked up etc

1) can someone help on how to get myself up and running? what connectors, switchs, valves, etc
2) what bags ( i want to atleast reuse them) , plys etc do i use and where?? Whats the best way to use them
3) seals, i dont want any leaks
the back of my molds have some small spikes, that i think i will sand down b/c its from the fiberglass matt i use.
please, if anyone can help with pics of their setup, some model #'s of things i should get, urls, etc please please post! thanx!

Newc

Here are a few links that you may find of interest. The first one is for ACP Composites. Their $100 set up is all I have needed to vacuum bag the wings and tailfeathers for my 104" WS Nomad, and I doubt that you can buy all the equipment that you need (including the reusable bags and sealing system, valve, etc.) for significantly less than their price. And you get a very good video covering the process and more advanced procedures. http://www.acp-composites.com/

The second link is to a very good free video by Jim Young, an expert in the art, who uses a very simple system - http://www.rcgroups.com/links/index.php?id=4901

Finally, you may be interested in the following thread covering an experiment that I conducted with the result that I used Gorilla Glue for my vacuum bagging - http://www.rcuniverse.com/forum/m_38...tm.htm#3815201

Hope that these help.

chelapa

Hey, i actually was in that thread! =)

well heres the thing, i dont know what connections to get, lines, etc. i want to try an exp. with the bags that someone got from Ace hardware and using bating cloth!? from walmart as a breather. lets see what happens. do you guys put some kind of release in the bag? like a spray so it doesnt stick to the epoxy. plastic bags shouldnt stick anyway.

chelapa

I want to try this since i have most of the hardware for it

http://www.rcuniverse.com/forum/m_4538380/tm.htm

Newc

For the breather cloth you can even use paper towels. I think that's what Jim Young uses - haven't watched his video for a while. To keep the bag from sticking to itself or to the foam, balsa, epoxy, etc,. cover the part(s) being vacuum bagged with waxed paper just like you cover plans when building. At least some plastics (bags) will stick when exposed to epoxy.

By the way, depending on what foam you use, you will need to get a regulator switch to keep from developing too much vacuum and crushing what you are trying to vacuum bag. The typical foam we use will only withstand about 7 - 8 psi vacuum and the pump you are contemplating using is likely to develop quite a but more than that.

chelapa

question thou, how much preasure should i put that the fiberglass wont print out on the other side? ex: i spray my molds first with primer, then epoxy and layup. what type of valves, hoses, connectors, gauges, etc do i use? also a res. tank, any plans on this site on how to build it all out?

chelapa

so heres a list of things i got from home depot

2 types of plastic sheets
3mil and 2 mil. i think i like the 3 mil better
clear sealant (dry in 10 mins) hope less
hard 3/8" tubing
DUCT TAPE! =)
Shutoff Valve for the hard tubing
2 split

So now here is what im going to do

first make the bag, let it dry make the shape etc. put it aside

im going to try and get to the plumbing store and get some PVC pipe for the res. tank

so heres whats going to happen

Air Compress -> Car Vacuum tool in the link above. -> hard tubing -> shutoff valve -> tube -> elbow -> Res. Tank -> Elbow -> tube -> t split (only if i deside to vacuum from 2 places in the bag) -> bag.

Now, im going to get some batting from walmart for a breather (or paper towels) but heres my thing, what do i use at the end of the tube going into the bag so no air comes out, i can get at a local store???

i hope this works for the very little money i can ONLY put into the test. i can afford right now for anything exp. so guys, for those of you out there with a nice system, pitch in to help, not bash on me =(

i want to see if i can get this done by this weekend for some results for all of you

chelapa

So my experiment was a dry one. And it was pretty successful i say. It went into very tight corners well, i might see if i should use 2 mil plastic instead of 3. BUT 3 mil sound like it should be it b/c of the sharp corners. it didnt tear. i was losing air somwhere so the min i took shutoff the vacuum, air slowlly got in. i need to buy a real connector to get into the bag. i also need a better way to airtight the seals. but all in all, it went very well. the area in which the actual hose was placed inside the bag was sucking so much, even the paper towel i used had NO air and was REALLY tight. hope to get a much better seal.

question, lets say i get a very tight seal. if i shut it off, what are the chances of air still getting in?
is there a electronic switch i can install in b/t the aircompressor and the vacuum and then b/t the vacuum and the bag to shut off and on?
what type of connector should i use at the end of my hose going into the bag?

T_om

Go here: http://www.joewoodworker.com/veneering/welcome.htm

He talks about the different vacuum arrangements and methods. Mostly directed at veneer work, but a vacuum bag is a vacuum bag.

Tom

chelapa

i bought the kit! =) i will update you guys soon

Newc

Which kit? How much?

chelapa

Its a kit that converts Air Compr. to vacuum. I already got it!!! 1 day delivery since im not far away from them. all together with things i needed cost 160 shipped. I will take pics soon. i got the premium version

T_om

Build it EXACTLY as the instructions say and it will work perfectly. I have one too.

I also have a vacuum pump version I built using a Gast pump but I hardly ever use it. I use the venturi setup all the time as it weighs almost nothing, hangs on the wall ready to go, and is quick to set up. I almost always have my air compressor on anyway so it works well for me. Veneering 8 foot long table tops are a piece of cake with this unit.

Tom

Newc

Why did you go this route instead of the complete system from ACP Composites for $100?

T_om

Look at the sepecfications for both and it will become pretty apparent. The ACP $100.00 EZ_Vac "system" is a toy in comparison.

Tom

chelapa

Tom thanks for replying. yes the ez-vac system is a toy. I hooked everything up and WOW im very impressed. Think of it this way. veneer finishing is i believe a MUCH thicker resin base and for it to soak through wood, and this system, it must have a lot of power. i bought the 6$ attachment for the bag system. i also made a bag using silicone, forgot which one from home depot) and wow it held like crazy glue! i will test tonite to see if it will hold air thou. i switched to 4 mil just incase the bag tries to rip on corners. report coming soon. by the way i fully recommend this system so far.

Newc

Yes, but we are dealing with 'toy' planes here.

Seriously, the $100 ACP system may be a lot less robust than the other system which is designed for furniture veneering, but for our purposes the larger system is probably heavy handed overkill. Not only does the 'toy' ACP system work well - it was fine for my 104" WS Nomad - but an even less expensive Food-Saver vacuum system will do the job for our stuff, as shown in Jim Young's video. That's why I was wondering why spend the extra $$.

chelapa

well for me, since i have a 80 gal compressor, just having an addon was ok for me. i can switch back and forth and still have a lot of power. another reason i got this system was for the shutoff controller. Check the video out

http://www.joewoodworker.com/catalog...ctv2-large.wmv

T_om

I agree that we are, indeed, playing with toys. However, this toymaker prefers something a bit more robust when building his toys.

Vacuum bagging systems are simple devices. The only variable is the pressures each can apply. A system that can only pull 8 inches is VERY weak in comparison to most other vacuum systems on the market, not just the veneer press systems. 8 inches of Hg is fine for lots of things, but too weak for lots of things too. There is also the volume of air that can be evacuated, which limits the size of the bag you can use.

If you are a handy type and already have an air compressor and a 30-year box sitting around, then the venturi system shown on the joewoodworker site is a no-brainer. You do not even have to buy his "kit", just get the components of it that you do not already have laying around. That would reduce the price to well below the ACP system cost of $100.00. I only had to buy the venturi and MAC valve. And even the MAC valve is not absolutely necessary, it is a little luxury add-on. I already had all the other stuff.

Check out the people building serious composite stuff and you will find most want all the pull they can get.

Tom

chelapa

I asked the question in another thread, im stuck on choosing what batting/foam/paper towel to use. is it a necessity? whats it for really. oh, and what happens when resin is being pulled into the line!?!?!?!

T_om

Almost anything porous can be used as breather material. Its only purpose is to give the air an escape route when the vacuum is pulled. I prefer either cheap cloth batting or regular old paper towels, depending on the size of the pull.

Do NOT allow resin to be sucked into your system. Needless to say, it will destroy some of the components. On our 'toy' layups, there is seldom enough excess resin to be concerned with. At least, there SHOULD be no excess. On large vacuum systems such as (full size) boat and veneer pulls, a resin trap is used before the pump, just as a water trap is used in an air line before a paint spray gun.

Tom