The pictures of the infusion grid didn’t materialize…
Here they are. It does’t stick to the epoxy so it’s reusable.
I initially considered the possibility for overheating and I did several dry runs with no resin and extended working times to check for heating. The thing never got any warmer than it did when it ran with no load at all. True story. I still keep a close eye on things when I use it mainly because I’m paranoid but so far it seems to be reasonably reliable.
This is what the interior of one of these pumps looks like. They’re not built like the industrial pumps. There is no physical connection between the motor and the bellows. Those are magnets at the ends of those arms. Under load the bellows collapse but because they’re rubber they never completely stop the oscillation of the arms. (pic is from the link I posted; mine looks a little different)
I’ve used the rig often enough to feel pretty comfortable with it running continuously. But, maybe the smart thing to do is connect it to a fuse that will shut it off it it gets too hot. At any rate, I can see that some smart people are real skeptical about both function and reliability. That being the case, anyone who’s considering taking up vacuum bagging might feel more comfortable going with the more sophisticated rigs. I’ve used both and they both work well for me but your mileage may vary.
I guess my point is that I do Timberflex boards, and I've done quite a few now. I bought my Gast 704 pump on e-bay for $45 or $50 bucks. I've used it to suck water out of dings, to suck the oxygen out of compass oil to fix and fill my Ritchie compass, I've made it blow to run as a compressor for my detail air brush, and it's filled up my bike tire & basketballs (although not so good) So I've amortized the little rascal on tons of projects.
I don't have a lot of room for single use tools. I use my Clark Planer as an actual door planer (weird), and I polish my car out with my 5455 big red. My HVLP sprays boats, cabinets, and fences, And I use my quality 3M organic filter mask to spray pesticide and weed killer. So while I appriciate the $5 dollar vac pump, and I think its cool & very inventive. That's $5 dollars more than I would want to spend on a one trick set up.
Double post
Hi, the aquarium pumps can not overheat but I doubt they can really generate useful vaccum pressure.
I have a fancy gast diaphragm pump I got on eBay for $27 in 2002. I built probably 75 kitesurf twin tips with it, repaired several surf and surfboard style kiteboards and built one compsand which was sort of like a mini Simmons. I also used it to make some cool resin infused carbon kiteboard handles.
When I tried to use the gast with aquarium airline to do resin infusion it did not work at all. initially I tried multiple lines to various parts of the laminate but the vacuum pressure just clamped the airline shut.
Oh, I also used it to bleed the brakes on my car once.
I got my pump cheap because the guy selling it spelled vacuum wrong. It is awesome, one of the best tools I own. They seem to be more popular now but if you keep an eye out you can still get a deal.
One more thing, if I am only laminating one or two layers of glass and there are no weird shapes or crazy corners and i want a clear laminate, I find I can do a better job just hand laminating. The vacuum removes a lot of resin that just needs to be added back in on the fill coat. If you get the vacuum to high, you can get micro dry spots in the laminate the won’t fill in with the fill coat.
Trent
I have used this brand of air pump for decades – never had one light up on me. They are designed to run 24/7 for years, because fish tanks need a constant/uninterupted supply of air. After a year or two the diaphragms begin to wear and lose efficiency.
These diaphragm pumps are little more than transformers. There is no spinning motor and bearings to heat up. It is just an electromagnet that changes polarity, pushing the diaphragm magnets back and forth continuously – like bellows. There should be no more heat generated pushing the air than pulling it. There is no doubt in my mind that 3 hours continuous operation would not phase these pumps.
This is why I was/am so intrigued with Gdaddy’s technology. It never occurred to me to use them to create a vacuum. I would only want it for laminating composite cloths/fabrics anyway, close enough to 7-10 Hg to work.
Plenty good enough for test projects in the shed.
Thanks for passing this one along Gdaddy.
another neat trick using aquarium pumps was taught to us by Charlie Wong when we first me him at Uncle D’s years ago.
Charlie ran Robbie’s sailboard factory till he got exposed to epoxy and had to quit.
He makes some nice custom boards under the Bubbaboards logo in kailua.
Anyway Charlie said they would buy the really small aquarium pumps and put them on their glassing racks for glossing boards. The very slight vibration on the glossing racks would assist the final coat to smooth out to get that perfect glass finish.
just something to think about in case you get too worried about fires and such.
A pretty elegant and simple idea to solve a common headache
Anyway Charlie said they would buy the really small aquarium pumps and
put them on their glassing racks for glossing boards. The very slight
vibration on the glossing racks would assist the final coat to smooth
out to get that perfect glass finish.
awesome idea… along with Mr. Clean’s “put a fluro light underneath” I now have 2 reasons to run wiring to my glassing area.**
**
ResinHead...your first photo disappeared. Thanks for the comments everyone. When I said the pump pulled down to 23....that would be 23hg ........and then the pumps shuts off until it bleeds down to about 18 and then it kicks back on....I think on and off and on and off is bad for the vac pump...but it was donated to the Lab so we'll use it!
Keeping everything away from the rails is best for a Low Tech guy like me......My friend read too much stuff on Swaylocks and all his Vac Bag projects have been nightmares. Flatter decks and basic single concaves are better for me. Noise is a big factor but it was solved if you look at my first post. Mark has a project he wants to bag so I'm out here testing our stuff to make sure it works right.
Here's another photo for Keith......Truck tire valve stem and inner tube patch kit from NAPPA Auto Parts.....Air Compressor quick connect....
You sabotageed'ded my picture...I blame you StingRay....May the fleas of 1000 camels infest your armpitz.
my bag
Its a tad heavy. This board is going to travel 3,000 miles. Unless it gets hit by a truck it should be OK.
Perrrrfect.....if you are having second thoughts about all this vac bag stuff take a good look at Resinhead's last photo. The blank has a stringer. The wood looks good....at least one inch off of the rail....no complex curves for the skin. Looks like some scrubb pads or something........all this High Tech talk.......it's really not much Tech.
.....and Gdaddy is the real deal. He's been by the Lab...the guy does nice work with very little Tech......Carry on...
You guys are a bunch of hosers!
Get it?
Take off, eh???
Good idea for the muffler Ray. Wish I’d thought of it, ha ha.
Inserting the attachment fitting over the deck or bottom while pulling a lot of vacuum might leave an impression on the surface.
It's been suggested here to run the vacuum attachment off the edge of the board but have it 'connected' by way of breather material to the rest of the board. I think one guy has called the breather material path an 'ear.' Anyway, just run a narrow strip from the deck to the vacuum attachment and pull all the vacuum pressure you want as long as your foam density is 2+ lb/cu ft. The .75 lb/cu ft compsand stuff can crush with too much vacuum.
I did a bunch of test panels and read the Bert Burger thread carefully before I jumped in on a real board. And yes, I crushed a few.
The main advantage of the larger pumps over the smaller pumps, which indeed are capable of pulling enough vacuum, is that the bigger pumps can evacuate the extra air in a bag pronto if you are using fast resin. The 'CFM' spec will tell you how many cubic feet per minute the pump will pull. That is a separate spec from the vacuum pressure.
Some guys have recommended using a standard shop vac to evacuate the bag and when it is starting wrap around the board, attach any pump you want... the bulk of the air volume has been evacuated at that stage. An aquarium pump with the diaghragm reversed is a brilliant solution but expect it to take quite awhile to pull everything tight.
It is also possible with breather peel-ply fabric and absorbant layers to get such an efficient removal of excess resin that you end up with pin air. Most of the guys on Compsand.com have ditched the outer vacuum bagging completely and simply bag the veneers to the blank before hand laminating the outer layers. As far as I know, that's how Paul Cannon and Huie have done it in the past and I respect what they've accomplished.
[quote="$1"]
Perrrrfect.....if you are having second thoughts about all this vac bag stuff take a good look at Resinhead's last photo. The blank has a stringer.
[/quote]
The stringer is a cut off from the veneer skin. It's 1/40 inch. so it's just enough to hold the shape and assist in shaping, but not much good for anything else structurally. All the strength comes from the glass under the wood. So far i have only had one of these boards break, and the break was because of the delamination spot under my ass.
When the board broke the first time it was more of a buckle than a full garage sale. So i fixed it, and it broke again on the veneer patch. So the story is once they break they really can't be fixed like a standard board. The wood needs to be consistent throughout the board, the wood is a very intergral part of the structure, it disperses the load. Any deviation in the ability of the wood to flex consistently will put additional pressure on that spot and cause failure.
Notice in this picture the board broke in a clean line where I had cut back the veneer. Note: The area on the rebreak was reglassed with 2x 4 oz, and 3 x 6oz.
Edit; One more thing. This board originally was made out of stringerless 1.5 EPS. Deck was 4 oz under the wood, with 4 oz over. The bottom was straight wood to foam, and 4 oz over. So it was very light. I surfed it for 3 winters, 2 -3 times per week. Was extremely strong & held up like a champ. Like I said, the only reason it broke was because of a delam under my ass. All boards now get a bit more bonding glass, tad more epoxy, and I keep the foam pre-vacbagging roughed up under the ass and feet.
To get a strong lightweight board is not rocket science, and no fancy materials are required. You just need to pay attention to the details in the build.
Also try the plastic vacuum infusion grid I showed a picture of if you want to ensure a well clamped veneer.
Place it directly on the wood veneer .
It eliminates the possibility of any of the epoxy bleed through sticking to the bag material resulting in trapped, bubble causing, air pockets because the bag can’t clamp evenly due to it being stuck to the wood in some of the resin bleed through areas… The flat area’s on the deck and bottom are more prone to this possible problem…
Just my $.02 for what it’s worth… I like to go into things with secure feelings of guaranteed success… The grid is one more step in that assurance…
VH.
NO breather?
No not a normal breather, you don’t want anything sticking to the wood veneer and possibly lifting it off the foam as you tear it off.
A peel ply can work ok like some do with cork, but for wood veneer the grid plastic works best for me and doesn’t stick…
Breather material is generally soft and about 1/4 thick not ideal for the simple step of glueing down wood to foam.
The grid is really meant for resin infusion, but works great in this application too, insuring even air flow and clamping pressure to every sq. in. of the bag.
You can put a thick breather on the opposite side of the board being veneered, this improves air circulation even further…
I like to keep the bag dry and free from sticking to the epoxy bleed through epecially when bagging wet laminates… I belive it does a better job of applying an even and constant clamping force to the entire board… That’s just my opinion …FWIW
I never put the vacuum hose directly onto the area being glued as shown in some of the photo’s in this thread. Mainly for the reasons I’ve described above and elswhere in this thread but somtimes it can also cause localized denting especially on lighter foam cores.
Once the bag is stuck down to the skin or laminate with excess resin, you might as well turn off the pump because you aint’ moving any more air out of that bag. The excess resin is doing all the work.
Maybe I’m way off on my ideas and theory, but I’ve had good success so far…
VH.
Hi VH -
I've also used shade cloth and even regular old fiberglass window screen which didn't seem to stick all that bad. they both peeled off like your basic nylon cloth breather. I do not pull it straight up though for reasons you point out... more like back and at an angle to the surface.
I know the guy that took that photo....no amount of high tech breather cloth would have mattered on that day......
good times..........
"no amount of high tech breather cloth would have mattered on that day......"
Maybe 2 stringers?