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darryl
11-05-2004, 03:56 AM
Have done some work for a cabinet maker friend lately. Amongst all the specialized gear for edging, cutting, gang hole drilling, etc, lies the age old standard glue bottle. You know, tip it upside down, wait for the glue to run, wipe up the unexpected over-dribble, etc. I came up with the idea of having the glue supply tank overhead, and a dispensor nozzle hanging from the ceiling, spring loaded, whatever- just push a button, glue is there instantly and comes out at a rate that you adjust separately. When you release the button, glue stops. Period. I'm wondering first of all if anyone's had experience with any similar system, and second, how would I make up such a valve arrangement. This is white glue, pva, and being water based, it would likely rust steel. I could or would use brass, aluminum, or some type of impact resistant plastic. I would think that pressurizing the tank and having a spring loaded miniature ball valve in the nozzle could be the answer. The ball would have to be at the very end of the nozzle so that no glue could sit and cause a clog. Either vary the pressure, or have some kind of restriction in the line to vary the rate that glue comes out. I would want the valve to be trouble free and not need cleaning constantly to keep glue flowing. Any ideas?

Swarf&Sparks
11-05-2004, 05:55 AM
What about a CV carby type needle? SU, Amal, Mikuni etc. They're a long needle with gradual taper. Turn up a brass jet, press fit, solder, thread, wotever, into the emd of a brass tube and arrange a spring and trigger. Lift the needle, glue flows, drop the needle, glue stops and it' self-cleaning (with the jet at the bottom of the tube)
Rgds, Lin

Allan Waterfall
11-05-2004, 07:40 AM
Darryl....

Depending how big the bottle is,but I made a little stand out of wood for my PVA glue bottle,stored the bottle tip down.
Never had to wait for glue to run to tip,just take it out of the stand and remove closing cap.

Allan

bernie
11-05-2004, 08:52 AM
Likely have a clogged tip every time it were used. I keep my glue like Allan, upside down.

Ted Coffey
11-05-2004, 09:30 AM
There are companies like this one:
http://www.gluemachinery.com

Joel
11-05-2004, 03:56 PM
Sounds like a good idea. For the spot oiler on my lathe, I used a brass needle valve assembly from Enco ($10) to regulate the liquid volume, and a ball inflating needle for a nozzle (cheap and common). Keep the nozzle in a holder with some water in the bottom when not in use. You could plumb the storage tank to a cheap regulator and provide positive pressure with the air regulated to low very pressure. Not sure what to use as a discharge vale, but I’ll bet McMaster Carr has something that would work.

Andrew
11-06-2004, 12:39 AM
There was a tip in fine woodworking about building a pressurized glue sprayer. Basically it's just a pvc piple with a compressed air outlet and a regulator on one end, and an air gun on the other. I'm probably going to have to try this idea out myself.

Their are specialized spray guns for spraying glue as well. Mostly seen this used for contact cement.

With your idea, are you thinking of a refillable bottle, or something disposable?

J Tiers
11-06-2004, 12:49 AM
You can get glue roller bottles also. I forget where, we tested tham in the old woodshop.

Roller applicator on the bottle. gives a nice even coat. I have seen brush tip bottles also.

The bead from a regular bottle is stupid, always the wrong amount, placed wrong, etc. I got so mad at the woodshop for using them, and then complaining about fits...the thick bead held parts apart.

PVA glue sucks. Sucks bad. Might be good enough for cabinet makers, no good for PA / MI speakers.

We ended up getting a Kor-Lok variety from National Starch. The wood shop fought and kicked and screamed against it.

The first time they dropped a finished cabinet off the table, and it bounced, they shut up. The PVA glue let it just come apart.

darryl
11-06-2004, 04:50 AM
Thanks for all the replies, fellas. I'm thinking of a pressurized container that gets refilled, maybe a gallon in size. Fairly low pressure, regulated. I don't see a problem making that mechanism up, I've built a few regulators in my time that work well. My wish is to have the least clogable tip that I can, and maybe the internal needle valve idea will be the way. I am considering trying to make it a blade instead of a needle, but the same idea. It will close off the opening from the inside of the rectangular nozzle, and right at the tip, so there won't be any hidden passageways that can't be cleaned out easily. A clip on cap with a piece of moist sponge could be good to keep the tip flowing after some idle time, like overnite, or a few days. I like the idea of a ribbon of glue vs the bead, so I'm giving that some thought.
I also concur that white glue isn't the best, but my friend wants to stay with what works for him, and what he was taught on. I agree it's good enough to hold a drawer together, but I stopped using it long ago in favor of yellow glue, and some of the better alternatives between that and epoxy.
Interesting web site, Ted, I guess glue is a big industry, I never thought about it much.
A closing thought- when you staple pieces together, the staple 'blows out' the wood at the exit hole through the first piece it penetrates. This separates the pieces being glued by some amount, unless the pieces are securely clamped before stapling. Clamping doesn't usually happen in a production environment, as there isn't time for that. Anyone recognize what I'm saying, and maybe have some ideas on minimizing that? Is there a quality nail or staple gun that would give a 'kick' to the top piece just at the point where the staple or nail would be sucking the pieces together?

J Tiers
11-06-2004, 10:14 AM
<font face="Verdana, Arial" size="2">Originally posted by darryl:

Clamping doesn't usually happen in a production environment, as there isn't time for that. Anyone recognize what I'm saying, and maybe have some ideas on minimizing that? Is there a quality nail or staple gun that would give a 'kick' to the top piece just at the point where the staple or nail would be sucking the pieces together? </font>

The woodshop used "pins" not nails. They actually are like thin flat nails. The "knockout" was minimal.

As far as clamping, I think it happens MORE in volume production, or in very low production. In medium volume, the fast cure equipment is too expensive, and clamping until cured takes too long.

The glue we got was actually made for clamped, ultrasonic or RF curing. It did cure without that also, and was nearly as strong when room-temp cured.

The *real* production folks clamp the assembly, and apply ultrasonic energy. Cure is 1 to 3 minutes to 90% strength. That is fine for production, as it is less time than assembling the next piece, in general.

darryl
11-06-2004, 04:45 PM
J Tiers, you're probably right. I'm only going by what I've seen in local shops, where no more than maybe five guys work. These are cabinet shops, working five days a week, but probably do still qualify as 'mom and pop' shops. The shop I'm working in and some I've seen locally don't have much excess room even for a coffee cup, let alone a proper assembly table.
Anyway, I like the idea of using jigs wherever practical for glue, assembly, etc. I'm going to go ahead and come up with a prototype glue dispenser and see if it becomes something that gets preferred use over the standard bottle. That's kind of my forte anyway, making something to help make something. I'm starting to look at all the gear that's in use with an eye to improving some aspects if possible.

J Tiers
11-06-2004, 11:31 PM
Here is one:

I put glue bottle into google advanced find, with roller as required.

Got a bunch of hits on brush bottles also.

Here is one with roller applicators:

http://shop.woodcraft.com/Woodcraft/dept.asp?0=dept.asp%2Cdept_id%3D10000%26Tree%3D%2C Departments&1=dept.asp%2Cdept_id%3D1042%26menu_id%3D%26Tree%3D 0%2CFinishes%20%26%20Glues&dept_ id=2085