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| I hate go bars. http://luthiersforum.com/forum/viewtopic.php?f=10101&t=44768 |
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| Author: | meddlingfool [ Thu Dec 18, 2014 10:11 pm ] |
| Post subject: | I hate go bars. |
It's happened. They've slipped, sproinged, rotated, dented, flown and such enough times to irk me right proper. The tedium of taking them in and out gives me that feeling you get that is akin to road rage. I don't mind spending as much time as needed for any given task, but when I know there is a better/faster way, the slow ways grinds my gears. So, anyone here using a vacuum press, and can you give a brief breakdown on the ins and outs and costs of such a setup? Thanks... |
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| Author: | Josh H [ Thu Dec 18, 2014 10:21 pm ] |
| Post subject: | Re: I hate go bars. |
I've been looking at these ones. Not sure what sort of pump and other accessories you might need to make it work. http://luthiertool.com/vacuum_press.html |
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| Author: | unkabob [ Thu Dec 18, 2014 10:29 pm ] |
| Post subject: | Re: I hate go bars. |
I built go-bars from 1/2" dia. CPVC water pipe with a plate-nut glued in to the end and a flat-headed 1/4-20 furniture bolt threaded in. I have used this system for five years and the only problem was that there is no "spring" in the system to adjust the tension as glue is absorbed into the wood. I solved this by gluing 1/8" cork on the upper deck. It works for me. Bob 
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| Author: | Michaeldc [ Thu Dec 18, 2014 10:38 pm ] |
| Post subject: | Re: I hate go bars. |
My vacuum system is based on this http://www.joewoodworker.com/docs/proje ... pgrade.pdf |
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| Author: | difalkner [ Thu Dec 18, 2014 10:45 pm ] |
| Post subject: | Re: I hate go bars. |
When I had a woodworking shop in the mid 80's to around '91 or so we built a vacuum press for veneering on furniture (high end conference tables with exotic woods and veneers, end and coffee tables, etc.) and we scrounged around for parts locally. I think we made most of what we needed out of whatever we could find but it worked well. Now that I'm getting back into all this and gearing up to build guitars I thought about a vacuum press again. You can find most of what you need at these sites - http://vacupress.com/index.htm and http://www.joewoodworker.com/veneering/welcome.htm Edit: Haha - sorry, Michael. I must have been typing while you were posting. Either way the info is good. ![[:Y:]](./images/smilies/smiley20.gif "Thumbs Up")
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| Author: | Jim Watts [ Thu Dec 18, 2014 10:48 pm ] |
| Post subject: | Re: I hate go bars. |
I have both go-bars and a vacuum system. I actually prefer go-bars for bracing and the vacuum for larger surface area stuff ( bridge plates, double tops, etc..). It's so much easier cleaning up glue squeeze out on a go-bar deck while it's still fresh. |
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| Author: | WaddyThomson [ Thu Dec 18, 2014 10:49 pm ] |
| Post subject: | Re: I hate go bars. |
I use CPVC with a spring inserted, and a dowel. 7 lbs. of pressure. Works well for me. Attachment: P1060011 (Large).JPG
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| Author: | meddlingfool [ Thu Dec 18, 2014 10:49 pm ] |
| Post subject: | Re: I hate go bars. |
That's exactly it! But at 2k$, frankly it seems a bit overpriced for what's really involved, especially as one assumes that you still need to purchase a vacuum pump on top of it... But that's the concept all right. Anyone built one? |
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| Author: | klooker [ Thu Dec 18, 2014 10:50 pm ] |
| Post subject: | Re: I hate go bars. |
+1 on the Joe Woodworker plans for the pump setup. I've done some veneering in the past but have never used mine for bracing. Watch the Taylor factory videos to see how they do it. You'll need to make a template to hold the braces in position relative to the the soundhole/top shape etc. It's on the list of future projects. Kevin Looker |
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| Author: | meddlingfool [ Thu Dec 18, 2014 10:52 pm ] |
| Post subject: | Re: I hate go bars. |
That's a good point Jim. Though I use the glue most sparingly and get very little squeezeout. I could see HHG being troublesome. |
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| Author: | meddlingfool [ Thu Dec 18, 2014 10:55 pm ] |
| Post subject: | Re: I hate go bars. |
That's how we did it at the Larrivee plant too, so I'm quite familiar with the concept. Just wondering how applicable it could be to a veddy small shop... |
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| Author: | RusRob [ Thu Dec 18, 2014 11:51 pm ] |
| Post subject: | Re: I hate go bars. |
Ed, It sounds like something is wonky with your go bar setup if they keep slipping and springing out. I built mine and used 1/4" solid fiberglass rod I bought at a local supply house in 10 foot sections. I cut the pieces up and then applied a blob of hot glue on the ends. Not HHG but hot glue from one of those electric guns with the glue stick. When dry the glue has a tacky surface that doesn't slip around much. I also glued a piece of pegboard on the underside of the upper deck so when I put the bar in I register it in one of the holes of the pegboard. I don't get much slipping around even if they get bumped. I do occasionally get one that falls out if I put one in next to it that has a bit more tension but even then I have had them hit other bars on the way down and they are usually snug enough that they stay put. I would think a vacuum setup would be great if you are doing production work. Although there have been a few times I would have like to have a nice vacuum setup... Cheers, Bob |
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| Author: | Rod True [ Fri Dec 19, 2014 12:10 am ] |
| Post subject: | Re: I hate go bars. |
Ed, at your output I'm sort of surprised that you're not set up for vacuum yet..... +1 for the Joewoodworker set up, and there are several threads on making your own vacuum box. I'll do a search to see what I get. |
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| Author: | Ben-Had [ Fri Dec 19, 2014 12:13 am ] |
| Post subject: | Re: I hate go bars. |
I use a vacuum bag and pump system i got from Joe Woodworker. Inside the bag is a flat/radius dish and platen. The platen on the inside allows air to flow out. You can see the pump in the back ground. 
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| Author: | Rod True [ Fri Dec 19, 2014 12:31 am ] |
| Post subject: | Re: I hate go bars. |
Ed, check out http://www.veneersupplies.com/categorie ... ess__Kits/ you'll find nearly everything you need here.... |
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| Author: | J De Rocher [ Fri Dec 19, 2014 1:03 am ] |
| Post subject: | Re: I hate go bars. |
Another +1 for Joe Woodworker. I built my vacuum press based on the design on that site with some modifications that suit my work space. It works great with no hassle. Apply glue to the braces, place them in position, put the vacuum frame over the top or back with the braces on top of the appropriate radius dish, and apply vacuum. Break the vacuum after 15 min and clean up squeeze out and reapply the vacuum for 45 min. Done. My frame stores out of the way on edge on top of a cabinet. I spent about $75.00 for all of the required hardware and the vinyl sheet from veneer supplies, $96.00 for a used Gast MOA-V113-AE pump with a gauge, and about $25 for wood, drywall screws, and silicone. |
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| Author: | RNRoberts [ Fri Dec 19, 2014 8:11 am ] |
| Post subject: | Re: I hate go bars. |
I also +1 Joe Woodworker. They have an all in one controller kit that is easy to put together. You don’t have to build a reservoir tank. Any container that holds air will work, say an old can air compressor tank. I used an old style propane tank that I got for free when they changed the specs on them several years ago. The propane folks had piles of the old ones turned in and they flushed one with nitrogen, and stuck a fitting on for free. The other thing I’d highly recommend is using an old compressor from a refrigerator or freezer for your vacuum pump. They work really well, and you can frequently get them for free from refrig. guys. The biggest selling point though is that they are nearly silent ( think of your refrigerator without the ice machine noise). I’ve left mine on for 5 days, walking past it to get to the car, and not realizing it was still running. I'd go with the refrigeration compressor over a real vacuum pump even if it cost 3 times as much instead of free, just because of it being so quiet I used a discarded kitchen cabinet to make a work station with the pump and tank housed inside and it’s become the main place to work at now. If I need a larger work area I just clamp a larger piece of formica faced particle board on top. Plastic window screen works well as a platen. ( The lights at the left in the first picture is my low tech "glue pot"). |
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| Author: | Michael.N. [ Fri Dec 19, 2014 8:18 am ] |
| Post subject: | Re: I hate go bars. |
meddlingfool wrote: It's happened. They've slipped, sproinged, rotated, dented, flown and such enough times to irk me right proper. The tedium of taking them in and out gives me that feeling you get that is akin to road rage. I don't mind spending as much time as needed for any given task, but when I know there is a better/faster way, the slow ways grinds my gears. So, anyone here using a vacuum press, and can you give a brief breakdown on the ins and outs and costs of such a setup? Thanks... The spring loaded go bars avoid all those issues, the force being applied absolutely vertically. You can also have a much more compact go bar deck with the spring loaded type. In fact mine is fairly easy to dismantle. With the long flexible type go bars there is always a force that wants them to move in the wrong direction. |
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| Author: | kencierp [ Fri Dec 19, 2014 8:27 am ] |
| Post subject: | Re: I hate go bars. |
I agree -- go bar decks were removed for our shop decades ago for exactly the reasons/issues mentioned. Few things will tick you off more than discovering that your braces have slid around or tipped from the locations they were set thirty just minutes before. A vacuum clamp is a great alternative -- and inexpensive too. http://kennethmichaelguitars.com/vacuumclamp.html |
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| Author: | jfmckenna [ Fri Dec 19, 2014 9:07 am ] |
| Post subject: | Re: I hate go bars. |
Whats the matter with good old clamps?    Everytime I think about getting a go bar deck some one posts a thread like this and changes my mind. So the question is what is so great about them? They seem to take up a lot of room and have the potential to do some damage, not the spring loaded ones I guess. Is it because you can glue up all the braces at once? Saves time? What is it? |
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| Author: | Michael.N. [ Fri Dec 19, 2014 9:31 am ] |
| Post subject: | Re: I hate go bars. |
They are a lot cheaper than flip clamps. You can effectively glue all the braces at the same time. They are very quick to position and to remove. The only disadvantage I can think of is that the go bar deck tends to accumulate tools, wood and cups of coffee when it's not in use. I bought some springs from an engineering suppliers, some copper plumbing tube (many use plastic) and hardwood dowel. The trick is to buy the spring with the correct tension. |
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| Author: | guitarjtb [ Fri Dec 19, 2014 9:41 am ] |
| Post subject: | Re: I hate go bars. |
I have not used a vacuum clamp so I can't help with that. I would think that whether you are using go bars or a vacuum press you would still need to make sure the brace does not slide when pressure is applied. When I am using my go bar deck, I do that by holding a stop in place, on the top or back, with some of my go bars. I use a small piece of 1/4" scrap as a stop and place it on the down hill side of the brace, at each end. It makes placement of the brace easy when I am hurrying with the HHG. When I am installing the X-brace, I place 1 stop behind the intersection, with the front edge of the go bar right on the front edge of the stop. I place 1 stop at the rear side of the back legs of the X. Now, I can hold the X brace by the front legs, ease it in an inch or two above the gluing surface, and slide it down the go bar, into place on the top. The stops are removed as soon as the brace is stable for easy clean up. Another thing that helps to keep the go bars from pushing from side to side, is to make it more flexible at the top, so that you get better, straight downward pressure. I use 5/16" Poplar dowels from Lowes. $.88 each for a 48" one. I cut them into approximately 20" go bars, so they cost me $.44 each. I make the top flexible by cutting out one side of the dowel on the top half. I start about 2" from the top of the go bar, and use my band saw to cut out 5 or 6 inches in a nice radius. The cut starts at the edge of the go bar, gradually goes in about 1/4 of the thickness of the go bar, and then gradually goes back out. Now the flex in the go bar will be at the top third of the go bar, and the bottom 2/3's will give much better downward pressure. You can experiment with how much flex you want, and increase the depth of the cut. If you get it too thin at the center of the cut out area, they will break too easily. |
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| Author: | Michaeldc [ Fri Dec 19, 2014 9:49 am ] |
| Post subject: | Re: I hate go bars. |
This is the approach I learned. I glue my x-brace in as square stock then taper after. I use little scraps of wood and go bars to create index points at the ends, and center of the x-brace. This way I can apply glue, place the x-brace between the index scraps, and go bar away. Once all of them are in placed, it has tacked up enough to pull the index scraps and clean up any squeeze out. Once the x-brace is tapered and sanded, I move onto the other braces. I use scraps pieces of brace stock to bridge from the fixed x-brace to a new brace being glued. I place a go bar near the fixed x-brace to pin the new brace in place. Then I can place several go bars over the new brace, making for very good clamping force, and since the x-brace is fixed, the new brace can't skate around. I should mention that all of my other braces are pre-tapered, so setting a go bar on top of the brace would be almost impossible. I know this doesn't necessarily fit a large production operation. I am reluctant to vacuum bag because the braces can skate around even if you tape them in place. M |
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| Author: | J De Rocher [ Fri Dec 19, 2014 12:22 pm ] |
| Post subject: | Re: I hate go bars. |
I've not had any braces skate when applying the vacuum. Not so much as a 64th. The vinyl sheet pulls directly down on top of the braces and stretches uniformly around them. |
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| Author: | Ben-Had [ Fri Dec 19, 2014 12:42 pm ] |
| Post subject: | Re: I hate go bars. |
J De Rocher wrote: I've not had any braces skate when applying the vacuum. Not so much as a 64th. The vinyl sheet pulls down directly down on top of the braces and stretches uniformly around them. That has been my experience as well. I do use my go bar deck to place the x brace. Then all the rest go in the bag. |
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