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Anyone here using a vacuum press for glue ups?

Discussion in 'Luthier's Corner' started by thisSNsucks, May 5, 2019.


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  1. thisSNsucks

    thisSNsucks I build Grosbeak Guitars and Basses Supporting Member Commercial User

    Dec 19, 2004
    Yonkers, NY
    Grosbeak Guitars
    Hey all,

    Just curious if any of you guys are using a vacuum press for gluing on laminate tops/veneers, etc.

    I'm looking into getting one to potentially do some chambered bodies with bent laminate/contoured tops.

    I see LMII sells some stuff but it's more geared towards acoustic building.

    I was looking at this site and it seems to offer some good options:

    Vacuum Press Kits and Veneer Systems

    Anyone on here using something like this?
     
  2. Means2nEnd

    Means2nEnd Supporting Member

    I do.. But after a pretty big investment (not through LMI) and a bigger than expected learning curve I still use it time to time but it's not my go to thing. Your results will vary but there are things to consider at an almost zero atmosphere like say...

    epoxy boils and dries into foam if there is a gap..

    thinking the amount of pressure from the vacuum will completely pull a top down over an arm contour.....wrong

    Of course there are things to do in your prep to cut down on these things like say having a black veneer and a 1/4" maple top bend to that contour I rout out little channels on the underside of the top so there is room for material to collect on the underside of the bend and steam with an iron. I also "train" wood like a bad dog. I have an arm contour mold I do that prep to the wood and then clamp it to the mold so it will keep most of the form so clamping is a breeze but then it also after doing all that I have to ask myself why all the to do with dragging out all the bags/pump/lines ect.. It just as easily clamps up perfectly with standard clamps. Also I was told to add weights to the middle to ensure the top sticks to the areas between pickups it can leave a small gap... stuff like that keeps mine on the shelf with lots of saw dust on it. Just my .02
     
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  3. Means2nEnd

    Means2nEnd Supporting Member

    Oh yeh and by the way I bought everything but my vacuum pump from that guy you have a link to. He is awesome we called him for advise before pulling the trigger he was a great resource of info as well...
     
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  4. Beej

    Beej

    Feb 10, 2007
    Vancouver Island
    @Jisch uses a vacuum bag setup. :)
     
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  5. Bruce Johnson

    Bruce Johnson Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    I don't use a vacuum press myself on any of my basses, but my late buddy Mike Lipe used one on most of his guitar bodies, in his shop right down the hall from me. He put on all kinds of thin tops, spalted, burls, etc., flat and 2D bent. Beautiful stuff. I observed and learned and helped him work out his system.

    If you are looking at doing bent tops, where they curve down over contours, the vacuum system itself doesn't magically curve the wood to shape. We used moisture, saw kerfs on the underside, shaped caul blocks and big clamps to basically form the wood. The vacuum press just holds it in place while the glue dries. Lots of details to be worked out to keep the wood top from cracking and splitting. The technology of the press itself isn't difficult. A sealed up bag and a vacuum pump.

    I have no interest in vacuum bagging myself, because I'm not into the fancy wood tops thing.

    By the way, I actually have Mike's whole system here in my shop, for sale. The bag and pump, well used, but fully functional. PM me if you are interested.
     
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  6. bolophonic

    bolophonic

    Dec 10, 2009
    Durham, NC
    I’ve never used a vacuum rig for luthiery, but I used one extensively for fabricating prosthetics and we would frequently experiment with other uses for it in the shop.
     
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  7. I use a vacuum bag kit from these guys: (Roarockit USA). It has a manual vacuum pump and a fitting on the bag. I try to evacuate as much air as I can from the bag before I seal it, but even so it probably takes 50 or more pumps to get the air out. I understand that the fitting on the bag is similar to/the same as ones they use on wine bottles with systems that remove the air.

    I've used it anytime I'm laminating wood, probably about 50 or so glue ups. My only gripe is that the sticky stuff that is used to seal the bag doesn't work for very many cycles (and some of that is probably that I'm not careful enough when I store it). I just clamp the opening shut and check it every 5 or 10 minutes when I first take the air out of the bag. I've had it empty on me a few times when it wasn't clamped well.

    I haven't used epoxy in there, but Titebond foams up as well when you pull the air out, but not enough to separate the wood. I like that there is pressure all over the board and I've gotten really good results with it. The bag I got isn't big enough for a neck through body, I typically use it for wings on neck through basses and on bodies for bolt ons.

    My biggest accomplishment was gluing up a body out of 10 thin pieces of thin scrap wood. I put a board under that body and it really flattened out nicely inside the bag.

    I'm more than happy to answer any questions.
     
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  8. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Apr 18, 2021

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