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Thread: Alive And Well In My JBL Shop

  1. #16
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    Hi Rick,

    Just a question, where these cabinets ever flown or mounted by the side/end panels without support on the bottom back of the cabinets? Might produce the sag although the center of gravity with mounted drivers is likely frontwards and stressing the baffle. Was the cab in a relatively humid environment?

    Bart
    When faced with another JBL find, Good mech986 says , JBL Fan mech986 says

  2. #17
    Senior Member saeman's Avatar
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    Quote Originally Posted by mech986 View Post
    Hi Rick,

    Just a question, where these cabinets ever flown or mounted by the side/end panels without support on the bottom back of the cabinets? Might produce the sag although the center of gravity with mounted drivers is likely frontwards and stressing the baffle. Was the cab in a relatively humid environment?

    Bart
    Bart:

    From my initial post, none of these possibilities apply. This is just poor workmanship/poor quality control.

    Rick

  3. #18
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    Quote Originally Posted by saeman View Post
    I ALWAYS use paperback veneer with PCV glue and heat bond it to the substrate.
    Can you expand on this? I'm pretty much a veneer neophyte. What are usual sources of paperback veneer, and is that how it is described in sales terms? Is the thickness a certain standard? Any details on the PCV glue? Is it brushed on? To both pieces, (cabinet and veneer)?

    'Sorry for all the questions, but I definitely have cabinets coming up that will need veneering, and I'd just as soon learn from a master.

    John

  4. #19
    Senior Member saeman's Avatar
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    Veneer

    Hi John:

    I can give it a try but the topic will be hard to keep on track. I've talked about veneering in many other threads and then regretted that they could not all be tied together - anyway!

    There are several types of veneer on the market and I have used most all of them. Some are better suited than others for veneering cabinets like those we are talking about but I will give you my OPINIONS on the use of the different types that I have used.

    1. Raw unbacked veneer - not readily available. When available it's usually in small pieces and seldom in sizes needed to veneer a large cabinet. It is thus required to be seamed and joined to desired width. This is a task in itself to yield a proper seam - not for me. Raw veneer also is more fragile and easily cracked and split. Withous any backing there is a major risk of having the bonding glue weep thru to the surface that you intend to stain and oil - major problem as there is no glue that I know of that can be cleaned from the grain. Also, the lack of some sort of backing may allow stains and oild to penetrate to the glue and break it's bond.

    2. 3M adhesive Back Veneer - I've used it with good results on large flat surfaces that are properly prepared. It does not bond consistantly well to bare wood (P.B., MDF, etc.). If you seal the wood before hand you will get better results. I have coated the substrate first with a polyeurethane varnish and then lightly sanded it smooth. This has given me good results with this type of veneer. If your project has any exposed veneer edges, don't use this veneer. If you can cover the edges and corners and prevent lifting then it will give good results. JBL cabinets all have corners and long exposed edges and somewhere in time (likely sooner than later) you will notice a corner lifting up and it's very hard to affect a repair. Small lifts can be layed back down with super glue but once this starts it will continue.

    3. Phenolic Backed Veneer - a lot like formica, very stable, will lay down with PVC glue, epoxy glue and contact cement. Best suited for projects where there are no exposed edges as this product is very thick (like formica) and the exposed edges are very difficult to hide. No chance that glues will seep thru to the wod veneer layer and no chance that oils will interfere with the glue bond. I like this product but trying to hide the exposed edge has left me frustrated too many times.

    4. Paper Backed Veneer - commonly refered to as 10 mil Paper Back Veneer. Available from anyplace that sells veneer. This has a veneer layer that is bonded to a paper backing that is 10 mil thick. Overall thickness varies by manufacturer. The paper backing provides good stability and allows handling without damage. It also provides a good barrier between most glues and oils and the veneer. Excess contact cement will leach thru the paper if brushed or rolled on in thick layers. It's best to use the industrial 2 part contact cements that are sprayed on if you desire to use contact cement with this type of veneer.

    GLUE - Epoxy, Contact Cement, PVC (wood glue)

    Two part epoxy is most often used in conjunction with the bag and vacuum pump system on pieces that will fit into the bag or when you have a flat press available to maintain the piece until the epoxy sets. This method has little application in veneering or re-veneering whole cabinets so there's no merit in further discussion.

    Contact Cements - water based, stinky regular old contact cement or sprayed industrial types (3M offers a couple different options) as does Glaserith and others - offers great bonding for flat surfaces. Problems occur at exposed edges and at corners. A contact cement bond is a flexible bond, even if on a microscopic scale. No matter what base material you use (P.B., MDF, plywood) it will have it's own unique expansion coefficient which determines the rate the material will expand or contract with changes in temp and the absorption of moisture. The veneer also has it's own characteristics. As your cabinet flexes, expands and contracts with changes in humidity you won't notice problems with the bond on large flat surfaces but you will notice the effect at corners and along exposed edges. The bond gives way at the weakest points. I've seen this many many times after using contact cement and also with self adhesive backed veneer.

    PVC Glue - Wood Glue - Yellow elmers, tite-bond, etc. This glue is used by everyone who does work with wood. It is a plastic based glue (Poly Vinyl Chloride) and is water soluable when in liquid form. This glue provides a solid bond between the veneer and substrate - as does epoxy and all of the hot glues used by the furnature industry years ago. It is likely, based on the time frame. that all of the veneered stock used by JBL was made using the hot glue and pressure roll process. At that time the exotic contact cements used today were not in use in that industry.

    The nice things about PVC glue is that once it has dried, it can be reactivated with the application of heat - and when it is it's a nasty stickey glue that is like contact cement. PVC glues generally do not fully cure for about 48 - 72 hours. Up to that time you can heat and reavtivate/ after that - good luck.

    With good technique I have found this option to be fool proof and over many years of use I have yet to have any lifting issues. If desired I can continue on with this thread and discuss my application techniques.

  5. #20
    Senior Member grumpy's Avatar
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    ... appreciate the time that went into that post. Nice to have both a
    recommended path, as well as a description of what didn't work so well & why. Thanks!

  6. #21
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    Thanks for the detailed post! What had me most confused was the PCV/PVC glue, since both terms showed up on the internet. Even more confusing is the glue I have in my garage for using on PVC irrigation pipe. Your post clears it up pretty well.

    Quote Originally Posted by saeman View Post
    If desired I can continue on with this thread and discuss my application techniques.
    I may take you up on that, but won't be able to apply it until near the end of the summer...

    Thanks again!

    John

  7. #22
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    Excellent...:)

    Thanks for clearing up the acronym issue - you had me scratching on that one..:o)

    I also have had issues with the contact cement lifting and the inevitable residual "stuff" that caused it.

    I'm curious on how you deal with the front trim issue on the older big blues. 3 years ago I redid a group of (4) 4343's that had issues everywhere ( and did the same hardwood corner inlay as you ) but I could not reuse the original front trim due to the small increase in the cabinets overall dimensions with the new veneer added.

    I purchased a bunch of walnut and made new trims but if there is a "trick" to reusing the old, would be grateful for the advice.

    And I now have 12 cabinets in storage awaiting the big ( haha ) block of free time to rebuild.

    I had thought about making a very large overhead router / arm assembly to actually plane an entire surface ( and BTW would of removed the dip found on your big cab ) but the mechanical stiffness and calibration needed is a LOT of work for a single-use machine and justifying the space in a "hobby" shop is very hard to do since we all do this for a less than break even $$ adventure.

    Please elaborate on your glue techniques - perhaps a dedicated thread that can be put into a sticky ( aka the packing one ) and placed in the tech ref forum.

    I have a pair of plastic veneered 4648's that I want to wood veneer for my daughters college room before august....

    sub

    btw - I thought you got all the brackets since they all disappeared in just a few minutes and I only saved one link...

  8. #23
    Senior Member saeman's Avatar
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    Rules

    Rule Number One - never use PCV Glue to assemble PCV piping, use PVC Cement instead.

    Rule Number Two - never use PCV Cement to lay down wood veneer, use PVC Glue instead.

    How's that for confusion??

    Let's just refer to it as wood glue and things will be less confusing. These are several options for wood glue and the choice is likely a matter of availability however you should buy the better product that any manufacturer offers. I've used Elmers Professional yellow glue with no problem but I hesitate to use their regular old white kids craft glue. Tite Bond offers Tite-Bond, Tite-Bond II and now Tite-Bond III.

    I use Tite-Bond II - coz I always have and because I can get it in Gallons at any Home Depot store. Menards typically does not carry it in gallons. Tite-Bond and Tite-Bond III might both work just as well but I'll stay with the product that has given me repeatedly good results.

    Application - I roll the glue onto the surface using a 4" wide short nap paint roller - 3 coats on the substrate and 2 coats on the paper backed veneer. I use 3 on the base material because that material typically absorbs the better part of the first layer and the paper backing on the veneer does not. Most veneer suppliers state that a glue layer of about 6 mil. is required to ensure a proper bond.

    Allow each layer to dry to the touch - nothing left that's sticky. I go one after the other as fast as they dry and I'll quite often force dry the layers with a fan to speed up the process. Direct sunlight is the very best.

    Warm weather is the best time as the glue dries fast with no clouding. When the temp is 60 or less the veneer will take longer to set and also it will dry with a milky appearance.

    It's best to bond the veneer as soon as the glue is dry although I have gotten side tracked and waited as long as 24 hours. After about 48 hours the glue starts to cure and WILL not reactivate with heat. If this occurs you're screwed and need to start over.

    When the glue is dry enough that you can still sink your fingernail into the layer is the best time to heat and roll.

    I will usually apply a 18" x 48" piece on the bottom of a 4350 in about 15-20 minutes, breaking the work up into aout 2 square foot sections.

    Use a clothes iron at full heat and apply the heat thru a piece of old cotton tee shirt - start at one corner and work it in rows and columns fashion. Keep the iron moving and don't stop too long in any one place. Apply even pressure and go over the entire section while listening for crackling under the veneer.

    After this initial ironing I start at the beginning corner and apply heat while applying pressure with a 4" wide veneer roller. Corners require a little more effort to prevent rolling over the edge and breaking the veneer that is hanging over the edge. I do this seconf step while rolling in the direction of the grain.

    Third step is to leave the cloth in place, trace a pencil line at the boundary of where you left off, reheat the whole section and remove the cloth. Then roll over the section going against the grain (cross grain). At this time with the cloth cushion removed it's very important to listen for crackling under the roller as you move it along. Crackling means poor bond - either not enough glue or you didn't apply enough heat and/or pressure to affect a good bond. This is a somewhat forgiving process. Reheat any bad spots and roll again. If the crackling fails to go away you either have a trapped air bubble or a spot with insufficient glue. We can talk about the fix for these issues later.

    I cut all of my veneer pieces to allow a 3/16" overhang at all sides, that will be trimmed off after the veneer is applied. I pick 3/16" because I usually try to grain wrap the cabinet from a single piece that is long enough to give me a side-top-side continuous grain. Leaving more than 3/16" overhang can side shift the grain wrap.

    More later - I'm at work and heading for home - Rick

  9. #24
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by saeman View Post
    PVC Glue - Wood Glue - Yellow elmers, tite-bond, etc....
    Hi Rick,

    Excellent coverage of this topic... no pun intended, but I think you mean PVA glue when you talk about the family that includes Elmer's and TiteBond etc.

    http://en.wikipedia.org/wiki/Polyvinyl_acetate


    Widget

  10. #25
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    I copied this info from their websites.

    Titebond - Aliphatic resin emulsion
    Titebond II - Cross-linking polyvinyl acetate
    Titebond III - Advanced Proprietary Polymer
    Elmer's Carpenters Wood Glue - PVAC Based Adhesive

    I think Titebond and Titebond II react differently with heat. I've never tried Titebond III.

  11. #26
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    Quote Originally Posted by 4313B View Post

    I think Titebond and Titebond II react differently with heat. I've never tried Titebond III.
    I believe traditional PVA yellow wood glue, i.e. Elmer's Carpenter's Wood Glue, Titebond I, and the many other brands along with good old white glue are all fine for heat bonding. I am not sure about the newer Titebond glues.

    I have used both Titebond II and III, but typically use the original for most work. Titebond III has very different physical properties and is rather runny.


    Widget

  12. #27
    Senior Member saeman's Avatar
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    Quote Originally Posted by Mr. Widget View Post
    Hi Rick,

    I think you mean PVA glue when you talk about the family that includes Elmer's and TiteBond etc.Widget
    Hi Widget:

    You're quite right but what's an acetal and a chloride among friends. These glues have for a long time been loosely and improperly refered to as PCV's, even amongst woodworkers. Who knows, maybe it's an easier acronym to remember.

    On the web site for Oakwood Veneer there is a lengthly discussion on the installation of veneer using 10 mil P.B. and PVA glues. My thread is just a rehash of this info with a few of my little habits thrown in.
    http://www.oakwoodveneer.com/tips/ironon.html Oakwood Veneer's is my major supplier and their site has been mentioned on the Forum many many times. I think that very few have ever taken the time to see what they're all about. There's info there on the merits of all bonding methods as well as info on veneer manufacturing, different cuts, etc.

    Later - Rick

  13. #28
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    Mr. Widget turned me on to Oakwood Veneer. Previous to that I used Rockler or Paxton.

  14. #29
    Senior Member saeman's Avatar
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    Quote Originally Posted by 4313B View Post
    Mr. Widget turned me on to Oakwood Veneer. Previous to that I used Rockler or Paxton.
    These guys are the best - not only in selection, in-stock product, one day shipping to me and quality of their material - but - their customer service really stands out. I've called their sales manager many times and described to him my needs and he's taken the time to hand pick and ship same day and I'm not even close to being one of their biggest customers.

  15. #30
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by saeman View Post
    ...but - their customer service really stands out. I've called their sales manager many times and described to him my needs and he's taken the time to hand pick and ship same day...


    They are awesome... I have sent them veneer samples from my scrap pile and have had them search through their stock to match it. They are not the least expensive, but their prices are very fair and their quality is top notch. I have never been disappointed by them.


    Widget

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