Page 3 of 6 FirstFirst 123456 LastLast
Results 31 to 45 of 87

Thread: Are Your Glue Joints Repairable?

  1. #31
    Join Date
    Nov 2004
    Location
    Belden, Mississippi
    Posts
    2,742

    Question Question for Bob.....

    I used the Resorcinol on an outdoor project several years back, and I seem to remember that it was purple. No prob since the project was to be painted. Is there a color issue with all plastic resin products? Curing time? Can it be sanded? Etc., etc.

  2. #32
    Resin is noted both for its sandability and glue lines than nicely match the wood.
    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  3. #33
    Here’s an update of interest to furniture folks.



    In my initial screening, I found cyano to be the only glue to stick to PVA residue – here, Titebond III.



    I hadn’t factored in clamping pressure. When PL Premium is clamped to PVA residue for 24 hours with high clamping pressure, it adheres well….but the glueline is soft and gummy, somewhat akin to a contact cement glueline. It appears to have potential to repair PVA-contaminated joints, so I’ll do some more tests here for repeatability and with liquid poly to perhaps see why this is.



    After 3 weeks in 60-degree pond water, the 3M 5200-Western Red cedar bond is beginning to lose adherence even where it received high clamping pressure.



    The PL Premium also has lost adherence where it wasn’t tightly clamped….but the actual joint remains sound.



    The epoxy has also lost adherence where it wasn’t clamped…but its joint remains sound, too.



    Finally, the resorcinol remains rock solid.

    But you can also see from the wood color beneath the lifts, that the wood is far from fully-saturated yet.....it will need a lot more time submerged.
    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  4. #34
    http://home.pacbell.net/ebeniste/gluearticle.htm



    I'm not alone in my condemnation of PVA glues for heirlooms.

    The author is over generalizing about modern glues in the second paragraph, but his repairability theme is spot on:

    There are several problems associated with synthetic glues which make them unattractive to furniture makers. These problems are often overlooked in favor of the generally perceived "easy to use" features that make a ready to use product handy around the shop. One of the most overlooked problems is the most obvious: lack of reversibility. Most furniture makers today do not consider the future problems synthetic glues create when it comes time to repair their creations. However, all furniture is subject to use and damage, and all furniture needs to be repairable if it is to survive the generations. Synthetic glues cure by a catalytic conversion from one chemical to another, and are irreversible. This means to take apart furniture made with synthetic glues requires destructive intervention and physical removal of all glue prior to repair.

    Modern glues have a mechanical bond only, and require tight fitting joints and even clamping. They do not bond to themselves, and set up unevenly, remaining wet in one area of the joint while setting dry in another. These glues seal the wood surface and prevent stains and finishes from penetrating evenly. They are difficult to sand and remove from the surface when set. One of the greatest problems is the lack of resistance to sheer forces, which allow the wood to "creep" along the glue joint. This "creep" allows veneer joints to open up, and solid wood joints to move over time as wood movement occurs relative to humidity and temperature fluctuations, as well as wood shrinkage due to aging.

    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  5. #35
    Join Date
    Dec 2004
    Location
    Andersonville, TN
    Posts
    157

    PVA glues may be better for m/t joints

    Thanks for your excellent contribution, Bob.

    I wonder, though, if PVA glues may not have a critical strength advantage over less elastic options where cross grain movement is an issue, such as in mortise and tenon (m/t) joints.

    The reasons are:

    1) Wood will move cross grain as its moisture content balances with relative humidity
    2) The amount of movement is proportional to the width of the tenon, so a 4" tenon will move twice as far as a 2" tenon
    3) If wood did not move, or if glues were perfectly elastic, then joint strength would be proportional to tenon width
    4) PVA glues do allow creep; they are relatively elastic when cured

    If the amount of wood movement exceeds the elastic limit of the glue bond, then something is going to break.

    Wider tenons will make for stronger joints up to the point where wood movement starts to weaken the joint by splitting one of the members or destroying the wood-to-glue bond. I suspect that PVA glues will allow wider, and stronger, cross grain joints than less elastic options such as UF or resorcinal glues.

    If I'm correct, then there may be less need to repair m/t joints that are made with PVA glues, as long as tenons are kept to a reasonable width.
    Last edited by Jay Knepper; 07-30-2005 at 1:18 AM. Reason: typo

  6. #36
    The longevity of PVA glue isn't the big issue....more brittle glues last many decades in M/T joinery. The glue joints may break eventually, or they may not.

    The big issue is repairability. If they do break....or if your piece is damaged in shipping ( probably the most common M/T glueline break)...you can't repair it without disassembly and plugging and recutting the bad joint.

    That PL poly construction adhesive may have potential to repair PVA-contaminated joints economically......but a whole host of restoration folks are gonna have to use it successfully before I switch from plastic resin and hide to PVA's.
    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  7. #37
    Join Date
    Feb 2003
    Location
    Conway, Arkansas
    Posts
    13,181
    OK Bob....I'm going to stick my neck out here.

    I like using liquid hide glue for most of the interior pieces. I have used PVA glue a lot before and that was before I found liquid hide glue. I don't have the Hot Pot type yet....but I will one day. But my burning question is: Do you use a plastic resin glue, UF glue, or what would you use for your indoor furniture pieces? I like using epoxy, but have never used it in standard furniture building...have used it a LOT in building radio controlled airplanes.
    If hide glue isn't the best and pva is good and poly is fair, then what is it to use and yes....I care about repairability and is one reason why I switched to liquid hide glue. Works very nicely.
    Thanks & Happy Wood Chips,
    Dennis -
    Get the Benefits of Being an SMC Contributor..!
    ....DEBT is nothing more than yesterday's spending taken from tomorrow's income.

  8. #38
    Join Date
    Dec 2003
    Location
    Laguna Beach , Ca.
    Posts
    7,201
    This is an excellent thread! I use West systems for anything outdoors and some furniture including chairs. Tightbond III is very good for normal use. I never use Poly Urethane glue...it is a mess and not reliable in strength. Plastic resin is excellent. I use Hide Glue occasionally
    "All great work starts with love .... then it is no longer work"

  9. #39
    Quote Originally Posted by Dennis Peacock
    OK Bob....I'm going to stick my neck out here.

    ... I don't have the Hot Pot type yet....do you use a plastic resin glue, UF glue, or what would you use for your indoor furniture pieces?
    Have a mason jar, a thermometer, a pan of water and a hot plate? Old electric crock pots are better.

    I've used plastic resin glue in most interior furniture and boat interior applications for over 40 years. At least a 55gal drum of the powder. Never had an inside joint break with it yet. I've used hot hide glue for chairs, musical instruments, hammer veneering, and trying chipped glass decorations. When the time comes for me to do more chairs, I'll use hot hide glue. Disassembly of epoxy is problematic.

    I use poly in outdoor furniture and have been replacing resin glue with it on a trial basis in interior boat applications.

    I use resorcinol in boat hulls when I can live with the dark glue line and get it to the right temperature for curing (that can be difficult here)...otherwise I use epoxy.
    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  10. #40
    Join Date
    Feb 2003
    Location
    Granbury, TX
    Posts
    1,458

    Sources?

    Well, after reading this thread and another where KC talked about glue, I went out to the two local borgs looking for Weldwood plastic resin glue. No luck. So, do you have to mail order this stuff?, or do I need to find a good old fashioned hardware store instead of the borg? Anyone got a favorite source?

    Also, I have been using "Old Brown Glue" for my joints, but PVA for long grain panel glue ups. Would hide glue be acceptable for long grain? Would plastic resin glue be better? What about joints? Hide or plastic resin?

    Durability and long term repairability are both important. I want my great grandkids to fight over my furniture. (Well, I am not quite there yet, but there is hope.)

    Great thread, Bob, you should write a book, or several!!
    Martin, Granbury, TX
    Student of the Shaker style

  11. #41
    Join Date
    Apr 2005
    Location
    Ks. City, Ks.
    Posts
    113
    Martin, I found the same thing, or rather I didn't find the glue anyplace I went. That included a hardware store or two. I've been buying from Highland Hardware (on-line). Really like that place, great products, great service.
    Feel the wind and set yourself a bolder course

  12. #42
    Ace Hardwares and any boatbuilder supplier like Jamestown Dist will have plastic resin.

    Hide glue I get from Highland.
    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  13. #43


    The WRC heartwood test layup that included resorcinol, West System epoxy, liquid polyurethane, 3M 5200, and PL Premium polyurethane construction adhesive was pulled from the pond water after 6 months of submersion, cleaned, and a sample removed from one end and resoaked while the large end was allowed to air dry.



    There were no differences in adhesion between the sample allowed to dry and the one that remained soaked.



    Destructive testing showed that all the products tested continued to bond strongly after 6 months of submersion. The 3M 5200 poly sealant and PL Premium poly construction adhesive, when applied without clamping pressure, lost adhesion in saturated cedar…but with a clamping pressure suitable for resorcinol, their bonds remained strong.



    The “saturated” cedar test layup stabilized at only 24% EMC when corrected for species and temperature. I expected a bit higher reading, but this is consistent with the 30% moisture content of cedar heartwood in the log and the 21% of submerged bilge planking protected by paint. Cedar logs do sink, however, and remain sunk long after their heavier sapwood has rotted away. So this test layup goes back in the water to see if more time will provide a higher reading. I also intend to do another layup of White Oak, which I suspect will rise to over 30% EMC with saturation.

    General Notes on Glues and Goos


    Resorcinol: The marine standard. If you can get 70 degrees F or higher for an overnight cure and consistent and high clamping pressure with no gaps, you won’t go wrong using it. Likes wood at 10-15% EMC, according to Navy tests. Long open time. Repairable with epoxy. Ugly red glue line.

    Marine Epoxy: The repair and restoration standard. Bonds well to a wide variety of materials, and usable in almost all flexibility and temperature conditions. Needs no clamping pressure, only contact…fills gaps well. Likes wood below 12% EMC. Repairable with itself, joints can often be broken apart for repair with using heat. Clear glue line and can be dyed to match the wood. Controllable open time with different hardeners. Slightly permeable to water vapor and there are reports of failures in fully saturated wood and with White Oak. Very sensitive to UV, requiring protection.

    3M 5200: A rubbery, polyurethane sealant in various colors with adhesive properties sometimes used as a glue. Fails as a glue under water saturation without high clamping pressure, and without the proper strength testing I couldn’t do here, it’s not recommended as a stand-alone marine glue. Repairable with epoxy.

    Liquid Polyurethane: Gorilla Glue, Elmer’s Probond, Elmer’s Ultimate, and others. Versatile in temperature and bonding wet wood with moderate open time, these glues aren’t rated for below waterline use but initial use shows potential as a marine glue. Likes high clamping pressure and fits similar to resorcinol…it won’t fill gaps. Will successfully glue green wood at 30% EMC. Repairable with epoxy. Noticeable, yellow-brown glue lines.

    PL Premium Construction Adhesive: This polyurethane goo shows promise as a marine glue with further testing and use. Works like 3M 5200 but cures and behaves like liquid poly. Appears to bond well to everything epoxy does, and more where epoxy and liquid poly won’t, perhaps because of a higher isocyanate content…it bonds to difficult surfaces only cyanoacrylate super glues will bond to. The only general-use glue I’ve found that will bond difficult aliphatic-contaminated surfaces. Appears flexible to temperature and moisture content with gap-filling ability, but as a construction adhesive, its open time is shorter than liquid poly. Appeared to like high clamping pressure, and unlike other glues, wouldn’t bond at all without at least some. Repairable with itself and epoxy. Glue line as in liquid poly.

    Urea Formaldehyde Plastic Resin Glue: The old interior furniture standard, and in older marine applications that required well-blended glue lines. Still preferred by many, as it is a no-creep glue easily repaired using epoxy. Long open time, it needs tight fits and 65 degrees F or higher for an overnight cure…it doesn’t fill gaps. Best glue line among them all and moderate water resistance still make it useful for protected marine brightwork applications. A relatively brittle glue and UV sensitive, it requires protection….but its brittleness is an aid to reparability, as joints can be broken apart for repair. An inexpensive powder with a short, one-year shelf life.

    The Titebond Family of Aliphatics: Convenient. No mixing, just squeeze. Short open times, fast tack, and short clamping times. Flexible in temperature and to a lesser extent in moisture content, but the bottled glue can freeze in unheated shops. A flexible glue, it has been reported to creep under load, sometimes several years after the joint was made. The latest “Titebond III” appears to be a stronger glue than its two predecessors. Difficult glues to repair, as they won’t stick to themselves and no other glues will except cyanoacrylates, which are too brittle for general use. Epoxy and fabric aren’t bonding to aliphatic glue lines in marine strip construction, compounding repair difficulties. While not definitive, the new PL Premium appears to bond well to Titebond III residue and is worth pursuing by those repairing old white and yellow aliphatic joints.
    “Perhaps then, you will say, ‘But where can one have a boat like that built today?’ And I will tell you that there are still some honest men who can sharpen a saw, plane, or adze...men (who) live and work in out of the way places, but that is lucky, for they can acquire materials for one third of city prices. Best, some of these gentlemen’s boatshops are in places where nothing but the occasional honk of a wild goose will distract them from their work.” -- L Francis Herreshoff

  14. #44
    Join Date
    Dec 2003
    Location
    SF Bay Area, CA
    Posts
    15,332
    Anything new, Mr. Smalser?
    Wood: a fickle medium....

    Did you know SMC is user supported? Please help.

  15. #45
    Join Date
    Feb 2004
    Location
    Modesto, CA
    Posts
    2,364
    Thanks for bumping this up Chris. I missed it the first time around.

    Bob, what glue then would be recommended for cutting boards, kitchen utensils and the like?
    Mark Rios

    Anything worth taking seriously is worth making fun of.

    "All roads lead to a terrestrial planet finder telescope"

    We arrive at this moment...by the unswerving punctuality...of chance.

Similar Threads

  1. Rehabbing Woodies
    By Bob Smalser in forum Neanderthal Haven
    Replies: 16
    Last Post: 12-22-2011, 11:08 AM
  2. glue problem
    By Larry Reimer in forum General Woodworking and Power Tools
    Replies: 10
    Last Post: 06-26-2005, 8:17 AM
  3. The USDA Bottom Line on Poly Glue
    By Bob Smalser in forum General Woodworking and Power Tools
    Replies: 2
    Last Post: 01-31-2005, 11:55 PM
  4. Gorilla Glue
    By Betsy Yocum in forum General Woodworking and Power Tools
    Replies: 14
    Last Post: 08-02-2004, 1:15 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •