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Thread: Cold creep in modified PVA glues?

  1. #31
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    Quote Originally Posted by Mike Henderson View Post
    I've made quite a few laminated parts for projects, including rockers for several rocking chairs, using Titebond glue and none of them show any "creep".

    During one of my visits to Sam Maloof, I asked Sam what he used for the laminations for his rockers (the actual "skates" or rockers). He pointed to a shelf with several bottles of Titebond glue, from Titebond I to Titebond III and said, "I choose which one to use by the color of the wood."

    Mike
    Well, if it's good enough for Sam...

  2. #32
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    I think creep also must be affected by design and accuracy of fit ups.

    I have a table in front of me that has been in direct sunlight hours a day, made with Titebond III that shows nothing of creep or even much of a seam at all. Of course the tenons are flush twice a year. This table is about 5 years old now.

    Bumbling forward into the unknown.

  3. #33
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    Quote Originally Posted by Tom Trees View Post
    Random thought about this
    Does thickness of a table or more importantly a workbench come into the equation.
    I was thinking of laminating my bench with hide but chose regular Titebond in the end.
    Wondering if you folks think a workbench is less likely to creep at 4" thick?
    Not that I'd be getting it wet or in the sun, but for interests sake.

    Tom
    Creep is the response of the glue to shear stress on the joint. In bending, thickness makes a difference in that thick lumber will deflect less than thinner stuff for the same applied load. With respect to the impact of seasonal expansion/contraction on shear stress due to mismatched grain orientation from one board to the next, however, thickness makes no difference.

    John

  4. #34
    Quote Originally Posted by Brian Holcombe View Post
    I think creep also must be affected by design and accuracy of fit ups.
    There is no thinking about that one. Thats plainly obvious. But in a lot of day to day work there is no time/profit in buddhist monk style fitup, grain/board/material selection, highly detailed fitment (doesnt mean your a slob), and so on. And it makes you look to options that allow you to move fast, make a quality product, with perfectly acceptable fitment, and take a few weeks of vacation over the course of the year that isnt funded by a spouses salary and health care.

    Who would care if you could feel a fingernail of creep in a Maloof inspired rocker or seat for that matter that is against the floor and will likely never see the touch of a hand other than the cleaning staff who wipes down the hardwoods on their sweep through of your $3K rocking chairs? But when youre making reasonably every-day work and you have a supposed bread and butter adhesive that creeps to the point of being noticeable or even worse breaking the finish with reasonably modest production methods, it gives you a bit of pause.

    I have personally never had a creep problem with TB Original or Super and that's what I stick with for interior day to day work.
    Last edited by Mark Bolton; 09-12-2019 at 2:01 PM.
    Sometimes I just want to look at pretty pictures,... Thats when I go to the Turners Forum

  5. #35
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    Mark, I've moved away from using Titebond III mainly because of your posts and the because I want something more easily repairable than Titebond III (which is not easily repairable as I understand it). So please don't confuse me with writing off what you're saying. I did want to point out my experience, which IMO is quite valid for small craft where the joint can be obsessed over a bit. Still, my time is valuable as well hence my reasoning behind doing my best to understand glues and their effect over time. For me, however, it is worth it to tune a joint lightly by hand. The extra 30 seconds per glue up has little effect in my shop.

    When I first started reading posts about the problems with TB III I had an immediate raised eyebrow, but I've been keeping an eye on my older work but haven't found anything that is out of line with similar work. I have Moller (Danish made) chairs in my office, I feel the joints and there is a very minuscule amount of raised area at some joints most are flush. My work seems to be about the same.

    Oddly enough I've had more issues with Hide glue which supposedly does not creep, so anymore I'm using mainly Titebond II and will probably move to Titebond original for work that could possibly need repair at some future point (chairs, tables, etc).
    Last edited by Brian Holcombe; 09-12-2019 at 2:22 PM.
    Bumbling forward into the unknown.

  6. #36
    Quote Originally Posted by Brian Holcombe View Post
    I'm using mainly Titebond II and will probably move to Titebond original for work that could possibly need repair at some future point (chairs, tables, etc).
    We all have to do what works for the work we do. My point with II and III is that TB is pretty much screwing the retail consumer with their marketing and people think if original is good, I has to be better, II is even better, and now III is "THE ULTIMATE". Wonderful for them, masterful marketing. I will guarantee you their marketing department will directly reflect that campaign in their home center sales.

    Any work that is put together with the utmost of precision, barring resistance to water, can probably be held together with a film of water. Thats not the world the bulk of us live in. And laying up a bread and butter table top when your trying to be productive and competing on price that will creep enough to break a high end film finish is a no go. But if your work affords prime material, edging/jointing oversize, stickering, two weeks edge and joint again, two weeks, on and on (not that Im saying that you),... then yes... pretty much any glue will do.
    Sometimes I just want to look at pretty pictures,... Thats when I go to the Turners Forum

  7. #37
    Years ago I had to "sponge" just completed furniture. Let it dry then sand real lightly to remove fuzz. In that process
    I sometimes noticed a slight shift at a joint would appear ...and require more sanding. We were told that step was especially important as we were using machine planed wood. Is it possible that some shift
    attributed to glue creep is just shift on non sponged pieces? We were using hot hide glue, so no creep there.

  8. #38
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    Quote Originally Posted by John TenEyck View Post
    Leaving the joints clamped long enough to assure the glue has dried sufficiently is always a good idea but it won't prevent creep afterwards. It's an inherent property of the glue itself. If you want to minimize creep use a glue with better creep resistance.

    John
    Ok, thanks John
    “Pay no attention to what you cannot control..” Epictetus, 100 A.D.
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  9. #39
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    Quote Originally Posted by Mark Bolton View Post
    We all have to do what works for the work we do. My point with II and III is that TB is pretty much screwing the retail consumer with their marketing and people think if original is good, I has to be better, II is even better, and now III is "THE ULTIMATE". Wonderful for them, masterful marketing. I will guarantee you their marketing department will directly reflect that campaign in their home center sales.

    Any work that is put together with the utmost of precision, barring resistance to water, can probably be held together with a film of water. Thats not the world the bulk of us live in. And laying up a bread and butter table top when your trying to be productive and competing on price that will creep enough to break a high end film finish is a no go. But if your work affords prime material, edging/jointing oversize, stickering, two weeks edge and joint again, two weeks, on and on (not that Im saying that you),... then yes... pretty much any glue will do.
    I agree, I think they should be sold more along the lines of what their purpose is but not much I can do to change that.

    That actually describes my work because I have a long lead time for finished projects and so my prep can be done in stages with very little effect on the overall time consumed because I prep for multiple projects at one time. I like to bring in lumber early, acclimatize it to the shop. Rough cut, leave it for a week, joint, leave it overnight, joint again, thickness oversize. Build a panel, re-joint, then thickness tp final. If you have 2 months lead time, there is no harm in doing it this way. When you're doing this for every project needed for the next few months it doesn't mess up your schedule or add much to time frame and it helps me to produce a better product.

    I make things like shoji screens where the it is much more time wasteful to throw away a stile that bowed than it is to work in stages. Throwing away material that costs $15/bf and is only available in 20" x 8/4" slabs gets pricey in a hurry.

    I chucked a bunch of yellow cedar that all bowed from fast processing and I learned that lesson, once was painful enough.
    Bumbling forward into the unknown.

  10. #40
    Quote Originally Posted by Mel Fulks View Post
    Is it possible that some shift attributed to glue creep is just shift on non sponged pieces?
    This is something I am sure many here are especially tuned to. We spray nearly 100% waterborne finishes in the shop so its a daily issue. Nearly 100% is like 99.999985%. And using waterborne this sort of stuff rears its ugly head constantly and water grain raise is critical.

    Shops that plane a lot of material and no onboard sharpening, and you run your knives down a ways you will #1 develop a knick or knicks in your knives that will pound down the wood fibers at that knick as opposed to cutting. You will never see the issue. You can run the material through a widebelt or drum, sand with RO til your blue in the face. Take every pain in the world. Stain, and into the booth, and on the first coat of finish... poof. Up comes a perfectly straight planer mark. On any stained material that mark will appear as a light streak because the wood fibers when re-hydrated swell up and expose the raw wood below. Raw material its so obvious you can feel it with your hands and see it in low angle raking light.

    We will raise grain with water usually twice and sometimes more way before any material ever makes it to final sanding.

    Of course there could be an argument that water grain raise is contributing to what we think of as creep however agan there is no issue (or far less than perceptible) with TB original and Super. So my guess has always been that the practice of grain raising with water is a good one. Surface water on KD material is a zero issue for us. I also make it a practice to water-wipe most everything anyway in the event there is a rogue waterspot or something that will pop out on finishing. Thats an old trick from the construction days. You have a bunch of pine doors that may have been unloaded in a light sprinkle of rain or a passing shower. Sand them, hit them with stain, and the waterspots are out like a sore thumb and there is no way to get rid of them. Get in the habit of a water wipe on everything by default and you simply turn the entire door into a giant water spot and go on with your day.

    Im sure many here have read about issues with biscuits telegraphing through finish when using PVA and people leaving the biscuit slots unglued and only gluing the face of the boards as opposed to the NYW practice of brushing the biscuit slots and biscuits full of glue. The same issue would be true for Domino's. If the slot/biscuit/domino is close enough to the surface you could have a swelling/shrinkage issue there due to moisture in the glue an so on.
    Last edited by Mark Bolton; 09-12-2019 at 3:53 PM.
    Sometimes I just want to look at pretty pictures,... Thats when I go to the Turners Forum

  11. #41
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    [QUOTE=Brian Holcombe;2951151]I think creep also must be affected by design and accuracy of fit ups.

    I have a table in front of me that has been in direct sunlight hours a day, made with Titebond III that shows nothing of creep or even much of a seam at all. Of course the tenons are flush twice a year. This table is about 5 years old now.



    Whether or not creep happens is very much affected by design. Maloof's rockers didn't exhibit creep because the laminations he used were thin enough that the stress was lower than the creep strength of the glue he used. But whether or not he started out with thicker laminations, had problems, and moved to thinner ones or just got lucky to start with is unknown to me. Most folks are familiar with spring back with bent laminations. That happens when the shear stress on the glue joints exceeds its creep strength. Switching to a glue with higher creep strength will yield lower or no spring back. This is where UF and epoxy glues excel. Maloof either through trial and error or luck ended up with laminations that kept the shear stress of the laminations in his rockers belong the creep strength of TBIII.

    Similarly, your table shows no creep for the same reason, only more so. Where is the stress? Being in the sun doesn't increase the stress. It only lowers the creep strength of PVA and other thermoplastic glues. Unless you racked the joinery during glue-up there's essentially no stress on the joints in your table. But build an exterior door with TBIII, especially with wide panels glued up from several boards, and put it facing South or West with direct sun exposure. I think you will be disappointed.

    For most interior applications you can use pretty much any glue you want. It's only when you add temperature and/or stress that creep strength becomes important; bent laminations, joints and panels under stress at elevated temperature, extreme temperature during shipping, etc.

    John

  12. #42
    Thanks, Mark. Good detail that is not seen much. Seeing " sponging" in a place that is not a baby magazine will be new to
    some, and helpful.

  13. #43
    Quote Originally Posted by Tony Zona View Post
    What, pray tell, is PU?

    Why do we have to use acronyms? It makes reading posts so difficult sometimes. And who wants to have to search anywhere to figure out what somebody said?

    I know as soon as somebody says what PU means I’ll say, “Aha, I should have guessed that."

    But right now what is PU, please? Have mercy.
    I believe that PU is referring to polyurethane.

  14. #44
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    I have bent laminations I can show also I used TB III. I take no issue with people on the opposite side of my viewpoint and experience but my interpretation of glue creep is that the effect is minimal. I recognize that it is very important for certain finishes.
    Last edited by Brian Holcombe; 09-12-2019 at 5:13 PM.
    Bumbling forward into the unknown.

  15. #45
    Thanks John for that John

    Tom

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