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ssorli Junior Member
Joined: 19 Nov 2017 Posts: 10 Location: Amherst, MA
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Posted: Sun Nov 19, 2017 4:45 pm Post subject: Hide Glue Experiment |
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I have been doing some tests with 251 gram glue (from Milligan &Higgins) without urea to see how much open time I actually have. I did some test pieces with the glue at 135 degrees and the room temperature at 72 degrees. I would brush the glue on one surface and leave it open to the air for various periods of time before attaching a second piece on and clamping for 30 minutes. I then waited 2 weeks before attempting to break the bond with a mallet. The test pieces with up to 3 minutes of open time were all very strong, requiring a strong blow of the mallet and many fibers of wood were pulled indicating a very strong bond. It seems to me that the glue exposed to the air for 3 minutes would be gelled and certainly close to 72 degrees in temperature, yet the joint held just as strong as a 10 second open time. It has been my understanding that a gelled glue will not allow a strong bond. The glue after 3 minutes does not seem very liquid, is cool to the touch and is slightly tacky. I have repeated this experiment several times and am getting consistent results. Can anyone explain why this is happening? Has anyone done similar testing of hide glue? |
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FiddleDoug Member
Joined: 08 Sep 2007 Posts: 227 Location: Hilton, NY
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Posted: Sun Nov 19, 2017 7:02 pm Post subject: Gelled glue |
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A real problem with having the glue gelled before making the final joint, is that the gel will prevent the joint from closing tightly. It won't squeeze out if it's gelled. _________________ Doug Wall
www.wallindependent.com |
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ssorli Junior Member
Joined: 19 Nov 2017 Posts: 10 Location: Amherst, MA
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Posted: Sun Nov 19, 2017 8:52 pm Post subject: |
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There is no trace of any glue in the joint. Only the torn out fragments of wood. I brushed the glue medium to heavy. Wood joined was basswood. |
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Dave Chandler Super Member
Joined: 31 Oct 2007 Posts: 691 Location: Mt Mitchell in North Carolina
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Posted: Wed Nov 22, 2017 10:41 pm Post subject: |
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What I consider a strong bond, is where the break follows a weaker grain line, not just evidence of some fibers. Not familiar with basswood though.
I will usually test my joints after cutting the outline, then see how well the the joints hold in the waste pieces. If at least half of the original glue joint comes apart at the seam, I think it is weak, and likely will recut and reglue, or at least cleat the joint on the inside for insurance.
Gelled glue may leave a strong bond, but also leaves a visible seam line. _________________ Dave in the Blue Ridge
Southern Violin Association
"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill
"I took the road less travelled, and now I don't know where I am." Marco Polo |
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ctviolin Super Member
Joined: 07 May 2009 Posts: 961 Location: Roswell
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Posted: Wed Nov 22, 2017 11:31 pm Post subject: |
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Dave Chandler wrote: |
Gelled glue may leave a strong bond, but also leaves a visible seam line. |
A well glued, (well flattened) center joined plate - will NEVER show a glue line.
Period. End of sentence. _________________ Look,
Listen,
Learn. |
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ctviolin Super Member
Joined: 07 May 2009 Posts: 961 Location: Roswell
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Posted: Wed Nov 22, 2017 11:51 pm Post subject: |
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Of course - I always have a good deal of 'press out' on my center joits. And - I believe that the glue I make, is ALWAYS fresh, hot and (brush) applied to both surfaces.
Glue that 'presses out' of the center seam...
A certain "feel", of when properly glued plates "grab" each other, and then you can be certain that you have a stronger bond than anything else I can think of.
Well, I also plane both surfaces with my 22" joining plane, and glue with freshly made hide glue.
That the plates contact fully along their surface is something else that I have found works for me. Those who have a hollow at the center of the plates that they then press together with clamping?
Sorry - it has never worked well for me, and my 'invisible seam' method. _________________ Look,
Listen,
Learn. |
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SioFong Tong Junior Member
Joined: 20 May 2017 Posts: 10
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Posted: Thu Nov 23, 2017 8:15 am Post subject: |
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I always have a little bit of hollow in the middle. it can just close perfectly without any clamp by a rubbed joint. After glued, there is no visible line under a 60x magnifiers.
Clamps are just for holding it. Especially on deep flame maple. I size them with thin glue before the last cut.
I was taught soaking the glue overnight before heat it. I found soaked one is better. |
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ctviolin Super Member
Joined: 07 May 2009 Posts: 961 Location: Roswell
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Posted: Thu Nov 23, 2017 10:56 am Post subject: |
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SioFong Tong wrote: | I always have a little bit of hollow in the middle.
I was taught soaking the glue overnight before heat it. I found soaked one is better. |
Yes a little hollow in the middle, (where the ends touch), is the other method that most makers use. I have not found this method works well for me - but, I do know that it also works when done well.
soaking first for some time before heating the grains... yes I do this also _________________ Look,
Listen,
Learn. |
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Dave Chandler Super Member
Joined: 31 Oct 2007 Posts: 691 Location: Mt Mitchell in North Carolina
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Posted: Thu Nov 23, 2017 12:10 pm Post subject: |
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ctviolin wrote: | Dave Chandler wrote: |
Gelled glue may leave a strong bond, but also leaves a visible seam line. |
A well glued, (well flattened) center joined plate - will NEVER show a glue line.
Period. End of sentence. |
No Argument Here! I'm countering the argument that waiting 3 minutes to assemble a glued joint leaves as good a joint as immediate assembly.
AND, of course a plate will looked nicely joined if the outer edges are nicely met...but hollowing in the center? The center is where most of the final arch will be, it is THERE that the joint must be in full contact. Also, if you leave a hollow in the joint, the glue cannot press out properly. I just don't see any benefit in this approach, unless you're making kitchen tables. _________________ Dave in the Blue Ridge
Southern Violin Association
"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill
"I took the road less travelled, and now I don't know where I am." Marco Polo |
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ssorli Junior Member
Joined: 19 Nov 2017 Posts: 10 Location: Amherst, MA
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Posted: Thu Nov 23, 2017 6:05 pm Post subject: |
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One of the tests I did was at 76 degrees room temp. 251 gram with no sizing. The 15 second open time test broke at the joint whereas all of the other test pieces broke the wood and the joint stayed glued. The open time ranged up to 2 3/4 minutes. Maybe because the wood was not sized, the short open time allowed the glue to penetrate deep in the wood and the longer ones it remained on the surface more. I will try testing with sized pieces. I talked with Jay Utzig, the tech expert at Milligan & Higgins, and he stated that you do have up to 3 minutes to assemble a joint as long as it is tightly clamped. This is with a room temp. in mid seventies. And the joint will be just as strong. Apparently the notion that a jelled glue will not hold as strong, relates to rubbed joints where it is quite true. |
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ctviolin Super Member
Joined: 07 May 2009 Posts: 961 Location: Roswell
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Posted: Thu Nov 23, 2017 9:18 pm Post subject: |
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ssorli wrote: |
...with no sizing.
Maybe because the wood was not sized,...
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Please describe exactly how and why you "size".
Thank you,
ct _________________ Look,
Listen,
Learn. |
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SioFong Tong Junior Member
Joined: 20 May 2017 Posts: 10
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Posted: Fri Nov 24, 2017 1:18 am Post subject: |
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My experience is one of my unsized deep flame maple plate was failed after 30minutes because the flame sucked all the glue in the end grain.
I think Maple can suck gelled glue as block endgrain. |
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ssorli Junior Member
Joined: 19 Nov 2017 Posts: 10 Location: Amherst, MA
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Posted: Fri Nov 24, 2017 11:25 am Post subject: |
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Size helps to keep glue from soaking too much into the wood and leaving too little in the joint to make it strong. I dilute a mixed batch of glue with 7 parts more of water. That is 1 part glue and 7 parts water. |
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Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
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Posted: Sun Nov 26, 2017 11:00 am Post subject: |
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Dave Chandler wrote: | ....Not familiar with basswood though.....
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Dave... try some... you'll love it. It is also known as American Linden. real easy to work with, somewhat similar to poplar. great for patterns & stuff that you don't want to twist or warp.
I have used it for bow plugs... does a nice job. Years ago I used to cut up truckloads of it to make honey comb frames for our beehives... and Basswood when it blooms oozes with nectar and yield a super high quality honey.... nice memories:)
https://en.wikipedia.org/wiki/Tilia_americana
Cheers... Mat |
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