Shopsmith Forums

George Vondriska from Wood Workers Guild of America (WWGOA.com) interviewed Bob Behnke, the Technical Service Manager for Titebond Glue. Very very interesting. I think it debunks some of the misconceptions out there about glue and glue joints.

https://www.youtube.com/watch?v=XbrmQBwXLyc

Yes, that was informative! (Although I did turn the speed up on the video.)

Thanks for the link, I enjoyed the video. Now I can justify a new tool purchase, a refrigerator to protect my glue.

Too long of a video, but I got through the first 10 min. What was discussed there is what has been discussed before, i.e. that the chemical bonds of the glue are always going to be stronger than the wood itself. The implication is that more glue, i.e. thicker glue joint is always better. I do find this questionable and wonder how far this theory carries. Often this joint/glue stress testing is on brand new joints that have just recently set and many times the test method & apparatus are factors as are the type of joint selected, so sometimes joint test results are mixed. As a woodworking hobbyist, I am more concerned with longevity of projects that I build. Is that piece of furniture that I build going to have a strong joint for 5, 10, 15, 20, 25, 30+ years. Is the glue chemical bond going to degrade with time? Honestly, this is never covered. No one talks about glue degradation and joint deformation over time and probably because there are too many variables - too many joint types to consider as well. I know some have done work on for example chair spindles related to glue strength and joint deformation versus time and I posted an article about this in the past here, but I wish there was more information related to this available to the average woodworker like myself.

Of note IMHO, in the first 10 minutes, was the discussion regarding clamping pressure and glue line width versus wood density. I did find this interesting. I have wondered about these overboard clamps from brands like Bessey that cost a fortune and all the major woodworking social media influencers continue to peddle to unsuspecting hobby & professional woodworkers. I have seen YT videos of them struggling to turn the handle to get that 600-1200 psi clamping pressure (at the clamp head) in an attempt to achieve imperceptible glue lines and maximum glue squeeze out. While miniscule glue lines in a project are desirable, you also need a joint to hold, so I appreciate hearing the advice from George of getting just enough clamp pressure to have the joint to close and stopping there. I had never considered the amount of glue application related to softwood versus hardwood. This is definitely something interesting to consider and none of the previous joint/glue strength tests I can remember seeing really covered this from what I can remember which could explain some of the variation of joint strength test results amongst them. Will try to get time to watch the rest of the video, but these are my musings after watching the 1st 10 min. Thanks for sharing John.

A LOT of supporting discussion in the remaining time. Of more interest to me was the difference between the three TB I II III and how they affect the decision of which to use and why they exist. Shelf life discussion was elucidating. Time consuming, yes. Worth watching the whole thing, yes.

JPG wrote: ↑Fri Aug 11, 2023 1:28 pm A LOT of supporting discussion in the remaining time. Of more interest to me was the difference between the three TB I II III and how they affect the decision of which to use and why they exist. Shelf life discussion was elucidating. Time consuming, yes. Worth watching the whole thing, yes.

JPG,

Thanks. Good to know. I'll try to get back to watching it then. My YT time is less and less these days as my priorities are elsewhere, but I did see/learn enough in the first 10 min that I am intrigued for sure. The Wood Whisperer (Titebond sponsored) did a good discussion a while back on the differences between TB I, II & III that was useful (see below). I think it was a dedicated video from him and was concise. Would be interesting to see if the advice from the company representative differs from what he shared previously from them. Thanks again.

JPG wrote: ↑Fri Aug 11, 2023 1:28 pm A LOT of supporting discussion in the remaining time. Of more interest to me was the difference between the three TB I II III and how they affect the decision of which to use and why they exist. Shelf life discussion was elucidating. Time consuming, yes. Worth watching the whole thing, yes.

+1

For the most part equivalent with WWGA broader discussion.