I'm about 650 instruments into building at this point, about 2/3 ukes and 1/3 guitars, and still puzzle over the visible Titebond glue creep, or swelling, or whatever it is on the top and or back joints. Although I don't get to see many of my instruments again once they leave my shop, I think that glue creep shows up fairly soon on some of them. It makes a visible , but not tactile noticeable, unevenness of the joint. I've always used Titebond for all joints. I have no problem with how it works on any other joint besides the top and back. Recently I was reading Romanillos's latest book , with whom I studied with 15 years ago and greatly respect. On page 34 of Making the Spanish Guitar he says that he has seen the the same thing and that he finds it" aesthetically unpleasing". Those are my sentiments exactly. I have never witnessed a glue failure on those joints using Titebond, and I trust it, but the look basically sucks! I have hesitated to try other glues, precisely being concerned about glue failure in the high heat and humidity conditions that I live in in Hawaii. My shop is dehumidified day and night, but the instruments can be subjected to a wide range of climates once they leave my shop. Actually very few of them stay here in Hawaii, but still I'm concerned about humidity elsewhere. I don't really see any other glues that I might want to try other than hot hide glue. Because I'm only considering using it on a couple of joints, I can't see having a $100.00+ glue pot sitting on my bench unless I'm pretty sure it is the answer to my problem. On the web I find scientific test results that indicate hot hide glue actually resists heat better than Titebond. That's good. However, probably just because I've used Titebond for over 40 years I'm still resistant to change. I am also wondering why I don't see more of the glue creep problem in factory made instruments. I've got finely planed glue surfaces and tight fits, so that can't be the problem, Anyway, I'm interested in responses that relate to the use of hot hide glue on the top and back joints. Thanks, Bob
So, after all this input on HHG, I'm off and using it. I love it, and much of my trepidation about using it has been dispelled. Using Franks microwave idea and ideas from other posts, the prep time at the beginning of the day is only about 5 minutes. I had also thought that it would be a mess using this stuff. It actually turns out to be tidier than Titebond. Not a lot of gooey yellow squeeze out to clean up. Of course if things start to fall apart, I'll be singing a different tune. Ukuleles are so small that working fast enough to get parts together is not a problem,. Yesterday, while putting a top and back on a uke, I started to think about how I'm going to pull that off on a guitar in a few days. How do you get guitar tops and backs on before the glue dries? Wondering how builders approach that.--Bob
Here ya go Bob: Mario Proulx HHG Attaching Back
Thanks. Food for thought.--Bob
Mario is very clever and even uses HHG's tendency to jell on the outside of the bead as a feature for his method.
Having started this thread, I'm onto the next stage of actually trying out the HHG. I bought the little HHG pot and warmer that is sold on the web. Photo attached. It has instructions that are quite different than some things I've seen. For one thing they say just put the glue granules and water into the pot that floats in the water, add water, and wait 45 minutes to get workable glue. That seems to work just fine. What's with the soaking overnight that is often recommended? Not wanting to reinvent the wheel, what's the deal with clamping? I see some info that you don't need to clamp at all on stress free joints. I'm also wondering about clamp or set time. With Titebond you don't really need to wait long at all before a glued up top or back can be removed from the clamping jig. At the moment I'm just gluing little pieces of this and that together during the day and then seeing if I can break them apart later. Dragging my heels on actually using it on something important. As far as viscosity goes, it seems to work fine as long as it is not lumpy. I wonder if viscosity matters. Most recipes say a spoon full of this and that and then heat it up and use it. Not very controlled, but then maybe there is some lattitude on that issue. Thanks again for all the thoughtful replies. Enjoy your building.--Bob
Bob, If you have not seen Frank's pages. They are worth a look. Check the Data Sheet link at the bottom of page two as well. I have been following his process for several years with great results.
Thomas- Thanks for the reply. Still wondering about clamping times. There are occasions where I need to turn over various jigs in a timely fashion. I'm sure that temps and humidity are factors, but I'm usually working in a fairly stable environment of less than 50% humidity and 70-80 degrees temp. Is there some consensus about clamping times for bracing in go bar decks or top and back halves in joining jigs?--Bob
After reading some of the responses I thought I'd give my experience with HHG. I've used a couple different ways to heat the glue, but what I use now, and what has worked the best, is the glue pot that SteMac sells. It's a quality product that looks like it would last a lifetime and is made in the USA, and I found you get what you pay for.
I mix the glue in a pint glass jar and then place that in the glue pot filled with tap water. I mainly do repair work and only mix small batches at a time. My mixing procedure is 1 slightly heaping tsp of dry glue, add 5 tsp of boiling tap water. Place mixture in glue pot and heat for 40 minutes, stir occasionally, glue will be clear and amber when ready. I like to mix it water thin, yet slippery between your fingers. I pretty much mix it the same for all uses, even bridge re-gluing.
I store unused glue in the refrigerator.
I leave under clamp pressure for at least 2 hours, and wait 24 hours before putting into use.
Jim, Thanks for your input. Good luck with your projects.--Bob
Most people clamp the joints to tight and that could be the creep probulm.
Ron, So what is your take on too tight and are you talking about Titebond or other glues. It is a difficult subject to determine what is right or wrong, but I'm sure clamping pressure is important. I started this discussion specifically talking about top and back center joints on instruments and that's still my concern. I've never, ever had a complete failure, and I'm up to several thousand joins with building and repair, with Titebond, but I've see a lot of seams that show some appearance of not being flat in time. The variables are extreme. Hardness of the wood, type of glue, clamping pressure, adequate prep of the wood before joining, heat, humidity, and many more. At the moment I'm turning my attention to the glue itself. Today I finally did my first HHG top. I did the clamping with my usuall wedge method shown in the photo. I know that some people don't even clamp HHG, so I'm wondering if I'm over doing it. Any responses appreciated. As a side note, since it is said you can rejuvenate HHG jin a glued joint just by adding more HHG, why can't I just let the small ounce or so of HHG that I have in my glue pot just harden on it's own right there?. Today I just turned on the pot, added a little water, and the glue softened just fine. I can see the refrigeration idea for large batches of glue, but is it necessary for for a small batch? Just curious. I have already decided that the reason HHG is not used more is because builders don't want to fool with the prep. It's a lot easier to come in the morning and just chew the crusty Titebond off the bottle and get to work!
Seems you may be over analyzing the process. Most of the questions you've asked I never thought of.
I don't think you can over clamp, I clamp as tight as possible. When done for the day with the glue, store leftovers in the refrigerator, otherwise mold can form and it can go bad quickly. I always use a small glass jar for the glue mixture, I don't have it directly in the pot. When I'm done I just unplug glue pot, remove glass jar of glue and place in refrigerator. There is just water in the glue pot, the glue mixture is in a jar.
Once you've used HHG for awhile you forget the slight inconvenience in using it.
Titebond isn't much fun to work with after you get used to HHG. Also HHG has minimal creep when clamping. Just an all round better experience using it.
I've been using HHG for over 30 years now and enjoy using it.