LMI Help Center

LMI Yellow Glue – Full Text

Today’s Tips du Jour Mailbag question comes to us from South Carolina.

“Dear Robert, there are so many glues available that it can become confusing. Which glue do you use? – Mark in South Carolina”

Mark, I have used just about every glue out there, including hide glue, fish glue, LMI instrument makers glue, CA glue, epoxy, polyurethane glue, you name it, I’ve probably used it. For most of the applications in my shop, I use the LMI yellow instrument maker’s glue. It has excellent sanding properties, cleans up easily, dries harder than most other commercial glues, has excellent hold strength, and even has a discrete fluorescent dye added to it that allows me to clearly see, under a black light, any invisible glue that can ruin my finish. No matter what glue you choose to use in your shop, one factor determines the durability of the glue joint and that is surface preparation. The sticking and bonding mechanism is based on two key points – adhesion and cohesion. Adhesion is what holds together atoms and molecules of different bodies, in our case wood and glue. Cohesion is described as what holds together atoms and molecules together of the same bodies, in our case the glue. Cohesion we really can’t do much about unless you’re mixing your own glue. Of course, you want to pay attention to mix ratios and you also want to pay attention to expiration dates. Now, adhesion we can certainly do something about. We can directly influence that. Make sure that the joint is clean and free of grease and oil. Now, this is very important when you’re using oily, exotic woods like Cocobolo. Most people like to wipe the joint down with acetone or alcohol before applying the adhesive. Also, when applying the glue, make sure that it is thinly and evenly applied. If not, the bond strength can be affected, therefore compromising the strength of the entire joint. Mark, another common question that most people ask is “how do I know if I’m using enough glue?” Well, I’ve got some guidelines here that may help you. For example, if your glue works better as a lubricant than an adhesive, you’re probably using too much glue. If you need to wear goggles when applying the glue, you’re probably using too much glue. If you have more glue on you than on your guitar, then you could be using too much glue. If you have to use all ten of your high tech glue spreading devices, then you’re probably using too much glue. If you have glue stalactites and stalagmites on the inside of your guitar, then you’re definitely using too much glue. If the set time of the glue exceeds the number of days in the week, then you’re probably using too much glue. If you find yourself going through rolls of shop towels through the gluing process, then you’re probably using too much glue. And finally, if you find yourself using glue by the case and you’re only on your second guitar, then you’re probably using too much glue.

So thank you very much for your question, Mark. I hope this has been helpful.