Bamboo Tips - Tips Area |
|
< Home < Tips Area < Glues < Hide Glues I haven't heard much about using hide glues recently, and I've never tried them myself. What sort do you use? Are choices of products still available, or has this part of the industry been pretty much reduced to just one glue? (Bill Harms) I use granular hide glue from Luthier's Mercantile, a guitar builder supply house. I bought the glue pot a long time ago from Garret Wade, but Stewart MacDonald (Luthier supplies) or Woodcraft all sell the same electric glue pots. You can buy liquid hide glue in a bottle, but I would not recommend it. The acoustic guitar guys tell me that the liquid hide glue has preservatives that weaken the glue and make it subject to creep. Anyone who doubts the strength of hide glue should calculate the stresses on a bridge of a steel string guitar. Take a look at a 1925 Martin strung with steel strings. Calculate the tension of those six strings combined on that little piece of Ebony hanging on the soundboard (guitar top) with all its might. That's hide glue holding the bridge on -- not screws. I have never made a vat of hide glue to drop strips in before gluing. I have never glued more than a dozen sections at a time. I simply bush the glue on to the warm blank (furnace room warm) and bind away. The initial tack of the hide glue makes it easy to nest the strips. Hide glue may not be toxic, but it sure stinks. You asked why people don't use hide glue for rods today, well more people probably do than you think. Especially if they are trying to replace a broken tip of a vintage rod. I think most do not use hide glue because they think they need a stronger glue. Why are people looking for tougher varnishes? Why do we need UV protection in a rod varnish? I use modern varnish (Interlux Schooner) because it is easy and I am trying to make my Pre-EPA changes (pre-1974) Man-O-War last. I use it on wraps only. Copal varnish is all we really need to keep a rod sound. Hide glue is all we really need for strength. If you are going to store your rod in the trunk of a black car in heat of a Desert August you may experience problems, but I wouldn't recommend that for any rod, or musical instrument, or anything for that matter. Cold water Casein glue is another interesting old glue that is stronger than we really need, but that is another story. (Chris Lucker) I was looking around the frets.com web site Ralph provided and read the description of using Knox gelatin to glue wood. Are any of you using hide glue for your rods, and if so, what are the pros/cons for it? (Claude Freaner) Hide glue is great, as long as it doesn't get wet. It doesn't creep, lasts many years, and is nontoxic. Unfortunately, if an item assembled with it is exposed to a humid atmosphere for very long, or if the item gets wet, the glue is "reversible" - it softens and releases its grip. Hide glue is not a candidate for any fishing rod I would want. (Howard Bryan) Even if the rod is varnished with polyurethane, and then waxed, would it still tend to soften the glue from, say, fishing in the rain, and occasionally dunking the tip of the rod in the water? (Claude Freaner) Personally I wouldn't chance it. There are too many well proven products out there that do not have the potential for disaster. If I were going to spend the hours needed to build a decent rod I certainly would not fool with a glue or a finishing material that is known to have weaknesses related to the environment where I intend to use the rod. It may sound a bit strange, but when I'm looking at a glue system for long-term structural use one of the first questions is "Does the FAA (Federal Aviation Administration) approve it for wooden aircraft structures?" These guys are pretty good, very conservative, and not swayed by manufacturers BS. If they'll let me build an aircraft from with the stuff I am assured that any properly fitted joint made with it will be at least as strong as any wood I might use and won't let go if it gets wet. They have, through the years, approved Plastic Resin (Weldwood), Resorcinol, several urea-formaldehyde glues, a number of epoxies, and possibly others. They will not license an aircraft whose structure is made with hide glue, caseine glue, or any PVA that I know of, including the Titebond products. Given that the WWI aircraft were made with caseine glue, and hide glue was used for attaching fabric, they obviously delete from their list glues that prove inferior to newer products. (Howard Bryan) I've used it on several rods. I recommend the addition of 5% urea and a pinch of copper sulfate to the mix. The glue is very good and strong. The drawback is keeping the glue warm while binding. Granger had some steam heating lash-up on their binder. I think restaurant heat lamps would be fine. If the glue "chills" while you're binding, the glue seams might not be as tight as wanted. (John Zimny) Besides the wisdom that John and Howard have posted I can add the following, having used hide glue on things OTHER than rods. I am speaking of the glue prepared from dry granules. We talked about liquid hide glue in this list before. Hide glue is applied at around 140F and begins to gel around 100F; if it gels before you clamp, you start over. Unless you keep applying heat, you only get a few minutes working time. It sets in two stages gelling and drying. When it dries, it shrinks pulling the joint tighter which is one of its advantages. The water gel mixture ratio is important. It should wind up about the consistency of light cream. Different products vary. The product is graded by its gel strength. Knox, which I haven't tried, is supposed to have a very high strength. Rabbit glue is the highest. Most people use a medium strength, 200 gm, because it gives more working time (unless you keep everything hot) and because it can be taken apart more easily (which is one reason for using it in musical instrument manufacture). (Jim Utzerath) |