For thousands of years, wooden elements have been joined together with natural glue. Restorers, in particular, appreciate its water-solubility. This means that a corner joint or a damaged veneer can be removed without steam damage and then glued back on. However, many people are bothered by the process involved in these glues: The glue beads must be dissolved in a water bath at about 60 ° Celsius because once the glue gels, it loses its adhesive power. This invariably means a little organization and, above all: a little more hustle and bustle! However, there are now products on the market that offer premixed glue in a tube. The additives can then be used with white glue. Today I would like to make a small comparison of the three most familiar to me.
Titebond Original Wood Glues
Let’s examine the products of the American company Titebond. I have tried many products and do not see any advantage in gluing wood compared to white glue. But that would be worth another chapter;) I learned the “hide glue” while building my journeyman’s piece, which should consist exclusively of natural products. To date, no adhesive bond has come loose.
Conclusion: Titebond is the most expensive in the test of the ones presented here. It leaves a dark blue line, and I have not yet been able to find the exact composition (there is only the note ammonium thiocyanate, which probably serves as a preservative). In the case of large-area veneer work, the Titebond dries very quickly, which makes processing difficult.
Akanthus Helix Restoration Glue
The Akanthus Helix restoration glue is mixed according to an old recipe. Citric acid acts as a preservative, while urea, soy lecithin, and borax ensure greater strength and reduce gelling. Veneer work can be carried out very well with this glue. Its low viscosity also allows a needle to be injected into the restoration when the veneer is loosened. Due to the higher solids content, imperfections can also be filled in with repeated use.
Conclusion: Of the ones presented here, acanthus is the cheapest in the test, leaves a light glue joint, the manufacturer is open about the ingredients. For me, an increasingly important factor.
Sturgeon Glue (Isinglass)
Isinglass is available from various suppliers. Compared to skin/bone glue without additives, the gelling point is only 8-10 °. There is no information about other additives. However, some manufacturers add formaldehyde. If in doubt, it is better to find out again. The good adhesive effect in connection with metal is interesting, provided that this has been sanded beforehand. Tom Fidgen advises brass to rub one over with a clove of garlic ahead. In the workshop, however, I usually have a piece of sandpaper in hand. Isinglass is said to have a higher elasticity. But I have not noticed anything in furniture construction so far, and there is no difference in the glue test either.
Conclusion: Isinglass is unfortunately by far the most expensive of the glues shown here.
The temperature changes the viscosity: Acanthus and Titebond show an increased viscosity below 25 degrees and isinglass below 15 degrees. Therefore, it is best to place it on the heater or briefly hold it under warm water before use in winter.
I was aware that white glue has higher adhesive strength, but the difference is more significant than I thought. Therefore, none of the natural glues shown are recommended for statically stressed elements. However, the glues are ideal for making furniture in the interior and especially for professional restoration.
Nice side effect: In contrast to white glue, gluten glue on clothing can be washed out again.