February 28, 20197 yr I saw a video on glueing 3 one inch boards together, face to face to make one 3" thick piece. He used normal procedures, except he sprinkled salt on the glue surfaces to prevent slipping while clamping. (I've never heard doing this.) I could see where grit of the salt could keep slipping down. He claimed it nearly stopped all slippage and the salt dissolved as the glue dried. Seems like it could work, I wonder if the salt would have any effect on holding power. Anyone have any info on this procedure?
February 28, 20197 yr Hello Ron Like you, I have never heard of using salt. I've never had a problem with slippage during a glue-up so I suppose it would something very specific. I would question the effect of salt on bond strength. Just don't know. hat Edited February 28, 20197 yr by hatuffej
February 28, 20197 yr 11 minutes ago, Ron Altier said: Anyone have any info on this procedure? Ron, I just saw (again) an 2016 episode on PBS of A Craftsman's Legacy where Master Craftsman and Master Wooden Plane maker John Wilson used that procedure. He said is doesn't take much and presents no problems to the joint, glue or wood. He teaches others how to make planes as well as tools and woodworking. He's best known for his Shaker Oval boxes. I've seen the plane episode 3 or 4 times. He is fascinating to watch. Makes all of his own plane irons too. That said, I've tried it a few times with some difficult joints and it really does work well.
February 28, 20197 yr 45 minutes ago, Ron Altier said: I wonder if the salt would have any effect on holding power. I would be more worried about the finish... salt doesn't dissolve.. it suspends...
February 28, 20197 yr Popular Post 1 minute ago, Stick486 said: I would be more worried about the finish... salt doesn't dissolve.. it suspends... I have to disagree . Sodium chloride forms a solution (dissolved) and not a suspension. Most salts are soluble . For a suspension you would see that because it would be cloudy. As to the salt trick I have heard of it but never tried.
February 28, 20197 yr 28 minutes ago, Gerald said: I have to disagree mix the salt in water... dissolve it even... evaporate the water... what's left behind???
February 28, 20197 yr I have used a few grains of sand in this situation. Unless you get the sand from the ocean shore salt is not a factor.
February 28, 20197 yr Popular Post 9 minutes ago, Stick486 said: mix the salt in water... dissolve it even... evaporate the water... what's left behind??? Solids dissolved in water or any solvent will reappear when the solvent is evaporated or distilled off. This is a physical chemistry fact. Oh I forgot to tell you I have a minor in Chemistry. Plus in a coarse called Physoical Pharmacy they also teach this same stuff. Now for a reference. https://en.m.wikipedia.org/wiki/Solution
February 28, 20197 yr Author I was thinking about the corrosive nature of salt and its effect on the glue holding properties. I'm sure the salt would go into solution after a short period, if you didn't put too much. I just don't think the extra step of applying salt would be worth the effort. I'm sure that all of us take a lot of care glueing and clamping, so I don't it would be worth extra steps of using, clean up and storage of salt.
February 28, 20197 yr I wonder about spilt salt granules getting worked into the grain that gets a finish....
February 28, 20197 yr Author Popular Post I don't think that would be much of a problem, the salt would start to dissolve as soon as it touched the glue and weaken the structure of the crystal. Clamping would complete the destruction/dissolving as it held it in place. However, I'd like to pry the joint apart after it is dry to see if the holding power was effected...........I may try that.
February 28, 20197 yr Popular Post I tried it. It works. Can't tell the difference in bonding after the glue dries, but I didn't test to destruction. The dissolved salt just "rides" with the water as it penetrates the wood, and then reforms crystals as the water evaporates. The penetration of the wood by the water, and the glue material that's carried by the water, is what creates a wood surface that can bond with the remaining (very thin) layer of glue between the (now-penetrated, and now-changed) wood surfaces. The amount of salt is really small compared to saturation levels (the max salt water can hold), and the amount of glue (the part remaining after evaporation of water) is much larger than the salt content. "Corrosion" is a complex process, and depends on the material. Salt increases corrosion on metals because it facilitates oxidation. I don't think the same mechanism applies to wood. If you heap salt on the surface, yeah, probably inhibits glue action, and also wicks up water before it can penetrate the wood. If you stay within FDA recommendations for daily use, I don't think it will matter. :-)
February 28, 20197 yr Popular Post Salt works well when the pieces to be face glued are of different dimensions. I use it (sparingly) when gluing up for bandsaw boxes. However, if the dimensions are identical and, even edges are critical, a couple clamps across the boards to hold the edges even, is a more better solution. Edited February 28, 20197 yr by Gene Howe
March 1, 20197 yr On 2/27/2019 at 10:55 PM, Stick486 said: I would be more worried about the finish... salt doesn't dissolve.. it suspends... I'm thinking that in any glue that's got water in it (PVA) it would definitely dissolve. I have heard of this procedure but never tried it. Franklin International (Titebond people) recommend against it.
March 1, 20197 yr 8 minutes ago, kmealy said: I'm thinking that in any glue that's got water in it (PVA) it would definitely dissolve. I have heard of this procedure but never tried it. Franklin International (Titebond people) recommend against it. My bandsaw boxes hold together. But, there's not a lot of strain on them. The linked picture illustrates the obvious need for the clamps across the work to keep the edges even. Forget the mallet. Even if it is calibrated.
March 1, 20197 yr 38 minutes ago, kmealy said: Franklin International (Titebond people) recommend against it. Good enough for me...
March 1, 20197 yr Popular Post The other side of the spectrum... https://www.woodworkweb.com/woodworking-videos-1/general-woodworking-videos/719-strength-testing-salt-and-grit-on-glue-joints.html They add salt to hide glue... http://bearmeadow.com/build/materials/glue/html/hideglue-faq.html There appears to be NO evidence that it is detrimental to the bonding power of PVA (Poly Vinyl Acetate) polymer chains or affect its bonding power. In addition, if added to PVA (Poly Vinyl Alcohol) it appears to enhance the polymer Chain, not degrade it. I have to ask, why does Franklin International recommend against it. Just saying that that don't recommend, doesn't answer the question. I'm sure they don't want anyone adding anything to their glue for product liability reasons...doesn't mean it's bad. I have used salt and have NEVER had a joint failure because of it. Make your own decisions...use it or not. However, just because you are not convinced, don't tell the rest of the world, that they are wrong and not to do it. I would like to see some empirical evidence that it is detrimental and why, before following blindly. Edited March 1, 20197 yr by schnewj
March 1, 20197 yr Popular Post I had a chat with some larvae in wormy maple, and they said they enjoy the salt. Would like a little pepper, also. hat
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