Shopsmith Forums

While gluing 1/8th” thick by 2” wide panels to cover edge grain on some glued up legs, I once more found out how slippery glue can be/is.
I think remembered reading somewhere that to minimize the slippage, you could sprinkle a bit of sanding grit or household salt on the glued piece. I don't know whether I read it or dreamed it. But, I threw caution to the winds and gave salt a try. It may not be to everybody’s taste, or conform to a heart healthy diet, but it does work as advertised.
I'd bet sugar would work just as well.
Bon appetit.

I'm sure I read recently, in either Wood Magazine, Woodsmith or Fine Woodworking, that you should not use salt. It wasn't part of an article on glue-ups but one of those Q&A sections.

Hey Gene,
I admire your dexterity, being able to glue some boards that are located aft and to the left of your shoulder !!!


Chris

nuhobby wrote:Hey Gene,
I admire your dexterity, being able to glue some boards that are located aft and to the left of your shoulder !!!


Chris

???????

Just an old superstition of mine, throwing salt over my shoulder .

nuhobby wrote:Just an old superstition of mine, throwing salt over my shoulder .

Aha.

Nick Engler mentioned using sandpaper grit in one of his sessions. I have used it and it does work. I have also used salt which works equally as well. Note that it does not take much of either to stop the slipping. A few grains is all that is required so the effect it would have on the bond would seem quite negligible if any.
Regards,
Dwight

berry wrote:I'm sure I read recently, in either Wood Magazine, Woodsmith or Fine Woodworking, that you should not use salt. It wasn't part of an article on glue-ups but one of those Q&A sections.

I agree with this recommendation because--

Wood glue contains moisture. The moisture is needed to carry the glue molecules and also to allow the glue to penetrate into the wood. The fact of carrying the glue into the wood is necessary to achieve penetration into and around the wood fibers.

To better understand gluing one needs to think of two major factors. 1) Drying glue creates a chemical bond. 2) Glue penetration creates that bond deeply into the wood and forms a physical hold in the wood fibers. Both of these factors are needed to achieve a strong bind.

Ever hear of "glue starvation"? This can be caused, as the term implies, by applying to little glue. It can also be caused by gluing together wood that has sealed surfaces - wood that has aged and has case hardened surfaces. This is why it is best to sand old wood before gluing. Sanding removes hardened (sealed) surfaces.

Now back to salt - Does the salt affect the chemical function of glue? I don't know. Does salt affect the penetration of glue into wood? I suspect the drying effect of salt probably retards the ability of the water in glue to enter wood. Without the mechanical affect of a glued joint it becomes one that likely has "glue starvation".

The real question is how much glue is used. A few grains relative to the size of a joint will certainly have little affect on a joining, but a sprinkling of salt certainly seems like a bad idea.

If the salt truly 'absorbs' water(more likely the water absorbs the salt) one would thing the anti-slip effect would be short lived. Maybe it lasts long enough for the glue to 'set'.

I vote for sand(crushed variety).

I don't think I used nearly enough salt to dry out the glue.
Sand would be better, I'd agree. But none is available anywhere close. Coulda used sugar, I guess.