Shopsmith Forums

I can see that putting a bit of "grit" on/in the glue will keep the pieces from moving around but what about working the pieces after the glue dries? Seems the grit will have an adverse affect on saw blades, router bits, jointer and planer knives, drill bits and the list can go on. What's the general opinion out there?

About like cutting teak, a few sparks.....fine sand #20 silica and very little....carbide tools.
ldh

My take is to use sand ONLY on glue-ups that do not require finishing other than some edge routing or sanding. Remember, the tip is for only a few grains and you can get these pretty close to the middle (at least centered) on the glue-up.

If there is sawing work or planing work to do - why worry about a little slipping?

While I hadn't used or even seen that very good tip before, I could not help but to think that ground walnut shells would do the same thing. They would certainly not hurt your equipment and they are readily available at paint supply stores.

WOW! A Google search got me nearly 90,000 hits for "ground walnut shells". There are a lot more uses then I would ever have thought of: Sand-blasting, rock tumbling, (dust free) pet bedding, and mixing them in paint to create anti-slip coatings are just a few. They even come in different "grits". Here is one site that offers them: http://www.kramerindustriesonline.com/tumbling-media/walnut-shells.htm
For those of us that are concerned about harming our equipment using sand, this is a great alternative. This site has a lot of info about their use: http://www.optaminerals.com/walnut_shells.html

drl wrote:I can see that putting a bit of "grit" on/in the glue will keep the pieces from moving around but what about working the pieces after the glue dries? Seems the grit will have an adverse affect on saw blades, router bits, jointer and planer knives, drill bits and the list can go on. What's the general opinion out there?

To me this is an unnecessary worry. If you use the very very small quanity that Nick recommends the chance of you hitting one of the grains is probably astromonical. Then add to that the chance of causing damage if you do hit a grain of sand and the odds soar out of sight. Then add to that the number of saw teeth and again the number becomes something like your chance of winning the lottery if you never buy a ticket.

One time had to rip a bowling alley (to make a work bench top) which is held together with cut nails. I used my circular saw, after donning what amounted to a flak suit with full body and head protection. I don't know the exact number of nails I cut through that day but I do know I never got hit with any of the scrapnel nor did I ruin the blade. In fact that blade has been to the sharpener once or twice and is presently mounted on the saw.

So I think the fear of a hitting a grain of sand or two is without consequence.
Ed

Ed's excellent discussion of probablities not withstanding, you might also consider a little botany that pertains to the material which you're cutting. A piece of wood -- any wood -- is 95% cellulose and lignin. But there are always a small amount of "extractives" in the wood, mostly imbedded in the cellular walls. Many of these extractives are no harder than the cellulose itself, but a few are crystals and hard minerals. These have exactly the same effect on your cutting edges as sanding grit -- they dull the blades and knives. Why do you think that teak occasionally sparks when you cut it? Or that you can burn a piece of wood so nothing remains but a fine ash (containing the extractives) and use this as a very fine abrasive to remove rings in a lacquer finish? The fact is, the few tiny grains of aluminum oxide needed to prevent boards from slipping during glue up increase the risk to which the cutting tool is already exposed by a miniscule amount.

With all good wishes,

My husband and I have developed an arrangement that works out well for both of us. He buys cheap furniture and I get to fix it a few weeks later when it falls apart. I’ve discovered a way to minimize the mess when regluing joints. Just rub a little paste wax on the finished surfaces next to each joint. Cleaning up squeezed-out glue is a snap because the glue won’t stick to the wax.

__

Daphne Rose

Salt works as well as sand.