There are several procedures to ponder in the

by:SANDAO     2020-06-16
GLUE-UP AND CLAMPINGThere are two ways to clamp up a glue-up: Horizontally on the work bench top and vertically with the first board mortised edge-up in a woodworking vise on the end or side of the bench. In the case of the horizontal glue up, place pipe or bar clamps about 2 feet apart on the work surface top with the clamp handles hanging slightly over the edge of the work surface. Pre-adjust the clamps to an inch larger opening than they will be when tightened. Place the first board on edge on top of and across the clamps with the mortises facing up. Do the same with all the pieces, in proper sequence. Make sure you have a supply of biscuits for the job ready. A small dispensing glue bottle with plenty of glue for the job should be nearby. The kind of glue is important: If the glue adheres too quickly you will have a predicament. If the glue dries too slowly, you will be losing valuable production time. I like to use Franklin Titebond I Glue indoors or Franklin Titebond II for outdoor applications. These are 'aliphatic resin' type glues that can be easily cleaned up with water. Ether formula gives a very strong joint and has a reasonable, 45-minute clamping time. Both of these glues are widely on hand in hardware stores, home improvement centers and woodworking stores.Run about a 1/8'-thick line of glue down the center of one edge of the first board, making sure that the glue drops into every biscuit mortise along the path. Then apply short glue lines on both sides of every mortise. This should result in sufficient glue so that it appears squeezed out of both sides of every glue seam after clamping. Insert a biscuit into each mortise. With 2' lumber, you may need an extra glue line for the full length of the joint. There is no such thing as too much glue because you can wipe up the leftover with a wet rag. There is, however such a thing as too little glue and you will recognize that state when you see that glue is not being excreted from the full length of both sides of the glue joint. That is called 'starving the joint' and starved joints often open up later. Glue is cheap! Don't skimp on it!Situate the first plank with the letter or number up and the mortised edge away from you. Apply glue in the same manner to each succeeding board wherever there are mortises and place biscuits in the far edge of each plank, except, of course, the last board.The board ends should be flush and the left clamp should be about 6' in from the end. The right clamp should be about 1-foot six inches in from the right end. This is because you will be placing alternately spaced clamps on the top side of the glue-up so that there is a clamp (top or bottom) about every foot. The top, right clamp will be in about 6' from the right end.Once you have all of this in place, start tightening the clamp handles. Clamp all the bottom clamps finger tight, then the top clamps finger tight. Then, go down the row of clamps tightening them fully, bottom, top, bottom, top, etc. With a wet rag, wipe off most of the excess glue. Turn over the entire glue-up and wash the other side. Look at your watch or clock and add 45 minutes to the time. This will be the minimum clamping time, any time after which you may release the glue-up from the clamps. Mark this future time on the glue-up with a felt pen. If you have multiple glue-ups, you can rest this glue-up against a wall to get it out of the way while it dries.If you have been reading the above, then you can put together how to do a vertical glue-up in a vise: This procedure is applicable for smaller glue-ups and is easier to manage. The difference is that when it comes time to apply the glue, you will clamp the first plank at its center in the vise with the mortises facing up. Add the glue and biscuits. Apply glue to the mating edge of the second board and place it in correct position on top of the first plank, and so on. Place the first clamp 6' in from the end, in front, the second clamp a foot away from the first clamp, in back and so on.Once your glue-up is out of the clamps, it is ready to be thickness sanded either in a drum sander or wide-belt sander. If you don't have either of these machines, don't worry. Most professional furniture-manufacturing shops in your area will be happy to thickness sand your glue-ups for an hourly cost. You might want to consider buying your own drum sander or wide-belt sander, if you can justify the price.It is best to know the maximum width capacity of the sanding machine you will be using: 48'-wide glue-ups will not pass through a 36'-wide sander. If you know that you will have this limitation in advance, simply make two, 24' glue-ups and glue those together with biscuits after the thickness sanding is complete. The glue line won't be completely even and so it will have to be sanded true with a random orbit sander. Your glue-up should be sanded to at least 150 grit. 220 grit is even better. Trim the finished panel on the table saw to its final size, rout the edges, if appropriate, and then random orbit sand the final piece to 220 or 320 grit before adding the finish.For some woodworkers, gluing up lumber may not be the most appealing part of the craft. It is one of the most crucial, however, because a glue-up done improperly can be a recipe for disaster. Furthermore, the way you place the boards in the panel will have a lasting and irremediable effect of the quality of the finished work piece.WOODWORKING ARTICLES: TOOL REVIEWS: GillespieWoodworker 2010 Robert M. Gillespie, Jr.
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