Gluing boards for a tabletop
I have seen this in more than one place. I have noticed that when gluing boards together that it is a common practice to glue up all the boards first and then to cut them to get all the boards even. Well, why not just cut the boards equal ahead of time instead of after gluing? I have seen this shown twice in woodworking magazines and was just wondering.. Thanks..
You trim to length after glue up because it's practically impossible to keep the ends perfectly aligned during the process of glue up.
Trimming to length after gluing is S.O.P
Edited 2/6/2004 8:58:05 AM ET by CHASSTANFORD
thanks for your reply. it appears that it was SOP but I was just wondering why. i think it would be easier for me to cut my boards to length with my crosscut sled and glue up afterwards just ensuring everything was flush. interesting...ThanksRegards,
You can try it but you will end up trimming afterwards to get a nice flush end so be sure to make it a bit longer in your experiment. Wet glue is slippery so the boards tend to slide a bit as clamping pressure is applied. What you perceive to be easier you will find it is actually harder when you try both methods.
thanks for the info. sliding boards make sense to me when clamping. this board is great...Regards,
Hi Buzzsaw ,
Not only do the boards tend to move and slip a bit , but the width can be a bit over to give you a chance to clean up the edges , in case they get marred from the clamps. Lastly the seams can have some snipe or run out near the ends of the boards from sawing or jointing or shaping a glue joint or what ever. It is always safer to leave them long . good luck dusty
I agree with what the others have written, its very difficult to align EVERYTHING during clamping. But of course, there's always another way (which is what makes this so much fun). If you don't have a means of getting a clean cut afterwards, you could build a jig (clamp a couple of 2 x 4's to your assembly table) to hold the boards length wise while you wrestle with getting them otherwise aligned in the clamps. If you are using splines, biscuits, or t&G, it will be easier and you won't need clamps on the ends for surface alignment. Then, when you pull the clamps the next day, sanding the ends flush should be easy.
When I do a wide and long glue up, I trim the ends afterwards with my router using a guide board. I take several passes with a 1/4" bit making progressively deeper cuts each time. Lastly I take a very thin cut with a 1/2" spiral router bit. Any burns are cleaned up with a shallow angle block plane or sander. Rarely get burns with a sharp spiral bit. I have skipped using the 1/4" bit using instead a sharp blade on a circular saw. Then clean up with a 1/2" bit and/or block plane. Tape the edge first with masking tape to help prevent tear-out.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
Edge to edge parallelism isn't absolute either. Even if you gang planed them on edge. By the time you arrange them and glue them up as even on the end as possible the cummulative error may leave the ends out of square anyway. Plus it's next to impossible to get a framing square where you'd need it with the clamps in place. There's only so much you can do during a glue up. It's enough to get even clamping pressure so the joints are closed and keep the panel flat at the same time.John O'Connell - JKO Handcrafted Woodworking
Life is tough. It's tougher if you're stupid - John Wayne
1. This very issue is covered in a recent issue of FWW. Take a look.
2. The moment you glue up your first group of boards, whether for a tabletop, a benchtop, or anything else, you will understand the answer to your question better than anyone can explain it.
that is the best answer to any question I have ever seen.
you learn by
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