# Glueing workbench top: maximum gap?



## Smile_n_Nod (Jan 20, 2011)

I'm starting to glue the assemblies that will make up the top of my Roubo bench. Each assembly is made up of 4 yellow pine boards. I'm trying to flatten the faces that I will glue together (each face is about 5 in. x 8 ft) and it's proving to be more difficult than I thought. My current maximum-gap size is about 0.004". Is that close enough to ensure that a wood glue like Titebon III will adhere the boards together?


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## KenBry (Sep 13, 2011)

Are you flattening with hand tools, jointer, or planer?


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## TCCcabinetmaker (Dec 14, 2011)

are you jointing these boards? and .004 is rather small, most people can not even see that… but yes tightbond 3 will fill and bond in .004 spaces.

Most high end industrial flattening machines are only guaranteed to .007, they can be done better but they require a bit of finese and fore thought on how to get to do better than that, but then you're talking like .003 accuracy…..


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## Smile_n_Nod (Jan 20, 2011)

The individual boards were flattened on a large thickness sander in a friend's cabinet shop. I glued the assemblies (each made of 4 boards) with yellow glue and clamps, but the opposite sides of the assemblies are no longer perfectly parallel or perfectly flat. I've been trying to joint with my jack, try, and smoothing planes. I've got them in pretty good shape, and I use winding sticks and a 3-foot straight edge, but the sheer size of the assemblies make it tiring to work on them.

I thought about running the assemblies through the thickness sander, but since the assemblies are 5" thick, the infeed and outfeed tables for the sander are too high. I'm thinking it might be easier for me to use my sawhorses and my Workmate and make some supports for infeed and outfeed on the thickness sander.


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## TCCcabinetmaker (Dec 14, 2011)

yeah, I had a hunch, wide belt sanders tend to do that, but it should be fine.


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## Oldelm (Jun 11, 2012)

If you are at .004 now and you wait until tomorrow to glue up, that will change somewhat unless you are in a strictly controlled environment. I would say you are more than ready to go. Unless you are using a platten press or something similar to glue up just the additional moisture of the glue and a slight difference in clamping pressure could make for signifigantlly more gap than what you have IMHO.


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