question on table top glue up

[Frank J Hall]

Question for you guys on gluing up boards for a table top... when using 4/4 material, would you consider only flattening the face of the boards, then glue up, aligning the faces only?

this would make it worthless to use cuals since each board thickness is different, and I probably could only go one board at a time. I'm concerned I will loose too much thickness if I flatten and then thickness each board.

What is standard practice here?

Thanks for advice

[Prashun Patel]

I prefer to thickness before glue up. If you line up well then playing down the seams won't remove appreciable thickness.

[George Bokros]

I would plane to close to desired thickness, glue up, then complete the thicknessing.

[Pat Barry]

The bottom side of a tabletop doesn't always need to be pretty, or flat, so flattening the show side and two edges for glue up can work in those situations. Maybe after glue up only take down any excessively high spots on the bottom that might interfere with table aprons, etc. Note - I always do both sides so I can really see the grain pattern and make choice about what will be the show side.

[Brian Holcombe]

Typically I joint the edges independent of the face. When I place one on top of the other I can tell if I need to adjust the edge to straighten the assembly. I do this so that I have a full panel to joint and thickness once rather than doing so to the individual boards first and again to the full panel.

Machine user's work differently becuase they need a wide reference face to put against the fence while they edge joint. So typically one would work by face jointing, edge jointing, glueing then face jointing the full panel then thicknessing.

Hand tool users are typically done working when the board is uniform. I could care less if it winds up at 53/64" or some goofy number like that, where a machine user is working to a number like 3/4". This is done for practical reasons in both instances, for the hand user it's simply a waste of effort to hit a number when most of the working reference is to gauge lines. Machine users are typically working to dimensions and so accurate numbers are important.

Neither is good or bad, simply different.

[andy bessette]

...I'm concerned I will loose too much thickness if I flatten and then thickness each board...

Use thicker or better quality lumber. Flatten, then thickness plane all the same size.

[Robert Engel]

I would plane to close to desired thickness, glue up, then complete the thicknessing.

This ^ and also what Pat said. You really only have to worry about the show face.

It is necessary to face joint one side in order to get a reference face for edge jointing. After that, I skip plane the opposite face to get the boards close.

I used to do it but now I never thickness to final dims before glue up. For me, all that does is raise the stress level and cause extra work because it gets into the whole biscuit scenario, particularly if I have a bowed board in the mix.

I try to start with 5/4 material for tops. Hope this helps

[Kees Heiden]

The boards I buy, even expensive ones, always have enough warp and cup and bow to make pipedreams out of the idea of using 4/4 as table top material.

[Derek Cohen]

Question for you guys on gluing up boards for a table top... when using 4/4 material, would you consider only flattening the face of the boards, then glue up, aligning the faces only?

this would make it worthless to use cuals since each board thickness is different, and I probably could only go one board at a time. I'm concerned I will loose too much thickness if I flatten and then thickness each board.

What is standard practice here?

Thanks for advice

Frank, it depends on the material I have. Some boards are bookmatched or are resawn from thick stock, and then it pays to thickness first.

On the other hand, if the top is to be built of reclaimed boards, and they are different thicknesses - some of which are on the thin side - then I will only joint the edges and flatten the top.

Here is a table that is made of mismatched boards. Only the surround is the same thickness ...







Regards from Perth

Derek

[Charles Guest]

This ^ and also what Pat said. You really only have to worry about the show face.

It is necessary to face joint one side in order to get a reference face for edge jointing. After that, I skip plane the opposite face to get the boards close.

I used to do it but now I never thickness to final dims before glue up. For me, all that does is raise the stress level and cause extra work because it gets into the whole biscuit scenario, particularly if I have a bowed board in the mix.

I try to start with 5/4 material for tops. Hope this helps

If your table's aprons are flat, and all in the same plane, then the bottom of the tabletop had better be flat (or very slightly and regularly concave) or you're in for a gappy, crappy fit. The top of the top, exposed to nothing but air, can be as undulating as you like. It registers to nothing but said air.

Whether or not the bottom of the top requires extensive planing in order to register well to the aprons depends on a lot of things, but it must register all the way around, or it stands a good chance of pulling the understructure into twist.

[Frank J Hall]

thanks everyone for the great advice and explanations! I appreciate it.

[Bill McNiel]

Typically I joint the edges independent of the face. When I place one on top of the other I can tell if I need to adjust the edge to straighten the assembly. I do this so that I have a full panel to joint and thickness once rather than doing so to the individual boards first and again to the full panel.

Machine user's work differently becuase they need a wide reference face to put against the fence while they edge joint. So typically one would work by face jointing, edge jointing, glueing then face jointing the full panel then thicknessing.

Hand tool users are typically done working when the board is uniform. I could care less if it winds up at 53/64" or some goofy number like that, where a machine user is working to a number like 3/4". This is done for practical reasons in both instances, for the hand user it's simply a waste of effort to hit a number when most of the working reference is to gauge lines. Machine users are typically working to dimensions and so accurate numbers are important.

Neither is good or bad, simply different.

Very well said Brian!