Thread: Joining boards face to face for thickness

You want to try and have the heart of the board on the one side for best match and best matching movement for any change in dimension it may go through later after its glued up . So if you cut a board into three , lay it up like this . Get the gluing faces as flat as possible . They should be extremely flat. I used to Buzz, thickness then toothing plane each gluing surface . I now have a twin drum sander and that thing gets it so perfect after the buzzer and thicknesser that I'm getting laminations better than Ive ever seen before.
grain direction.pngI need this sort of thing for Table legs , and trestle table base sections . If its got to be turned its important that the three or what ever amount are either from the same board or if from two boards make sure they get laid up so the turning is balanced . Other wise you can have an unbalance leg in the lathe . the lathe will be chasing you around if its not bolted down .

Originally Posted by auscab

You want to try and have the heart of the board on the one side for best match and best matching movement for any change in dimension it may go through later after its glued up . So if you cut a board into three , lay it up like this . Get the gluing faces as flat as possible . They should be extremely flat. I used to Buzz, thickness then toothing plane each gluing surface . I now have a twin drum sander and that thing gets it so perfect after the buzzer and thicknesser that I'm getting laminations better than Ive ever seen before.
grain direction.pngI need this sort of thing for Table legs , and trestle table base sections . If its got to be turned its important that the three or what ever amount are either from the same board or if from two boards make sure they get laid up so the turning is balanced . Other wise you can have an unbalance leg in the lathe . the lathe will be chasing you around if its not bolted down .

can a hand plane get it even flatter than a thicknesser?

is wood movement a big issue with face joining boards? I know jointing is important for edge joining, but that's smaller surface area and a lot less glue

Originally Posted by yoboseyo

can a hand plane get it even flatter than a thicknesser?

Not unless you're really, rEaLlY, REALLY good, and even then probably not.

I used to do laminations the same way as auscab if there was more than 2 pieces, but if it was only 2 I'd have them so the heart was facing out on both pieces. This was in the hope that it would keep the forces balanced against each other and meant that any movement would force the outsides of the joins closed and try to open the middle (which is much harder than opening the outside edges).

Originally Posted by yoboseyo

can a hand plane get it even flatter than a thicknesser?

is wood movement a big issue with face joining boards? I know jointing is important for edge joining, but that's smaller surface area and a lot less glue

A hand plane is how it was done before thicknessers were around . Yes planing gives better results than just a thicknesser. Machines are great for getting it pretty close first. The finish left by the plane is preferred though.

Its more successful with good stable well dried wood. Some woods are better than others . A lot of the common standard cabinet timbers are pretty good .

Some of our rock hard heavy Aussie timbers are so strong and Glassy hard that they don't hold so well being used that way.

If you needed a finished thickness of 40 mm and your pieces were 30mm thick . Having 10mm stuck onto 30mm can be less trouble than two at 20mm . The 10mm may move with the 30 . The two at 20 may fight with each other and the glue line gives way .

Don't leave a piece that's laminated near a heater. I did a table once , similar cold weather as it is now where I am . As I was polishing it, one leg got cooked in front of a heater and the glue let go .

Is the risk of instability gluing face grain more than gluing edge grain?

Originally Posted by yoboseyo

Is the risk of instability gluing face grain more than gluing edge grain?

You will get a better understanding by knowing how wood expands and contracts depending on how it is cut from the log .
With two square bits of wood where one side is face cut and its side is 1/4 cut on both, joining them face to face are not as good as side to side. The timber moves more over the face than the side . If you can use 1/4 sawn wood to your advantage you end up much better off . edit . When it matters.

look and read through this sort of thing and it should help.

https://www.google.com.au/search?q=w...w=1120&bih=573

I am just working on a cabinet and have just done that very thing.
I needed a back for my cabinet and was going to use some teak veneered ply, which turned out to be unusable. I have therefore made a back panel from solid marri timber, resawn on the bandsaw ,run through the thicknesser and then edged on the jointer. I needed 4 widths to get the 430mm I needed. I glued in two stages so I didn't have to worry about jostling the joints for evenness in one go. After gluing I scraped most of the glue off and ran through a drum sander. The finished panel is a mere 5mm thick.
I tend to concentrate more on acheiving the a good pattern match than the aesthetics of alternately flipping heart-sides.

Originally Posted by auscab

You will get a better understanding by knowing how wood expands and contracts depending on how it is cut from the log .
With two square bits of wood where one side is face cut and its side is 1/4 cut on both, joining them face to face are not as good as side to side. The timber moves more over the face than the side . If you can use 1/4 sawn wood to your advantage you end up much better off . edit . When it matters.

look and read through this sort of thing and it should help.

https://www.google.com.au/search?q=w...w=1120&bih=573

So plain sawn face expands more than quarter sawn face. So face gluing plain sawn onto quarter sawn is a no-no, but quarter sawn on quarter sawn is yes-yes? Have I gotten that right? What about plain sawn on plain sawn?

Depends what your doing and with what . What are you doing ?
If its a back or a top then as Mark said . It may be more important that it looks good. If its a column for a table base or legs , as I said before .