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I potentially have a large amount of solid beech flooring 20mm thick, 85mm wide and various lengths. I'd like to repurpose some of it to make a work bench entirely from the beech.

I'm inexperienced in wood working generally, but want to experiment a bit, and would like to know if the following are possible/realistic:

1) Can I glue the slats together and make suitable strong table legs and other structural parts, e.g. 80x80x900.

2) If I then cut mortise/tenons in there, will they then be strong enough, or will the wood break up?

3) For the bench top I have considered either joining the slats horizontally with two layers to produce a 40mm thick top, or putting the slats on their side to produce an 80mm top.

4) If I can't find long enough pieces to make the table top, and instead make the top up using overlapping shorter pieces, will that make a strong enough table top?

Sorry if these are very basic questions.

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  • Just a reminder to try and stick to a single question at a time so you get good, complete answers. The core of your question seems to be "can I glue up smaller pieces of lumber into larger dimension pieces and use that to make something robust?" If so, maybe edit the question and make it clear that is what you are asking. – jdv Feb 10 '19 at 15:02
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In general, modern wood glue is stronger than the wood it is gluing. With a good glue joint on long grain wood, you should expect no problems. A good glue joint is one where the parts mate well (in case of laminating several pieces together, they should be completely flat against each other, without any gaps), adequate glue is used (coat both parts to be glued) and adequate clamping pressure is applied (this is open for debate, but some sources say you'd need pretty high pressures for hardwood).

As for the table top, your main issue would be with joining shorter pieces together - you can just butt them together, as that would lead to a poor glue joint. You'd want to use a proper joint, either a long scarf joint or a finger joint. Finger joints are easily done on a router table with the right bit.

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  • Great thanks. Finger joint looks straight forward, and I can make a few boxes with them by way of practice. – Slicc Feb 10 '19 at 7:39
  • @Slicc, just to clarify something that has been mentioned in previous Answers, wood glue is not stronger than wood. It is well-made glue joints that are stronger than the wood around them. This is an important distinction to make so you don't consciously or unconsciously expect the glue to do things it isn't capable of doing. – Graphus Feb 10 '19 at 10:45
  • @Graphus technically you are correct, but the glue itself does play a role here - the same joint quality made with hide glue will not be as strong as a comparable joint glued with modern PVA (yellow glue). Hence the common advice today of "glue is stronger than the wood" - it is just being implicit on the "with a good quality joint" part, which applies to all woodworking joinery (glued or not glued). – Eli Iser Feb 10 '19 at 14:50
  • I've stated it before that this is a vitally important distinction to make because people reading it put the wrong way can and do go on to incorrectly use their glues. To put it simply, people can go on to think a thick glue line can be strong (because, strong glue... right?) when in fact, with almost all adhesives, ONLY thin glue lines are strong. – Graphus Feb 10 '19 at 18:56
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1) can I glue the slats together and make suitable strong table legs and other structural parts, 80x80x900 e.g.

Yes. This is quite commonly done.

2) if I then cut mortise/tenons in there, will they then be strong enough, or will the wood break up?

Yes this is fine, particularly if you orient the glued-up legs so that you're cutting the mortises through the continuous face that will be on two sides of each leg. However, this construction affords another option and that's to form the mortises during the assembly process by leaving the space in one layer of the lamination, see Simplifying construction in the last link at bottom.

3) for the bench top I have considered either joining the slats horizontally with two layers to produce a 40mm thick top, or putting the slats on their side to produce an 80mm top.

Either of these could work fine in practice. The second option would generally be considered the better of the two by woodworkers.

The second option will make for a very heavy, stout benchtop (often desirable, especially for a bench intended for hand-tool work exclusively or primarily) but bear in mind the eventual weight of a beech slab 80mm thick! This method of construction has another advantage in many cases, with most boards being flat-sawn or plain-sawn turning them on their sides and glueing them together face to face makes for a top that is effectively quarter-sawn wood. This orients the main seasonal movement direction up/down and not across the width which comes with some advantages including, in general, greater stability.

4) if I can't find long enough pieces to make the table top, and instead make the top up using overlapping shorter pieces, will that make a strong enough table top?

Yes. This is commonly done in the manufacture of modern built-up work surfaces and benchtops.

The staggered joints, although individually weak, become essentially irrelevant because they're supported by the wood around them. You want to try to space them out sensibly for maximum strength, three close together could be a weak point, but the entire structure becomes so strong you don't have to be overly concerned.

Important tips
You're going to need a lot of clamps to do this properly, and for best results they should be strong because you want to achieve high clamp pressure. The number of clamps becomes more important the thicker the piece being glued because clamp force spreads out from the point of clamping.

Clamps cannot be too tight and the tighter you make them the better and more reliable your joints will be.

Some further information from previous Answers will be of great benefit to you as an inexperienced woodworker:
How long after cutting wood can I wait to glue?
What do I need to do to prepare wood for gluing?
Should I orient the cupped sides toward each other when laminating boards?
How to join short boards to make a longer panel
What is the benefit to gluing boards together instead of buying a thicker board?

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  • In reference to your response to point 3, plain sawn wood placed side on would presumable have quite an uneventful grain on display, is this the case? Would a router based finger bit (rather than creating the finger joint with a deal bench saw) potentially add a little more character here? – Slicc Feb 10 '19 at 21:07
  • Not sure what you mean here with the reference to the finger-joint bit. Are you referring to what will become the top surface? If so, beech is one of those species that exhibits a particular figure — called ray fleck amongst other things — when the grain is perpendicular to the cut surface or very close (=quarter-sawn). This is much more pronounced in oak but in beech it can still be quite beautiful, so there's potential in a certain proportion of the boards for the edge grain to be much more exciting than normal for beech, which is, generally, a fairly unexciting looking wood otherwise. – Graphus Feb 11 '19 at 7:52
  • The above is based on the assumption that the floorboards aren't quarter-sawn wood already! It's not impossible that they are, but I think it would be relatively uncommon for beech flooring to be cut this way because there isn't the high premium put on the QS figure as there is in oak. – Graphus Feb 11 '19 at 7:54
  • Looking at pictures of quarter sawn vs plain sawn, I'd say the wood is definitely plain sawn. Regarding the finger joint, I really just meant creating the finger joints such that they were visible when the table surface was created (so 2 fingers present along the short 20mm edge, rather than 7 or 8 along the 80mm edge). – Slicc Feb 11 '19 at 14:14
  • No need to guess at plain-sawn, rift-sawn or quarter-sawn — just look at the ring structure at the ends of each board. Re. the finger joints, I get you now. This is entirely an aesthetic decision on your part, use them if you like the look of them, don't if you don't. – Graphus Feb 11 '19 at 14:51

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