Face Jointing Old Floorboards

[Northers]

Hi all
I want to join some old floorboards (face to face) to create some thicker boards to produce a table top.
I’ve got access to a planer thicknesser to flatten them off first but I’m looking for tips/tricks to face join them.
Best way to clamp? Best adhesive? Use biscuits?
The floorboards will be about 1.8m long, 15mm thick when planed and I want to join 4 together to make 60mm x 125 x 1800 boards.
Any suggestions gratefully received!
Thanks
Andy

 

[spb]

On a bit of a tangent here - you say you want to laminate the thin boards into thicker ones, to then use for a table top. That usually means edge jointing narrow boards to make wider ones. If that's the case, the I'd say that's probably the wrong way to go about it - first, you'll waste more material in edge jointing the laminated boards, and second, you'll get a stronger result if the joins in each layer are offset from each other. I'd be building the top bottom up in layers - edge joint the thin boards first, then offset the next layer so that the joins are in the middle of the previous layer's boards. This way will also reduce the visual impact of any slight inconsistencies between boards.

As for the glue up itself, nothing too fancy. Make sure your glue is spread thin and even, as there's not really anywhere for squeeze out to go from the middle of a face. A glue roller might be useful here. Lots of clamping, with cauls to spread the pressure as evenly as possible. Think about clamping blocks on the edges as well, to stop them sliding side to side. Don't take your machined surface for granted, either - while it might be fine, some P/Ts will leave little scallops in the surface from the rotating knives, depending on the depth of cut used. Have a close look and give it a pass with a hand plane if it looks uneven.

As for which adhesive, which ones do you usually use? Most of the usual suspects will do the job, as long as they've got enough open time for you to get everything in position. I'd do a dry run, including time for glue rolling, see how long you need, then look at which ones will work.

 

[spb]

Oh, and make absolutely sure there's no metal in those floorboards before you let them anywhere near a planer/thicknesser.

 

[Argus]

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Well-spread-out glue and lots of clamps should do it, but beware of hidden metal and ingrained grit which can make a mess of your jointer.

.

 

[marcros]

do you definitely want 60mm thick pieces? that is a very heavy duty/chunky table top, which may not suit narrow boards joined together. I think that it will also look out of proportion to a 1.8m table in a normal domestic dining room. you know the setting, I dont.

you say that you have access to a planer thicknesser. Assuming that this isnt yours, does the owner know that you are putting floorboards through? I would be very hesitant to do this on mine because of the metal and grit that is often hidden in them.

if I were making a thicker top than the boards I have, I would make your top and then add some extra around the edges only in order to make it look thicker. The problem is that as a single thickness, 15mm is a bit thin, particularly if the glue isnt perfect and it needs a bit of flattening.

 

[AndyT]

I agree with Marcros. It's called "lining up" in old books about furniture making and is a standard technique. As well as being economical, it has the advantage that you are less likely to get a hernia moving the finished table.

 

[MikeK]

If the floorboards are in decent shape, it would be a shame to hide one in the middle to build up the thickness. I don't know how feasible this is, but what about gluing a floorboard to a length of MDF to get a reasonable thickness and strength and then finishing the edge with the process marcos and AndyT described?

I looked at a new workbench while I was killing time waiting for some parts, and noticed it wasn't as thick as it appeared. The boards for the surface were only about 30mm thick with a thicker board around the four edges. As I looked under the table to see how it was built, there were thick runners across the bottom of the work surface, and this is where the dog holes were drilled. The bench appeared to be sturdy enough.

 

[SamTheJarvis]

The #1 thing to watch for when planing reclaimed floorboards is embedded grit (pressed in by footfall). If time allows, I would have to recommend going over them with a wire-wheel, as this will hopefully pick up the majority and will at least loosen the fibres around any grit so it does less damage if the blade does come into contact with any.