Making wood blocks

[elizabeth]

Hi! I want to make a 1 1/2"+ thick block of wood from two pieces of wood. My questions are how do you glue the two pieces together without leaving a seam? and, secondly, when I glue these pieces using either wood glue or CA, won't the glue prevent oiling and finishing in the seam making it more visible?

I've seen you all do this but it will be a first for me.

And yes, I'll show I'm still and Agee by not starting with a thick board to begin with! ;D

Thanks!

[rhull]

Jan 12, 2010 14:40:57 GMT -6 elizabeth said:

And yes, I'll show I'm still and Agee by not starting with a thick board to begin with! ;D

That's what I'd do if I absolutely had to be sure there was no visible seam...

Otherwise, I'd cut the boards so the grain runs in parallel with the edge of the boards and simply glue with wood glue (not CA). Provided you've properly face jointed the boards, once you plane/scrape/sand the edge, the glue line really won't show. For example, look at tabletop glue-ups; if the glue line was problematic, all large tabletops constructed from multiple pieces of lumber would show glue lines.

[sawduster]

For any sort of glue-up, matching of the grain will go a long way toward hiding the joints. Also, you can get wood glue that is a darker tint which can be used with darker woods and will better camouflage the joints. Might be helpful in grain matching to cut the two pieces from a single longer board.

Best bet, though, would be to start with 8/4 stock to get your 1 1/2" final thickness if that is a possibility.

[Ruffnek]

Match the grain and start with flat stock. You can face joint a long board to get it flat. If you are working with very short stock, a piece of 9 x 11 sandpaper stuck on a flat surface makes a good jointer. Just rub the mating faces on the sandpaper until they are absolutely flat. They should go together without any visible gap just by light hand pressure. After you apply glue and clamp them securely, the grain should be the only indication of a glueline.

A good trick for having even edges is to glue together oversize blocks and then trim to fit after the glue dries. That way, the edges are perfectly even.

[Doug B]

Elizabeth, Titebond III glue dries with a light brown or tan color and can sometimes help hide the glue line,,,depending on the wood you are using.

Of course, to get the best results a jointer helps a whole bunch.

What kind of wood are you working with?

By the way, I are a Aggee too (NM not TX) ;D

[TDHofstetter]

The whole trick... is to "lap" the two pieces of wood together so they fit together as perfectly as possible without glue. If either piece has any imperfection, that imperfection must be matched, in mate image, on the other piece. For a truly well-lapped joint, providing the best possible "airtight" fit between the two piece os wood, you'll lap one piece to the other piece.

To get that done, cover the one piece (we'll call it the "platen" for now) with a single sheet of A-weight sandpaper of a fairly high grit count - we'll say 220 for now. Scribble pencil lines all over the face of the matching piece of wood (we'll call it the "mortar"). Now scrub the "mortar" over the "platen" in small circular motions. This is how people grind mirrors for homemade telescopes, by the way.

Lift the mortar off and examine it. All the pencil lines should have been scrubbed off. If not, blow the dust out of your sandpaper and scrub a little more. Continue until the whole surface is completely scrubbed clean.

Now reverse the situation, making the second piece your platen and the first piece your mortar. Scribble pencil lines again, and scrub them off.

When both pieces are scrubbed clean, they're matched as well as you can do it with A-weight paper. If you want an even finer match (I doubt you'll want it better, but it's possible), you can repeat the process with pumice powder. For wood, though, your lapping with A-weight paper will PROBABLY be about as good as you need it to be.

Once the pieces are lapped, glue them with yellow PVA glue. Thoroughly wet both surfaces, align them carefully, and clamp them tightly. Not hydraulic-jack tight, but as tight as you can reasonably get ONE woodworking clamp to tighten. Too tight and all the glue will migrate out from between the pieces and your joint will be starved & weak.

That lapping, plus careful grain-matching, will give you as invisible a joint as you're likely to want. The only improvement left to make is...

Where possible, place the seams at corners - along edges - where two planes intersect. It may take clever sawing to make it work right, but a glue seam along an edge is much harder to detect than a glue seam in the middle of a flat surface.

[elizabeth]

Oh, this is great. Thank you. I'll print all of this and take to the shop.

What I wanted to experiment with is to sandwich boards so I can rout out the insides giving me a box case without joints. Your advice in all of this is doable for me. Just a little practice and some elbow grease. Thanks!