Joining Boards


DaveB

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Sorry if this has been covered elsewhere and I just haven't found it yet.

I'm pretty new to woodworking. For my first real project I'm building a changing table for the baby we're having in October. I'm now on my second attempt at it which is looking like it will work well (and it better for the money I've spent so far!)

The problem I was having was joining the boards together for the top and sides. I was trying to join 1x6 boards together to make a 24" wide top. I bought a lock-miter bit for the router and fought the thing for a week trying to get it to work right, but I always ended up with sloppy and uneven joints. Later I discovered that there are setup blocks for them- something I will definitely need to buy down the road.

The finger joint bit looked a bit easier. After a few tests with that, it's back in the toolbox with the lock miter bit. Oh I haven't given up on them, just need to learn a little more first.

I ended up buying pre-made panels at Lowes. I feel like I'm cheating, but the baby's coming soon and I need to get it finished.

Anyway, That's kind of the long way around to my actual question- What is a good way to join boards like this? I'm sure there are hundreds of ways to do it, What is a good not-so-difficult way?

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Long-grain to long-grain joints are plenty strong without any fancy joinery - I know, it surprised me, too. The standard way to do this is to make sure the edges to be joined mate perfectly. Usually this means that they are both flat, but theoretically, they could look like puzzle pieces as long as they matched each other. You can flatten them on a table saw with a good blade, a router table, a hand held router with an edge bearing (you run the bearing along a known straight-edge), or with hand tools (I think it's a jointer plane, but you should ask someone who knows if you go that route).

Once the edges mate cleanly, you need some way to clamp them together while the glue dries. You want to spread the glue evenly, and clamp until you see the glue squeeze out evenly along the joint. You also want some way to keep the boards in line. People often use biscuits or cauls, but you can also use dowels, splines, Domino, etc. Or, rest them on something flat and put weights on top.

Oh, and it would probably be easier to only do one joint at a time, rather than try to glue all four boards at once. Do two, and once they are clamped do the other two (assuming you have enough clamps), and when they are both dry glue the two glued up panels together.

I'm sure that Marc and Charles Neal have done videos where they show this. If you can't find them let me know.

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Have a look at the thread "Gluing up a table top" in this forum. I described a method I use involving cauls and bar or pipe clamps. The cauls keep the boards aligned vertically and the clamps pull the edges together.

Cauls are boards with one convex edge. They are used in pairs and clamped on opposite sides of the joints with the convex edges facing. When the ends are brought together, the curved edges flatten out distributing the force along the length of the caul. I outlined a method for making these cauls in the thread (2nd posting)

I haven't found any need to add biscuits, dowels, splines or groves to align the edges or strengthen the joints.

Mike

PS - I gave away my lock miter bit a long time ago.

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I agree that no fancy joinery is required to glue narrow boards together to produce a wide one. As stated, what is required is that the edges being joined by very straight/flat. I disagree that table saws provide sufficiently straight edges. Most power tool guys opt for a jointer to prep boards for 'joining.' I've never seen the need for one myself and thus I use a #7 jointer plane, planing both boards simultaneously. It's quick, and once you've gotten some practice using handplanes, easy.

Some will use biscuits, dowels, or Festool dominos to help with alignment when joining. This isn't necessary but it does making alignment easier. But once you have glue on the edges, it's a matter of putting clamps above and blow the boards and holding them together while they dry. Often I see guys applying lots of pressure while doing this and I think this is more a reflection of how the edges were prepped than anything else. In my view, if you have to apply a lot of pressure, you're building tension into the board may separate the joint at some future date.

Cheers --- Larry

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Often I see guys applying lots of pressure while doing this and I think this is more a reflection of how the edges were prepped than anything else. In my view, if you have to apply a lot of pressure, you're building tension into the board may separate the joint at some future date.

Cheers --- Larry

Long ago before parallel clamps, panel joints were rubbed with hide glue until they tacked then set on the side to cure. Once I read about that long ago, I eased up a lot on the clamping pressure seeing as how remarkable works were made with none. I do rub joints with PVA glues for small items; usually only stuff that doesn't show or is something for the shop. It works well although PVA shows more of a glue line that way than the clamped-all-to-hell way. This isn't to say, though, that I haven't compensated for a lot of mis-milling with clamps!!

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David, just happens I just finished up a panel glue up. I picked this up watching David Marks on Woodworks. I joint the two pieces with opposing faces against the jointer fence. This gives a mating joint whether the jointer dead square or not. Then I barely drive a few brad nails into one of the jointed edges and clip it off, so just a nub protrudes. Be sure to place these where you will not be cutting in the future. I spread the glue on, bring the board close and just before the brads engage the other piece, get everything flush and clamp on. Worked perfectly. About fifteen minutes later, I used a sharp chisel to get the squeeze out off and done!. I'll clean the little bit of offset (less than 1/128) with a card scraper, sand and it's ready for finish.

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Long ago before parallel clamps, panel joints were rubbed with hide glue until they tacked then set on the side to cure. Once I read about that long ago, I eased up a lot on the clamping pressure seeing as how remarkable works were made with none. I do rub joints with PVA glues for small items; usually only stuff that doesn't show or is something for the shop. It works well although PVA shows more of a glue line that way than the clamped-all-to-hell way. This isn't to say, though, that I haven't compensated for a lot of mis-milling with clamps!!

I use rub joints all the time in my work. I do work with hide glue, however. PVAs are plenty strong but hide glues are simply stickier when wet, allowing a rub joint to hold itself together better. Like you, I used to take boards off the saw and try to build a panel. Once I figured out that a couple swipes with a #7 between saw and glue up created a much better fit, I found that lots of pressure was no longer necessary.

Cheers -- Larry

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Okay. I know I'm going to catch h**l for putting this here, but, if you're struggling with doing a glueup to get a flat panel, been there, done that. All of the previous advice here is great. The lock miter is a real difficult bit to work with. Now here's a way to cheat (meaning easy) and have a dead flat extremely strong table top. Use a Kreg jig and screw the boards together on the bottom. There, I said it. The screws act like clamps. The vice clamp used when driving the screws will keep the panels registered and all but dead flat. After the glue dries you can remove the screws (if you want) since the glue joint should be plenty strong. The screw holes are on the bottom where they won't be seen.

This does not mean you should stop your woodwrking education with the Kreg jig. It simply means that it is an easy way to get a very good result when you are starting out, especially if there are faces that won't show where you can hide the screw holes. Once you have a success you can move on to learn more challenging ways to do things.

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Here is my approach. I watched these videos which were fantastic http://mattsbasementworkshop.com/videos/ check out the joinery series. So Using Matt's approach I place two boards close together, use a saw with a guide between them (in my case festool with the guide). Then I cut them and in theory these are mating surfaces. After this, I use my Nbr. 7 as Larry Marshall does and plane both mating edges ... and here is where I go crazy.

After the two surfaces are planed and jointed, I use dominos to make things easier. I glue two boards at the time and use a million clamps because more is better.

After I have my glue up done, then I use my nbr 7 again and make sure the top is flat. Next step is to use my smoother and I did not do this yet but will on the next one because I just got my scrapers.

There you have my process, and yes everything I do is overkill.

That is why nothing gets done.

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T&G and lockmiter bits are fine as long as you are joining up boards that will have their ends hidden. If you use them for a table top, the end grain of the top will have the funky joints showing instead of a nice thin line. Even worse, if you cut away the edges as in a raised panel, the joint is going to be magnified.

As far as strength is concerned, I have tested my glueups by taking the short offcut when I trim the panel and try to break it at the joint. I have never had the joint break at the glue line. The only upside for the fancy joints is alignment of the boards. The added strength is overkill.

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Mike, You raise a great point on the edges and I wonder if having the edge joint as a decorative element would be a good thing like a "reverse angle" as opposed to a straight 90 degree. I agree with you that I use the dominos just for alignment and making my jointing easier, then again the cauls could be sufficient to keep the boards straight.

T&G and lockmiter bits are fine as long as you are joining up boards that will have their ends hidden. If you use them for a table top, the end grain of the top will have the funky joints showing instead of a nice thin line. Even worse, if you cut away the edges as in a raised panel, the joint is going to be magnified.

As far as strength is concerned, I have tested my glueups by taking the short offcut when I trim the panel and try to break it at the joint. I have never had the joint break at the glue line. The only upside for the fancy joints is alignment of the boards. The added strength is overkill.

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