Domino Alternative

[Jesse Cloud]

At the school where I take woodworking classes, there is an exercise in the intro class where everyone edge glues two pieces of wood together.  After only 30 minutes clamp time, you take them apart, put them on sawhorses and whack them with a big hammer.  The wood always breaks before the glue line, never seen an exception.  If you are making a coffee table, you should be able to dance on it, without dominoes.  I'm a big fan of the domino, but in most circumstances, certainly in 8/4 stock, they are not needed for edge glueups.

Theoretically, the domino should help you get the boards aligned.  Again, I'm skeptical.  Too many chances for an error.  If you have dominoes and discover your error during glueup, you are in trouble.  Without dominoes, you can tweak it till it is perfectly flush.

The domino is an incredible time saver and makes great joinery, but its overkill for edge gluing unless you have an unusual glueup where you just can't reach all the boards that need attention...

My two cents, different folk make great furniture in different ways.....

 

[grobin]

Some from everyone knows… but some from doing tests.  I was told that biscuits added strenght.  So I borrowed a biscuit joiner and tried them.  The joint broke before the wood did.  A similar spacing of loose tenons did not.

Give it a test.

 

[Sparktrician]

Some from everyone knows… but some from doing tests.  I was told that biscuits added strenght.  So I borrowed a biscuit joiner and tried them.  The joint broke before the wood did.  A similar spacing of loose tenons did not.

Give it a test.

 

Fine Woodworking did "the" definitive test of various joints using pocket screws, dominoes, biscuits, lap joints, m&t, etc., a couple of years ago.  You might want to look for that article to see what they found out about the strength joint types.  

Edit: Fine Woodworking, Issue No. 203, February 2009, pp. 36-41. 

[smile]

 

[truck90278]

I am about to make my first (and probably only) coffee table from a pair of 8/4 book matched walnut slabs and have a question about gluing the slabs together.  This project is the main reason I bought my TS55, Rotex 150, and ETS150 - to joint the edges, flatten the top, and finish the surface.

But I seem to missing a tool.  In a perfect world, I realize that I need a Domino to complete the job properly. But it's not a perfect world and a Domino's not in the budget right now.  I assume that I need something other than glue to keep the two halves connected to each other and was wondering if there is an inexpensive alternative.  I don't want to waste the money on a cheap mortiser, because I do want to be able to buy a Domino eventually.  Ideally, I would love to do this with hand tools or some inexpensive mortising jig.  I know that it will take a lot longer than with a Domino and that the alignment will not be as precise, but can't I just cut mortises into the edges and use hardwood domino-like tenon inserts? 

Thanks for the help.

Steve

I was in my local Rockler dealer about a month ago and some US Coast Guard folks were in the store.  They were in the process of RENTING some RO150s and CTs from Rockler.  The sales folks told be it was a new service being offered. 

 

[grobin]

Sparktrician thanks for the link.  Very interesting.  I wonder why the dominoes failed so easily on racking?  I did two tests one was a 3'x6' plywood in a but joint 3' long and the other a end to side joint in #2 or better pine both pieces 10"x7'.  I also used Titebond III.  Tried to get the same spacing for both the biscuits and the dominoes 8x40mm.  On the ply I used seizing on the wood before plunging and then glued the biscuits and dominoes as well as the joint.  I wasn't set up to measure force—I had wanted to rent a press that would give me that but would have had to wait 3 weeks.  I supported the ply by the ends and applied force over the joint with an about 1.25" steel bar.  For the domino joint the ply broke about 6" from the joint.  The biscuit joint broke at the joint.  The result was essentially the same for the pine.  But I was testing load bearing not racking.

A very interesting article overall.  Looks like I may need to rethink an outdoors project I have been looking at.

BTW I am really surprised that pocket screws did as well as they did.

 

[Sparktrician]

BTW I am really surprised that pocket screws did as well as they did.

Frankly, I'm not.  Several years ago I built a ramp for the handicapped mother of a friend using all pocket screws and only six nails.  After she died, my friend hired someone else to take it out and restore the house to a normal configuration, since I was committed at the time.  He told me later that the removal contractor cussed me up one side and down the other because it was so tight and difficult to dismantle.  And I didn't even glue any joints. 

[big grin]

 

[grobin]

I tend to think poorly of screws but maybe that's because I have been restoring circa late '40s early '50s furniture that is now coming apart because of them.

BTW better link to the Fine WW issue is here.

Very interesting but I could wish for some detail on how the dominoes and pocket hole screws were used.

 

[mikeneron]

When I clicked on that link, I got this from McAfee Site Advisor:

avaxhome.ws/magazines/YELLO_037.html
may cause a breach of browser security.

Why were you redirected to this page?

When we tested avaxhome.ws/magazines/YELLO_037.html
, it attempted to make unauthorized changes to our test computer by exploiting a browser security vulnerability. This is a serious security threat which could lead to an infection of your computer.

 

[Jesse Cloud]

Sparktrician thanks for the link.  Very interesting.  I wonder why the dominoes failed so easily on racking?  ....

As I recall they used only one domino per joint, which is just silly given how easy it is to add a second one.  But I guess one could also argue that the second domino would be an unfair advantage compared to a single real tenon....

This is why I don't have a high opinion of the "tests" magazines do on tools and joints.

 

[grobin]

mikeneron I am running the latest version of McAfee anti virus  with the latest updates (just got updated this mourning) with Firefox 3.6.12 and no problems.  But if you click on the high speed download link you get into a pay situation where I think the site may have been hacked.  Use the slow alternative no problems.

 

[grobin]

Jesse thanks; I thought something like that. Also if they used the narrow or wide settings makes a difference.  The article online had a lot of pictures but didn't provide the specifics that I would like.

 

[grobin]

Forgot to mention a rough hickory test that I did.  I had two old ax handles laying around and cut them at the same diameter.  Did but joints using one biscuit and one 8x50 domino again TiteBond III.  The biscuit joint broke and the domino joint held (the hickory broke about 3" from the joint).  They were about 18" long for the biscuit and about 15½" for the domino.

 

[Toller]

A few years ago I made a deck for my swim platform by fastening pressure treated wood together with pocket screws.  5 years later I threw it out because it warped horribly, but no joint ever failed.  And it was outside in the sun and snow. 

Likewise, I didn't have clamps big enough for my kitchen table, so I made it in halves and pocket screwed the two halves together.  It is still good after 6 years.  No sun or snow...

Anyhow, pocket screws does a good job and I wouldn't be afraid of them if you don't want to clamp.  Just use a lot of them.

 

[Steve F]

Likewise, I didn't have clamps big enough for my kitchen table, so I made it in halves and pocket screwed the two halves together.  It is still good after 6 years.  No sun or snow...

Just curious how big the halves of your table were.  Mine is a coffee table and will be about 45 x 45 of 8/4 maple and I was hoping for something to pull the two halves together until the glue dries in areas where I am afraid clamps will crush the live edges.  I found something called a Scrooge Clamp at Lee Valley and thought that might be just the thing.  But pocket screws are much cheaper.

http://www.leevalley.com/en/wood/page.aspx?p=44908&cat=1,43838,47843&ap=1

Steve

 

[Wood_Junkie]

I think that Scrooge clamp would introduce some non-linear forces to your glue up, since its force probably won't / can't be centered across your workpiece.

I'd suggest, using basic F-clamps, clamp some ¾” scrap on the top and bottom of the live edges, protruding over/outside the edges by a bit.  Really cinch them down.  It also might be worthwhile to put a thin layer of non-slip pad or even fine sandpaper.  Maybe even create some "saddles" that you clamp on.

Anyway, this will give you a decent anchor point for bigger parallel clamps or pipe clamps.  The clamps will span from the anchor on one side to an anchor on the other, without compressing your live edge.

 

[Kevin Stricker]

Hey Grobin,
  No disrespect, but I think you might learn a lot if you studied the differences in strength between face-edge, edge-edge, face-end, edge-end, and end-end grain joints.

Your tests were on face-end(pine) and end-end (plywood) grain tests, which are relatively weak joints.  Edge-edge is one of the strongest glue joints there is.  A spline will improve the strength because it incorporates face grain into the glue-up, but a domino will do little to improve strength with this joint.

Back to the OP, if you do use pocket screws for a live-edge glue up make sure you have a way to index the center of your piece.  It is easy to clamp the two ends but in the middle you may have problems with the pocket screws pulling the top out of alignment.

Usually strap clamps are used with live edge glue ups.  I would add a spline or biscuts for alignment though. 

 

[fdengel]

If doing joints involving end grains, make sure you are using a poly glue such as Gorilla Glue -- much stronger than the non-foaming glues when end grains are involved (not neccessarily when they aren't -- if only faces and edges are involved, the poly glues are still strong, but there are other stronger glues, such as Titebond, which work in those cases).

 

[ScotF]

I really think that the edge-to-edge joint is the best way to go on this application.  You will not need biscuits or dominos or anything to help improve strength.  As long as you have straight and square stock as Jesse and others have mentioned and use enough clamps to close the seam and get consistent squeeze out, you are going to be fine.  I personally would not use pocket screw joinery on the underside or any mechanical fasteners in this application.  If you are concerned with alignment, you could use biscuits or dominos or dowels or you could also use a edge-glue bit in a router to give a slight profile on the two peices.  Clamps on top and bottom of the assembly will aid in keeping it flat while it dries.  I have yet to have a glue failure on a long grain to long grain glue-up and with today's glues, I do not see this happening.  The glue joint will be stronger than the surrounding wood.

Scot

 

[grobin]

Kevin no offense.  I did the tests that I did because those were the kind of joints that I was making.  I have sense made some shelves by joining 4½" wide boards to make a 9" wide shelf.  I used dominoes and glue and have not done any strength tests.  I have a shelf made with dominoes and no glue under test now, really just a curiosity.

I find that I prefer to prototype and test rather than rely on anecdotal "…What everyone knows…" approach.  Everyone knows that power tools are faster than hand tools; but in reality it ain't necessarily so.  I tend to design so that racking forces are minimal and shear forces the main forces.  I can make a more graceful piece with less wood than I could otherwise; although, this limits my design choices. 

 

[Steve F]

I'd suggest, using basic F-clamps, clamp some ¾” scrap on the top and bottom of the live edges, protruding over/outside the edges by a bit.  Really cinch them down.  It also might be worthwhile to put a thin layer of non-slip pad or even fine sandpaper.  Maybe even create some "saddles" that you clamp on.

Anyway, this will give you a decent anchor point for bigger parallel clamps or pipe clamps.  The clamps will span from the anchor on one side to an anchor on the other, without compressing your live edge.

That sounds perfect.  It seems that the pressure of the pipe and parallel clamps would move the F-clamps, but I believe you that they don't - probably something to do with friction, but I am decades past high school physics.  My real concern is how to finesse the glue up with the extra weight of the F-clamps.  I know that the Domino would solve that, but that comes full circle from my original post.

Thanks

Steve