Domino instead of haunched tenons?

[dgage]

Hello everyone,

I am looking at building the base of the following workbench with a large MFT style top.  Once completed the workbench will be about 50" x 100" so that I can handle full sheets of plywood and use my vacuum press.  I have already ordered the edge rails to make my own MFT table. 

http://www.shopnotes.com/files/issues/sample/sample-30-31.pdf

My main question is that the workbench plans called for haunched tenons for the rails and I would like to know if I can/should use the domino tenons instead.  The root question is related to how strong the Domino tenons are compared to a traditional haunched tenon.

Thanks.

David

 

[Jesse Cloud]

Hey David,
I'm shooting in the dark here, because uncle Bob won't ship my domino until April , but, regardless of whether you use a domino or other tools, a haunched tenon is stronger than a regular loose tenon.  It provides extra protection from racking, which you could use in a bench.

Having said this, I'll bet there's someway to trick the domino into making a haunched tenon, maybe two passes with the domino for the mortise and glue together two dominoes (or one and part of a second)....  Gee I wish I had my domino. :

 

[mystry tour]

ok guys here's my tale on this subject. I would make the haunced tenon in tow steps. First a large mortis and then a smaller tenon. I woul dmake my won "loose tenon" out of the same material the parts going to be mated with. Do a little chisel work and wala. haunced tenon.
I will be makeing my own tenons from scrap material. It won't swell and hold as fast but i see no reason it wouldn't work
Tour
Oh Jesse...Bob is sending ine last day of March....hehehe

 

[John Stevens]

The root question is related to how strong the Domino tenons are compared to a traditional haunched tenon.

Hi, David.  If the aesthetic appeal of a haunched tenon isn't important to you, then the issue is whether a floating tenon is strong enough for the job.  Whether it's stronger or weaker than a haunched tenon is irrelevant.

I have a traditional-style workbench that's on a base made of 2x4s joined with 1/4" thick floating tenons made of pine.  You could park a truck on it and it wouldn't budge.

Different strokes for different folks, but I like to spend as little time as possible making stuff for my shop, so I can spend the rest of my limited time making stuff for my home.  Life is short, and time is always running out.

Regards,

John

 

[Ted Miller]

dgage, I have used haunches on small doors when the client wanted to see the joint work on a bookcase. It took some extra time to cut them out and in the end the 8 doors I did them on looked very good. I did those tenons maybe 5-6 years ago and I have not done them since. IMO the domino will be just fine for your job...

 

[Jerry Work]

Hi David and all,

Don't worry about strength, the 10 x 50mm Dominos are plenty strong for your applications.  Put in two if your wood is more than 5x the thickness of the Domino tenon.  Space them so the outside edge of the work piece to the wall of the mortise slot is equal to the thickness of the tenon leaving the middle space to be whatever it is.  For example, if you are using stock that is 50mm thick you will have 10mm over to the outside wall of the mortise, the 10mm mortise, a 10mm space, the second 10mm mortise and then another 10mm space to the far edge of your stock.  With 60mm thick stock all that chances is the center space becomes 20mm instead of 10mm.  It is easy to align these mortises in both work pieces given all the alignment aids built into the Domino fence.  Use a solder brush to coat the inside walls of the mortises and the outside walls of the tenon and push the tenon fully into place.  Any glue that is scraped off the walls will be pushed up the flutes of the Domino tenon as you push it fully to the bottom of one mortise.  That opens up space at the bottom of the mating mortise to prevent hydro lock on assembly.  If you are still worried about hydro lock then just make a short saw kerf in the ends of the Domino tenon with a band saw to create still more excess glue storage in the bottom of the mortise slot.  I never find that necessary and have cut joints apart for photographing as part of the Domino manual (which will be transmitted to Festool for internal review shortly) and have yet to find one with anything but a perfect glue joint along the edges of the mortise and tenon.  That is where all the strength is in a M&T joint anyway.  If you calculate the amount of glue surface with two 10 x 50mm tenons I think you will reach the same conclusion I have - such joints are plenty strong enough for even very large and highly stressed projects like exterior doors.  If you are still concerned about rack strength on the stretchers on work bench legs over decades of side thrust then just add a barrel bolt through the center portion of the joint and rack away.

I hope you will enjoy the build along projects I am featuring in the Domino manual as I tried to cover a range of things you might want to build.  They include a butterfly leaf dining table (where for the first time I disclose the design I use for engineering the mechanism to eliminate all measuring to achieve the critical locations of the pivot points), a double pedistal desk, a conventional leg and skirt table, a serving chest with sliding doors and a unique "convertible" coffee table.  This broad range of projects showcase the many different uses for the Domino machine.  Such uses goe far beyond "simply" joining two pieces of wood in all six ways one can join two pieces of wood.  Cheers.

Jerry

Hello everyone,

I am looking at building the base of the following workbench with a large MFT style top.  Once completed the workbench will be about 50" x 100" so that I can handle full sheets of plywood and use my vacuum press.  I have already ordered the edge rails to make my own MFT table. 

http://www.shopnotes.com/files/issues/sample/sample-30-31.pdf

My main question is that the workbench plans called for haunched tenons for the rails and I would like to know if I can/should use the domino tenons instead.  The root question is related to how strong the Domino tenons are compared to a traditional haunched tenon.

Thanks.

David

 

[Wim]

Please forgive me my ignorance but could somebody explain to me what a haunched tenon is. On this forum I see a lot of woodworker-jargon that is not in my dictionary. I hope you do not mind explaining now and then some of your Chinese.

 

[dgage]

Here is a picture with a regular tenon on the left and a haunched tenon on the right.  As Jesse Cloud stated, it provides a little more strength in racking (twisting).

 

[dgage]

Thanks to everyone that replied.  The correct question was posed and answered, related to the Domino loose tenons being strong enough for the work bench.  While a haunched tenon may be a little stronger, I want my project done as efficiently as possible so as soon as I get my Domino, I have a project lined up.  This should give me just enough time to get all of my wood ready for the big day with Domino.

Jerry - I can't wait to see your manual.  It sounds outstanding and will definitely help this hobbyist grow in capability.

David

 

[Wim]

Thanks David, your answer could not be clearer. In Dutch it is called a "spatpen", that will be Chinese to most Dutch people. A mortise & tenon is called in Dutch a "pen & gat", where mortise = gat and tenon = pen.