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KatieK

mortise and tenon sizing

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Hi. I will be attempting to build a queen size bed frame out of solid maple. I am designing the bed frame based off of one that I saw and have dreamed of ever since! The footboard legs of the bed are only 1" deep and will be attached to a footboard that is 4.5" wide. I would like to stick with mortise and tenon for the footboard to legs joinery but am concerned it would be too short of a tenon. My thought is that I would construct it with two stub tenons that are each a 1/2" long. 

Leg dimensions are 5 inches wide by 1 inch thick. Foot board rails 4 1/2 inches wide. Should I have two m&t joints? One? Also, is it necessary for it to be reinforced with a bolt or some sort of hardware. The small width of the leg is limiting those options as far as I can tell. 

Any input would be greatly appreciated. 

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Hello, Katie, and welcome to the forum! We are happy to help, but most of us are more visually oriented when it comes to assessing such questions. A photo or two will go a long way toward a more effective answer.

Now, from your description, a question comes to mind: What is the orientation of the leg in relation to the foot board?

Is the 5" face of the leg joining the 4.5" face of the footboard? or are the 1" edges joining? Or is one thin edge joining to a wide edge? Different solutions apply for each scenario.

 

 

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Great! The illustration is very helpful.

Will the foot board integrate a ledger to take some of the box spring / platform weight? Also, will this joint require disassembly for moving?

This construction is not typical of most bed frames, in my experience. The leg is more often a permanent part of the foot board, with the side rail being the removable component. This can work, though.

For a permanent join, standard mortise & tenon should work. Glued in, side-pegged, or wedged, it should be strong. Although for a bed, adding an angled gusset across the bottom of the joint provides a real belt and suspenders solution.

For a removable joint, there are multiple options. Commercial bed frame hardware of several types is avalable. Ask Google to show bed frame hardware. Or a bolt through the leg, with a barrel nut embedded in to foot board, works as well. You might do a through-tenon, wedged on the outside of the leg, if that appearance suits you. You MIGHT get away with cutting a dovetail along the end of the footboard and sliding it into a mating socket in the leg, but I think that would be pushing the envelope for joint strength in a bed frame. Beds are subject to more odd forces than a table, or enen a chair.

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The legs will be permanently attached to the footboard. The rail fasteners will be mortised into the legs and side rails. I would like to avoid a through tenon as I like the aesthetic of a clean look to the outside of the leg. Is it your opinion that standard mortise and tenon and glue could do the trick?
I would prefer that but was wondering if adding a draw bolt or something as an extra precaution would be necessary. If it’s not needed I would love to avoid it! I’ve seen some demonstrations of draw bolts installed in a way that draws them through the mortise and tenon. Would this be an option for such a thin tenon? 
Another scenario I wondered about would be a single tenon on the lower half of the footboard combined with a draw bolt on the upper half of the footboard. Is that crazy talk? 
Lots of ideas but would love to hear that m&t with glue would be enough. 
thank you again!

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40 minutes ago, wtnhighlander said:

 Beds are subject to more odd forces than a table, or enen a chair.

KatieK, this is only meant as humor, so please take it with a grain of salt.........Ross... I'm gonns fill in for Steve on this one.........."What odd forces are you referring to'?

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A 1/2" tenon with glue will not be strong enough.  I have repaired old beds, and the last had a giant Walnut headboard, built soon after the mid 19th Century.  It had cast iron hidden hardware very similar to what can be seen holding the sideboards onto modern beds, although it's not typically cast iron these days.  That makes it possible to move a bed.  You just bump up the sideboards, which releases them from the head, or foot, and the frame becomes four pieces. 

The metal fasteners are both very strong, being in their own mortises, and secured with large screws.  This particular bed had woodscrews that did not have points on the ends.  I think pointed screws were invented in 1844, but were seen still in use for another 20 years.  My repair was to replace one of the sideboards because the original had grain that came across the board, from one side to the other, and the board broke there.  There was no evidence of any issues with the hardware.  I only found out about the screws because I had to take the pieces out to reuse in the new board.

You can find that hardware in a number of places.  The bed would appear no different to someone looking at it once it's assembled, than if it was mortised, and tenoned.  Even the old rope beds for feather mattresses had some method holding it together that could be disassembled.

edited to add:  I was going to grab a link to an example, but think instead it would be better for you to do this Google search.  There are many variations in quality, and cost.    copy and paste this into the Google search box:

knock down hardware bed rail fasteners

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I defer to Tom's experience regarding the strength of the glued mortice. However, the addition of pegs through the tenon & mortise walls should prevent the joint from separating. The tenon should be as large as you can manage from the 1" board thickness. If the pegs would ruin the aesthetics of the leg, you might hide them in the mortise for the knockdown hardware on the rail side of the leg.

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Tom, I will be using hardware for the side rails so that they will come apart easily. I'm referring to the permanent joinery of the footboard to the legs. Are you saying that the tenon would be too small for any of the joints? 

wtnhighlander, love the idea of hiding a peg in the hardware mortise but it will be too far from the tenon joint. 

 

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9 hours ago, KatieK said:

Tom, I will be using hardware for the side rails so that they will come apart easily. I'm referring to the permanent joinery of the footboard to the legs. Are you saying that the tenon would be too small for any of the joints? 

wtnhighlander, love the idea of hiding a peg in the hardware mortise but it will be too far from the tenon joint. 

 

Sorry, it was late, and I had just given a talk at a heated county Board of Supervisor's meeting against a new Dollar General location, so I probably wasn't clear headed when I read your post.

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They do.  We lost, even though there is already one every five miles around here.  They're putting this one in the backyard of a fine 19th Century house, with no other such new,  ugly commercial building anywhere near there.   They want one at every road intersection.  

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You ever notice that every dollar store, no matter the chain, has the same weird smell? Sorta like a combination of toxic plastic off gassing & sadness.

My wife love the dollar stores, but I can't stand them. Whenever I go in one I instantly feel my will to live being sucked away.

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3 hours ago, Tom King said:

They want one at every road intersection. 

They're going to be like the gas stations in the late 70's early 80's one on every corner then they became one on every corner but closed for business.

And we have hijack Katie's conversation.  By the way Katie, welcome to the forums.  Post some pictures as you build your bed.

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You can make the tenon thicker, even up to 3/4”—leaving you with 1/8” shoulders. That would give you more strength without moving to a thicker rail. If you are working from 6/4 stock, going to an 11/4” thick rail won’t change the look much, but also give you more strength.

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Barron, I have been thinking that I will go to a thicker stock for the rail. The frame design is so that the legs are the same thickness as the rails. I posted a picture above. Everything I have read says that the tenon length should be a minimum of 5 times the tenon width. So I suppose a tenon into a 1" or 1 1/4" stock isn't an option. Originally I thought I would join the footboard to the legs permanently. It's hard determining the best path! My newest idea is abandoning the idea of permanently fixing the footboard to feet joint and installing the same mortised bracket hardware that I will be installing on the side rails. We shall see. 

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So you’re thinking of having the feet as four separate pieces, joined to the footboard, headboard and rails with mechanical hardware? 

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No that sounds terrible after reading it aloud to myself haha. The legs will at least be attached to the headboard. There has to be a solid way to permanently join the footboard to the 1" thick leg. There just has to be! 

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Is there some reason you can't use thicker stock? 1" is pretty thin for the aforementioned "odd forces". Most all-wood beds I've seen use 6/4 to 8/4 material for the frame.

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Katie, the proportions of the leg just seems odd and will lack stability.  Putting screws through the leg may work, but I still think stability will be an issue.  If you have kids jumping on the bed or toss and turn in your sleep, that is a good amount of racking forces and no matter how it's connected will most likely fail.  I would recommend redesigning the legs. 

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I think a thicker leg is the way to go. If you align the outside of the rail so that it meets the foot “edge to edge”, no one will know that the leg extends beyond the rail on the on the inside.  Once you put the mattress inside, add blankets and bedspreads the inside of the leg will be almost invisible.

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