# Dovetail Router Bit Question



## nightowl (Oct 21, 2013)

I want to build a raised garden bed for my wife this weekend and was wondering which dovetail bit I would use and or if there is a better way than a dovetail to recreate the look below. The grove on the 4 x 4 looks like a dovetail to me and I have ordered a Freud 3/4" (Dia.) Dovetail Bit with 1/2" Shank (22-114). It should be here Saturday. I plan on getting some 3/4" cedar or pine depending on whats at the big box store and if the later treat it with linseed oil or something similar. My question is I see that the dovetail makes the slot but is there a matching bit for the 7 degree angle on what will be the rails? I saw a "Butterfly Spline" bit in my catalog but it specifically states it is for 14 degree dovetail bits. I am till trying to learn how these things work around here so sorry if it is a silly question.

Thanks in advance


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## Stick486 (Jan 4, 2013)

the same bit that cuts the slot cuts the tail...
what you show is not a sliding DT..
it's a grove/slot in the corner pieces w/ the side panel boards inserted into them... 
FWIW.. the neck on the dovetail is a weak link.. one would work w/ 2x material but 1x might not be such a good plan...

..


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## Herb Stoops (Aug 28, 2012)

Stick is right, it looks to me from the picture that it is4X4 posts and 2X4's stacked for the sides.
I would guess that a 3/4" dove tail that long on the posts (4 sides) is going to take a pretty strong router. you may want to run the dove tail full length of the post and chop them to length, for the posts.
The sides may have to be clamped upright on edge on a saw horse and routed with the router held horizontal, with an edge guide on the router.
That design opens up all kinds of options for flower beds.
Be sure to take some pictures of the build and the end result. It is an interesting idea.
Herb


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## nightowl (Oct 21, 2013)

Stick486 said:


> the same bit that cuts the slot cuts the tail...
> what you show is not a sliding DT..
> it's a grove/slot in the corner pieces w/ the side panel boards inserted into them...
> FWIW.. the neck on the dovetail is a weak link.. one would work w/ 2x material but 1x might not be such a good plan...
> ...


Stick486 - Thanks for the information on the wood. Very concise! This is the kit 



 I had in the picture being built in my original post. What router bit would I need to make the groves shown in the video?


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## nightowl (Oct 21, 2013)

Herb Stoops said:


> Stick is right, it looks to me from the picture that it is4X4 posts and 2X4's stacked for the sides.
> I would guess that a 3/4" dove tail that long on the posts (4 sides) is going to take a pretty strong router. you may want to run the dove tail full length of the post and chop them to length, for the posts.
> The sides may have to be clamped upright on edge on a saw horse and routed with the router held horizontal, with an edge guide on the router.
> That design opens up all kinds of options for flower beds.
> ...


Herb Stoops - Saw this one after I posted a response to sticks. The corners are 4 x 4 posts but the planks are only 3/4" thick cedar. It's one of those raised flower beds things that will win me great hubby points to keep her out my hair for a while...lol. I think its a project I can finish this weekend once I make a big box store run or two. I had planned to cut the posts to size first so my router would not have to work over time making the groves. It may be something I cant do and may just have to use a 3/4" grove. You guys are the experts so let me know your thoughts. I figured the offset would make it look nice.


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## Stick486 (Jan 4, 2013)

Herb Stoops said:


> Stick is right, it looks to me from the picture that it is4X4 posts and 2X4's stacked for the sides.
> I would guess that a 3/4" dove tail that long on the posts (4 sides) is going to take a pretty strong router. you may want to run the dove tail full length of the post and chop them to length, for the posts.
> The sides may have to be clamped upright on edge on a saw horse and routed with the router held horizontal, with an edge guide on the router.
> That design opens up all kinds of options for flower beds.
> ...


you see it the same way...
but the OP is planning to use ¾'' material... that is one weak joint where the DT necks down...
a normal router will be fine if he uses a dado blade or straight bit to hog out the waste material 1st...

*NOTE:*
a joint like that tends to collect fine dirt, water, ice, etc which all contribute to a self destructing joint that will develop rot easily...
two fixes...
a very sloppy joint so it drains and dries..
close the grove on the top..
also..
cedar hasn't much strength to it..
reducing panel thickness is a step in the wrong direction...


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## Stick486 (Jan 4, 2013)

Henry ..
that is a sliding DT... scale the panel boards to the corner posts providing the posts are 3½²..
the side boards are not 3/4'' but either 4/4 or 5/4... the hardware cloth lends to 4/4...
the bit you picked out is fine..
what ever you do, straight or DT, add table leg or corner braces to the inside corners... use the Simpson style hardware.. ready made or modified..
when the guy set the hardware cloth did you see the side board bulge...
image that w/ the box full of dirt and given time...
I'd plan on keeping the corner joints from failing/pulling apart..

plan ''B''..
build the box w/butt joints w/ brackets..
seal the end grain w/ wax. caulk or glue...
cut/rabbet out the 4x4's to form a ''corner molding''...
faster..
less work...
and you can use 5/4 deck boards as long as they are rated for ground contact..
same looking results..
words to the wise if you consider PT ... the big box stores don't usually/rarely carry ground contact rated PT... read the lable..

.


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## Guitfiddle (Dec 14, 2014)

I built my raised beds about 4 years ago-I used red cedar for rot resistance (not proof) because I am growing vegetables and didn’t want any leaching of pressure treated chemicals into the soil and therefore into my food. If nothing but flowers it may be ok. 

I used 4x4 posts and 2x6 boards just lapped at the outside of the posts and attached with HD coated exterior joist screws. I did 3 boards high and looks like a box joint at the corners. The 4x4’s go into the ground about 10” for some extra stability and are capped on top with solar light post caps. I added a top 2x4 rail for a little more edge sitting comfort. 

I would show pics but they are covered in snow right now! I know I went a bit beyond basic but they (2) have held up very well so far with no bulging etc. and expect about a 10 year life. I would recommend checking out “square foot gardening” for ideas.


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## hawkeye10 (Jul 28, 2015)

I agree with Wes, you shouldn't use PT lumber for raised beds. If it were me I would use 2X lumber and join the corners with those metal braces used for decks. We are building raised beds, not furniture.


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## DesertRatTom (Jul 3, 2012)

I'd go tongue and groove, use 4x4 posts (grooved) and 2x6 redwood (tounge). Thin materials are going to bulge from weight and the pressure of expanding soil when you water. The screen on the bottom will prevent underground attacks on those lucious roots and crops. Keep the bottom open for drainage, maybe even add a layer of river rock an inch or two deep on the bottom to help drainage. Four feet square is about as large as I'd make it, but I might make it 24 inches high as a back saver. That's a lot of soil, which I'd mix up to match what I was growing. 

For flowers, I'd raise the bottom up since you don't need deep roots. Use a layer of window screen and the rocks over the critter shield. And I'd put a 2x8 across the edges on two sides so you can sit there. Definitely would assemble all using coated deck screws, including through the posts and tongues. I would probably use some sort of rubberized coating on the inside corners to help keep grit out of the joints.

I live in the desert, and summer would require a sun shield for many veggies (tomatos for example) so I'd add a way to put a pvc frame on during summer. I used to have a couple of these, but they inevitably deteriorate and mine are now long gone. Wife doesn't want to garden anymore.


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