# Pre- Dovetail / Butterfly / Dutchman joints question



## barnabaas

*Pre- Bow Tie / Butterfly / Dutchman joints question*

Hey guys. Fairly new to all this but have been reading through the forums and lurking for a while. I'm learning things as I go and have no real wood working experience behind me so bare that in mind with my novice type questions.

So I have a piece of wood that's 3" thick and has a decent crack towards one of the edges that's roughly 13" long. Since we'll be turning this redwood slab of wood into a dinning room table I was thinking of adding some dutchman / bow tie / butterfly joints to this crack to help deter it from cracking any further and to add to the aesthetics of it. I've never done one though so i'm trying to get as much info on how to do this right the first time. (I'm hoping to do some smaller ones for practice before if i can)

Since the slab is 3" thick and the crack seems to run through the entire piece, how deep of a butterfly joint should i use? 1" or maybe 1 1/2" ?? Also how many do you think i'll need. Would one be suffice or would you recommend 2 in this case? Top AND bottom? or just would just Top be ok?

Lastly I've been watching videos on youtube and reading up on how to do the process but one thing I haven't really seen is how people are getting the bottom of their keys / holes so smooth after they've chisel'd the edges. They always fast fwd to the completed product. I assume they're using a router, but if not how are they doing it?? Also how they maintain a certain depth throughout the process if they aren't using a router? I don't have a router so I'd have to do them all by hand which is why i'm asking. (or i might just go buy a router if that's the best option)

Anyways, I'll start there and post up the pics of the crack if it helps.
Thanks for any advice / help in advance.




















Almost forgot, maybe someone can clarify that this is correct. As far as when making the butterfly keys the grain should run parallel with the keys shape to add strength? If it wasn't this way it'd make for a weak joint? Is this drawing correct as far as what I should shoot for, grain wise, when setting these up?


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## brown down

my rule of thumb when adding a dutchman is to cut them in at least half of the thickness of the piece. in your case i would cut them out to 1 1/2 inch. i learned to cut them by hand that way you can add different sizes without making a template up every time. your drawing show the correct way to cut them. your grain pattern should not run with that of the piece you are fixing. practice a lot and make sure your chisels are sharp!!!!! i put 5 on the top and also put 4 on the underside to make it real strong. my piece was also around 3 inch thick. they do take some time but will be well worth the effort when the piece is finished. these are the first ones i did, they took around 1 hour to do a piece, i am faster now, but they still take time! i spent a few nights just practicing cutting them. 

hope i helped


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## barnabaas

I saw and read through your thread actually so I'm glad you commented here!! That's good info to know! Your top turned out beautifully! Perhaps I should then do 2 up top and 1 on the bottom in my case. I'm not too worried about time as I'd rather do it right and make it nice than rush it. (easier said than done though i know)

Thanks for the tip on half the height of the table, that's good to know for sure, and when you said cut them by hand you meant the keys your starting with? Then from there trace the piece( s) onto your top? I'll def. try and do some practice templates by hand before jumping straight into my final piece.

Thanks again for commenting!


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## Dominick

brown down said:


> my rule of thumb when adding a dutchman is to cut them in at least half of the thickness of the piece. in your case i would cut them out to 1 1/2 inch. i learned to cut them by hand that way you can add different sizes without making a template up every time. your drawing show the correct way to cut them. your grain pattern should not run with that of the piece you are fixing. practice a lot and make sure your chisels are sharp!!!!! i put 5 on the top and also put 4 on the underside to make it real strong. my piece was also around 3 inch thick. they do take some time but will be well worth the effort when the piece is finished. these are the first ones i did, they took around 1 hour to do a piece, i am faster now, but they still take time! i spent a few nights just practicing cutting them.
> 
> hope i helped


Nice bow ties brown. They look like there cut from a template. I see no reason to put on the bottom. I also cut mine by hand. I usually do mine half the thickness to. Nice slab by the way. Here's some I did in a crotch slab back rest.
Why double pic I don't know what just happened. Lol


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## barnabaas

nice! did you guys both use routers to remove the excess middle part of the wood or did you chisel them all out by hand?


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## Dominick

barnabaas said:


> nice! did you guys both use routers to remove the excess middle part of the wood or did you chisel them all out by hand?


Yes I used a router for the bulk of it. First I cut the bow tie to the size and thickness I wanted, then traced with a sharp pencil. Then take chisel around pencil lines. Just to score it. Then router what you can get. Finish with a sharp chisel.


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## barnabaas

thanks :thumbsup:

my next question i guess for you guys is, considering my slab is redwood. 

Here's the bigger pic / coloring. What type of wood would you recommend i use for the bow ties?? This is the bottom side - you can see the crack at the base.


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## Dominick

First off.....wow thats a big slab. Probably pretty heavy. 2nd what other wood do you have? I usually use what I have. You want something different than what the bow tie is going in to. 
Adds contrast.


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## barnabaas

yea the slab is roughly 5' x 3' x 3" it's fairly heavy. The only other wood i have lying around is some old douglas fir. So I might go try and find some scrap wood someplace or just buy a few small pieces to use for this project. So I'm pretty open to whatever. I agree I'd like a darker wood I think for some contrast.


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## Dominick

barnabaas said:


> yea the slab is roughly 5' x 3' x 3" it's fairly heavy. The only other wood i have lying around is some old douglas fir. So I might go try and find some scrap wood someplace or just buy a few small pieces to use for this project. So I'm pretty open to whatever. I agree I'd like a darker wood I think for some contrast.


Yea doug fir wouldn't be my first choice. I would wait for something else. There's endless amount of species to choose from. Im wondering if when you finish that slab if it would darken up with reddish color like ERC (eastern red cedar). Would it be wise to use a lighter color wood for bow tie?


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## tc65

I noticed a big difference in the "waist" size between Dominick's and Brown Down's bow ties. Is there some sort of rule of thumb on what is the minimum size to use across the narrow, or is it just aesthetics and common sense? I.E. if I had a three inch slab, would 1/2 inch waist be too narrow? BTW, I wish I had a slab, but I don't - just curious and for future reference.


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## brown down

barnabaas said:


> nice! did you guys both use routers to remove the excess middle part of the wood or did you chisel them all out by hand?


I cut all of my dutchmans by hand on my bandsaw, i clean them up so i have a very clean edge, and sharp points. i than trace them on the work piece with a mechanical pencil so my line is the same throughout all of them, or use a knife. now unless you use a template to cut all of yours out, each key will only fit that one spot. as for cleaning out the key hole, i get it as good as i can with my chisels. i own several routers, just choose to do it this way. they do sell templates for the router. i personally haven't used any
nice work as well dominick


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## brown down

trc65 said:


> I noticed a big difference in the "waist" size between Dominick's and Brown Down's bow ties. Is there some sort of rule of thumb on what is the minimum size to use across the narrow, or is it just aesthetics and common sense? I.E. if I had a three inch slab, would 1/2 inch waist be too narrow? BTW, I wish I had a slab, but I don't - just curious and for future reference.


i think it really depends on the size of the crack you are fixing. i went with larger keys because of the size of my crack. i too don't see the need for putting them on the underside, but this was a hefty crack and ran further on the underside. the stress will be on the middle part of the key so you have to size it correctly for the crack and also make it look ascetically pleasing to the eye. hope that answered your question


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## barnabaas

brown down said:


> I cut all of my dutchmans by hand on my bandsaw, i clean them up so i have a very clean edge, and sharp points. i than trace them on the work piece with a mechanical pencil so my line is the same throughout all of them, or use a knife. now unless you use a template to cut all of yours out, each key will only fit that one spot. as for cleaning out the key hole, i get it as good as i can with my chisels. i own several routers, just choose to do it this way. they do sell templates for the router. i personally haven't used any
> nice work as well dominick


so you did use the router though to remove the excess wood? or did you just chisel them out by hand getting them as close as possible and not worrying too much about the smooth bottom?


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## brown down

barnabaas said:


> so you did use the router though to remove the excess wood? or did you just chisel them out by hand getting them as close as possible and not worrying too much about the smooth bottom?


i do all of that type of work by hand with chisels. the bottom of the key really isn't crucial considering you will never see it!! the sides and the ends are the critical cuts. thats what holds the crack from moving. cutting them square to the piece is the most crucial part. if you are doing it by hand, make sure when you are driving your chisels down straight , that they are plumb with the piece you are cutting! i practiced for several nights, before i attempted to do these. like i said you want a sharp line for your chisels to follow. work from the center of the key out to your line. do not try to take more than what the line is drove to from your chisel or you will take more than you want!!


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## barnabaas

great thanks! now to find some super sharp chisels. =)


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## mtroilak

Im new to slab wood working but have my first bookmatched pair of 2" slabs with live edges and very excited. I plan on using bowties and glue to join them but my question is about step order. Should I glue the slabs together, let it dry and then cut in the bowties? Also when gluing the wood how do I not damage the live edge with the bar clamps? Is there another option besides glue, maybe just clamping and bowties with supports underneath? 

One last thing is that right now the slabs are rough on the surfaces so Im going to sand them with a belt sander (good idea?) but the question is should I sand them before or after the bowties or both?


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## mdntrdr

If you are gluing the two slabs together you can machine/plane a good glue joint and there is no need for Dutchmans. I guess you could add them after if you wanted to. :smile:


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