How about some dovetail help?

[Claus]

Practicing on some scraps, looking to make a small step stool for the shop. Obviously this isn’t the perfect material to learn dovetails but it’s what I have.

So the internet is full of basic instructions but I can’t find any “troubleshooting“ advice, as in “if that‘s wrong, try this”. Obviously the gaps are too big, does anyone have some suggestions as to what to do differently or what aspects to focus on going forward? I realize repetition will make this better, just don’t care to repeat the same mistakes

Thanks for any and all advice.

 

[RichardH]

Those are pretty good, you should be proud. I find pine is a pain to get good shape edges with handtools.

It looks to me like you need to adjust your scribe lines down a bit so the pins and tails are flush or even a bit proud. Either that or look at the bottom of the pins to make sure there isn't a hump in the middle that is preventing the pieces to seat together fully (really easy to do). Your saw cuts look straight from the picture angle so it seems you have a good handle on that.

One thing I learned last year from a class with Michael Pekovich that I find really helpful is to put blue tape over the endgrain of the pieces before doing the transfer than when you using a marking knife you can peal back the parts of the tape you want to remove and you have a easy to see reference for what needs to be removed as well a small ledge the thickness of the blue tape to reference your saw against. You place your saw so the teeth are against the keeper part of the tape (don't want to cut into the tape) and you will get a tight fitting joint.

 

[Graywolf]

From what I can see those aren’t bad. The material you are using doesn’t matter. A few more pictures would help assess a couple things. It also would help if you describe your process, ie step one, did you cut to the line or did you pair material away to the line details like that. It’s not easy to teach this not face to face.

 

[Mike Davis]

One mistake I see a lot is not getting the bottom of the cuts pared on the line, either cutting too much or leaving material that interferes with the mating piece sliding to a fully seated position. It is easier to cut toward the center of the board and make a concave surface that will hold glue and allow the tails to slide over the pins without leaving a gap.

Always check this first before paring anywhere else to make it fit. If you trim the pins or tails to fit and then find the bottoms are not flush you risk ending up with a loose fit or gaps.

 

[mdbuntyn]

When I zoom in, it looks like there's still some material in a few corners keeping the joint from seating fully

 

[Rwe2156]

The pins and tails are too short. Did you set the marking gauge to the thickness? Better to have them protruding than too short b/c if you correct you're thinning the boards too much. Not necessarily good when making drawers.

Gaps are caused by inaccurate sawing. One big key to dovetails is sawing. You want to saw on the waste side. If you mark the pins and tails with a pencil always leave the line. Easier said than done when starting out! The painters tape trick also works well.

I would also suggest using a different wood to practice. Pine like that with hard and soft grain is a lot harder to mark, saw and chisel. But avoid a really soft woods as they require super super sharp chisels. Poplar is a good wood to practice with.

It might be helpful to know how you are marking out, what saw and chisels you are using.

Hope this helps

 

[Wiley's Woodworks]

Usually the cause of ill-fitting dovetail joints is inaccurate placement of your saw cuts and chisel points. Make these changes in your technique.

• Stop using pencils to mark your saw cuts.
• Use a wheel marking gauge to mark the bottoms of your cuts. Run it several times to make a deeper cut. This lets you sink your chisel into the cut and gives you precise placement of your chop down.
• Use a compass to mark the placement of your saw cuts on the end grain of the tails board. Sink the point of the compass a little deeper.
• Use a marking knife to lay out the saw cut lines. Sink the knife point into the compass hole, then slide a pocket square up against the knife. Mark the cuts a little deeper than you need just to see them, then deepen them with a chisel. Use several light taps instead of one heavy mallet blow to avoid splitting the board along the grain. With a sharp chisel come in from the waste side of the lines and cut a shallow bevel. This gives your saw blade a pocket to sit in.
• When you lay your pins board on the cut dovetails, follow the same procedure above. Don't lay your pins board on the tails board; clamp it so it can't move.
• When you cut your dovetail sides angle the board in your vise so you are cutting straight down rather than trying to cut on an unfamiliar angle.
• When you start your saw cuts, angle your saw on one face to start a notch and then rock it flat to complete the cut. Pick which face so you are cutting into the board; this minimizes tear out.
• When you chisel out the waste use a chisel slightly narrower than the bottom of the pins. Your corners will be cleaner when you make two passes rather than trying to clear everything out with one full width pass.
• Any joints that are too tight, pare them with a chisel rather than filing or sanding.
• This is personal preference; I make cleaner saw cuts with a Japanese style thin blade pull saw rather than a conventional push style backsaw. The thinner blade will fit better into the saw guide lines and may let you skip the bevel-with-a-chisel step.

Whatever extra time it takes to follow these steps will be less than the time you will have to spend to make sloppy look good and fit right.

 

[Claus]

Thank you all for the encouragement and lots of good advice. These are exactly the kinds of comments that I was looking for. I’ll report back when I get some shop time and implement these fixes on the other side of my step stool.

 

[Roy G]

Claus, you may consider cutting a shallow rabbet on the tail piece. Only a 1/16" is all that is needed. This will allow you to register the pieces when you are marking the pins. If you cut the pins first, the rabbet will let you get the pieces in the right orientation. I saw this on one of the Woodwright shows.

Roy G

 

[Rwe2156]

Just something else, using a knife was mentioned and while that's going to give you a more accurate line to saw to, in practice, it is very difficult without a saw guide. If you're going to use a knife I recommend the tape method.

If you don't see yourself doing them a lot, a saw guide is a consideration. . I've done them freehand for a long time but I used a magnetic guide on my last project in conjuction with a Ryoba and I'll tell ya', I'm kinda hooked on it now. At first it felt like cheating but I got past that pretty fast.

And yet another thing, there is "pins first" "tails first”. An advantage of tails first is you can gang the sides together and cut multiples at once. Also more accurate b/c you are cutting square across a longer distance.

The rabbet mentioned is a good idea, too.

 

[Daniel Bradford]

Usually the cause of ill-fitting dovetail joints is inaccurate placement of your saw cuts and chisel points. Make these changes in your technique.

• Stop using pencils to mark your saw cuts.
• Use a wheel marking gauge to mark the bottoms of your cuts. Run it several times to make a deeper cut. This lets you sink your chisel into the cut and gives you precise placement of your chop down.
• Use a compass to mark the placement of your saw cuts on the end grain of the tails board. Sink the point of the compass a little deeper.
• Use a marking knife to lay out the saw cut lines. Sink the knife point into the compass hole, then slide a pocket square up against the knife. Mark the cuts a little deeper than you need just to see them, then deepen them with a chisel. Use several light taps instead of one heavy mallet blow to avoid splitting the board along the grain. With a sharp chisel come in from the waste side of the lines and cut a shallow bevel. This gives your saw blade a pocket to sit in.
• When you lay your pins board on the cut dovetails, follow the same procedure above. Don't lay your pins board on the tails board; clamp it so it can't move.
• When you cut your dovetail sides angle the board in your vise so you are cutting straight down rather than trying to cut on an unfamiliar angle.
• When you start your saw cuts, angle your saw on one face to start a notch and then rock it flat to complete the cut. Pick which face so you are cutting into the board; this minimizes tear out.
• When you chisel out the waste use a chisel slightly narrower than the bottom of the pins. Your corners will be cleaner when you make two passes rather than trying to clear everything out with one full width pass.
• Any joints that are too tight, pare them with a chisel rather than filing or sanding.
• This is personal preference; I make cleaner saw cuts with a Japanese style thin blade pull saw rather than a conventional push style backsaw. The thinner blade will fit better into the saw guide lines and may let you skip the bevel-with-a-chisel step.

Whatever extra time it takes to follow these steps will be less than the time you will have to spend to make sloppy look good and fit right.

great tips!! attempting my first pass at dovetails.
Daniel

 

[Claus]

Got back at it and cut some more dovetails. Actually the tails were pretty good, had most of my issues with the pins. I found my biggest issues were with the scribe lines and the bottom of the cuts, as several suggested.

A few pictures of my tools/setup. Needed a real saw, the dovetail saw was no match for the lumber. And yes tails first, ganged up and cut together. Using a chisel to start the cuts really helped the sawing. I think to get the cuts right the start needs to be almost perfect, once you cut a few strokes you’re committed and can’t do much to change the trajectory. And lastly a shot of the end result.

Thanks again everyone for all the input. I think more practice and repetition will pay off for me.

 

[Westpacx3]

Not bad, I need to get back to my own practice with this. I bought a marking gauge and fret saw and already had the proper Japanese pull saw gifted by a member here. Seems I always chiseled to much of the line on the pins which opened the gap.

I don't recall if it was said here but some have suggested that pine is a poor wood for practicing dovetails due to the grain. My worst practice was on pine although it cut easy.

 

[Rwe2156]

Wow I'm impressed at the cut quality with a carpenters saw!!

Anytime there are gaps it's b/c you're not leaving enough of the line.