This morning I’m finishing up all the small drawers for the gallery in this campaign secretary. The dovetails are little buggers, and the mahogany drawer front material is really dark stuff.
So I stole some of my daughter’s sidewalk chalk.
Chalking your knife lines and gauge lines makes your lines really easy to see, even in walnut. I usually rub some chalk onto the board coarsely, knife in my lines and then rub the chalk into the lines. This removes it from the face of the board and leaves it in the crevices.
However, today I learned something new, thanks to the kinda-creepy mind-reading power of carpenter Jeff Burks. He sent me a nice little article from an 1869 edition of The Manufacturer and Builder on dovetails.
There are some interesting tidbits in there, and in the discussion of chalk it implied you could pencil over the chalk. As I am somewhat dense at times, this had never occurred to me. So this morning I chalked my pin boards, knifed in the pins and then penciled in the vertical lines on the inside face.
It worked great.
Thanks dead guys. You’re the best.
You can download and read the entire article here.
http://www.carpentryarchive.org/files/dove-tail_joints_1869.pdf
— Christopher Schwarz
after knifing the lines, I just use a crayola white pencil.
Hi Chris
Seeing lines on dark wood is Hell at the best of times, and worse when your eyes age.
An alternative to chalk is this method using blue tape …
image: http://www.inthewoodshop.com/Furniture/HalfblindDovetailsinJarrah_html_1b83051.jpg
pictorial: http://www.inthewoodshop.com/Furniture/HalfblindDovetailsinJarrah.html
When transferring tails to pins it is necessary to score a line with a marking knife between the tails. It can be difficult to achieve accuracy when the tails are really skinny. Where the tape method scores for me over chalk is that one only requires a single knife cut. This will penetrate the tape which, when peeled away, leaves the perfect contrast for sawing.
Regards from Perth
Derek
Derek –
That’s a good idea! The thing I like about it is you can really visualize the part of the dovetail you are trying to remove and what you are trying to keep. Very helpful for the split-the-line/leave-the-line conundrum. Thanks.
Jonathan
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Is that adhesive-up or adhesive-down?
🙂
okay guys now for my goofy question for the day. What do you use to remove the chalk?
Unicorn tears
Snort.
Kenny,
The dust comes off when you glue the joint and wipe the excess glue away with a damp rag.
Change topic. I forgot to mention in the above post: The real problem with the chalk technique is that it prematurely dulls your chisels and saws. It stops the glue from adhering and it also interferes with finishing. It also makes your hair fall out and contributes to “shrinkage.”
“Thanks dead guys. You’re the best.” (smiley wink, fist pump!)
And this is why I read your work, educational AND entertaining.
Jonathan
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Seems like the ideal use for your pounce bag technique, though. Is this really so much better?
James,
The pounce bag works in the same manner. The downside to the pounce bag after much use is that you end up covered in the dust. Like you have a powdered wig, eyebrows, beard etc.
And the detail here was I didn’t know you could pencil over chalk. I know, I know. I’m such a moron it’s amazing anyone comes here.
Yeah, I wouldn’t have thought of it either. It’s a glorious ‘duh’ moment.
Chalk works great for this. I also use chalk to mark the stamped numbers on my molding planes. Makes them very easy to read and is easily reversible.
I love that the “technical term” is “out of square” which implies that “rhomboidal” is something that the uneducated would say…
This reminds me of an old article from dead guys that I read recently (perhaps you posted it? I don’t remember know, it’s been at least 5 minutes and you know the first sign of aging, right? I can’t remember what it is.) Anyhow, as I was saying, the article talked about chalking the straightedge when squaring a board. Never heard of that. Would you use the pounce bag or rub it with a stick of chalk?
In addition to the other bad side effects of chalking does it make you go blind too like other activities? I’ll take my chances! 🙂
Keep up the good work Chris! You’re the best!
You can the complete “The Builder and Manufacture” here; http://ebooks.library.cornell.edu/m/manu/index.html
Go to the craft store and get a pen with white ink, when you mark with a knife go ove the mark with the white ink, it leaves the ink on both shoulders with the cut difined between the shoulders.
Chris – Here’s another method for those that like to use mechanical pencils in the shop (I do – they’re always “sharp”). You can buy white and other colored refill lead for mechanical pencils, and it works just as well as normal graphite lead.
I tried using colored lead in my mechanical pencil, but the lead was so soft it broke instantly, and wore too fast. Do you know a lead that does not have this problem?
Staples carries a Pentel Liquid Gel in white, that is what I use on dark wood. With a defined knife cut the roller ball will leave ink on both shoulders of the cut and the trough will be untouched so you get a dark line , the wood, between the two white lines. With a roller wheel marker, it presses the wood and it is not as sharp, at least my Stanley 87, it leaves a wider depression so that the pen roller ball fits into so you have a solid white line.
I could not find a fine point only the med point Pentel Liquid Gel pen.