Page 1 of 2 12 LastLast
Results 1 to 25 of 34

Thread: Practice cutting dovetails by hand

  1. #1
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Practice cutting dovetails by hand

    I want to learn to do dovetails. I don't want to build a bunch of complicated fixtures, I don't want to do it on my bandsaw, I don't want to buy jigs. I want to learn to do it freehand, so I understand exactly what I'm doing. Can someone give me a hint of how I'd go about it? I thought about using a 2x4 block as a faux neckblock and a 1x2 as a faux neck, but I am not sure if the dimensions would be right. Thoughts?
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  2. #2

    Default Re: Practice cutting dovetails by hand

    I realize you want to learn by hand, so maybe this isn't the best suggestion... But when I was testing out my bandsaw jig for dovetail cutting I used pieces of 2x4 for my neck and also sandwiched pieces of leftover 3/4" plywood for the neck block. It got me close enough to an end product that I'm comfortable using the jig on my next mandolins.

  3. #3

    Default Re: Practice cutting dovetails by hand

    That seems like a do-able exercise. If you have plans you can go ahead and shape the head block and the neck heel to approximately the correct shape and size, too.
    After you are in command of the dove tail joint you will need to add in the neck angle, ending up with the proper elevation over the top plate, keeping the neck centerline to the tailblock, and keeping the "fretboard" level and keeping the neck sides flush with the rim.
    Piece of cake.
    I'm in your corner!

  4. The following members say thank you to Eric Oliver for this post:

    hank 

  5. #4
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    "Piece of cake"! That's like when people in the country are giving you directions--turn right at the barn, then go past three cattle gates and bear left around that old broken down tractor--and they end with: "You can't miss it." Yes I can. Watch me.

    I've spent most of my shop time in the last 7 years (I can't believe it--I could have been paroled from a murder charge in less time than that) working on fixing a neck joint that I screwed up in a 2013 build. So it's clear that this is a critical bit of knowledge that I'm sadly deficient in. I probably need to cut dozens of these joints by hand before all of the geometry becomes crystal clear.

    So … I'll have a lot more questions, no doubt.
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  6. #5
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    15,863

    Default Re: Practice cutting dovetails by hand

    Choose wood that is easy to cut. Some 2X4s are easier than others; some are spruce, some yellow pine, some various other. (SPF stands for spruce/fir/pine, but I suspect that doesn't limit what you might get to those species.)
    Get a decent dovetail saw. (I prefer one that cuts on the push stroke, though many people prefer one that cuts on the pull stroke. Either way, I like a stiff back saw for cutting dovetails.
    I'd say start out just fitting the dovetail mortise and tenon with straight cheeks. When you get comfortable with that, then try curved cheeks like we have to deal with on mandolins.
    Roll, pitch and yaw, plus center line. When we fit a dovetail, those are the things we must consider when we make each cut. In other words, before you make a cut to improve the fit, consider how the cut will affect each of those; roll, pitch, yaw, center line.

    By the way, David Houchens (Bryce on here) said his Dad got directions, and one bit of instruction was to turn at the white horse in the pasture.

  7. The Following 5 Users Say Thank You to sunburst For This Useful Post:


  8. #6
    Registered User Marc Berman's Avatar
    Join Date
    Dec 2007
    Location
    New Lanark, Scotland
    Posts
    471

    Default Re: Practice cutting dovetails by hand

    I was on the Isle of Barra, one of the Outer Hebrides, Scotland. I was told to take the first turn after I pass the trees. I asked which trees? It turns out they are the only trees on the island.

  9. The Following 2 Users Say Thank You to Marc Berman For This Useful Post:


  10. #7
    Registered User Timbofood's Avatar
    Join Date
    Mar 2007
    Location
    Kalamazoo, MI.
    Posts
    7,487

    Default Re: Practice cutting dovetails by hand

    Once again, John has said it thoughtfully:
    “Roll, Pitch and Yaw”
    Well said!
    My cousin owned that horse, trained him to stand at a different corner of the lot when he heard someone coming!
    Timothy F. Lewis
    "If brains was lard, that boy couldn't grease a very big skillet" J.D. Clampett

  11. #8

    Default Re: Practice cutting dovetails by hand

    How 'bout bolt on that 2013 neck and move on from that Odyssey of an adventure, and then build a few more with bolt-on necks while you become a dovetail master?

  12. The Following 3 Users Say Thank You to Marty Jacobson For This Useful Post:


  13. #9
    Registered User Charles E.'s Avatar
    Join Date
    Feb 2007
    Location
    Saint Augustine Beach FL
    Posts
    6,634

    Default Re: Practice cutting dovetails by hand

    Here is a video from a member on a recent mandocello build...


    Charley

    A bunch of stuff with four strings

  14. The following members say thank you to Charles E. for this post:


  15. #10
    Registered User
    Join Date
    Mar 2013
    Location
    Brooklyn, NY, USA
    Posts
    1,249

    Default Re: Practice cutting dovetails by hand

    I used to go to a beach in Puerto Rico. The directions were turn at the first left after where the horse is tethered then look for an orange juice can in the bush. Go on that path. It worked.

  16. #11

    Default Re: Practice cutting dovetails by hand

    for a violin I use a template to get it close, along with the proper angle of the neck , which I don't know if that applies to mandolin never built one. also a sanding block that is shaped to fit inside the mortise , fit tight and remove ever so little till it almost fits , then use a little pressure to fit to bottom, But lately I have been putting the top on first and then fitting, cutting the bottom of the heel and then put on the back. it takes one blind step out of the calculation

  17. #12
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    Quote Originally Posted by kjbllc View Post
    mandolin never built one
    Well I hope now you repent of your mis-spent youth. It's never too late to see the light and give your life over to … mandolin building.
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  18. #13
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    I used to joke about the country directions until this happened to me. I was in Tampa, downtown, getting directions from a guy who claimed to know where a restaurant was that I couldn't find. He said: "What you do is, go up to the corner and turn right. At the next corner turn right again. Then go down two blocks and turn right." I said: "Doesn't that take me right back to this street here?" He looked puzzled and said, "No, I don't think so. Let me do it a different way. Go north a block. Then turn to the east. When you get down two streets turn to the west and walk two blocks …"
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  19. #14
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    15,863

    Default Re: Practice cutting dovetails by hand

    Two wrongs don't make a right, but three lefts do...

  20. The Following 2 Users Say Thank You to sunburst For This Useful Post:


  21. #15
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    Quote Originally Posted by sunburst View Post
    Two wrongs don't make a right, but three lefts do...
    But not if you're going north.
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  22. #16
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    Quote Originally Posted by Charles E. View Post
    Here is a video from a member on a recent mandocello build...
    Thanks for posting this. I'd seen it before but never WATCHED it. I did this morning (to keep from having to actually, you know, WORK) and I learned some things I'd never seen before. I'm going to be watching and rewatching.
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  23. #17
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    A follow up, if you please. Is the direction of the grain in the neck block different than the direction of the grain in the neck? I'm assuming that the neck grain runs along the long axis of the neck. But the neck block: It's at right angles to the direction of the grain in the neck, right?
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  24. #18
    Registered User sunburst's Avatar
    Join Date
    Nov 2003
    Location
    Kentucky
    Posts
    15,863

    Default Re: Practice cutting dovetails by hand

    The neck block can have grain running nearly any direction in various instruments. There are traditions, of course, but the procedure is the same regardless.
    In mandolins, A-styles usually have blocks with grain running 90 degrees to the neck, but I've done them the other way too. In f-styles, the grain is usually somewhat diagonal. In violins, it's often 'up and down'. Guitars, parallel to the rim...
    Grain direction is not important to the process of fitting the dovetail.

  25. #19
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    3,462

    Default Re: Practice cutting dovetails by hand

    I think I posted some parts of this before but her eis how I cut tapered dovetails on my mandolins all by hand(saw).
    1st I mark my rims while still in mould for exact centerline of body and centerline of neck (you know the Loar shifted/skewed position of neck), the two intersect right under center of bridge. You can use just one centerline if you are not Loar nut like me. I also make sure the rim is perfectly square at the neck block and I sand smooth the area at the dovetail (pays off as you won't have such good access after gluing the neck). Then I mark the exact position of dovetail with sharp pencil on both top and back of rim and connect them. I mark the bottom same as top and just eyeball two parallel lines 1/16" inside to make the dovetail tapered.
    Click image for larger version. 

Name:	Dovetail01.jpg 
Views:	268 
Size:	105.1 KB 
ID:	185182
    I take small saw and make two straight cuts just hair inside the lines and one down the center for easier wood removal. I mostly use the cheap small saw but recently I tried japanes saw for the straight cuts
    Click image for larger version. 

Name:	Dovetail02.jpg 
Views:	233 
Size:	141.8 KB 
ID:	185181
    I still think the ceap saw is better as it has wider kerf and that makes it easier to chip away the wood from inside the dovetail.
    Click image for larger version. 

Name:	Dovetail03.jpg 
Views:	260 
Size:	114.3 KB 
ID:	185180
    Then I clean up the sides with few strokes of my sanding stick. (80 grit Norton paper - indestructible) on stick with angled sides so it sands right to the edge. DOn't round the inside of the dovetail you want it perfectly flat. I check flatness with my cabinet scrapers and scrape any bad spots level if needed. These steps take better part of 5 minutes including the drawing.
    Click image for larger version. 

Name:	Dovetail04.jpg 
Views:	232 
Size:	137.7 KB 
ID:	185179
    Then I mark the exact shape of both sides on clean piece of stiff cardboard for marking on neck later.
    Click image for larger version. 

Name:	Dovetail05.jpg 
Views:	228 
Size:	139.7 KB 
ID:	185183
    Adrian

  26. The Following 5 Users Say Thank You to HoGo For This Useful Post:


  27. #20
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    3,462

    Default Re: Practice cutting dovetails by hand

    Later, on neck blanks I draw position of two or three frets that cross both neck and body (12, 13, 14) and also mark them on body, now thatthe crosspiece is on, also mark centerline of neck on both top and bottom of neck and project the fret positions all around the neck (using 5 degrees angle going down the sides of neck). I cut out the template with scalpel (cut the top of dovetail a bit wider as the crosspiece makes it a bit wider than before) and trace it on the neck making sure all the pencil lines are aligned.
    Click image for larger version. 

Name:	Dovetail06.jpg 
Views:	238 
Size:	130.2 KB 
ID:	185184
    Then cut away as close to lines as you dare with the small saw. I also remove most of the wood from heel to create the wedge shape.
    Click image for larger version. 

Name:	Dovetail07.jpg 
Views:	218 
Size:	135.1 KB 
ID:	185186
    Click image for larger version. 

Name:	Dovetail08.jpg 
Views:	237 
Size:	121.7 KB 
ID:	185185
    Adrian

  28. The Following 6 Users Say Thank You to HoGo For This Useful Post:


  29. #21
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    3,462

    Default Re: Practice cutting dovetails by hand

    Nw starts rough fitting.
    Notice I have marked exact position of fingerboard (and with locating pins it will be glued exactly there) so I can chamfer the edges of the blank very close to final width. That makes the edges less vulnerable during fitting and the contact between neck and rim is not obscured. And of course there is less wood to remove for fitting.
    Click image for larger version. 

Name:	Dovetail08.jpg 
Views:	249 
Size:	121.7 KB 
ID:	185187
    I flatten the sides of dovetail with the sanding stick and also the curved cuts with curved sanding stick (piece of split tubing with sandpaper attached) and check initial fit. When I'm pretty brave and my hand is steady it looks like this (but most often the necks stays somewhere between 3/8" and 1/2" above the surface):
    Click image for larger version. 

Name:	Dovetail09.jpg 
Views:	250 
Size:	89.1 KB 
ID:	185188
    I check the centerline and angle of neck and use chalk fitting next. I use one long plastic ruler with scribed line to check alignment and edge of ruler standing on neck surface projecting at the bridge position and check clearance with my special measuring gauge (fancy name for box of mechanical pencil leads that happen to be approximately 1/2" wide, which is how high I want my neck to project without fingerboard). I check alignment of all the lines I drew on body and neck and gap above the crosspiece and above the gauge. SLowly chalk fit till I get the neck to seat 1/16" above it's final position. There must be perfect contact between neck and rim.
    Click image for larger version. 

Name:	Dovetail10.jpg 
Views:	212 
Size:	102.4 KB 
ID:	185189
    Click image for larger version. 

Name:	Dovetail11.jpg 
Views:	228 
Size:	104.0 KB 
ID:	185190
    Adrian

  30. The Following 4 Users Say Thank You to HoGo For This Useful Post:


  31. #22
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,283
    Blog Entries
    3

    Default Re: Practice cutting dovetails by hand

    Thanks, Adrian. Very helpful!
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  32. #23
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    3,462

    Default Re: Practice cutting dovetails by hand

    The last bit I do after final shaping of neck before gluing it in. But basicly just the few strokes of scraper to refresh the surfaces for gluing are enough for tehneck to slip in fully. You want a snug fit but not too tight as adding HHG will swell the wood and your neck may get stuck short of final position and almost impossible to knock out (DAMHIKT). The last surface to fit is the bottom of heel against back heel button. That is simple with sanding stick and scraper (dont round over the edges!)
    I check alignment right before the gluing and again after. I want all thelines I drew to align perfectly and see only wood to wood contact, no gaps allowed! The scribed line of the ruler should just split my mark under bridge on centerline.
    Click image for larger version. 

Name:	Dovetail12.jpg 
Views:	252 
Size:	106.8 KB 
ID:	185195
    Click image for larger version. 

Name:	Dovetail13.jpg 
Views:	216 
Size:	109.2 KB 
ID:	185194
    Click image for larger version. 

Name:	Dovetail14.jpg 
Views:	249 
Size:	102.8 KB 
ID:	185193
    Click image for larger version. 

Name:	Dovetail15.jpg 
Views:	213 
Size:	101.9 KB 
ID:	185192
    Click image for larger version. 

Name:	Dovetail16.jpg 
Views:	248 
Size:	119.1 KB 
ID:	185191
    I also check if I'm not fitting the neck rotated. I either put the ruler across the neck at 12th fret position and look down the body if it is parallel to edges of body or I lay the neck with body inserted on a flat plane and measure distance from the plane to edges of body (gap above plane) at bridge position crossection, should measure the same on both sides.
    Adrian

  33. The Following 5 Users Say Thank You to HoGo For This Useful Post:


  34. #24
    Registered User Tom Haywood's Avatar
    Join Date
    Oct 2008
    Location
    PTC GA
    Posts
    1,348

    Default Re: Practice cutting dovetails by hand

    What we casually call "the mandolin dovetail neck joint" or the "Gibson mandolin dovetail neck joint", is actually, in my opinion, the ultimate type of dovetail joint in carpentry. It is a combination of the sliding, tapered, and blind dovetail joints. Doing any dovetails by hand is also the ultimate skill. I think just doing a decent "drawer" style 90° joint by hand will give you a good appreciation for the skills of cabinet and furniture carpenters. The only way I know to truly understand all the angles, movements, and tools, and to get the skills that have to be accounted for at each step is to start with the simple butt joint dovetail and work your way up through each type. This can actually be done in three or four days and is not very difficult. Buy a 1"x6" poplar board at Home Depot. Cut it into 4" pieces to use as blanks for "neck blocks" and "necks". When you are ready to try a straight, sliding joint, glue two pieces together to get 1.5" thick blanks. This will get you close to the size needed for the mandolin. Keep all your cut blanks in a box for that future day when you want to do another dovetail neck joint. They will help you remember all the steps.
    Tom

    "Feel the wood."
    Luthier Page: Facebook

  35. The following members say thank you to Tom Haywood for this post:


  36. #25
    Registered User David Houchens's Avatar
    Join Date
    Apr 2005
    Location
    North Garden,Va
    Posts
    1,610

    Default Re: Practice cutting dovetails by hand

    Thanks John for reminding me. My Pa passed away last June but that white horse may very well still be there .

  37. The following members say thank you to David Houchens for this post:


Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •