Posts: 2,382
Threads: 0
Joined: Dec 2011
01-25-2021, 12:37 PM
(This post was last modified: 01-25-2021, 01:00 PM by Handplanesandmore.)
(01-24-2021, 10:48 PM)OneStaple Wrote: 2. So, for gaps that are too big just to let glue fill but too small for a sliver of wood, what do you do?
3. If the end grain was proud of the surface, I'm sure I could remove some of this. Do you use a different approach besides dividers to do the initial marking if you leave the end grain slightly below the surface?
Where are all the other dovetail experts on this forum? (Are you reading this, Rob?)
2 - Cosman would vouch for making the gap wider (saw kerf) and fix it with a veneer; some go with hide glue depending on the wood tone/color and finish used; or if really small oil finish could hide it. More methods out there. I even tried gap filling CA glue.
3 - The dividers are fine, just go with a light touch.
Welcome to the prestigious dovetails club (joke).
Simon
Posts: 869
Threads: 0
Joined: Jun 2008
(01-22-2021, 10:04 PM)OneStaple Wrote: Things I noticed or need to work on:
1. Straight saw cuts. This is the biggest issue and harder than I expected. None of the pin cuts were exactly straight up and down, and the tail cuts were all at slightly different angles (most obvious on the center tail). And worse, I noticed that some of my tails are essentially tapered (in the wrong axis) due to the saw not being perfectly perpendicular to the board during the cut. If it looked like I was following the line on the front and top of the board, it didn't necessarily mean I was following the line on the other side.
2. One of the middle pins is much wider than the other. That's because one of my first cuts between the tails was so bad that I moved the saw over 1/8" to try again.
It would seem that the remedy to all of this is simply practice, practice, practice. Tips/pointers welcome.
Thanks,
Tyler
Practice always helps. But its not always the best answer....It looks like you placed your saw flat on the end grain and tried to just Use The Force to get perpendicular. Is that right?
I recommend sawing the corners out instead. Holding all three lines simultaneously is pretty tricky.
Agree with increasing chisel bevel angle, but not universally. I find 1/2" chisels need the highest angle (approx 30 degrees) They get lots of use dovetailing and their size impacts their edge wear. >3/4" I hone close to 20. 3/8" and below are so small, you can grind almost any angle and they will work. I usually default to 25 for these and 5/8".
Here's another tip I'd like feedback on from the rest of you guys. Does anyone else see edge retention changes based on what sort of mallet you use? Does steel hammer, wood, urethane or leather wrapped wood make any difference? For carpentry, I've been using a dead blow and I really like it. I think it helps.
mv = SFdt
so for a given hammer mass (m) swung with velocity (v), that is converted into an impulse at impact where the force exerted (F) varies based on the length of time (dt) the contact (hammer to chisel/nail) occurs. This means a steel hammer will produce a higher contact force, and a dead blow probably the lowest. I think low force maintains edges better. You can also swing a heavy dead blow slower and achieve equal momentum.
Like your thoughts
Posts: 3,066
Threads: 0
Joined: Jan 2004
01-25-2021, 02:35 PM
(This post was last modified: 01-25-2021, 02:35 PM by TomFromStLouis.)
I don't have any tips or pointers because while I have been cutting them for years most of my efforts look worse than your first try.
Posts: 16,609
Threads: 2
Joined: Oct 1999
No handcut dovetail expert here, but I think your first effort is exemplary! "Practice Makes Perfect" applies here as well as in most other things in life. Of course you must practice with improvement in mind, which I'm certain you already knew.
There is a thread running concurrently by Derek Cohen on cutting half blind dovetails. While he acknowledges that all his methods aren't his own, his execution approaches close to perfection IMO. Anyone would do well to cruise his web site for articles on the subject.
Good luck,
Doug
Posts: 2,726
Threads: 0
Joined: Dec 2005
(01-23-2021, 05:51 PM)Handplanesandmore Wrote: Words from someone who knows the dovetail business.
Simon
Simon: almost missed that (I'd hate to think I missed someone actually saying something positive about me): Thanks!!
Posts: 2,726
Threads: 0
Joined: Dec 2005
Tyler:You gotta be kidding me: those DTs look great!!! See, a little glue, a little planing, and life is good. Keep up the excellent work! Phil
(01-24-2021, 10:48 PM)OneStaple Wrote: Ok, I glued together the dovetails and cleaned them up a bit (pictures below, wiped down with mineral spirits). Doing so makes them look a bit better, but obviously doesn't fix/cover everything.
Questions/comments:
1. I figured out that my dovetail marking gauge is way off. Basically, the part that is used for angles is skewed sideways by a few degrees. And when marking lines for tails, you use one side of the gauge to mark the line on one side of the board and the other side to mark the same line on the other side of the board. So, while I'm sure my cutting wasn't straight, it was also made to look much worse by non-matching angles. I need to get/use something better.
2. The glue filled some of the gaps between the pins and tails, but not all. I've tried the mix-glue-with-sawdust approach in the past and never been impressed with the outcome. So, for gaps that are too big just to let glue fill but too small for a sliver of wood, what do you do?
3. You'll notice in the pictures that the endgrain of the tails shows a few marks. One was from a saw kerf that jumped (whoops). The others are pin holes from a divider that I used to mark out the distances of the tails. If the end grain was proud of the surface, I'm sure I could remove some of this. Do you use a different approach besides dividers to do the initial marking if you leave the end grain slightly below the surface?
4. You'll notice that I cut just a couple inches containing the dovetails off of the boards. I plan on going down the length of the boards repeating this process as practice.
Thanks,
Tyler
Posts: 10,718
Threads: 1
Joined: Jan 2006
Location: Orlando, Florida
(01-23-2021, 07:56 PM)OneStaple Wrote: The reasoning for letting the end grain be slightly below the surface makes sense. I feel like most instructions that I've seen have it slightly proud of the surface, I assume because it's a much smaller surface area to make true (although you have to plane end grain). Would you change your approach for the marking gauge with half-blind dovetails? I plan to work on those after I've gotten a bit more comfortable with regular dovetails.
Thanks,
Tyler
One major advantage of tails being proud of the surface is that once you plane them flush, you haven't changed the width of the drawer. If you need to plane the drawer side to be flush with the tails, you are removing width from your drawer (and much more wood than just removing proud tails), which may cause the drawer to fit loosely in the drawer opening. The fix to a loosely fitting drawer is more difficult than a tightly fitting drawer. Easy to remove wood. Harder to add it.
Still Learning,
Allan Hill
Posts: 863
Threads: 0
Joined: Jan 2007
Location: Fairfax Station, VA
Thanks for the encouragement, all! I'm certainly amazed at how much the gluing and planing cleans up the joint, so thanks for the recommendation.
adamcherubini Wrote:It looks like you placed your saw flat on the end grain and tried to just Use The Force to get perpendicular. Is that right?
I recommend sawing the corners out instead. Holding all three lines simultaneously is pretty tricky. I started it flat on the end just to get a single kerf line, then tilted back to saw the corner toward me first. Eventually, I had to lower the tip of the saw and cut the opposite side, which is hardest to see while sawing and make sure things are lined up right. When you say "sawing the corners out", are you talking about what I described or doing each corner separately and then connecting the kerfs somehow?
Tapper Wrote:There is a thread running concurrently by Derek Cohen on cutting half blind dovetails. While he acknowledges that all his methods aren't his own, his execution approaches close to perfection IMO. Anyone would do well to cruise his web site for articles on the subject. Yes, I am certainly aware of Derek's website and have read through his guides multiple times, using it as one of my primary references while figuring out how to cut dovetails. Thanks Derek! I certainly have a lot to learn to approach his level of competence with dovetails.
AHill Wrote:One major advantage of tails being proud of the surface is that once you plane them flush, you haven't changed the width of the drawer. If you need to plane the drawer side to be flush with the tails, you are removing width from your drawer (and much more wood than just removing proud tails), which may cause the drawer to fit loosely in the drawer opening. The fix to a loosely fitting drawer is more difficult than a tightly fitting drawer. Easy to remove wood. Harder to add it. Hmm, this is almost directly contradictory to Simon's earlier comment (second reply in this thread). Is the difference in your two approaches simply a matter of what is being measured as the reference to fit the drawer opening? I think I could see how both approaches would be useful.
I received some Japanese chisels the other day (used, from ebay) and am cleaning/fixing them up. I am supposed to receive a rough whetstone today to help with that process, but USPS says the package is running late. Once I have that, I'm going to try another few rounds of dovetails. I'll post more pictures when done.
Thanks,
Tyler
Posts: 2,382
Threads: 0
Joined: Dec 2011
(01-27-2021, 11:41 AM)OneStaple Wrote: Hmm, this is almost directly contradictory to Simon's earlier comment (second reply in this thread). Is the difference in your two approaches simply a matter of what is being measured as the reference to fit the drawer opening? I think I could see how both approaches would be useful.
The way I read his (tails referring to tail boards) is that our comments are identical.
Simon
Posts: 10,718
Threads: 1
Joined: Jan 2006
Location: Orlando, Florida
01-27-2021, 02:38 PM
(This post was last modified: 01-27-2021, 02:43 PM by AHill.)
(01-27-2021, 11:41 AM)OneStaple Wrote: Hmm, this is almost directly contradictory to Simon's earlier comment (second reply in this thread). Is the difference in your two approaches simply a matter of what is being measured as the reference to fit the drawer opening? I think I could see how both approaches would be useful.
I received some Japanese chisels the other day (used, from ebay) and am cleaning/fixing them up. I am supposed to receive a rough whetstone today to help with that process, but USPS says the package is running late. Once I have that, I'm going to try another few rounds of dovetails. I'll post more pictures when done.
Thanks,
Tyler
Not to put words into Simon's mouth, but I think his preference was that if the tail was short, it was easier to plane off saw marks and the marked baseline. My point was based solely on drawer fitting. the tails on the front or back faces won't matter much to whether the drawer fits into the opening. You can always put a drawer stop in the back to move the drawer flush to the front of the case.
The real solution is to make the drawer where the dovetails fit as closely as possible, so that if you need to plane them to remove a baseline or tooling marks, only a couple of plane swipes is required. This what Cosman recommends. Two or three swipes might make 0.006 x 2 = 12 thou difference between in width, which is a little more than 1/64" inch. I remember going to a class once with Mario Rodriguez, who said he used to spend more time fitting drawers than he did building them in the first place. His drawers were piston fit and flush with the case.
I've also read in another thread where Adam's cautions that additional practice may not solve the problem if you don't know what you're doing wrong in the first place. For me, it was learning how to saw to the correct side of the mark, and to keep the saw in the right orientation so you're aligned to both the horizontal and vertical marks. I blame my astigmatism.
Perfect practice yields perfect results.
Keep striving to improve. I think your dovetails are pretty darned good for the first time.
Still Learning,
Allan Hill
|