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View Full Version : 1 On 1 sharpening session with Dave....



Zwiefel
07-08-2013, 11:35 PM
I recently had the opportunity to spend a day in the shop with Dave for a 1:1 sharpening class and wanted to relate my experience to the community.

It's always a bit difficult to set expectations for what to anticipate of someone who frequently interacts with you in an authority/expertise function, and that purely online. But....Dave was relaxed, quick to laugh, and has a wide range of interests, including human nature. His shop is located in Fleetwood, among the beautiful, rolling hills of the nearly stereotypical Pensylvannia Dutch--some of which you have seen in another thread. When driving throughout the area you will encounter signs warning you to be aware of horse-n-buggies on the road, many signs for local handmade furniture/meats/cheeses/etc. The barns, fields, and other farming facilities in this area are also astonishing...I really wish there was a well-designed tour just for these things. Anyway, back to Dave....

I arrived around 10am, Dave answered the door and immediately and ushered me in. He had stocked the shop fridge with my preferred (non-alcoholic) beverages and we talked a bit about how our time would go, the forum, and then looked over my knife/stone collection. We proceeded to a discussion about asymmetry of edges, and blade construction itself, followed by a practicum of putting a straight edge against blade faces and discussing what we saw. This was very beneficial as I understood the principles, but hadn't been able to see it with my own eyes.

After this, we moved to the sharpening table. Dave took his time sharpening one of my knives, going over the process in great detail...explaining what he was looking for on the knife, the stone, the light, the sound, feel, etc. and esp how it was changing as the steel was abraded, the stone was abraded, the angle of the knife was changing, etc. We spent a while talking about stones, stone maintenance (just learning a new way to lap my stones was extremely valuable, and fixed a problem I had with flattening a stone for several months now!), and how different stones respond to pressure. Then we switched places and Dave watched me in great detail, providing consistent, regular, and gentle feedback while I sharpened one of my knives on my stones. I learned a considerable amount about my knife any my stones in this process. We next spent a while talking about stropping, and doing some stropping.

We then moved on to my only single-bevel. Dave did a through break-in on it, revealed some flaws in the grind* (which also explained a little bit of waviness in the shinogi), and corrected all but 1 of the grid issues (too much work to fix in the class), next I did some work on the Ura (Uraoshi?) and the bevel(s) itself under Dave's close supervision.

Dave then spent some time talking about the value of natural stones for single-bevels (and we got to play with some which had just arrived from Maxim!), and Dave spent a little time pretty-ing up the bevel with some finger stones.

After that I had to run in order to prevent my spousal unit from receiving a lengthy prison sentence...though Dave (and I!) could have spent quite a few more hours chatting about a variety of things...and I suspect the discussion would have neccessitated the consumption of malted barley products at some point.

I had 2 specific items learned that will make a huge difference (though I learned many many things): 1) sharpening and thinning aren't different activities or different parts of the process...they are the same activity in 2 phases; 2) stropping is where it's at...seriously (testing sharpness at multiple phases along the way made this even more clear than my experience with MuchoBocho a week earlier).

To sum it up: I learned a lot, I had a lot of fun, I was made to feel comfortable and welcome, and I will definitely drop back by if I'm anywhere nearby again....and perhaps Dave will open the door despite recognizing me.

TX Dave!

*I should mention that Dave pointed out that these particular flaws are common in a single-bevel in this price range.

tripleq
07-08-2013, 11:45 PM
Wow. Thanks for the info. I would love to spend a day with Dave. If only he wasn't so far away..

jared08
07-09-2013, 12:01 AM
Some day I can only hope to venture down the highway and meet dave. Thanks for sharing. Im sure it was a great time!

Zwiefel
07-09-2013, 12:08 AM
Wow. Thanks for the info. I would love to spend a day with Dave. If only he wasn't so far away..

I drove about 2500 miles to make it happen :nunchucks:

Of course, I got to meet a number of other forum members along the way....so bonus!

berko
07-09-2013, 05:16 AM
how do you flatten your stones now?

Zwiefel
07-09-2013, 09:08 AM
how do you flatten your stones now?

Ive always flattened before every session....but I'm more effective with it now.

Dave Martell
07-09-2013, 11:34 AM
Danny, it was a blast having you here, lots of knifegeeking fun indeed!. :D

Thanks for the kind review, it's very much appreciated. :)

Dave

Mucho Bocho
07-09-2013, 12:00 PM
Danny, thanks for the write up too. I'm glad you see the use of stropping. Have you had a chance to mess with that HA Diamond spray on boving leather?

Bram
07-09-2013, 12:22 PM
What was that lapping thing you learned?

Zwiefel
07-09-2013, 02:38 PM
Danny, thanks for the write up too. I'm glad you see the use of stropping. Have you had a chance to mess with that HA Diamond spray on boving leather?

Not yet....kinda hard to start a project like that in the RV. BUT....I got a spray bottle and some felt from Dave...so closer! Will be on the top of my list when I get home.

Zwiefel
07-09-2013, 02:39 PM
What was that lapping thing you learned?

Hi Bram, welcome to the Forums!

I don't know if this is something that Dave has shared publicly, so I'm a bit reluctant to share....don't want to step on toes.

Dave Martell
07-09-2013, 03:18 PM
What was that lapping thing you learned?


Hi Bram, welcome to the Forums!

I don't know if this is something that Dave has shared publicly, so I'm a bit reluctant to share....don't want to step on toes.



Feel free to share Danny. I've been talking about this for years but not much in the last couple.

Zwiefel
07-09-2013, 03:57 PM
What was that lapping thing you learned?


Feel free to share Danny. I've been talking about this for years but not much in the last couple.

Cool....I like to share!

Here is the before image of a pretty standard chamfering that we probably all learned:
http://farm3.staticflickr.com/2823/9250686606_5ee8b4f473.jpg

Dave proved to me by multiple metrics that this approach will leave a very slightly raised ridge around the perimeter of the stone...kind of like a burr. this will affect your flattening as well as your sharpening....and it caused a flattening problem I've had with one stone for several months now.

by taking this approach:
http://farm4.staticflickr.com/3805/9247901497_6f45a6e699.jpg

Starting about 2" from the edge and going all the way out, create a continuously decreasing radius compound curve. This is guaranteed to eliminate the ridge and reduce the chances of gouging the edge of the stone with the edge of your knife. It has the adverse effect of reducing the (easily) useful area of the stone.

Hope this makes sense.

berko
07-09-2013, 05:46 PM
i think i know and have the same problem, but my english is not good enough to understand the problem solving. need to read through this a few more times :D

keithsaltydog
07-09-2013, 06:49 PM
I drove about 2500 miles to make it happen :nunchucks:

Of course, I got to meet a number of other forum members along the way....so bonus!

Knife sharpening geeks unite.Enjoyed reading your travel thread:cheffry:

Zwiefel
07-09-2013, 08:13 PM
i think i know and have the same problem, but my english is not good enough to understand the problem solving. need to read through this a few more times :D

I would have to make a video to show how you do it....but in the second video above, the right-angle tool is flat against the side, and flat against the middle of the top of the stone. the gap you see is b/c the stone is no longer square.

berko
07-09-2013, 08:43 PM
i think i got it now, thanks. gonna try it out tommorow.

Dave Martell
07-09-2013, 08:58 PM
The idea is to remove the sharp corners/edges of the stone by rounding vs chamfering. By doing a series of overlapping chamfers you create a radius. If you start with the lapping plate on the stone's face and work in a series of bevels/chamfers the edge/corner becomes rounded.

While you give up a small amount of edge contact area you gain the entire middle of the stone as a contact area and that's because the knife now makes contact across the face instead of just the high edges/corners of the stone. This little trick can really make some stone's come alive, sure makes coarse stones cut faster and for naturals it keeps the edges from scratching that perfect finish.

This also serves you when lapping a stone - on a new stone or one that needs a lot of lapping - first round the corners lap and round as needed during the process to keep the corners down/away from the lapping plate to allow the plate to work the stone's face - because these high corners/edges won't allow some stones to be flattened correctly or efficiently.

Just a note on Danny's pictures above, the rounded corner he shows is either a tad too round (meaning maybe it's been rounded more than necessary up onto the stone's face) or the picture is macro showing a huge gap where this isn't necessarily the case. The pictures are a good representation of the difference between chamfering and rounding though.

Zwiefel
07-09-2013, 09:04 PM
Just a note on Danny's pictures above, the rounded corner he shows is either a tad too round (meaning maybe it's been rounded more than necessary) or the picture is macro showing a huge gap where this isn't necessarily the case. The pictures are a good representation of the difference between chamfering and rounding though.

Yeah, I was surprised by the photo too....this was one of my stones that was no longer square due to uneven wear...I think that's making this look exaggerated. But it makes the idea pretty clear.

keithsaltydog
07-10-2013, 12:55 AM
Japanese Sword sharpeners use stones high in the middle

Bill13
07-11-2013, 05:02 PM
What was the price point of your single bevel, if you don't mind?

Zwiefel
07-11-2013, 06:28 PM
What was the price point of your single bevel, if you don't mind?

$350 for a lefty kamagata.

Zwiefel
08-17-2013, 05:50 PM
I finally found time around my travel for work to spend a couple of hours taking care of my knives. I sharpened the watanabe SS kuro-uchi 186mm nakiri, Don The Nguyen 240 k-tipped gyuto, and 210mm masamoto VG.

I can definitely see improved results as a consequence of my time with Dave. Yes, I put a better edge on all 3 knives but there was something more significant: I was able to see what I was going right/wrong (well, see MORE), and understand better when I was done with each step. Therefore, I spent much less time on each knife and abraded less steel to get a better result.

Thanks again Dave! It's still paying off :)

Dave Martell
08-17-2013, 11:03 PM
That's so great to hear. Thanks Dan! :)

Lefty
08-18-2013, 06:38 PM
Dan, this is a lot like I felt when I went to visit Randy. He opened his doors, literally fed me for a day, and drank upwards of 10 coffees with me, into the wee hours. It was an amazing experience, and you sound like you had just as great of a time at Dave's. This is such a cool community!

Dave, if I'm ever in the area, I'm crashing your place!

Dave Martell
08-18-2013, 07:50 PM
Dave, if I'm ever in the area, I'm crashing your place!


You're always welcome here Tom! :)