Thread: My GDLP has issues...........................

As the title suggests, I want to stress that MY GDLP has issues; I have no reason to think or certainly no information to support any assertion that ALL GDLP's have the issues I'll describe here. I'm in the process of dealing with Harrelson Stanley, U.S. distributor for Shapton. My GDLP as of today is being Priority mailed back to Harrelson. I'm looking for an exchange, refund or a potential upgrade to the DRLP (unlikely that I'd want to pay the difference to upgrade to this even if Harrelson would offer this as an option).

In summary, my GDLP after using it lightly for just under six months has degraded in performance dramatically. What used to take a few minutes in re-lapping my Shapton Ceramic on Glass stones now takes upwards of 15 minutes or more.

Sadly, viewing the surface of the GDLP under 40x magnification appears to reveal the reason for the performance degradation. Approx 80% loss of diamonds. That's huge. Here are some pictures that have been emailed to Harrelson:

This first picture is a close up of one of the edges of the GDLP taken last week. The edges of the GDLP remain very sound; In addition to lapping my Shapton ceramic stones on the GDLP, I also lap my small number of Coticules, Thuringians, Belgian Blues and an occasional barber hone. These stones are all smaller than the Shapton plates and the middle of the GDLP has seen more use than the edges. I would expect a small loss of diamonds in the center vs. the edges then, based on my usage.


This next pic is a picture of the center of the GDLP. Almost no diamonds left. You see the occasional black fleck (diamond) and the nickel substrate.



Bummer. I viewed each picture on my screen and drew an imaginary line straight across each picture. Then I did a non-scientific count of the diamonds that the "line" ran across from left to right. I then divided out the numbers and came up with the approximated loss of diamonds in the 80% range if that makes sense.

I debated on posting this until AFTER this issue was brought to whatever resolution it will come to, but after talking with another longtime SRP member, he suggested I post my issues now.

I lap as directed by the Shapton website (basically back and forth with some diagonals thrown in) and, I lap lightly. I do NOT use excessive force or even use force when lapping. I keep the stones on the GDLP and try to let the diamonds do the work. I know how to lap.

Here's what I've found out from Harrelson that I did NOT know about the GDLP:

• The GDLP's diamonds bonded to the nickel substrate are actually found in several layers. More than one "coat" of diamonds and nickel. I believe this since when I view the surface of the GDLP under magnification, I can barely see the tips of diamonds barely peaking out from the nickel surface; some are almost completely covered by the nickel and therefore have no effect when lapping.
• Sometimes hardened slurry can coat the diamonds reducing performance. Soaking the GDLP in water overnight is recommended to soften the slurry then.....................the following is recommended much to my surprise:
• A Shapton Lapping Disc for $19.95 is recommended to actually lap the surface of the GDLP, nickel, diamonds and all! Harrelson explained that the ceramic disc is extremely coarse and removes metal and the diamonds. The idea here is that by lapping the GDLP's surface, you are able to expose the unused diamonds encased in a lower layer of nickel. Essentially hopefully refreshing the GDLP's surface.

I have issues with this and would NOT be comfortable lapping the GDLP surface. It's not even the principal of having to buy an additional accessory, it's the fact that if I manually lap GDLP's surface, IMO I can kiss the .5 micron flatness goodbye. By how much? Who knows?
I did not post this to discourage anyone from buying a GDLP and my greatest hope is that I got one that was defective and was an anomaly. Still I wanted to make you guys aware of this and also ask if others with GDLPs have had any issues even close to what I describe (basically a noticeable degradation in performance).

I've followed the instructions that came with the GDLP in that I have never lapped any stone coarser than the Shapton 500 grit stone. The instructions make reference several times to the fact that the GDLP was created to lap the Shapton Ceramic on Glass stones but nowhere in the instructions does it mention that lapping any other TYPE of stone is prohibited.

Chris L

It's good to hear about things like this because it'll show what kind of customer service they have.

I am also suprised that they would recommend lapping the lapping plate. Periodic resurfacing at the factory would make more sense than passing the work on to the customer.

Thanks for sharing the story in progress as well, that way other guys can check their own plates and add info as necessary.

Hope it gets resolved for you.

Thanks for posting this Chris, I will be watching this thread with continued intrest......

Originally Posted by Russel Baldridge

I am also suprised that they would recommend lapping the lapping plate. Periodic resurfacing at the factory would make more sense than passing the work on to the customer.

I know the DRLP (Diamond Reference Lapping Plate) has a trade in option where the factory sends out a factory resurfaced (to the same specs as the original) DRLP. No such trade in animal exists for the GDLP. The website says the DRLP can be worn out after 2-3 years of "hard use".

Chris L

Geez Chris, I hope this is as you said an anomaly. I went for the GDLP and so far so good. I haven't lapped anything under 1000 with it. I am not sure how much more or less I have used mine then yours but mine is still hitting on eight. I have the pro shapton stones but I don't think there is much of a difference. I hope Harrelson makes it right for you.

Im very sorry to hear your trouble but do thank you for posting. Im getting ready to buy my GDLP by the end of the month.

Originally Posted by JimmyH-AD

Geez Chris, I hope this is as you said an anomaly. I went for the GDLP and so far so good. I haven't lapped anything under 1000 with it. I am not sure how much more or less I have used mine then yours but mine is still hitting on eight. I have the pro shapton stones but I don't think there is much of a difference. I hope Harrelson makes it right for you.

It makes me feel good knowing that you're lapping stones other than the Ceramic on Glass stones, Jimmy. I've reread the GDLP instructions and nowhere do they say you CAN'T use the GDLP to lap other kinds of stones (as long as they're over 500 grit). I rarely lapped my 500 grit ceramic stone since I have not had much use for it. The large majority of my lapping has been 4K grit or higher.

Chris L

I have seen similar results with my DMT 8" Coarse. DMT's question/response was 'Will it still scratch a glass surface? Yes? Then there are still diamonds and it is still doing its job.' Well, it does still scratch glass but it does not cut as fast as it did before.

Hopefully Shapton's response is better.

Originally Posted by Chris L

It makes me feel good knowing that you're lapping stones other than the Ceramic on Glass stones, Jimmy. I've reread the GDLP instructions and nowhere do they say you CAN'T use the GDLP to lap other kinds of stones (as long as they're over 500 grit). I rarely lapped my 500 grit ceramic stone since I have not had much use for it. The large majority of my lapping has been 4K grit or higher.

Chris L

I still have my D8C and I use that for coarse stuff. A friend of mine said that Shapton suggests only lapping their stones. I figure that is because they can't be sure of what the grit is on another manufactuer's stone. I have also lapped coticules, and Eschers and no worries so far.

The re-manufactured lapping plate that Shapton offers costs $325.-00 so it ain't a bargain. The steel backing being the more expensive component is for flattening planes. Harrelson said that if you drop it can go out of true so the GDLP is probably the best bet of the Shaptons for lapping. I imagine if the diamonds don't last in the glass plate they won't be any better in the steel. Let's hope this is a defective plate and not the norm.

OK, no tool is perfect and the limitations of this hone are now being seen.I also hope that this is an anomaly. Time will tell.

Since Shapton has a work around they must have expected this but a better response would be to offer a resurfacing at the factory. It would instill a lot more confidence that the job was done right and the flatness preserved. The flatness of these hones is the main selling point for the guys in the straight razor world. I hope Shapton realizes this.

Just my two cents,