Adding a Koto Outer Ply to the FH of blade?

[Love_TT]

Hi everyone,
I’m currently using Yinhe 980 (a classic 5-ply ayous defensive blade), BH: 388D1 1.2mm, FH: 729 Battle 2 prov. While I absolutely love its control and "dampening" effect for chopping on the backhand, I find the forehand a bit too slow and "mushy" when I try to transition into a counter-attack.

I am considering a DIY project: adding a thin Koto veneer (approx. 0.4-0.5mm) to the FH side only to create an asymmetric blade. My goal is to gain a crisper feel and more speed for looping/driving without sacrificing the defensive properties of the BH.

I’d love to hear your thoughts on a few points:

• Balance & Feel: Has anyone experimented with adding a ply to a 5-ply defensive blade? Does it ruin the "sweet spot" or introduce weird vibrations?
• Thickness: Do you think a 6-layer (5+1) construction will make the blade too stiff for modern defensive play?
• Installation: For those who "mod" blades, what adhesive would you recommend to ensure a thin, even bond that doesn't kill the dwell time?
• Alternatives: Would I be better off just switching to a faster FH rubber (like a hard Chinese sponge), or is the Koto upgrade a viable way to get that "outer-ply crispness"?

Looking forward to your opinions!

 

[golden_son]

I think the issue you run into is having your new surface veneer oriented horizontally (which changes its properties), or else reducing the structural integrity by stacking two vertical veneers. Both of these run counter to conventional blade-making wisdom, though I don't fully understand the latter issue. I would also think having an extra layer on one side would make the balance feel funky, but that's just a hypothesis. Fortunately there are at least three experienced blade makers on the forum who may be able to weigh in (@Wakkibatty @SDC @Nexy designer)

 

[belllfador]

Hi everyone,
I’m currently using Yinhe 980 (a classic 5-ply ayous defensive blade), BH: 388D1 1.2mm, FH: 729 Battle 2 prov. While I absolutely love its control and "dampening" effect for chopping on the backhand, I find the forehand a bit too slow and "mushy" when I try to transition into a counter-attack.

I am considering a DIY project: adding a thin Koto veneer (approx. 0.4-0.5mm) to the FH side only to create an asymmetric blade. My goal is to gain a crisper feel and more speed for looping/driving without sacrificing the defensive properties of the BH.

I’d love to hear your thoughts on a few points:

• Balance & Feel: Has anyone experimented with adding a ply to a 5-ply defensive blade? Does it ruin the "sweet spot" or introduce weird vibrations?
• Thickness: Do you think a 6-layer (5+1) construction will make the blade too stiff for modern defensive play?
• Installation: For those who "mod" blades, what adhesive would you recommend to ensure a thin, even bond that doesn't kill the dwell time?
• Alternatives: Would I be better off just switching to a faster FH rubber (like a hard Chinese sponge), or is the Koto upgrade a viable way to get that "outer-ply crispness"?

Looking forward to your opinions!

I tried something similar in the past with an extra 0.5mm cork layer. The result was not so magical and I removed it. Still have sinful thoughts about adding an extra layer, but I am stopping myself from that rabbit hole. For now.

Consider the next points:
-BH side will also be affected - extra overall stiffness, speed and weight;
-there is a possibility of blade surface bending due to shrinking of the new glue layer;
- use of a vacuum pump to remove possible air bubbles in the glue;
- just the use of a hard lacquer layer - will add some speed but not much;
- faster rubber on FH - boosted H3 BS or G1, for example;
- faster carbon blade and Ilius S 1.3mm on BH.

What is the frequency and weight of your blade? My 980 is 1210Hz at 83g and play like ALL++. Speed was never a issue.

 

[Wakkibatty]

Somebody call? 😂

(Reads thread)

Gotcha... asymmetric all wood blade mod.

One of the biggest problems I find with any attempted asymmetric build or mod, is isolating the two sides from each other.

Adding one hard layer to one side of an existing blade, then hoping the rest of the blade remains unchanged, simply doesn't work sorry -- the nature of the entire blade is affected. Both sides of the blade will change in their playing feel, to become an amalgam of the two different playing feels / playing speeds you are after.

The second big problem is asymmetric panels usually have huge trouble staying straight over time, and all wood blades are especially prone to this problem.

The thing that keeps an all wood blade straight, is its symmetrical wood layers. Making one side thicker / harder / stronger / heavier tend to create an imbalance in the blade that can cause it to warp, twist, bow or cup -- usually through wood movement due to changes in humidity.

To combat both these problems, you need an internal layer structure that both:

• Isolates the vibrations of one side of the blade from the other, and...
• Provides sufficient stiffness to counteract the inevitable asymmetric wood movement.

Achieving this is all technically possible, but is also problematic, as it involves fiddling around with your composite layers. And speaking purely personally, while I have seen, and tried asymmetric blades that work, I've yet to see one that I personally want to play with, or that surpasses the effect you get from sticking with a symmetrical blade, by changing the playing rubbers you use on one side.

The asymmetric blades that work best, tend to achieve the effect through using two different synthetic composite layers, while keeping the rest of the blade layers symmetrical. And even then,the effect is only mild, not marked.

Here, you're using a blade where the internal ply structure was not designed from the ground up to resist any asymmetry in wood movement.

By all means give it a go if you want to, but I think you'll find it won't give you the result you want. Other blade makers however may know of other methods to get around the various issues above though, so don't be afraid to ask around.

 

[Love_TT]

Thanks everyone for the incredibly insightful feedback!

@golden_son : Stacking two vertical veneers (the existing outer and the new Koto) would definitely create a structural imbalance that I hadn't fully considered.

@belllfador : My 980 is around 85g, but the 'mushy' feel I mentioned might be more about the feedback/vibration than raw speed. Your point about the glue shrinking and warping the blade is a technical detail I will definitely take to heart.

@Wakkibatty : Thank you for your blade maker's perspective. The warning about warping due to humidity and lack of internal symmetry is the final nail in the coffin for this DIY project!

After reading your comments, I've decided to scrap the DIY modification idea. Instead of messing with a symmetrical defensive blade, I'm going to transition to an Inner-fiber structure.

I’ve been looking at the Nexy Joo Saehyuk (2nd Gen), which reportedly uses an Inner-ALC construction similar to Hurricane Long 5. It seems like a more evolution: having 'wood feel' and control for chopping on lower impact, engaging the carbon 'kick' for those FH counter-attacks.

Thanks again for saving my Yinhe 980 from a failed experiment

 

[Wakkibatty]

Thanks everyone for the incredibly insightful feedback!

@golden_son : Stacking two vertical veneers (the existing outer and the new Koto) would definitely create a structural imbalance that I hadn't fully considered.

@belllfador : My 980 is around 85g, but the 'mushy' feel I mentioned might be more about the feedback/vibration than raw speed. Your point about the glue shrinking and warping the blade is a technical detail I will definitely take to heart.

@Wakkibatty : Thank you for your blade maker's perspective. The warning about warping due to humidity and lack of internal symmetry is the final nail in the coffin for this DIY project!

After reading your comments, I've decided to scrap the DIY modification idea. Instead of messing with a symmetrical defensive blade, I'm going to transition to an Inner-fiber structure.

I’ve been looking at the Nexy Joo Saehyuk (2nd Gen), which reportedly uses an Inner-ALC construction similar to Hurricane Long 5. It seems like a more evolution: having 'wood feel' and control for chopping on lower impact, engaging the carbon 'kick' for those FH counter-attacks.

Thanks again for saving my Yinhe 980 from a failed experiment

You're welcome. But please don't be put off too much -- all I've done here is highlight the biggest and most common problems with trying to make an asymmetric blade mod, but that doesn't mean it's impossible to do... Just hugely difficult and fiddly.

Changing the sponge density & thickness with one of your playing rubbers however does the exact same thing, and doesn't require you to ruin a blade (or several 😂) in the process.

Good luck with it 👍🏻 Feel free to reach out via PM if you want any more feedback, always happy to help if I can.

 

[lodro]

i had similar idea once but instead of adding a thin wood veneer I laid up a very thin layer of fiberglass using epoxy. Hardly a difference.

I tried using 2 identical rubbers (even of the same color) but i never got a difference out of it.
So i gave up.
One could have of course kept on adding bits and pieces but I finally ended up getting a DHS Hurricane G 😁

 

[SDC]

Making an asymmetrical blade from scratch is not the same as modifying an existing blade. Sure, it's possible to achieve different speed and feel between sides, but there are many restraints and you have to know how to make them. You cannot isolate the stiffness between sides, and stiffness is one of the major components for the response of the blade. If you increase the stiffness, then both sides get faster, and vice versa. However, it's possible to play with other characteristics such as hardness and dampening of certain layers, and those have less of an effect on the opposite side. Just changing the top ply on each side is not enough to achieve a different performance, you need extreme differences in the composition for that to happen.

In your case, I'm not sure because you didn't specify it, but unless you remove the handle scale on that side and fully cover it, you will barely change the stiffness of the blade. All you are doing is adding weight and thickness to the blade, which will of course change how it responds and feels, but not how you want it to. The balance will change, you will be making it more head heavy which means a bit more power as well, but again, this goes for both sides.

I see no issue with the structural integrity of the blade. Warping is for sure a big issue with asymmetric blades, but not in this case. This mostly happens when the medial is different, not the top ply. Usually, different top plies cause no problems, so I don't see a reason why adding another layer would. However, if you want to fully minimize this risk, just use a non water based glue like polyurethane glue.

 

[releted]

I think I can make a good reply here because I used a 6 ply (DIY 1 extra layer of wood) for quite a while and only stopped when I switched shakehand/penhold. With the added layer it was about 6.1mm thick.

In my case it was a Korbel which I bought 2nd hand. Someone else had added a layer of ayous, I used the ayous on the BH side because I mistook it as koto. When I played shakehand that blade played very well - great dwell, not too flexy. Great for FH loop and powerful far from the table (I guess some flex kicked in at this point). It is my belief that the 6th layer of wood stiffened the blade to a certain "optimal" degree, still had good control, but also more power.

However, I should add, when I started playing penhold I found the backhand (ayous) side unusable for RPB... Not sure why - ball always going into the net, and it does feel mushy. Forehand was still killer though.


Furthermore - I later tried to replicate this blade. 1st, having mistaken the ayous layer as koto I made a new version with koto. I didn't play with it much because the effect was different. I later removed that koto layer and added ayous myself - yep, can remove the wood with a chisel and switch it because the grain was perpendicular. I ended up selling the one I made because I didn't use it, and the headsize was not as large as the original version.

The additional layer on the original blade had the ayous wood grain in line with the Korbel's limba. For mine, I added it perpendicularly. The original blade, it looked like they used a synthetic glue. I always use wood glue for wood on wood bonds because I believe it has less "interuption" to the blade's natural characteristics (flex etc).

**

As I said, when I started playing penhold, I couldn't use the backhand with RPB. So I bought another korbel and considered adding an additional limba layer... or even koto. But I haven't decided to do it yet as I am using a 301 instead at the moment.


To answer your questions:
No weird vibrations - provided the glue is properly bonded.
No effect to sweet spot that I am aware of
Definitely not too stiff for modern play. Mine was much less stiff than clipper and has HEAPS of dwell for super spinny loops.
I recommend woodglue - titebond is what I use; epoxy will affect the properties - presumably making it even stiffer. I used regular clamps, rather than an industrial press


I would suggest that you can consider to add a layer of limba rather than koto, since limba is also harder than ayous.

Based on my experience I would also add the new layer with the wood grain in line with the layer beneath...

Adding an additional layer will make it stiffer and it will play like a new blade. But it might be worth trying!