OOAK Table Tennis Forum

I love this pragmatic approach to create an endgrain verneer from what is available!!
Thanks for sharing this idea!

Two questions about this:

1)
Does this "assembled" layer violate the ITTF rules?
<< 2.04.05 The blade, any layer within the blade and any layer of covering material or adhesive on a side used for striking the ball shall be continuous and of even thickness. >>
https://cornilleau-tabletennis.com.au/o ... nnis-rules

(Not that I would care too much about violating this part of the) rule(s), because I see no unfair advantage gained by your good idea, and it would produce what would otherwise be obtainable with a larger piece of balsa. But does anyone know whether a "hawk on rules" could theoretically attack using such "assebmed core layer"?)

2) Addy, did I understand your previous posts correctly that you did not really put much importance to the "end grain" or "not end grain" topic?
If that is is so, why did you go through the effort of getting such structure made? Just curiosity? OR were you following some other idea that might be interesting to hear?

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

Hi MalR!
I'll be curious to hear about your experiences with a styrene core!
However, after having thought about the topic of compression for the core layer (see my sketches in yellow/brown in the posts above on blade deflection), I would conclude that the extremely low compressive strength of styrene (and not much "springiness to it either) will give you still a very dull and uncomfortably slow blade.

Have you tried it already?
...I'd be curions to learn from your experience whether it would either validate or falsify my claims on the importance of the compressive strength of the core.

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

Viel re sketch 2, the ball should never (generally) compress the sponge so that it touches the veneer. If it does you have selected the wrong thickness sponge because the ball will fly off erratically. It is not possible for the ball to compress the veneer. Think hit angle 35° not 90°.

All sketches were deliberately exaggerated, otherwise nothing would be visible.
It’s the same about deflection and vibrational modes: Way too small to see.

But that does not mean that it does not happen, even without full compression of the rubber (that I even left out in my sketch to just illustrate the topic I am referring to).

The interest of blade builders in janka hardness seems to me a strong indication that compression effects do play a role in determining playing properties, even though the actual deformation is dramatically smaller than in my cartoon sketch.
Your experiment with a styrene core will probably show it, too. (« Showing » as in « making it possible to feel ».)

One additional anecdotal example or indication for the importance of layer compression effects:
The "boutique" manufacturer SoulSpin uses relatively soft pine verneers as outer layers in some of their blades to increase the ball contact duration (and achieve a « softer feel »).

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

I do not think so, since the wood fiber is not cut/interupted. If you glue the "squares" well enough with just a tiny bit of glue this will not be seen once the blade is finished.




Exactly like you, I was puzzled by this idea of using cross-cut balsa.
I have built a blade similar to TSP but it went unexpectedly hard and discovered very fast that it is complicated design and its hard to obtain something that has that spring effect.
The problem with the cross-cut blasa is that when you glue a layer on top of that, the balsa capilar tubes are sucking all the glue in. Its like putting glue inside a honeycomb. At the time when I tested this design - around 4 years ago - I was not very experienced about how to laminate a blade and I have used a lot of very thin epoxy. So I used way more than needed and it got into the balsa pores and made it plastic like. There was no spring effect into that blade.

Now, I would do the lamination in a totally different way, for this type of blade construction.

I would say spruce, I doubt its pine.

Hi Adyy!



You are absolutely right! "Pine" was my erroneous translation when I heard the German word "Fichte". "Spruce" is the correct English translation.

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

Yes, I can very well imagine, and had the same concern, even before your helpful comment/warning.
I therefore was quite interested when I found the description of this product: Baltek SealX
https://www.3accorematerials.com/upload ... 3.2022.pdf
I have not yet found a vendor for it, though; only for the Baltek without seal.

I will do my first trials with hide glue, because I have read in two different places that it has the least tendency (if at all?) to soak/seep into verneers.
Since I read that without explicit reference to end grain wood, let alone with respect to balsa, I am not sure that this is the best way to go, but it is presently my best guess.

You seem to have some concrete ideas, though, how to do it, since you wrote:
"Now, I would do the lamination in a totally different way, for this type of blade construction."
Would you mind sharing your thoughts?

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

I found an old patent, filed 1969, that describes an interesting procedure that adresses the pore sealing of end grain balsa.
https://patentimages.storage.googleapis ... 616112.pdf

The passage that I found instructive is:
"The crucial feature of the present invention resides in sealing the top and bottom ends of the balsa blocks so that they
are considerably less permeable to moisture or resin and thereby resist printout effects. This is best accomplished by coating the balsa boards from which the strips are made with a polyester resin, or other sealing agent which may be applied by a roller, by spraying, or other known techniques. In prac tice, the sealant may be applied at any stage in the production of the blocks and to the edges of the blocks as well as to the
ends thereof.
Suitable for this purpose are the following commercial types of polyester resins: Aeropol 7720 M, Aeropol 7240 MC and
Berton's 58094. The sealant must be of a chemical composi tion compatible with the laminating adhesives later used.
The sealant which is applied forms a superficial film, just sufficient to seal up the pores of the end-grain balsa without
materially increasing the weight thereof. Hence, relatively little sealant material is necessary for this purpose. Preferably, in order to provide enhanced resistance to the absorption of moisture or resin, before the sealant is applied, the surface of the board is sanded and the resultant sawdust is
powder removed from the surface but is pressed therein, e.g., by the roller applying the sealant which also acts as a binder
for the sawdust particles. This has the advantage of reducing the amount of sealant necessary, for the sawdust particles
serve as a coarse sealant. In place of sawdust, one may use other types of particulates or powder material, such as Cab O-Si."

There is a weird statement, which I believe is actually a mistake. They write:
"the board is sanded and the resultant sawdust is powder removed from the surface but is pressed therein"
I might have a language problem or lack some knowledge on processes that are referred to here, but due to the end of that phrase, I believe to understand that the sawdust is actually _NOT_ removed, at least not all of it, or rather in a way that leaves some dust to clog the pores.
This way of reading the sentence above corresponds to replacing the word "powder" with "not". A daring proposal to postulate such error in the text.
But the resulting logic sounds plausible.

My main takeaway from this is:
Whatever sealing product or sealing technique one may use, or whatever glue: It might be beneficial to sand the balsa before in a way that leaves its dust to pressed into the pores.

ARe there any comments on this by people who are used to work with wood?

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

Adyy, about your experience with balsa end grain (cross-cut) turned into a very hard blade:
How did you press the verneers? Did you possibly use a vacuum press? PErhaps that causes additionally the glue to penetrate deeply into the balsa?
Possibly just pressing without vacuum would be better?

_________________
Re-Impact - Taipan --- Donic Vario Big Slam (RH+VH)
JOOLA - K3 --- Donic Desto F1 (RH+VH)
TSP - Balsa 6.5 --- Donic Desto F2 (RH+VH)
Re-Impact - (Achim) M3 --- Donic Desto F1 (RH+VH)

From what I understand - Baltek is one of the makers/suppliers of end-grain balsa. I've still got some I bought years and years ago, it came in a huge sheet, the thinnest they had was 1/4" (6.5mm or so). I shipped some to a balsa mail order place and asked them to run it through their thickness sander to get 3/16" sheets. I suppose if I were to make blades out of it again I'd try something like nitrate dope (you can tell I was into making model planes) - you can get it from furniture making supply stores as "wood lacquer" - check the ingredients. Brush on a light coat, then sand lightly when dry, then maybe another light coat. On the other hand, I wonder if it's actually necessary if you get a vacuum bagging setup - people who put skins on styrofoam cores will apply thin epoxy, then wipe almost all of it off before putting the whole sandwich in a vacuum bag. The trick to getting weight down (important for model airplanes) and a strong bond is as little glue as possible and as high a pressure as possible without making the core collapse.

Iskandar

I have tried with the maple wood, But I did not make it smooth and light weight. After being away for a short time, I just finished my first Hinoki blade. I have a 5 ply all Hinoki. The core is 2mm, the middle ply is 1.2mm (horizontal), and the top ply is 0.6mm. Although it's not a flawless finish, it certainly looks playable. In the end, it weighs 94g, although the material for the handle (Walnut, Mahogany with 1.5mm Obeche) could have been lighter. In the future, I'd like to make similar blades like these https://pingpongacademy.org/table-tennis-blades/ with a different veneer thickness to see how it affects the feel. Unfortunately, I won't be able to test this until a few days from now, but I've taken some pictures in different lighting.

@VielAntrob - looks like the thread took a holiday ...
Any tries/tests? Have you built a prototype meanwhile?

Recently I am making some blades with 5 wood plies (using various woods like limba/ayous/kiri/balsa) and 2 layers of carbon, and all together with the handles it is about 20$ USD of material per paddle. I didn't buy anything in bulk so maybe its more expensive.

I am wondering if that price seems reasonable or other people are getting materials for a much less cost.

Hi everyone,
Sorry to just jump in this thread I just found out.
I am a supplier of ultra light weight balsa sheets and end grain balsa sheets (100kg/m3 or less) to a renowned blade maker in Germany

I am quite surprised many of you build your own blade too from balsa.
If what I am supplying catch your interest, I might consider selling online here..
Dean