What rubber is this?

[TensorBackhand]

I was cleaning out my house and stumbled on this old rubber. I believe it must be from 20 years ago, because I definitely didnt buy it in the past 3 years. Its still very tacky and grippy.

Maybe i should buy a cheap Kokutaku rubber to pair with it. It feels hard like H40 and maybe it will boost up quite well

 

[TensorBackhand]

 

[TensorBackhand]

It's weird because I don't ever remember using this rubber, and I don't see a red rubber that went with this, and there isn't any glue on the sponge.

 

[TensorBackhand]

I was curious so I glued it onto my Sanwei 75, and a few things surprised me.

One is that the rubber is cut very large and hangs over the blade head by about almost a full 1cm.

I was also surprised by the bounce. I thought a 20 year old rubber might be very slow, but its reasonably bouncy, like unboosted H3.

 

[ShoutGuy]

RITC 729 Friendship General ?

 

[TensorBackhand]

RITC 729 Friendship General ?

That sounds like a strong possibility.

What does it say on the sponge? does that provide any clue?

 

[TensorBackhand]

Wow I tried this 25 year old rubber, and it felt pretty bad. The speed is not low actually.

But its like the sponge is really hard and stiff and dry. The ball doesn't sink into the sponge, and the rubber doesn't catch the ball well at all, despite the surface being quite grippy.

When I hit the ball, I can feel the throw angle is low.

And when I loop, it seems like it's not producing much arc. The ball just goes straight on past the end of the table.

I decided to add a layer of booster to see if it can put some life back into the rubber. Maybe the booster can oil up the dried up sponge.

 

[H3R0]

Wow I tried this 25 year old rubber, and it felt pretty bad. The speed is not low actually.

But its like the sponge is really hard and stiff and dry. The ball doesn't sink into the sponge, and the rubber doesn't catch the ball well at all, despite the surface being quite grippy.

When I hit the ball, I can feel the throw angle is low.

And when I loop, it seems like it's not producing much arc. The ball just goes straight on past the end of the table.

I decided to add a layer of booster to see if it can put some life back into the rubber. Maybe the booster can oil up the dried up sponge.

Here is the link for the rubber:

https://sl.aliexpress.ru/p?key=gQcQOdK

It is called 729 Friendship Cross. They are still producing it and released new colors in green and blue. Imho best rubber for the price

 

[UpSideDownCarl]

When rubber is old, it loses elasticity. Elasticity helps with what we are using a rubber for in Table Tennis. The ball sinks into the topsheet and sponge. The topsheet grabs the ball. And the ball sinks into the sponge it stretches and distorts the topsheet. When the topsheet rebounds it propels the ball out with extra spin as a result of it having been stretched by the tangential force of the ball on the topsheet. An old rubber won't be able to do the stretch part because of the loss of elasticity.

It will be interesting to see if boosting helps or not.

 

[H3R0]

When rubber is old, it loses elasticity. Elasticity helps with what we are using a rubber for in Table Tennis. The ball sinks into the topsheet and sponge. The topsheet grabs the ball. And the ball sinks into the sponge it stretches and distorts the topsheet. When the topsheet rebounds it propels the ball out with extra spin as a result of it having been stretched by the tangential force of the ball on the topsheet. An old rubber won't be able to do the stretch part because of the loss of elasticity.

It will be interesting to see if boosting helps or not.

Maybe he should try the new innovative boosting method kindly proposed by igorponger?

 

[TensorBackhand]

Maybe he should try the new innovative boosting method kindly proposed by igorponger?

What is this innovation?

 

[H3R0]

What is this innovation?

Be careful

https://www.tabletennisdaily.com/forum/topics/dry-boosting-let-the-revolution-begin.33522/

I warned you. No turning back after this

 

[TensorBackhand]

Be careful

https://www.tabletennisdaily.com/forum/topics/dry-boosting-let-the-revolution-begin.33522/

I warned you. No turning back after this

I don't get it. How does rolling a cylinder on the sponge apply any booster chemical to the sponge?

 

[H3R0]

I don't get it. How does rolling a cylinder on the sponge apply any booster chemical to the sponge?

As all the other members of forum. I meant it as a joke

 

[UpSideDownCarl]

Just like an old rubberband that does not stretch any more and when you try to stretch it, instead, it breaks, when the rubber molecules have oxidized and lost their elasticity, I am not sure you can get the rubber to have elasticity again. But, nothing bad will come of trying.

 

[TensorBackhand]

Just like an old rubberband that does not stretch any more and when you try to stretch it, instead, it breaks, when the rubber molecules have oxidized and lost their elasticity, I am not sure you can get the rubber to have elasticity again. But, nothing bad will come of trying.

Right, i would say the rubber seems about 30% on the way to the broken rubber band image. When i brush my finger along the edge of the rubber, certain spots feel harder and oxidyzed. But overal, its still bendable and it didnt just tear when i glued and removed from blade.

And so far after booster, it did curl up. So lets just see what happens. Im not expecting too much.

 

[TensorBackhand]

Here's the rubber after one ample layer of booster.

 

[UpSideDownCarl]

I am interested to hear how it plays after boosting.

The image of the rubber band is imperfect. The amount of rubber and the quality of the rubber used is vastly different. And the amount you would stretch a rubber band for failure and the amount a TT rubber is stretched but the tangential contact of the incoming ball compressing the sponge and stretching the topsheet while the topsheet crabs the ball is totally different. Also, the amount of material (rubber and sponge) surrounding the TT rubber is very different than the amount of material in a rubber band.

But, I will be interested to hear how the rubber plays after boosting. If the sponge feels better, if the topsheet feels better.

In my opinion experimenting is always good.

 

[TensorBackhand]

I am interested to hear how it plays after boosting.

The image of the rubber band is imperfect. The amount of rubber and the quality of the rubber used is vastly different. And the amount you would stretch a rubber band for failure and the amount a TT rubber is stretched but the tangential contact of the incoming ball compressing the sponge and stretching the topsheet while the topsheet crabs the ball is totally different. Also, the amount of material (rubber and sponge) surrounding the TT rubber is very different than the amount of material in a rubber band.

But, I will be interested to hear how the rubber plays after boosting. If the sponge feels better, if the topsheet feels better.

In my opinion experimenting is always good.

After letting it sit overnight, this morning I went ahead and gave it another layer of booster. After 25 years of drying out in the closet, it probably needs enough booster to have any chance of being restored.

 

[lodro]

Just like an old rubberband that does not stretch any more and when you try to stretch it, instead, it breaks, when the rubber molecules have oxidized and lost their elasticity, I am not sure you can get the rubber to have elasticity again. But, nothing bad will come of trying.

In the old days (shut up 🤣🤣 ) when the tires on a car started to get a bit hard and nearly brittle on the sides I have seen people applying glycerine with a small brush to make the rubber soft and supple again. Spraying with WD40 might also soften the sponge.