To Boost or Not to Boost

      A topic that is primed to elicit controversy on table tennis forums is boosting, i.e., the practice of applying certain liquids and oils onto rubber sponges for performance gains. To place boosting in the proper context, we need to travel back to the late 1970s and early 1980s. It was during this time frame that speed-gluing, i.e., the practice of attaching a rubber to a blade shortly before a match using a glue containing highly volatile organic compounds (VOCs), became popular. Evaporation of the volatile solvent molecules from freshly glued rubber generates a catapult effect that increases a rubber’s speed, spin, and feeling. Perhaps most importantly, correctly executed strokes produce a very characteristic high-pitched sound - supposedly due to collapsing gas bubbles at the topsheet-sponge interface – giving players prominent auditory feedback that aids stroke development and feeling for the ball. Having speed-glued extensively as a kid, I can attest that speed-glue rubbers like Donic Vario Soft or Yasaka Mark V were absolutely fantastic to play with. In addition, speed-glued rubbers, together with the faster 38 mm ball, meant the game was less physically demanding than nowadays, allowing players with sub-optimal physique and footwork like, e.g., Jan-Ove Waldner to dominate their opponents because of their stellar feeling for the ball.     

     As of September 2008, the ITTF banned the use of VOC-containing speed glues to eliminate legitimate health risks arising from inhalation of VOCs and to slow down the game in order to make it more spectator-friendly and marketable. This marked the beginning of the water-based glue era. Unlike VOC-based speed glues, the use of water-based glues only results in minimal – if any – performance-enhancement of the rubbers. This, in turn, put a lot of pressure on manufacturers to develop new rubber technologies that would compensate for the loss in power and feeling. More than a decade later, it has proven challenging to recreate the power and feeling of speed-glued rubbers purely through improvements in rubber technology. This is where boosters come into the picture.        

     What are boosters? Let me begin by pointing out what they are not. They are not VOC-containing speed glues like the 275Lab VOC Basic Glue or water-based glues like Donic Glue Formula First, Tabletennis11.com’s “house glue”, or Revolution Nr. 3 glue, my personal favorite, which are applied on the blade and the rubber’s sponge for racket assembly. They are not sealants or lacquers like the Nittaku Blade Sealing Racket Protect or Blade Lacquer Revolution Nr.3, which are applied onto the surface of a blade to minimize splintering when rubbers are removed repeatedly. Nor are they rubber cleaners like the Yasaka rubber cleaner or the Revolution Nr.3 Rubber Cleaner & Rejuvenator, which are aqueous solutions of mild detergents that are applied to rubber surfaces to remove dirt, sweat, and grime, and restore grip and tack. 

      There are two main types of non-VOC boosters, i.e., paraffin/mineral oil-based boosters like the Haifu Seamoon booster (very popular in Asia) or Falco Tempo Long Booster (popular in Europe/US) or limonene-based boosters. They are applied onto the rubber sponges – either by the manufacturers and/or the players themselves before the glue is applied. The effect of applying a booster onto the sponge of a rubber is that the booster will absorb into the sponge, expand it, and increase the tension of the rubber top-sheet once it is attached to the blade.         

     So, why is boosting controversial? ITTF rule 2.4.7 states “The racket covering shall be used without any physical, chemical or other treatment”. However, as of May 2020, no approved test can detect if a rubber has been treated with a non-VOC-based booster. In other words, beyond ensuring that a rubber (including the adhesive layer) does not exceed the maximally allowed thickness of 4.0 mm or trigger the “VOC-sniffer” there is no way of determining if the rubber has been boosted (the sniffer is a photoionization detector that uses UV light to break down VOC molecules into electrically charged ions and detect those; the VOC limit is 3 parts per million). The controversy is compounded by the fact that some manufacturers apply boosters to their rubbers during production. Thus, players face a dilemma of either breaking unenforceable rules or to lose out on a potential performance benefit, all while manufacturers seemingly are allowed to use chemical additives during production.       

     What are the potential benefits of using boosters? First off, the increased tension of the rubber generates a catapult effect that increases the speed, spin, and feeling of a rubber. The performance enhancements are variable depending on the rubber/booster combination but are nowhere near the effect of speed-glued rubbers. Also, the effect is temporary, typically on the scale of two weeks to two months, depending on how often you play. For example, the use of oil-based boosters with traditional non-factory boosted tacky Chinese rubbers like Hurricane 3, does indeed render them a little softer and more flexible and dynamic, which increases the speed and spin of loops and power-drives in particular by ~5-10%. However, in my experience, it also reduces their control on blocks and short game due to the increased bounciness of the rubber. In my opinion, a similar effect to boosting can be obtained by using faster and stiffer blades and/or using a softer-sponged version of the rubber. Moreover, the increased top-sheet tension that ensues from boosting, accelerates chipping of the edges. Boosting can also weaken the interface between the top-sheet and the sponge – by dissolving the glue – resulting in the formation of “bubbles”, which cannot be undone once formed. The blue sponge versions of Hurricane 3 are notorious for forming such bubbles. For these reasons, I either don’t boost or only very lightly boost my Hurricane 3’s with the Haifu Seamoon oil-based booster, which in my opinion produces better effects than the Falco booster. Once the effect wears off, the rubbers can be re-boosted but they become softer with each subsequent treatment, with characteristics that progressively differ from the original rubber.

     Keep in mind that some tacky Chinese rubbers, such as the Hurricane 2 Neo or Hurricane 3 Neo rubbers, come pre-boosted from the factory (there is a thick tuning layer on the sponge), and there is, no reason for additional boosting until the effect wears off.

     The situation is slightly different with typical non-tacky European-style rubbers. Many of them come pre-boosted from the factories as indicated by a characteristic sweet limonene-like smell and/or slight doming of the rubber. These types of rubbers often have a very strong catapult straight out of the package and provide a feeling that comes close to – but never fully emulates – speed-glue like feeling. In my opinion, there is limited need to additionally boost new Euro-style rubbers. Generally, the speed-glue-like feeling subsides after 20-25 hours of playing and – in most cases – disappears quite noticeably after 40-50 hours of playing, by which point the rubber feels more “dead”. At this point, it is possible to re-boost the Euro-style rubbers with a limonene-type booster and get an additional 20-40 hours out of it, especially since most top-sheets still are in a sufficiently decent condition, at least for practice play. While this can bring some modest financial savings, don’t expect the rubber to return to like-new condition. A re-boosted rubber feels noticeably different than a brand-new rubber.     

How does one boost a rubber? There are many opinions on how one should boost rubbers. Here are some different methods that I have used in the past.

Method 1:

      Use an oil-based booster like the Haifu Seamoon or Falco Tempo Long Booster on an unboosted blue-sponge version of Hurricane 3. Apply a thin layer of the booster directly on the sponge. Wait 3-6 hours until the booster has been fully absorbed into the sponge. At this point, the rubber will have a moderate dome. Then, apply 3-4 layers of water-based glue, letting each water-based glue layer dry completely (it will go from white to transparent) before the next glue layer is applied. Then attach the rubber to the blade as usual. Observations: This approach produces the most tension in the top-sheet and strongest effect. However, it also increases the probability of edge chipping. If you wait for more than 3-6 hours (around 12-24 hours), there will be less tension in the rubber and mostly the rubber will become a little spinnier but less dynamic. Only one thin booster layer is used with blue-sponged H3’s to prevent the weakening of the topsheet-sponge interface and bubble formation. 

Method 2:

      Use an oil-based booster like the Haifu Seamoon or Falco Tempo Long Booster on an unboosted orange-sponge version of Hurricane 3. Apply a thin layer of the booster directly on the sponge. Wait 3-6 hours until the booster has been fully absorbed into the sponge. Then add a second layer of booster and wait 24-48 hours – during this period the rubber will curl extensively and then start to flatten out. Then, apply 3-4 layers of strong water-based glue, letting each water-based glue layer dry completely (it will go from white to transparent) before the next layer is applied. Then attach the rubber to the blade as usual. Observations: This approach softens the Hurricane 3, resulting in modest increases in speed and spin. The longer you wait after the second booster application, the lower the risk of edge chipping.

Variation 1:

     Some people add 3-5 layers of booster on their Hurricane’s. Be prepared that it takes a very long time to ‘prepare’ the rubbers as doming easily can take up to two weeks to subside. I have never bothered to do that, as I prefer hard-sponged rubbers and don’t want the softening effect.

Variation 2:

     Some players start by applying a layer of water-based glue, before applying 1-2 layers of an oil-based booster to their Hurricane’s, presumably as this method reduces the risk of booster-induced weakening of the top-sheet/sponges interface. In my opinion, this approach only results in very modest, if any, improvements in spin, and isn’t worth the bother. 

Note concerning re-boosting of Chinese rubbers:

     If you decide to reboost a traditional Chinese rubber like Hurricane 3, you should remove the glue layer completely, let the rubber flatten out completely, and then use method 1, irrespective of whether you are using an orange- or blue-sponged Hurricane 3.  

Method 3:

     Use a limonene-based booster on a Euro-style rubber. Many Euro-style rubbers come heavily pre-boosted from the package, and I would not boost a new rubber (but many players do). I have previously re-boosted Euro-style rubber to squeeze 20-40 more hours out of them. In those instances, I removed the old glue layer and let the rubber flatten out. You should then apply 2-3 layers of the limonene-based booster directly on the sponge. Wait for layers to become absorbed before applying subsequent layers. Wait 12-24 hours following the final booster application and then attach the rubber to the blade as usual. Observations: This approach can re-vitalize the rubber in terms of speed, but not spin. Moreover, the rubbers feel noticeably softer.

Note regarding which booster to choose:

     It is widely accepted that oil-based boosters should be used for Chinese rubbers which have solid sponges, whereas limonene-based boosters are better suited for the typically more porous sponges of Euro-style rubbers. The use of limonene-based boosters on Chinese rubbers will have a very limited effect on performance, whereas the use of oil-based boosters on Euro-style rubbers generally will result in very soft and mushy rubbers (unless a very, very thin layer is used).

Final Thoughts

      Boosting can improve the speed/spin characteristics of rubbers albeit not dramatically. If you are using Chinese rubbers like Hurricane 2 or Hurricane 3, but don’t want to boost yourself, you can purchase the pre-boosted Neo versions. Many, if not most Euro-style rubbers are pre-boosted and don’t require additional boosting in my opinion. Re-boosting can extend the longevity of rubbers but changes the characteristics of rubbers. ITTF rules – while unenforceable – are clear. Boosting is illegal and boosted rubbers should not be used in sanctioned tournaments. In my opinion, the ITTF either needs to, 1) put in place rules and develop tests that apply equally to factory and individual boosting, since the present situation has created an artificial ethical dilemma for players, or 2), legalize non-VOC-based boosting since the rule is unenforceable.