Introduction: Repair a Damaged Ball and Upgrade It to a Practice Ball for Training Stamina and Strength
When I was kid, I was playing rugby and soccer very often. I remember that the leather/fabric outside of the ball may develop cracks and even showing some failures.
But You could allways inflate them and play.
Anybody that looks to the instructables I wrote until now may notice that those are focused on reuse/upgrade of wastes. Especially because I am fed up of such products that just fail after a few years or even months: this is mostly done intentionnally -also known as programmed obsolescence- but this is another topic. I would not develop this but I am really really angry against this behaviour.
This instructable belongs to the same line of work. How to give a second life to a product that failed too fast.
So my primary intention was to repair basically a rugby ball I have that have a leak and cannot be inflated anymore. I noticed a second one was showing the same problem. I tried with some albumine from egg or even adhesives... Without success.
Then I decided to look on internet how to repair them. It seems not so difficult. You need to open the ball along one of fabric piece edges which faces the valve and then extract the whole bladder, get a new one, glue it where it needs to be glued and sew it together back.
Bad Luck for me, no way I can get those bladders... So I though I need to throw them away or find another solution.
I will described you how I repaired a ball by placing foam blocks instead of a bladder. As a consequence, the ball is heavier and does not really bounce.
But it still can be used for practice and can be a good way to improve your kicking/throwing/passing performance.
(I mean this works for a rugby ball but as well for football ball and a soccer ball --- Maybe avoid doing that for a basketball ball where bouncing is part of the moves)
I will detail the way I did it and will share with you some comments and points of improvement that will be benefitial.
Just a mention on the contents of this instructable-->attribution non commercial sharealike.
You can re-use my texts and my pictures, modify or whatever, if you do so please cite the author, my work or even better put a link to this instructable. I would appreciate your cooperation :) In addition if you have any comment or improvement that you would like to share with me please do it. I would like to make a gallery of balls at the end of this instructable, If you repair one, send me a picture :)
Legends or titles
safety issue or important notice
Step 1: Inventory
-a deflated leaking ball where repair trials failed
-a razor blade/ sharp surgery blade / or carpet cutter
Caution you can injure yourselves severly manipulating such a sharp blade so please work safe! Especially if you are under 18 years old please do that with at least an adult in the same room
- two long needles (curvated) with large pinhole that is suitable to receive the following cord.
Be Aware of stitching Hazard by sewing!There can be blood! :-P so work safe :)
- 5 meter 100% polyester cord / string (half a millimeter diameter maximum)
-a scissor and protecting gloves or sewing dices to protect your fingers
- a block of hard Polyurethane Foam for bed and sofa making with at least 1,2 times larger than your ball (in all dimension. The best is having a block that reproduces the shape of your ball. You can do without but it is the best solution.
Step 2: Getting Started: Cut Off One of the Seam Located Oppositely to the Valve
First be cautious, you need to preserve the stich holes sothat you can sew back the ball using those reference points.
This way works with soccer balls and football balls but maybe looks at some videos on the internet. Those described better how you can open those.
For the soccer ball I will try to open it following an imaginary line on a third of the soccer ball, the middle of this line must be located oppositely to the valve. You will cut the seam in a zig-zag manner along this imaginary line.
For the football ball, You have to do something with the leather laces.
So back to work:
1) take the ball and deflate the rest of air inside the ball to the maximum by pressing it wildly.
- squeeze the deflated ball sothat the seam appears at one point or at least a pit is observed.
2) cut the cord finely without damaging the ballon the first 5 points.
- try to separate the two sides, you must obtain an eye hole.
- keep cutting along the pit to obtain an opening as big as the half of the ball
- clean each holes along the cut to obtain empty hole space!
Step 3: Pull the Bladder Away and Prepare the Next Step
if the bladder is damaged, it will probably break under a pulling force so that you keep only the valve part.
which in our case still ok is.
3) squezze the ball to maximize the vision on the inner side
4) pull the bladder out of the ball
-remove extra bladder part still connected to the valve
5) cut foam block (with a bred knife for instance) with 8 sides sothat you reproduce the shape of a rugby ball at a slightely higher scale (1.2:1 < scale < 1.5:1)
for football ball this is still correct, fot the soccer ball, you need to cut a cube shape, then cut away triangles on all summit sothat you obtain on each side a regular octogone. With a marker divide each edge of the cube in three egal part. The middle part stay untouched. All others undergo a cut. I hope it helps you will obtain an icosaedron or something s alike :).
- press the shaped foam inside the opening of the ball
alternatively use different blocks but try at least to fill the volume of the ball with a bigger total volume of foam blocks and respecting a certain logic that follow the geometry of the ball.
6) impose curvature on your sewing needles, it helps if bending can be made on th needles you are using.
Be cautious I broke 6 needles trying to do that
- get the cord through the two pinholes and close the loop with a knot. You obtain a closed string with two needles.
Step 4: Fill the Ball With Foam
7) Squeeze the foam with your hands and slide it inside the ball, it works pretty well with this simple method
Be careful, the foam must be arranged as equally as you can.
This step is crucial to get a uniform weight distribution and at the end a well balanced item.
you must also consider as you put more foam volume than available volume inside the ball that the foam will not be squeezed equally. Hence, the applied stress causes the foam bubbles close to the inner walls of the ball would undergo the maximum deformation whereas the bubbles close to the center will remain unaffected.
Theoretically as each bubbles of the foam are independant and is not connected to the other by long range porosity, if you increase the size of the foam to be inserted inside the ball, you must obtain a tougher foam response and
better elastic properties. I guess yes it maybe the case, but you need to understand two points:
-if you apply too much stress, the foam may break and cracks, which at the end may result a snow of foam chips.
-If you insert too much foam, you will increase the weight at a point that is not anymore efficient.
Indeed you do not need to increase the weight 10 times, adding already half the weight will allow you to improve the performance an staying close to the reality.
Step 5: Start Sewing
8) First, Squeeze the fabric where the opening starts (choose one or the other side), squeeze the foam below. You aim at seing carefully the two corresponding holes or twin holes on each fabric sides.
When sewing please avoid injure yourselves (it hurts), you may use some reinforced gloves to protect your skin.
-Take your needles with the cords, make a complete loop at the first hole position start outside, finish with the two needles outside.
A)-Then pass the needles inside the same twin holes again but instead of making a complete loop there pass the needles to the next consecutive holes by crossing the strings from the inside. Squeeze locally the ball and pull strongly on the cords to make the fabric tight at that point without breaking the cords.
B)- Pass each needles into the opposite hole and repeat A-B (This pattern is illustrated on the handmade sketch)
Please securise your sewing:
Each 6 stiches, you need to make a stupid reef knot (aka a squarre knot) from below/inside. Be sure to have all 6 stiches still fasten before carrying out this knot. If not, try to fasten them by pulling each stiches from the oldest you made to the newest made and keeping the ball squeezed.
This is very important to get the fabric evenly fasten along the edges.
for the soccer ball, the squarre knot is allways made at the corner point
Step 6: Finished!
The final stage is quite tricky, the last two or three stiches may be not so easy to get by tightenning everything each step.
So you can cheat a bit there. :) do the last three stiches without fastenning them at first. On the last stich, you will need to make a half knot there. Tigthen all thre stiches from the oldest to the newest (do not forget to locally squeeze the foam from outside and keep it like that). When all 3 are tighten, make from outside another half knot and make it sliding under the ball skin.
:) Two half knots gives a squarre knot (if you did it correctly) that is found inside the ball! :)
cool isn't it?
then you must have 2 cords that are hanging outside (in fact each cord is a loop, so it makes 4 strings ), you need to cut away the unnecessary cord length with a scissor:
leavin alf a centimeter of strings outside the ball
The remaining string must be pushed inside the ball with the aid of a needle for example or a tiny stab/ or one fork teeth (easy to bend at 90° normally and to bend back to it original position with little deformation), sothat they dissappear from the ouside.
Illustration of the finished ball
You may notice in my case the fabric is not evenly distributed and forms some wave like stuff.
This is because I did it with many smaller strings, as I do not have at home the right cords, I used sewing polyester strings. As a consequence the holes in the fabric at some points failed: the strings cut the holes sliding down along the hole. So this is serious do use the appropriate cord to repair it otherwise you would end up like I did.
For me, this result is still satisfying, I do not see any big problem also in the balance of the ball.
A small thing more:
Step 7: Bonus
A) About the training with such a ball. Playing with a slightly heavier item than usual will enable you a faster game speed in normal conditions. In fact, this method is commonly used in different martial traditions. In particular some karate school (I think karate) propose to practice using iron made training sandals.
I personnaly trained with two jo (wooden sticks), one is for developping more muscles and strengh as well as precision (it is a thick octogonal shaped jo) and another for the standard training. When I do train 30 min with the thicker one and I then change for the normal, I feel the normal so easy to handle and with a much quicker response.
So I do believe by experience in those positive features. I am pretty sure that training to kick a slightly heavier ball would help you win additional 10 meters at least as well as strength.
B) I wanted to tell you about possible improvement:
the method is quite simple and can be done easil and maintining relatively low costs.
Nevertheless, number of aspects can be achieved by obtaining more bouncing balls or lighter balls.
For the second one, living hinges for foam material such as already mentionned in another instructables
can be generated with imposed hierarchical (fractal) design (outside region of the shape shows very fine foam bubbles whereas the inner region will be populated with very large bubbles and much less materials. This will enable to obtain low density of material with lot of free volume and high density material with lot of limited volume.
Such a method is possible with the aid of living hinges by cutting first the shape in 2 halves and material will be removed (respecting some simple pattern) by cutting away large structures close to the center and by cutting further smaller structure and further smaller structure as you come nearer to the side. Then fix all together with glue. I cannot tell which pattern must be followed but please be welcome to tell if you know!
For the first aspect about bouncing ball. Some bouncing coating can be purshased from one or the other supplier.
Apply those outside the final shape according to the instructions that are given there. It may bring you satisfaction. If anybody tried please let me know if your are satisfied.
A small thing more: (^^,) Yes I do really like Rugby