Wanted: pics of cracked js10

Discussion in 'Broken Rackets' started by DuckFeet, Jan 15, 2017.

  1. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    Per title. I've seen a few broken js10 and there seems to be a weakness around 3 and 9 o'clock. If I can collate images I hope to judge how large an area I need to cover with a repair. Thanks.
     
  2. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    [​IMG]

    I think I may have gone a bit heqvy with the grinding. Busted through completely. Oops. But the carbon does seem a little thin here. Also did a bs12 for larfs, that frame is a lot thicker.
    [​IMG]

    @Slade (I need to pic ONE thread to cover this repair) might want to see progress.
     
  3. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    [​IMG]
    Beefy BS12. Frame had collapsed whereas js10 was cracked but intact.
     
    #3 DuckFeet, Jan 15, 2017
    Last edited: Feb 2, 2017
  4. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    Grommet holes pegged with long grommets.

    [​IMG]

    Gloves, mask, goggles, overalls on!
    I made some 50cm or so strips of ribbon and wet them with the mixed epoxy resin. I then wrapped them as wide, thin and tight as I could around the ground area. I did 3 layers/pieces per side.

    Its cold out so I'm going to leave it 48 hours to cure. Then I'll attempt to grind it smooth. Expecting it to be bulky!
     
  5. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    Brought it inside to cure quicker. Hoping to string it 26lb at lunch tomorrow... its very messy so I'll more likely grind it smooth and do another layer first. I think I read that 7 layers of carbon are used and I've got to refill that hole I created.

    [​IMG][​IMG]
     
  6. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    JS10 #1. Some measurements
    74g bare (with grommets)
    I've taken 1.6g off (0.8g each side)
    78.1g with the wrap.
    I predict it will be around 76g when done. Which happens to be ideal bare weight for me.
     
  7. Slade

    Slade Regular Member

    Joined:
    Oct 12, 2015
    Messages:
    166
    Likes Received:
    20
    Location:
    NY
    Looks as if you have a pretty good wrap on there, though it would probably be better of more strands were running straight across the crack, maybe you did that on the lower layers? Epoxy needs some heat to fully cure so you definitely don't want to leave it outside. Put it near your heater if possible for a few hours.
     
  8. R20190

    R20190 Regular Member

    Joined:
    Jun 11, 2004
    Messages:
    2,458
    Likes Received:
    414
    Occupation:
    Chartered Civil Engineer
    Location:
    London, UK
    I presume that is carbon strands you used there mate. Did you put any of the strands in the opposite direction? I.e. along the frame or did you simply have them all wrapped around the frame?

    I suspect that if you only wrapped them around the frame, it wouldn't add that much to strengthen the area. Also where did you buy it from? I have a broken BSLHI which I might be tempted to try and repair.
     
  9. SolsticeOfLight

    SolsticeOfLight Regular Member

    Joined:
    Mar 29, 2012
    Messages:
    1,415
    Likes Received:
    216
    Location:
    Belgium
    When repairing a racket, how close can you get to the original?
     
  10. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    I did all 3 layers spiraling round like that, but there is an element of crossover. I probably should have laid some sections top/bottom too. Maybe on the next round.
    How do I know if I've got enough epoxy on the fibre? It was quite wet but I'm tempted to add a layer on top when done. Maybe a very fine superglue layer as it dries shiny. There was enough for it too ooze a bit when pulled tight so i hope thats enough and that I got a good covering.
    I managed to leave it about an hour before I brought it inside, its sat on a hook next to a radiator.

    If this works i might charge for my service ;) If it doesnt hold at least 28x30 then I'm not sure I'd bother again. I hope at least (if htis works) that it gives you the confidence to have a go.

    http://www.ebay.co.uk/itm/CARBON-FI...942988?hash=item237a8d684c:g:tTkAAOSwwo1Xdq8Q

    I bought this, there's enough for loads of racquets. like 10+? its tough to say, but there are cheaper sets available.

    I'd estimate I'm going to add 1g of carbon to each side of the frame. I'm taking measurements. Luckily I think the JS10 needs the extra headweight and I'm back on tk9000 so it should mod it more to my preference.
     
  11. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    I also wonder about the relative strength of this epoxyweave vs manufacturing process. So if its half as dense/strong then its going to need to be really thick. I presume there's a lot of heat and compression in machining process, which I'm obviously not able to recreate.

    Another one. Similar area
    [​IMG]
     
  12. Slade

    Slade Regular Member

    Joined:
    Oct 12, 2015
    Messages:
    166
    Likes Received:
    20
    Location:
    NY
    Yup, just as I told you to ;)
    If you end up sanding it to get it smooth then paint another layer of resin over that. Warm the resin a bit to thin it out for the final coat, work fast. Superglue only has strength when bonding two items, epoxy has some strength on it's own.
     
    BjornC likes this.
  13. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    Great info thanks. I kinda panicked and rushed a little when the epoxy was mixed so I Just went for wrapping.

    To make the first layer easier what do you reckon to double sided tape to hold the lengthways sections? I wouldn't do it between layers. I suppose that answers my question, don't want it between original carbon and tow. A ring above and below to hold the tow and then wet that in situ maybe.

    So I'll not be drilling and stringing today then!
     
    #13 DuckFeet, Jan 16, 2017
    Last edited: Jan 17, 2017
  14. R20190

    R20190 Regular Member

    Joined:
    Jun 11, 2004
    Messages:
    2,458
    Likes Received:
    414
    Occupation:
    Chartered Civil Engineer
    Location:
    London, UK
    You could sand down as you normally would which should give you a good key, then apply the resin, wait for it to get cure to a tacky state, apply your stand(s) to the now semi cured resin length-ways, then apply more resin, just enough to wet through (i.e. not too thick) and repeat. It's best if you have a vacuum bag kit but for the odd repair probably not worth the money.
     
  15. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    I'm hoping to make up for lack of vacuum with repeat sanding and layers, to fill in any air pockets. I'm abou to grind this layer to see how it is. Then I need to wait for delivery of a drill adaptor to drill out the gommets before another layer.
     
  16. Charlie-SWUK

    Charlie-SWUK Regular Member

    Joined:
    Dec 17, 2014
    Messages:
    4,398
    Likes Received:
    1,223
    Occupation:
    N90 sycophant
    Location:
    SW UK
    Thread title shortens to 'Wanted pics of crack...' :D

    Gonna be interesting to see how this works, the aluminium mesh didn't hold out well enough. Maybe I needed strong/more resin or something.
     
    DuckFeet likes this.
  17. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    Uh oh! Duckfeet found that a handdrill can get through carbon. Currently at 74.4g and barely bigger than stock size - had to use lower single pass grommets but that's about it. Goign to try slapping 24x26 non PS through it to test strength of work done so far.

    I'm not sure how much the paint weighed, but if I've removed say 1.5g form the frame. assume half of that was paint, and paint is weaker than carbon, I've effectively added 1g more carbon to reinforce it. Lets see how it goes... I hope it doesn't splinter when it goes bang. I've got another one here that was deforming at 24lb, currently holding 22lb, so I would hope to see during stringing if it's going to collapse.

    Finished with grinding flat, 240 grit, 600 grit. It snot as smooth and shiny as the TPK but its a really messy quick job. Aesthetics are out the window as there's epoxy all over the frame where I handled it.
    (also I find the JS10 ugly anyway, sky blue and red accents. woof. Also I'm going to make it worse but using orange string as that's what i have scraps of)
     
    #17 DuckFeet, Jan 17, 2017
    Last edited: Jan 17, 2017
  18. Slade

    Slade Regular Member

    Joined:
    Oct 12, 2015
    Messages:
    166
    Likes Received:
    20
    Location:
    NY
    I wouldn't think aluminum would be anywhere near as strong as carbon fiber. Epoxy resin is about as strong as you can get for laminating.
     
  19. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,025
    Likes Received:
    318
    Occupation:
    Computer rebooter
    Location:
    Swindon
    so 24x26lb done. Its holding save for a couple of the grommets have sunk a bit around where the crack/hole was. So I think another layer on that side and I'd be happy to step it up to 26x28. Might give this one a cheeky test tonight to see if it collapses under use.
     
  20. Slade

    Slade Regular Member

    Joined:
    Oct 12, 2015
    Messages:
    166
    Likes Received:
    20
    Location:
    NY
    Yeah, I've had them survive the stringing then collapse later under use.
     

Share This Page