CF REPAIR

Dave38

Dave38

theemperorhasnoclotheson
Silver Member
So after a customer brought me their Revo for a new tip, he asked about repairing the shaft as it had a ding....yes a ding in CF. I said I have an idea how to do it, and I could try but haven't done it yet. He decided to wait and maybe send to Predator. I decided to try my idea on a scrape of CF tubing. I took a round file and cut across the tube to similate the ding he had, then carefully filled the ding with CA gel using a small toothpick. Then sprayed with activator. Then using a new utility blade I carefully sliced the CA down flush in small passes. When pretty smooth to the touch, I used 400 then 600 using a popsicle stick to back the paper, then wet sanded using micromesh pads from 1800 to 10,000. I then took some solid paste wax and coated it and burnished it on the lathe. Came out smooth as original. Here are the pictures.


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Dave38 said:
So after a customer brought me their Revo for a new tip, he asked about repairing the shaft as it had a ding....yes a ding in CF. I said I have an idea how to do it, and I could try but haven't done it yet. He decided to wait and maybe send to Predator. I decided to try my idea on a scrape of CF tubing. I took a round file and cut across the tube to similate the ding he had, then carefully filled the ding with CA gel using a small toothpick. Then sprayed with activator. Then using a new utility blade I carefully sliced the CA down flush in small passes. When pretty smooth to the touch, I used 400 then 600 using a popsicle stick to back the paper, then wet sanded using micromesh pads from 1800 to 10,000. I then took some solid paste wax and coated it and burnished it on the lathe. Came out smooth as original. Here are the pictures.


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Your repair looks better than the original shaft!! Great work.
 
Looks good, but looks aren't everything. I'd love to see that after playing and flexing for a year.

The structural integrity is severely compromisable there. Much more than wood would have been. You then filled it with a brittle filter. You could have maintained some structure if you had filled with a reinforced epoxy.
 
DeeDeeCues said:
Looks good, but looks aren't everything. I'd love to see that after playing and flexing for a year.

The structural integrity is severely compromisable there. Much more than wood would have been. You then filled it with a brittle filter. You could have maintained some structure if you had filled with a reinforced epoxy.
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I understand what you are saying, but I have done this for yrs on wood shafts, which flex all the time, and swells/shrinks due to moisture etc and have not had problems. Revo CF do not flex much at all. The gel CA is not as brittle as say a thin CA puddled up and then activated...that is very brittle. Epoxy maybe an alternative, BUT as this repair...how do you keep it in the dent/ding without it running out of the repair area as it slowly cures?
 
BarenbruggeCues said:
Epoxy is no good for filling dings. It shrinks over time. CA will not shrink.
You did good Dave.
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Filled epoxy doesn't shrink much and pretty much none after cure. Wait the days to even it out.

You do realize that CF is filled resin, often epoxy resin, right?

CF with broken strands is a problem. CA doesn't have the strength to help with that problem.
 
DeeDeeCues said:
Filled epoxy doesn't shrink much and pretty much none after cure. Wait the days to even it out.

You do realize that CF is filled resin, often epoxy resin, right?

CF with broken strands is a problem. CA doesn't have the strength to help with that problem.
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The structural integrity was compromised when someone gouged the shaft. No matter what you fill it with isn't going to change that.
If you think putting a little dap of filled epoxy is going to strengthen that shaft back to original you need to cash in your medical card.
The only thing Dave was trying to do is fill the void so it can't be felt during a stroke and Looks like a fine job done to me.
Epoxy will shrink over time...filled or not. It's the nature of the beast.
How many cues have you built that you used epoxy as void filler that you seen 10-15 years later?
 
BarenbruggeCues said:
The structural integrity was compromised when someone gouged the shaft. No matter what you fill it with isn't going to change that.
If you think putting a little dap of filled epoxy is going to strengthen that shaft back to original you need to cash in your medical card.
The only thing Dave was trying to do is fill the void so it can't be felt during a stroke and Looks like a fine job done to me.
Epoxy will shrink over time...filled or not. It's the nature of the beast.
How many cues have you built that you used epoxy as void filler that you seen 10-15 years later?
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I never said it would be as strong as original, rkc. I said it would be better than CA.

I don't think you understand CF as well as you think you do.
 
How many cues have you built that you used epoxy as void filler that you've seen back in your shop 10-15 years later?
 
Well done Dave. I would use some carbon micro fibre as a filler or sand some carbon tube and use that. There is also milled or chopped carbon fibre. It's unidirectional carbon that is cut to about 1/6 inch, 1/8inch(Most common) and 1/4 inch long. you can carefully place some 1/6 in the bottom, then add the cyano overtop. then use some powder and finish with some uni fibre. You can make your own shorter fibre by taking some strands out of some cloth and then cut those into the lengths you need or want to use. Filling repairs are very difficult to do for sure . Repairs will always be seen . There is a new technology for joining and repairing carbon products, but sadly is very limited as to who is able to obtain the nano particle glue, also known as carbon nanotube reinforced resins.
 
DeeDeeCues said:
Looks good, but looks aren't everything. I'd love to see that after playing and flexing for a year.

The structural integrity is severely compromisable there. Much more than wood would have been. You then filled it with a brittle filter. You could have maintained some structure if you had filled with a reinforced epoxy.
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DeeDeeCues said:
How many multi-million dollar CF structures have you worked on?
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I hope it doesn't explode breaking wracks all over the place. It could get messy! "I'd love to see that after playing and flexing for a year" I bet it works good enough to tap a ball a few feet. I could be wrong though. I bet it lasts longer than the new $1180.00 tires on my truck that I'll have to completely replace in just a few short years. Is just me, or was this a nice fix for a simple little ding in a cue shaft? "Million dollar CF structures" What? Nice job!
 
Okay, before people start pulling out their body parts and comparing size.... I will clarify, as stated in my post, this is a piece of scrap about 9" long and 10mm dia. CF tube that I 'damaged' identically as a customer's shaft was. It was to test my idea on how to make such a damaged shaft playable again, without an expensive process. My thought process was along the lines that like wood, cf has fibers, and using CA and letting it set for a few minutes before spraying with an activator, will allow it to penetrate the fibers and become very solidly attached. I know some of you may have a CF engineering degree or whatnot....but seriously....we are not building a space shuttle....and DEEDEE if you are worried about failure due to flex, have you ever tried to flex/bend a Revo shaft while you shoot? They pretty much don't! As Dave said earlier, CA doesn't shrink over time, but epoxy does and if in the stroke range, would be felt big time down the road. Also DeeDee, you didn't answer my question earlier about how you get epoxy to stay where it needs to be on a round object while it sets and cures for 12 hrs or so? I did consider epoxy, but it likes to level out as it sets, and on a round tube, it will run out on a sideways dent/gouge before is becomes set. 5 Minute epoxy IMO, would not be a good option for this.
Nick, I like your idea of using some cf dust....for color and may make the repaired area blend more with less shine. Will try that next.
Dave
 
Dave, making little dams with modelling clay works if you want to use a epoxy resin or slow setting Ca. Just need to keep it about 1mm away from the edges so that any oils do not creep to the area being worked on. Have made dams out of plaster of paris before and that does work well, but takes longer than using a modelling clay. The plaster can be right up to the line of the area to be filled though. No matter what you do, there is always alternatives or other ways of doing things. You could also use masking tape around the edges to be filled, and layer it up with pieces of double sided tape is another way. It is just a matter of looking at it from a different perspective. Sometimes using epoxy can be tricky, as you just don't know what resin a manufacturer has actually used, and it's compatibility to it. There are also some very low shrinkage resins as well these days, used mainly for pattern making, and parts that are critical for size. Using a very this Ca for the initial prime or layer is a good thing, as the thin Ca will wick into any areas that have a crack or micro fracture. We use thin Ca to glue the tips of props for model planes. It fills any micro voids from the moulding process and reduces the chances of the tip splitting.
 
Dave38 said:
Okay, before people start pulling out their body parts and comparing size.... I will clarify, as stated in my post, this is a piece of scrap about 9" long and 10mm dia. CF tube that I 'damaged' identically as a customer's shaft was. It was to test my idea on how to make such a damaged shaft playable again, without an expensive process. My thought process was along the lines that like wood, cf has fibers, and using CA and letting it set for a few minutes before spraying with an activator, will allow it to penetrate the fibers and become very solidly attached. I know some of you may have a CF engineering degree or whatnot....but seriously....we are not building a space shuttle....and DEEDEE if you are worried about failure due to flex, have you ever tried to flex/bend a Revo shaft while you shoot? They pretty much don't! As Dave said earlier, CA doesn't shrink over time, but epoxy does and if in the stroke range, would be felt big time down the road. Also DeeDee, you didn't answer my question earlier about how you get epoxy to stay where it needs to be on a round object while it sets and cures for 12 hrs or so? I did consider epoxy, but it likes to level out as it sets, and on a round tube, it will run out on a sideways dent/gouge before is becomes set. 5 Minute epoxy IMO, would not be a good option for this.
Nick, I like your idea of using some cf dust....for color and may make the repaired area blend more with less shine. Will try that next.
Dave
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I didn't answer your question because I thought it was rhetorical and if it wasn't, I didn't want to spoon feed you something that shouldn't have taken more than a few minutes to think of a few ideas that would probably work.

As for shrinkage, you and rkc jr don't realize that many epoxies don't shrink after a few days. You also didn't ask how much fill should be used. The fill should account for over 80pct of the volume. You would then be looking at something that wouldn't flow much, would be strong, and the shrinkage would be about two percent of less than twenty percent (or less than .4 percent).

If you are using epoxies that shrink as much as you claim, they have solvents or other additives.
 
When it comes to Cues, for the most part, Carbon fiber = Tow + Epoxy.

24K Tow is simply 24 strands of 1K tow or two strands of 12K Tow and so on.

Twill = Tow that's been woven, it's all Black but the light reflects in a manner to show the standard Carbon Fiber look. Tow wrapped in one direction will be seen as all Black.

If shrinkage was a problem, it would have shown by now. If the other problems mentioned were true, they would have been seen by now.

How can you tell when the Fibers are not saturated well enough? Frayed ends from cutting. If a strand is blowing in the wind, it never got any Epoxy on it to begin with. I make my own Shafts and Butts with it and when I cut it, I need no tape to prevent frayed ends because I get full saturation on all fibers.

Great job to the OP on the repair and Thanks for posting.
 
Dave38 said:
So after a customer brought me their Revo for a new tip, he asked about repairing the shaft as it had a ding....yes a ding in CF. I said I have an idea how to do it, and I could try but haven't done it yet. He decided to wait and maybe send to Predator. I decided to try my idea on a scrape of CF tubing. I took a round file and cut across the tube to similate the ding he had, then carefully filled the ding with CA gel using a small toothpick. Then sprayed with activator. Then using a new utility blade I carefully sliced the CA down flush in small passes. When pretty smooth to the touch, I used 400 then 600 using a popsicle stick to back the paper, then wet sanded using micromesh pads from 1800 to 10,000. I then took some solid paste wax and coated it and burnished it on the lathe. Came out smooth as original. Here are the pictures.


View attachment 626737View attachment 626738View attachment 626739View attachment 626740
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Wonder if you was able to mix in some carbon fibers or dust even if it would blend in abit better but all in all looks great 👍
 
PracticeChampion said:
Wonder if you was able to mix in some carbon fibers or dust even if it would blend in abit better but all in all looks great 👍
Click to expand...
Tow can be cut into any size you want, added to the Epoxy, it makes a great filler.

I have made some solid Black joint protectors from Epoxy with cut Tow added. Mix the Epoxy, add in small cut pieces and put into a mold.
 
CuesDirectly said:
Tow can be cut into any size you want, added to the Epoxy, it makes a great filler.

I have made some solid Black joint protectors from Epoxy with cut Tow added. Mix the Epoxy, add in small cut pieces and put into a mold.
Click to expand...
No doubt probably stronger but how hard would it be to sand that one little spot back flush vrs some powder and CA
 
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