I have seen this happen to a few balls now, some not very old (just months). The ball will develop hairline cracks about 1/2" to 1" away from the finger or thumb hole, sometimes leading down to the hole but sometimes not. The cracks are not caused by the bridge cracking out as this area has remained intact, and the last ball I saw with this problem the crack was actually just outside the thumb hole. The ball weights have ranged from 12lb to 15lb so it's not a light / hollow ball thing.

My only thought is it is from a hard impact onto the lanes throw after throw, but am not sure. I am at work so can't post a photo right now but if needed can get one tonight / tomorrow.

Thanks.

I've had a number of plastic balls that cracked around the finger and thumb holes after a couple of years. All cracks touched the holes, though.

At the time, I chalked it up to my 'cup and collapse' release. I was told that fingertip inserts may have had something to do with it, though.

Thanks for the response. I asked a friend from another center and he thinks it could be from the super glue holding the inserts / thumbslug getting into the shell and eating away at it. Sounds plausible, but I'm not sure if that's it, it seems if that were the case it would crack from the holes out, not from further away from the holes. Or maybe it is just a random thing, it cracks wherever the most deterioration has occured. Anyway, it's something I will watch for when gluing things in.

Funny you ask; I just went to "bowl with a pro" and Mika Koivuniemi had the bridge of his fingers cracked. Our Pro Shop guy says that it is caused by the drilling. He says that when the holes are drilled out to fast; the heat from the bit causes the cover to become weak in that area.

I asked my ball driller yesterday and that is exactly what he said.

To combat this he drills a smaller hole first before drilling the insert size hole.

I have seen where when people do that, it can cause chatter. Which is basically where the drill bit "chatters" back and forth while you are drilling. If you drill it slow enough and take the bit in a out a few times to help decrease the heat, it should be fine.

Too many proshops do not keep their drill bits in top condition. Using dull bits will generate a lot of heat too.

I have noticed my 31/32 bit not cutting as well as it had been, it's been about 6 months since I had it sharpened. I've actually been thinking about getting a second 31/32 and 1 1/4 bits to help extend their life, and also so I won't be without those two bits for a week when I need to get them sharpened. I don't feel like I drill too fast, I take a few minutes per hole and I do pull the bit out a number of times while drilling, and always have the shop vac right up to the hole (not sure how much cooling that does). But there have been times when I was slammed and needed to just get things done where I know I pushed things a bit. It's only happened on a couple of balls I've drilled, I've actually seen it more on balls that were drilled elsewhere. Again, more things I will have to watch out for.

Thanks!

If you own a Pro Shop, I think that it would be good to invest in something that would sharpen your drill bits. In the long run, it would end up saving you time and money.

Its usually the drill bits being too dull and used too fast. So many drillers just line the bit up and plow on down. It generates heat and that's what we've found causes cracking. This is why it takes our shop a bit longer to drill balls, we stop, feel the bit, check see if its getting too hot, then might let it cool down.

Keeping drill bits sharp is not as easy as it would seem. Finding a place that does it inhouse is difficult and usually expensive. Cheapest we found recently was $7.50 a drill. So if you have a dozen or so bits you can see how that would be expensive. And then we have two sets, so we can get some sharpened while using the others. Because on some of the most popular size bits, we cannot be without them even a day. Those bits cost a lot too.

Erin

TenPin, your shopvac is sucking up the smoke from burning drill bits, and you won't see it. If you see a tinge of blue or darkening on the bit edges, sharpen them. A bit sharpener is not expensive, I have 2. And, use them often. A good investment.

I have a friend who is a CNC machinist and sharpened one of my bits for me earlier this year. He didn't recommend using any kind of manual / knife sharpening tool because of the precise angle of the cut on the edge of the bit. I'm sure most companies that offer sharpening would say the same, not sure how true it is but I trust his judgement and he has no reason to lie to me (I work on his equipment too, after all!). Dennis, where did you get your sharpener and what kind is it? I'm all for doing things myself, but only if it will give me the results I need and the equipment doesn't cost too much.

I know of one place that does sharpening for $7.50 per bit but it isn't local, so would take about a week to get them there and back. I had already decided next time I get some sharpened I would buy another of my most commonly used bits, I'm thinking that time has probably come now.

As for smoke, I have seen it once and I could smell it too, and it was one of those times I know I was pushing it a bit. Normally my bits come out warm to hot, but not so hot that I can't hold it in my hand. Erin, what would you consider too hot?

Smaller bit sizes sharpener is a Drill Doctor, for about $150.
The larger one at the shop is sold by Northern Industrial Tools, I think, about $400

One of my former drillers had his most used bits, 31/32(inserts) and 1 3/8 (slug size he used most often, sharpened several times and the size of the holes started to slowly decrease. I had a few balls drilled from before the bits were sharpened and a few from after and the same inserts would be tighter in the later drilled balls.

anyway, to get back to the original topic, i just found a ball at a tag sale, the guy was giving it away for free, so i picked it up. i took it in to my local Pro Shop and the owner said the ball was good quality, but that, due to the cracking around one of the finger holes (which he referred to as "stress cracking"), it was in its final days. the Pro Shop owner is very knowledgeable in the game, or at least it seems so to me. is there any way to fix the cracks around the holes, or is he correct in saying that it can't be fixed?

There is always the possibility of drilling out that area and plugging the whole area, but that's a lot of plug material and just increases the chance of it cracking again.

yeah, i actually decided to just have the thumb hole widened and just use the ball till it goes. it only cost me $1 to have the Pro Shop widen the thumb hole, and hopefully i can get some good use out of it until i can get the money to buy a newer ball with similar qualities.