Short lifetime of wire cup brushes

Hi all,
Today I've been cleaning off some rust off a backhoe using a wire cup brush on an angle grinder. I thought these brushes would last a fair
while, but after about 15 minutes of use it lost most of its wire (depositing quite a bit into my overalls, spear style :-D). Is this the typical lifetime for these brushes? I guess if the angle grinder does about 8,000 to 10,000 rpm, after 15 minutes each wire has probably been flexed enough times to create large fatigue cracks which cause the wires to snap off. I don't have a needle scaler and I can't really justify hiring someone to shotblast the rust, but these cup brushes cost about 5 each, so it's annoying. Maybe I'm using them wrong - I was using the edge of the brush to get into awkward corners, but this might reduce the lifetime of the brush. I guess even if I buy a box of 10 it's still a lot cheaper than blasting. Any thoughts?
Best wishes,
Chris
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The twisted rope style are likely to last longer than the straight wavy wire types.
It would appear that the ones you've been using are low quality. A good industrial quality brush should last longer than the particular job you're using it for.
With even moderate quality brushes, there's not much point in using a lot of pressure applied to the brush. You can accomplish more rust removal by carefully using an acid solution to loosen the rust (then rinse), before you brush.
When using a high quality brush, having a grinder handy to resharpen the wire ends (just a light touch to the grinding wheel) will keep the wire cleaning at top efficiency. This keeps the bristles cutting instead of just rubbing. Leaning hard on a brush shouldn't be required. It should feel like the motor is doing the work.
A sharp high quality brush will be able to remove metal because the bristle material is harder than mild steel.
WB ............

-
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I find that the harder of an angle or edge they are forced into into the quicker the wires will break. I get the best life out of twisted types of brushes.
=============================================Put some color in your cheeks...garden naked! "The original frugal ponder" ~~~~ }<((((o> ~~~~~~ }<{{{{o> ~~~~~~~ }<(((((o>
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Christopher Tidy wrote:

No. Spend *more* money per brush and get much much longer life. By the way, I recently got a wire cup brush which Tom made at Ohio Brush company, and it seems to last very well indeed. Might ping Tom for your next batch ..
GWE
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On Tue, 21 Jun 2005 06:39:12 -0700, Grant Erwin

Liked em huh? <G>
Gunner
"Considering the events of recent years, the world has a long way to go to regain its credibility and reputation with the US." unknown
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For some reason, Europe doesn't make many brushes from anything other than hard-drawn wire rather than oil-tempered wire like the US mfgrs. The common thing for an operator to do to make a brush work harder is to bear down on it...don't do that! The ends of the wire are the cutting edges and by applying more pressure you just lay the wire down and it quits cutting and fatigues the wire and turns you into Mr. Porcupine. Let the tips do the work! Find the best mix of speed, wire diameter, wire alloy and pressure to minimize your brushing cost. Even if you can only get Euro-crap brushes, see if you can get a larger dia wire or better yet, a knot-type brush. Look for Pherd brand from Germany or I can send you some.

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Tom Gardner wrote:

Tom,
Thanks for the advice. What you say fits exactly with my experience. I wasn't pressing really hard, but I'll remember to only press gently in future. Yesterday I ordered some twist knot brushes from a local firm (hopefully they'll be here today or tomorrow). These are made by Osborn, and even if they aren't American-made, I think they're American-designed. They also use 0.5 mm wire instead of 0.3 mm wire. Hopefully these will do the job for now, but I'll bear you in mind as a future source.
Best wishes,
Chris
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Osborn makes good stuff and the brushes you are getting are made in USA, in fact, they are probably made right here in their Cleveland Ohio plant, down the street from me. For some reason Cleveland has about 25 brush companies and we all buy and sell to each other. Tomorrow is the 35th. "Cleveland Brush Manufacturer's Golf Outing" where we all get together and have fun and do a little business.
Best luck and you will be pleased.

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Tom Gardner wrote:

Sounds like great fun. Enjoy the outing tomorrow!
Chris
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Christopher Tidy wrote:

I never got what I considered to be acceptable life from cup brushes on my little grinder, just the speed the thing turns seems to flex the wires more than is good for them. I use a straight brush on my little grinder now and get excellent life, flip it over when the cutting slows and it's ready to go again.
John
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Buy quality cup knot brushes. I do not ever buy straight wire brushes. Cup knot are the type that have bundles of twisted wire. The wire is thicker than regular straight brushes. The straight brushes lose a lot of wire, going into your clothes, arms, and face. WEAR A FACE SHIELD WITH ALL ELECTRIC WIRE BRUSHES.
I buy only Makita, as the cheapos consume faster. If I were doing finer work, I WOULD buy a regular brush, but only for finer uses where you don't have to press very hard. Or, I would just use a wire wheel on a bench grinder.
But for your use, get a cup knot. And that applies to any size grinder you are using. I just boughta Makita that has a 5/8" arbor, and I really like that size.
Keep us posted.
Steve
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On Tue, 21 Jun 2005 12:13:09 +0000 (UTC), Christopher Tidy

YES. www.ohiobrush.com makes the best wire cup brushes Ive ever used.
One should also note..the owner posts here. Tom Gardner. An evil nasty fellow of uncertain parentage..but he does make marvelous brushes. <G>
Check with him. btw..needles scalers are best used for cracks and crannies as no brush will hold up to tight quarters.
Gunner
"Considering the events of recent years, the world has a long way to go to regain its credibility and reputation with the US." unknown
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Gunner wrote:

I used the second cup brush I bought this afternoon. This one lasted 1/2 hour, but that still isn't great. I'll make a mental note not to buy Roebuck stuff again. This afternoon I searched around online and ordered some twist knot cup brushes made by Osborn. These have 0.5 mm wire instead of 0.3 mm. Hopefully they will turn up tomorrow or Thursday and I'll see how they fare.
Ohio Brush seem to be receiving a lot of recommendations. Do they have any UK distributors?
I do fancy a needle scaler, but that has to wait until I have a compressor. By the way, how often do you need to replace the scaler needles?
Best wishes,
Chris
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Christopher Tidy wrote:

Almost never. They do wear, but they wear lengthwise, and there's lot's of room to wear. Those needles are also very tough steel indeed, at least on my I-R needle gun (made in Taiwan, but has held up for me for at least 10 years).
GWE
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Grant Erwin wrote:

Interesting. Another reason to get a compressor.
Sorry if people received my earlier message several times. My ISP's news server is playing up again.
Chris
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Chris, you don't need a reason to have a compressor. Many people own them, and have never used them. They won't admit it, but I have known several personally. Huge oversized overkill compressors, and they use them occasionally inflate pool toys and camping mattresses. Some probably don't even know you can inflate car tires with them.
My news server has been acting up today, too. Probably hackers again. Wish they would shoot a couple of hackers and spammers just on GP, and maybe there would be some relief. I thought selling drugs without a license was against the law, but apparently not with all the solicitations I get.
Just go and get the compressor. ;-) And the needle gun. And the quick connects. And the air ratchet. And the inflator. And the chisel. And ........... anything else you think you might ever use.
Steve
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Gunner wrote:

I used the second cup brush I bought this afternoon. This one lasted 1/2 hour, but that still isn't great. I'll make a mental note not to buy Roebuck stuff again. This afternoon I searched around online and ordered some twist knot cup brushes made by Osborn. These have 0.5 mm wire instead of 0.3 mm. Hopefully they will turn up tomorrow or Thursday and I'll see how they fare.
Ohio Brush seem to be receiving a lot of recommendations. Do they have any UK distributors?
I do fancy a needle scaler, but that has to wait until I have a compressor. By the way, how often do you need to replace the scaler needles?
Best wishes,
Chris
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Gunner wrote:

I used the second cup brush I bought this afternoon. This one lasted 1/2 hour, but that still isn't great. I'll make a mental note not to buy Roebuck stuff again. This afternoon I searched around online and ordered some twist knot cup brushes made by Osborn. These have 0.5 mm wire instead of 0.3 mm. Hopefully they will turn up tomorrow or Thursday and I'll see how they fare.
Ohio Brush seem to be receiving a lot of recommendations. Do they have any UK distributors?
I do fancy a needle scaler, but that has to wait until I have a compressor. By the way, how often do you need to replace the scaler needles?
Best wishes,
Chris
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Tom,
Just a quick note to say that the Osborn cup brushes I ordered are excellent, as you predicted. I've used one all day without becoming a porcupine. Best of all, they're actually cheaper than the "Euro-crap" Roebuck brushes.
Thanks for the advice.
Best wishes,
Chris
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On Tue, 5 Jul 2005 02:41:25 +0000 (UTC), Christopher Tidy

Tom from Ohio Brush? Love those cup brushes!!!!!!!
Gunner
"Considering the events of recent years, the world has a long way to go to regain its credibility and reputation with the US." unknown
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