Saw Blade Damage

[Adam]

I recently removed the blade from my tablesaw (Scheppach TS2500). The blades been in a couple of years, and has only good wood (either hard of soft). Its always retracted when not in use, and hasn't cut anything it shouldnt (i.e aluminimum etc).

I've removed it to clean a couple of times (which is what I was doing recently when...) when I noticed this on the blade tips:

Is that normal? The damage is present on quite a few tips.

I started out like this:

This CMT Formula stuff is great"

Finished up like this just a few minutes later:

 

[Chris Knight]

Adam,
It's not good. That has only happened to me when the blade hit steel. I should be tempted to change the blade rather than risk a similar chip flying into my eye. But then if you always, always wear safety glasses, you might not be worried. :wink:

 

[Noel]

Adam, yes the CMT stuff is useful.
Time to get a new blade. The chipped carbide's not too healthy when spinning at 3,500 RPM and most likely contributed to the overheating marks on the blade. No matter how hard the timber being cut is, the tooth tips should not break like that, either the carbide was badly set or the blade hit something.
Anyway, buy a Freud or CMT combo blade. Although some users have had good service from Trend blades.

Noel

 

[Adam]

Adam, I should be tempted to change the blade rather than risk a similar chip flying into my eye. But then if you always, always wear safety glasses, you might not be worried. :wink:

I've bought a new blade - so perhaps its time to bin this one. Its not worth the risk. I was interested to know what you thought - I honestly cannot remember hitting anything metal - but perhaps I did (must have from the sound of it).

Adam

 

[Scrit]

Don't bin the blade yet. Get it resharpened and ask the sharpening service to retip it - they'll replace the broken tips before regrinding the blade (get a quote first). I do this all the time and I reckon on getting 6 to 8 sharpenings out of a blade, sometimes more (depending on whose it is). OK, so if I've lost 8 tips on a 36 tooth rip blade it's scrap bin time, but yours like its got quite some life left in it. Granted, the damage shown could be steel, but such damage can also occur when you hit something as innocuous as a shipping/timber merchant tag staple (ok, steel) or an inclusion (silicate or calciferous accretion, aluminium scrap, small screw - again steel . etc) especially in chipboard, most of which contains a percentage of recycled materials in any case. If I'm cutting something suspect I automatically swap onto an old blade on the basis that I tend to cry a lot less if I b****r up an old blade near the end of its life

Think green - repair and recycle

Scrit

 

[devonwoody]

Adam:

Perhps you hit a wireworm

 

[Anonymous]

Adam

Bin it without a second thought.

Possibly the damage was caused bt grit in some of the recycled wood I believe you have used?

Advice given to keep and resharpen/re-tip it is rdiculous and potentially dangerous and is also likely to cost you more money if new tips are welded on!!

Better quality, brand new Freud blades cost in the region of £25 - 30 from Machinemart for my tablesaw and I suspect the cost will be similar for yours.

 

[Alf]

Advice given to keep and resharpen/re-tip it is rdiculous and potentially dangerous

It's pretty common practice, I believe. Certainly I don't see how it's dangerous

and is also likely to cost you more money if new tips are welded on!!

Now that's likely to be a more convincing argument. Probably depends how much is invested in the blade in the first place.

Cheers, Alf

 

[aldel]

Advice given to keep and resharpen/re-tip it is rdiculous and potentially dangerous and is also likely to cost you more money if new tips are welded on!!

A good saw doctor will replace the broken tips with quality carbide, rebalance and retension the blade for a reasonable price. Blade tips are never welded on!! The tips are fixed using a special brazing process.
If only a 32 tooth blade it may well be better to replace it but bigger industrial blades are re-ground and repaired often.

Aldel

 

[LyNx]

we have TVS collect our blades weekly for shapening or repair. Cost to much the replace them all the time.

http://www.tvss.co.uk/index.html

Andy

 

[Adam]

Thanks for all the replies. I think I'll have to have another look at it, and see how many of the tips are damaged. The saw didn't "cost" anything as it came with the saw, but obviously I just bought a second one so that I could have a "one on", "one-off" policy whilst one was being sharpened. If I write this one off - I'm back to square one.

It sounds like I did hit something from whats been said. Thats annoying. I have once processed some recycled timber but I did use a metal detecting bleepy thing - and didn't see any problems with the same wood on the planer or thicknesser.

For all I know - I've just forgotten or didn't notice at the time :? Could have been like that for years....

I'll ask my local cabinet maker - as I give all my stuff to him to be sharpened normally - he then sends it off with his own stuff once he has a worthwhile amount to send off a batch.

Thanks for all the comments, its a whole area I knew nothing about. Both the damage and the ability to repair damage, and the possibility it may cost more than a replacement. I'll keep it all in mind, and most importantly I'll ask them to quote first.

Adam

 

[Losos]

Adam - I found this thread very interesting especially those close up pics. I'm getting a new table saw soon so I'll copy your 'one on one off' policy. There's no way I could get a saw blade re-tipped in this country so I might have to have two 'spares' (Sending one to UK for 'service')
FWIW it seems like the damage is 'metal' related, I don't think a small bit of metal would have (always) been noticeable.
Did you find any more teeth damaged?? If only one then that points to a very small bit of 'debris' in the wood being the culprit don't you think?

 

[Adam]

one then that points to a very small bit of 'debris' in the wood being the culprit don't you think?

Yes, there is more than one - i need to check if its all on the same side, or in a series. I'll try and do that tonight.

Adam

 

[Anonymous]

Advice given to keep and resharpen/re-tip it is rdiculous and potentially dangerous

It's pretty common practice, I believe. Certainly I don't see how it's dangerous


Cheers, Alf

Common on large and very expensive industrial blades maybe. But 2-year old 10" tablesaw blades??? We are talkiing less than £30 for a new blade here :roll:

Potentially dangerous if not done well and also if other teeth on the blade were damaged at some time but it does not show up yet. Structural integrity of the tip material (microscopic cracks or partial fractures) may be affected by impact with whatever damaged the blade in the first place.

You may be OK with carbide tips flying around, but I am not Is an eye worth £25-30?

As an engineer, I say bin it pronto and remove all doubt!

 

[Chris Knight]

I understand blades and tips are inspected for stress cracks by some saw doctors, using suitable kit but not all do this and at the risk of sounding like a needle stuck in the groove, I echo the junk-it advice - loudly!

 

[ike]

Tony said:

Advice given to keep and resharpen/re-tip it is rdiculous and potentially dangerous

Absolute drivel!. If it's just a few tips damaged, any compentent saw doctor can repair and regrind a TCT blade to normal condition without compromising safety. Replacing a tip is not expensive. Of course the economics depends on the cost of the original blade and the number of teeth involved.

 

[dennyk]

Hi Adam

I had the Sheppach 2500TS for about 3 years, a few months ago when the 2500CI came out , I bought the new model and sold the old one to a good friend.

I don't use the same blade all the time, I have 8 blades for the saw and change them depending on what type of cut I am doing.

I have one blade that is made for cutting through old timber that has the odd small nail in that I have missed when inspecting the wood.

I have had the odd tip replaced on some of the blades, if the blade has more than a couple of teeth broken, I would say replace the blade.

 

[Alf]

Tony, please don't edit away half my post when it includes the very thing you then disagree with me about; it merely misrepresents what I said. I clearly stated it depended on the cost involved whether it was worth it or not.

As for bits of carbide flying about, everything is potentially dangerous if it's not done properly. On that basis you'd never get your car repaired. :roll: Eyes should be behind <tap, tap> safety glasses anyway...

Cheers, Alf

 

[Anonymous]

Tony, please don't edit away half my post when it includes the very thing you then disagree with me about; it merely misrepresents what I said. I clearly stated it depended on the cost involved whether it was worth it or not.

Cheers, Alf

Sorry Alf, that was not my intention at all. I only left the bit I wished to comment on and did appreciate that your subsequent comment was in agreement with mine

 

[Scrit]

Lossos

There must be someone in the Czech Republic who does saw doctoring, after all you have some first rate industrial machinery manufacturers there including Rojek, so there's got to be someone doing saw blades.

Good hunting

Scrit