# IS it safe to mount a couple circular saw blades together, and use it as am Improv. Dado Set



## newbiewoodworker (Aug 29, 2010)

I have to make some dados, on an old TS. I couldnt find a manual, that says if it can use a dado(60's) but it has enough arbour to run a decent dado. I also dont think there are any throat plates available for it.

But There appears to be enough room to run 2 skil saw blades, in place of a single 7.5in blade(no longer made, so it is just a skil saw blade),

My concern is: Is this more dangerous than a regular dado? Do I need to worry about betting beheaded by a run away blade, by using this setup?

I need to make a 1/2in dado. But the current method required 4 passes, with a 1/8 blade. By using 2 I could reduce that to 2 passes…

I have read about it… but not nearly enough to do so, without first asking…


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## TheDane (May 15, 2008)

Newbie-If the saw has an arbor flange and nut you can tighten down, and if the blades fit the arbor (5/8"), you should be okay, safety-wise. I have hard of guys doing this, and never heard of anyone being injured this way.

That being said, circular saw blades aren't designed to cut a flat-bottomed kerf, so the dado you get may not have a clean bottom (don't know if that is important or not). You may also have an unacceptable amount of tearout.

If the saw has a 5/8" arbor, and if you are going to have to use it for awhile, it might not be a bad idea to invest in a set of 6" dado blades. You didn't mention who the manufacturer of the saw is, but you may even be able to make your own throat plates to fit different dado stacks.

-Gerry


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## Simons44 (Jan 9, 2009)

I wouldn't risk it, how much time are you really saving by going from 4 passes to 2? If you want a fast cheap solution, http://www.grizzly.com/products/7-x-16t-Wobble-Dado-Set/G2793 $15 bucks for a dado set is well worth the money compared to using a saw blades for unintended purposes.
-Jeremy


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## newbiewoodworker (Aug 29, 2010)

Im not touching Wobble Dados… sorry… heard too many horror stories… lol…

Thats what I thought.. I figured it would be safe enough, but I was just needing some reassurance….

I dont plan on using the saw for a while… I should be getting my own table saw within the next month or so… a 10"er… 

Its a 1960's Craftsman 7.5in… It has the old T style Fence and all(Fence looks like a T, and has a screw on the back side to tighten it down…

I am not worried about how nice it looks.. its all gunna be painted and sanded… plus Im sure it will be busted in the next year.. since it will belong to a 6 yearold…(toybox)


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## dbhost (Jul 20, 2009)

Do you have a router and a 1/2" straight cutting bit? That might be a safer method of cutting your dado…

I remember Norm Abram for the longest time used to just nibble away with a regular blade until he made the kerfs make up a dado… If I recall that was still his method for cutting box joints even up to the end of NYW…


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## oldworld124 (Mar 2, 2008)

You should have no problem running multiple blades on a saw. However, there are a couple of things to consider.

(There are special saws called gang rip saws that have 24" wide arbors where you put on many blades at once.)

The blade must be flat at the arbor flange. You are better off using a rip saw blade versus a blade with more Teeth. Your two blades will overlap and the number of teeth will double. You need the space for the wood chips to clear. The 2 or more blades should be the same brand and type. You want the outside diameters to be equal. MAKE SURE the arbor nut will fit 100% onto the arbor threads. This is the most dangerous area. The nut MUST be secure.


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## chrisstef (Mar 3, 2010)

You may think about installing a thin washer between them so the teeth dont hit one another.


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## patron (Apr 2, 2009)

just don't tighten it down
with the teeth touching each other
if they are carbide
it creates side pressure on them
and can make them come lose


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## newbiewoodworker (Aug 29, 2010)

I dont mind doing it… but my grandfather hates doing it… And I need a catcher, since I dont have an outfeed table, nor do I feel safe on the thing,alone, should I get into a hairy situation, since the off swtich is on the side of the table, and you have to actually look for it… its an old paddle switch…

I havent a router. Actually the first time I used one was today, in shop class… I had to route 40 some odd 4×4in blocks… A few scares, since It was too small to use a guard on the table(he approved of me not using it… but cautioned before hand, if I didnt feel comfortable, not to do it), and I hadnt actually any formal training(he did a practical safety test on me and I had watched him show us how to use it the day before, for the first block… it sufficed… although he noticed I was comfortable…. lol…) but none of them were actually hazardous scares… it was more the lip of the cut got caught on the mitre slot, and scared me…

Edit: I just looked, and there isnt a lot of room between the throat place and the blade… Can I just put a piece of tape over the gap? ITs only on 1 side of the blade(old CMAN design) and no more than an inch and a half wide(less probably)


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## newbiewoodworker (Aug 29, 2010)

Patron… are you saying NOT to tighten the nut on the saw? lol… They are cheap blades.. no carbide… just old all metal design… I dont even know where my grandfather got these… I thought all blades were carbide now…


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## SASmith (Mar 22, 2010)

Hey newbie. Patron is saying that you want the tooth of the second blade to be in the gullet of the first blade before you tighten it down. Below is a link showing just what you are asking about. A very nice site to poke around if you have yet to check it out.
http://woodgears.ca/shop-tricks/dado.html

scott


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