Wednesday, March 12, 2014

Make Dado Blade For Circular Saw

I need to widen the gaps on a 1x4 fir deck because the 1/8 gap fills with debris too easily trapping water and rotting the wood. A straight 1/4 bit in my router is slow. Wondering if I could stack 2 regular, non carbide tip 7 1/4 blades on my Skill worm drive circular saw so I can make, at least close to, a 1/4 kerf between each deck plank.
Thanks for any light you can shed on this.

I wouldn't recommend you make one since it would be against OSHA reg's. You could buy one, however... for example, this one at Rockler has a 5/8 arbor.
Non-carbide blades will make a very rough cut, will dull quickly and will vibrate wildly when they dull. The danger with making one would be that if the blades vibrated and the spacer you use isn't wide enough, and you use carbide teeth and they happen to collide, it could be like a small fragment grenade going off in your hand. Carbide cuts flesh quite efficiently.

Thanks XSleeper,
I checked out the dado set from Rockler (there's one 30 minutes from my house) but I'm not sure it'll work on a Skill worm drive circular saw. Any ideas?
THanks again
Don SW

Didn't notice you said it was a worm drive. Probably not compatible with the diamond knockout. Borrow someone's sidewinder.

It has a diamond knockout. I'll try it. Maybe there'll be enough room under the shield to put 1/4 worth of dado in.

I don't think you will find any dado that has a diamond knockout. And if that's the case, you won't be able to put a non-knockout dado blade on your worm drive, which is why you might want to look into borrowing or renting a sidewinder type skilsaw, since they usually do NOT have the diamond knockouts. You shouldn't have a clearance issue with a 1/4 wide dado inside the blade guard.

Looks like you're right. I'd understood that Oshlun's 6 stacked dado set had a diamond knockout. The pics on their web-site clearly show round. It's possible that I just can't see the perforations for the diamond knockout.... I tried using a large router with a 1 long 1/4? straight bit and it would be very tedious to do the whole deck not to mention that I can only get within maybe 6 of each side so I'd have to devise a way to expand the gap between boards for the rest. In the end, it's not worth the trouble. I'll have the deck scraped and painted and the fir will eventually rot. When I get rich, I'll replace the decking with something other than fir. Thanks for your help.

Tags: make, dado, blade, circular, diamond knockout, worm drive, drive circular, Skill worm, Skill worm drive, Skill worm drive circular, worm drive circular