Table Saw Cutting Cove Molding. Words of Wisdom?

[Scott Hildenbrand]

Gearing up to cut some cove molding out of 3/4" stock that I've doubled up. Worked it out to needing the fence set to 49 degrees.

Beyond advancing the blade a WEE little bit at a time and going slow, any further advice?

Quite confident that I can do it, but always nice to absorb as much info as possible first.

[David DeCristoforo]

There is one thing. Be sure to place the fence on the "front" side of the blade so that the blade pulls the stock into the fence. If you put the fence on the "wrong" side of the blade, you will be setting yourself up for a nasty surprise. Also, be sure to have plenty of eighty grit sandpaper!

[Lee Schierer]

I place fences on both sides of the piece to give complete control of the cut. You can also rip cut the piece with a dado blade or router to remove the bulk of the waste material and make the cove cutting much faster.

[Scott Hildenbrand]

There is one thing. Be sure to place the fence on the "front" side of the blade so that the blade pulls the stock into the fence. If you put the fence on the "wrong" side of the blade, you will be setting yourself up for a nasty surprise. Also, be sure to have plenty of eighty grit sandpaper!

I'd never seen it where the fence was strictly at the front.. Almost all the times I'd seen it done there was either a fence on the front AND the back, or the fence was at the back and a feather board was at the front to put pressure on the piece and keep it stable against the fence.

Far as sanding.. Plenty of paper on hand, so ready for that. But not much need to do alot. Since it's paint grade, I can knock the worst of it down and use a filling primer. Then finish sand it before painting.

[Richard Wolf]

Be careful about applying a lot of downward pressure on the center of the board. It will start to get weak and may split sending everything down on the blade, including hands and fingers.

Richard

[Scott Hildenbrand]

I doubled up the material since I'm going about 3/4" deep, so I'll still have a hair over 3/4" of material in the center. If however I was not going so deep, or planned on using a single sheet and leaving only 1/4" of material at the center I'd follow suit with that advice.

All things considered, you're dead on about it being able to collapse like that.. Since basically all you have supporting is the ENDS of the board once the cove is cut to any depth.. Be easy for thin stock to collapse on itself.

[Larry Edgerton]

I use a dado blade, less scraping/sanding. I grind a scraper to the finish curve and clean it up that way. I also use a power feed, but I did it by hand in my youte.

[Lee Schierer]

One more thing. A blade with raker style teeth will give a smoother finish to the surface than other types of teeth.

[sean m. titmas]

ive cut a lot of cove molding and use only one fence in front of the blade but for a beginner i recommend two fences for a safe and quality cut. i use 3"x6" push blocks lined with sandpaper for traction and a large handle to keep my hands away from the blade. for cleaning up the cut i use a curved scraper to take down the ridges and a sanding block cut to the profile of the curve. setting the angle of the fence and adjusting the height of the blade will produce a cove that is a segment of a circle but if you experiment with changing the bevel of the saw blade you can produce some nice asymmetrical coves.

[Joe Scharle]

Here's a chart you may find handy. BTW, I bought the Rockler cove jig on sale and it's pretty neat. For years I just used a board clamped to the table, but the featherboard over the blade is a good idea.

http://home.usmo.com/~rfwoodworking/cove.htm

[David DeCristoforo]

Two fences is not a bad idea. A fence and a featherboard is better. A fence and a power feeder would be "best". But I have never felt the need for anything beyond a single fence clamped to the saw table at the "front" of the blade. There really isn't that much force working here. I say that because you are limited in how much material you can remove in one pass. The theoretical maximum depth you could cut in one pass is limited to the depth of the blade teeth. Any more than that and the blade plate will hit the wood and prevent the material from advancing. So a brand new blade could remove more in one pass than one that had been sharpened many times or that had lower profile teeth. But that much material is rarely removed in a single pass. Typically a sixteenth to an eighth is considered to be the biggest bite you should try to take. That is really no more wood than you would remove with a 3/4" dado blade and no one hesitates to run a 3/4" dado in one pass, even on lower powered saws. The real limitation is the fact that you are cutting laterally, something that a table saw blade is not intended to do. So the main reason for light passes (beyond my first point) is not power but the need to limit distortion of the blade which will become more and more of an issue as the depth of the cove (and the amount of material removed) increases. The force exerted by these cuts will push the wood into the fence, not away from it. I would be much more concerned about the point Richard made about the material getting too thin in the center and being pressed down into the blade. That could get scary!

[Bob Wingard]

I don't do it often, but when I do, I use the 2-fence method .. HOWEVER .. I make each of the fences about 1/32" lower than the working stock. This allows for the paddles I feed with to get a good grip on the stock, but prevents me from varying the down force very much, yielding a pretty smooth cut. Still needs sanding, of course, but usually much less.

[Paul Atkins]

First time I ever did it was for 400' of oak crown. Used a powerfeed and a moulding head to get the right radius. I ran it through twice and made a hand scraper to fit out of sawblade steel. Also made a sanding block to fit. Boy, were my arms tired. The scraper was the ticket though.

[Scott Hildenbrand]

Well I finished the coves. Just needed two 4' sections, which I'd made out of 3/4" MDF glued up double.

Was easier than I'd expected but was surely as dusty as I'd though.. Really need better dust collection out of the saw than just a shop vac.. It's on my buy list, for sure.



Now I'm left with fuzzy coves, which I expected.. I'll be sanding them down with 120 to smooth things up and then will give it a good coat of primer and sand that.

Think I'll do a project down the road and use real wood next time, to see how it compares. Was an enjoyable process regardless.

Did it with a cheap stacked dado I'd had installed.. Was doing some rails and stiles earlier and didn't feel like changing blades, so I just checked to see how the profile looked at 45 degrees and it worked out great.



Proof that a shop vac is not enough.. I'd already cleaned it out before I started to see how bad the buildup would be.. This is after cutting the cove in 8' of material. Eeesh..

[John Keeton]

The scraper was the ticket though.

I just did about 4' of walnut today. Pretty shallow cut, but it only took two passes. This was my first cove and I was surprised at how easy it was.

I traced the radius of the cut on the end of an extra scraper blade and quickly ground it on my Wolverine jig to the radius. Using only the burr from the grinding, I was able to clean up the cove cut in 15 minutes to a pretty nice finish - ready for 220.

Slick!!