View Full Version : Need To Bead and Cove 3/4" Stock

01-07-2004, 09:00 PM
I need to bead and cove 3/4" stock for strips on an Ocean Pointer hull. I bought two cutters fron Grizzly Industrial, a bull nose bit that cuts a 3/4" diameter, and an internal radius bit that cuts a 3/8" radius. When I test mill the stock with these cutters, the resulting joint is not snug enough to use. Has anyone had good results beading and coveing 3/4" stock, and if so, what type and brand cutter did you use. Any information you have is appriciated. Thanks, George

Nicholas Carey
01-07-2004, 09:44 PM
I'm rather fond of CMT (http://www.cmtusa.com/) router bits (Italian and blaze orange). You can get CMT router bits from Sommerfield Tools (http://www.sommerfeldtools.com/). Local dealers for CMT tooling can be found via CMT's Dealer Locator Page (http://www.cmtusa.com/store/xdealerloc.ihtml).

Whiteside router bits (US-made, grey steel) are also good. They're available from http://www.routerbits.com/ as well as WoodCraft (http://www.woodcraft.com/).

And I've heard good things about the router bits made by Infinity Tools (http://www.infinitytools.com/) (US-made, white).

That's my vote.

I like CMT's bits. We pattern-routed out several hundred lineal feet of teak deck beams using a gonzo CMT flush trim bit and the bit's still sharp. Great cut quality too. Pretty much ready to finish straight from the router.

01-07-2004, 10:18 PM
Try running some sandpaper down the edges of the coved legs to shorten/open them ever so slightly, and see if the fit doesn't improve. What you'll find is that most often the cove needs to be opened up a bit to allow for the curvature/angle between the two pieces. It won't take much- even a few passes with 80 grit on some rolled newspaper (try different diamaters) will usually do the trick.

01-07-2004, 10:59 PM
I've milled cove & bead strips of 5/8" material using a core-box bit (http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_core.html) for the cove edge and a bullnose bit (http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_bull.html) for the bead edge. I used MLCS bits but they're nothin' special. Don't cut the cove so deep that it has feather edges. They'll be too fragile to handle.

[ 01-07-2004, 11:01 PM: Message edited by: JimConlin ]

Nicholas Carey
01-08-2004, 03:20 PM
The other thing is you don't want to cut the cove as a perfect semi-circle. it ought to be considerable more shallow than that, so the coved piece can rotate on the bead.

If the cove is a perfect semi-circle, and the bead is a perfect semi-circle tangent with the faces of the plank tangent to it, you won't be able to rotate the coved piece as the edge of the cove will be stopped by the adjacent face of the beaded strip. The coved piece will want to come up off the bead.

01-08-2004, 07:25 PM
Probably a bit late for this, but you really don't need to do anything to the strips - just leave them square edged and hand plane as required when the gap is too obtrusive. You will presumably be using a gap filing glue, and some sort of fastener to hold and align the strips to each other (screws, nails, dowels?).

You will have to do quite a bit of fairing when the hull is fully stripped, whatever methods you use, since a perfect fit is in practice not achievable by an ordinary mortal. In these circumstances, just go with the flow that is fastest in achieving a "reasonable" result, since it is probably all you are going to achieve anyway at the first cut (i.e. until fairing).

Good luck, Tony.

[ 01-08-2004, 07:28 PM: Message edited by: Tonyr ]

01-08-2004, 10:38 PM
The advantages of cove&bead planking are:
If looks matter, the joints are tight.
Strips help align their neighbors, particularly where there are joints in the strips.
THis yields a fairer surface, saving LOTS of time.
If looks don't matter, you can butt strips and the neighboring strips will keep things in line.
You use less bog, which is probably heavier than cedar.
The labor of bevelling strips will be lots more than the labor of milling cove&bead edges.

A few percent of your material will be lost in the C&B milling.

01-10-2004, 10:05 AM
George, I have found Dave Gerr's comments on strip planking quite helpful. Refer to his "Boat Strength" page 154 on.


01-10-2004, 02:32 PM
GW, I have a strip plank hull, 7/8 Phil. Mahog., probably 1" stock, before fairing up inside and out, the cove depth, bead height is about .33 in.,strip depth (plank width)total 1.33 in., you'll have to do the math, but greater radius ie. shallower cove allows for less waste and feather edge effect more accurate and quicker,easier alignment and fairing up. Reffering to the semicircle comments, I s'pose.