Thread: 3/4 round molding

If you really require 1/4 round, a 3/4 bit should work well. In reality, you could use almost any size smaller and produce something that resembled 1/4 round, however it would be a bit thinner because when you cut the molding off the main plank the cut should be at the tangent point. I've done exactly what you're planning except that I used red oak.

A wee hiccup with your terminology: You say "3/4 round" and "half moon." Usual practice is to use 1/4 round (or "quarter moon" if you prefer), with radius to suit - 3/4-inch in your case. A roundover bit, such as Grizzly C1189 (2007 catalog, p. 465), would be appropriate. That bit has a 1/2-inch shank, so you need a router with such a collet. Rout the edge of the plank, then cut off at 3/4 inch from the fence.

Alternatively, as Rich suggests, use a beading bit with 1/2-inch radius, such as Grizzly C1163 (ditto, p. 466); that bit has a 1/4-inch shank and should work in any router. If still cut off at 3/4 inch, it'd have a 1/4-inch x about 1/8-inch step on both edges; or you could cut off at less than 3/4 inch, for example 5/8 inch at the tangent point.

Is the MDF really necessary? Stock softwood moulding is available, usually 11/16-in x 11/16-in (close enough, I'd say). Might be less dear than custom cut MDF from the borg.

Joe

We call it quad over here and isn't all that expensive. Usually made from Meranti. Don't tell we can buy something cheaper here than the states.

Originally Posted by crookedcut

I have just installed floating wood flooring all thru my daughters house and now I need to put down 3/4 round molding against the baseboard to cover the 1/4 space left for expansion as per instructions on the box...the problem I have is that it will cost a lot for predone at the borg...I want to use my router table to make it for her...any advise on the size bit I need to get...3/4 bit doesnt seem to make a complete half moon or am I missing something..the molding needs to come out from the baseboard 3/4 and be 3/4 high...using 3/4 MDF....thanks alot

You need a 1-½in diameter round-over bit (for an example look at Lee Valley part number 16J27.58)
You will have to use a table and fence as with a 3/4 plank there is nothing for the bearing to ride against.


ian

BOY...that is a pretty big bit...I have a dewalt 618 kit...installed in table...it is 2 1/4 hp...is that big enough for that bit..... TIA

Originally Posted by crookedcut

BOY...that is a pretty big bit...I have a dewalt 618 kit...installed in table...it is 2 1/4 hp...is that big enough for that bit..... TIA

I don't know the 618, does it have variable speed?
if so wind the speed back to that recommended for a bit that big
regardless, get to the final dimension by taking a number of cuts

ian

yes it is variable speed...I will check what speed I need...thanks for the quick reply