Thread: Pencil or scribe?

Originally Posted by 3 cav 84a

Here is a dopey question for someone to answer. When do you use a pencil for marking timber on a cut line and when do you use a scribe to scratch the mark, and what are the reasons..........

Pencils are used for carpentry work where accuracy to 1mm or so is adequate. When cutting joints (ie dovetails or M & T) then one would use a knife to strike the mark. Reasons are greater degree of accuracy plus it also gives you a start for the chisel or saw.

Originally Posted by 3 cav 84a

.................Also is there a tool that can cut square cornered mortises, or do you normally use a router with the rounded ends and match the ends of the tenon by rounding them to match?............

You can use a mortising machine which uses a square hollow chisel with a drill bit rotating inside it. This will produce a square hole. See here for a picture. Otherwise you can use a router or a slot morticer, both of which will produce a mortice with rounded ends.

Mick

Yep. Wot Mick said.

A pencil is great for temporary markers; guidelines, side & face markers, etc. When framing a house, that's all I use. But when marking out pieces of cabinetry, for example, I'll often go over it with a knife to mark just the cut lines...

Better accuracy and it can also help prevent fine tear-out on the face.

Thanks a lot fellas I will be off to the hardware shop to get the required articles, regards Neil

Neil

As a patternmaker we always marked with a marking knife or a scribe but would use a 3H or a 4H pencil sharpened to a very fine point to highlight the scribed line especially in timbers where the scribed line didn't show up real well.

Also what Skew & Mick said as well.

Expressed another way, the knife creates a "stopping cut" to prevent tearout, as they said. For shallow mortises, e.g. for hinges, Google [corner chisel] - tonnes of hits for wee punches for just that purpose, although hinges are also available with rounded corners to match router bits, so the punch isn't needed. Joe

I use a knife for fine work but a very sharp pencil will do the job but the knife has the advantages as mentioned above.

When a chisel is to be introduced as the first cutting tool, a 'marking profile' would be used to help the chisel or edge tool to fall and be captured by the line. You'd use a marking tool that resembles the profile your chisel.
My best line is a Japanese scribe followed by a pencil which is first sharpened to a point and then chiseled with two passes on stick-um sandpaper (I make sure to drag the wooden part of the point in the laden paper which results in two lines delineating the chisel) This graphite 'chisel' paints the cut which is then lightly sanded - a fine line to which to cut.
I just finished a long job working with teak. So oily and dark was this wood, a pencil line would hardly show-up on it but a scribe would and a 'painted' scribe was best.
You are only as good as your line and your ability to cut to it.

Jay

Just to clarify a point. When we cut a pencil line, do we not cut to the edge so that we get the complete measurement, if we cut on the pencil line we would get the measurement less half the width of the saw cut.

However, with the scribe, it has been stated, that it is used for finer tolerances and also able to be used so the saw does not slip and it reduces tear out.

Now, I am only a newbie playing in a big boy's game but have I missed something and not measuring the correct way, because my joins are never 100% spot on.

Star, Re; 'spot on'
Often, we expect our chop saws to be dead on because they look so cool!
Take a 2by4 stood on edge and chop the 31/2" dimension, leave one half on the chop saw table and flip the cutoff, look for light. Once you know yr chop saw can lie to you.... tune it!
With hand cut dovetails I'll start my cut first and then make the line with a little 'air' between it and the cut - THAT'S my best cut.
Insist on providing yrslf with good chisels and sharp pencils.