I had long ago given up cutting strips of mat and glass with a razor knife and straight-edge because the tip always pulled the stuff on a bias, and I ended up with a mess.  I went to scissors,  time-consuming and tedious; but I ended up with some straight strips.  I gave up using manufactured tapes because the edges trap a line of air when doing multiple layups--the edges have to be feathered with a sander before the next layer goes on.

So, anyway, I was at Jamestown Distributors the other day asking about scissors, and the guy there told me to try using a sharp knife blade that had a RADIUSED BLADE along  the straight-edged guide.

I have this old carbon steel "Buffalo Skinner" sheath knife with a curved edge, and I used it today to cut about 30' of strips of mat and glass on a piece of plywood backing.  WORKS LIKE BUTTA!!!!  I am liberated!  Cut my prep time by 75% for tabbing the deck panels.

A lot of you guys and gals may have known about how to do this, but I only found it out today.  I want to pass the tip along for all the refitters among us who don't know.  A real frustration-reliever and time-saver.

Don Tyson, "Number Twenty"

I use a utiliy knife with a new or sharpened blade but youR Knife with the radiused edge is better providing its sharp. Q)what is sharp. a) sharp is not what the factory does. sharp for block planes pruners, fiberglass cutters and so forth is when the Knife can shave the hair on your arm without adding down pressure. Or, if you drag it accross the skin of your rough, callused palm and it cuts a little under its oun weight.  Or, when you drag the knife accross a sheet of note paper suspende between you fingers and it cuts down 2-3 ".  These measures were taught by my shop teacher 30 years ago and they have served me well.  Its hard to get non-corosive steel to keep this type of edge very long.

Tim Lackey, #381, Glissando
(www.triton381.com)

I use a big pair of scissors made for cutting fiberglass that I got during my time at Hinckley.  The blades are 12-14" long.   Mine haven't been sharpened since I left there 11 years ago, but will still cut fiberglass well, up to a few layers of 24 oz. roving.  When properly sharpened (hard to do--I hate sharpening and am no good at it anyway), they'll cut through 5-6 layers of 1808 or some such with no problem, and fairly easy on the hands--they have nice big handles that fit properly.

We used to even roll up widths of mat or cloth into a nice roll and then zip off nice 3" tabbing or whatever using a bandsaw.  Big scissors can do this too, depending on the weight of the cloth.

None of this is to say that the dedicated scissors are better than a good knife and straightedge--just another option.

Stephen

I always use a large pair of good upholstery scissors to cut fiberglass cloth - no problems.  But, as you note - they are expensive.