Utility Knife

dusty · Post by **dusty** » Mon Jan 06, 2014 8:22 am

I have a simple question regarding a knife that I have been using to cut Styrofoam insulation material that I am using for my RV renovation.

http://www.stanleytools.com/default.asp ... lity+Knife

The blades that I have been using are serrated. The blades tear at the aluminum covering on the Styrofoam sheeting yielding a ragged edge. By accident, I found a couple replacement blades that are not serrated. They cut great and as soon as the store opens, I am going to get a couple dozen and start this job over again.

But my question: Why might I want a serrated blade rather than a smooth blade? Is there an advantage of one over the other except that one cuts Styrofoam more cleanly?

Gene Howe · Post by **Gene Howe** » Mon Jan 06, 2014 8:40 am

Dusty,
I use only the non serrated blades. Ace sells them in a handy dispenser. 100 in the dispenser....I think.
How close are you to that HUGE Ace on 22nd?

dusty · Post by **dusty** » Mon Jan 06, 2014 8:49 am

Gene Howe wrote:Dusty,
I use only the non serrated blades. Ace sells them in a handy dispenser. 100 in the dispenser....I think.
How close are you to that HUGE Ace on 22nd?

I am about as far away from that Ace as I can get and still remain in Tucson but I go there frequently. It is a good hang out when the wife and/or daughters drag me out to go shopping. They usually bait me with an offer to eat at Fuddruckers.

JPG · Post by **JPG** » Mon Jan 06, 2014 9:41 am

dusty wrote:I have a simple question regarding a knife that I have been using to cut Styrofoam insulation material that I am using for my RV renovation.

http://www.stanleytools.com/default.asp?CATEGORY=RETRACTABLE&TYPE=PRODUCT&PARTNUMBER=10-099&SDesc=6%26%2334%3B+Classic+99%26%23174%3B+Retractable+Utility+Knife

The blades that I have been using are serrated. The blades tear at the aluminum covering on the Styrofoam sheeting yielding a ragged edge. By accident, I found a couple replacement blades that are not serrated. They cut great and as soon as the store opens, I am going to get a couple dozen and start this job over again.

But my question: Why might I want a serrated blade rather than a smooth blade? Is there an advantage of one over the other except that one cuts Styrofoam more cleanly?

I would have to put them in the same category as serrated knives.

An excuse to not have a sharp knife.

I refer to them as dull saws.

I have not seen that in utility knife blades, but then I do not purchase them often nor lately(I just keep on sharpening the ones I have!:D).

Gene Howe · Post by **Gene Howe** » Mon Jan 06, 2014 9:47 am

OK, now I'm officially hungry!

On topic though, I didn't know they made a serrated utility knife blade. What uses do you find for it?
Sometimes, I'll use an electric bread knife to cut styrofoam. But, it would probably tear the foil, too.

Kevin lives off East off Houghton and takes 22nd when Golflinks is busy. I'm really glad I don't live too close to that ACE. I'd be in their train room for hours.

db5 · Post by **db5** » Mon Jan 06, 2014 11:33 am

For making straight cuts on Styrofoam I use the SS table saw. When I have to use a utility knife I use a carpet knife. The blade is longer and sharper.

dusty · Post by **dusty** » Mon Jan 06, 2014 12:10 pm

Gene Howe wrote:Dusty,
I use only the non serrated blades. Ace sells them in a handy dispenser. 100 in the dispenser....I think.
How close are you to that HUGE Ace on 22nd?

I don't really know when I first started using the serrated blades but it has been long enough ago that I only had two regular blades left in the shop. However, unless I find a very specific reason for having serrated blades - these are the last ones I'll have. Those two blades cut that foiled backed Styrofoam so much better!!

I pulled out all of the previously butchered insulating panels and have begun redoing all of those panels. They now look like something that I could let someone see and I'll bet that they will make the trailer warmer too.

dgale · Post by **dgale** » Mon Jan 06, 2014 1:26 pm

db5 wrote:For making straight cuts on Styrofoam I use the SS table saw. When I have to use a utility knife I use a carpet knife. The blade is longer and sharper.

I'm guessing Dusty is taking about rigid sheet foam insulation with an aluminum facing on one or both sides (?) If so, I wouldn't want to cut this on my table saw due to the aluminum. As for the serrated ultility blades, they are touted as staying sharper longer, which I think is silly hype. Unless they could demonstrate that they have some specific use where the serrations are preferred, it is silly to pay more per blade (they are more expensive) for something that supposedly stays sharper but is ultimately disposable. I've also seen carbide-encrusted ultility knife blades...same deal - they cost 2-3x as much for something that probably doesn't perform better or last 2-3x as long...just marketing hype.

They key with utility knife blades it to replace them regularly. Go to Home Depot or Lowes and you'll find 100 packs of blades in a dispenser pack for fairly cheap. I replace my blades repeatedly as I use them, as a sharp blade is the only one that works properly (think about shaving with a dull razor they tear rather than cut). When I'm cutting sheetrock, for instance, I will often replace a blade after only a handful of cuts - it doesn't take much for them to dull and start tearing the paper as I cut. Of course, you can first flip the blade around as it's two sided, and once both sides are fading, toss it and put in a new one. The rate it will dull will depend on what you are cutting - sheetrock goes through them pretty quickly and I'm guessing the aluminum facing on the the rigid insulation would do the same. Once you notice the aluminum start to tear instead of cut, flip the blade around or replace as needed. The blades are cheap for a reason - much less frustration to replace liberally and cut efficiently.

robinson46176 · Post by **robinson46176** » Mon Jan 06, 2014 3:38 pm

I've never used the other blades but on the common blades I normally find a quick swipe on my flat diamond hone brings them back pretty quick and I keep going.

.

JPG · Post by **JPG** » Mon Jan 06, 2014 3:53 pm

robinson46176 wrote:I've never used the other blades but on the common blades I normally find a quick swipe on my flat diamond hone brings them back pretty quick and I keep going.

.

Amen!!!!!!!!!!!!