vonJaerschky

My Feedback: (3)

Just wondering why plastic coverings dull #11 blades as if I were cutting sheet metal. It seems strange, as plastic coverings are so soft and thin. I think Ultracote/Oracover are the worst offenders (love the results, though). it's not a big problem, as I keep a sharpening stone handy on the bench when building. When the blade starts to dull, a few quick swipes on the stone has it cutting as if it were new. In fact, I just built and covered a 65" Twin Otter with the same #11 blade, and it still cuts like a scalpel.

Cactus.

My Feedback: (1)

i don't think the blade gets blunter quicker on films, just the result is more noticeable quicker on film which NEEDS a clean cut rather than on balsa or ply which to be honest you butcher your way through even with dulled blades.
it's possible that the film being thin puts all the force in a tiny area at one time flattening off the edge.
i use my blades on white metal cars at work and they last a good couple of weeks or more!

3DFanatic

My Feedback: (5)

It's a conspiracy by the manufacturers

Deadeye

It could be what is under the covering that is dulling your blade.

ZAGNUT

My Feedback: (1)

get some #11 scalpel blades and forget the cheap hobby blades you get at the LHS.

much better tip that doesn't break off so easily and is also sharper, longer lasting and cheaper. they fit the x-acto handle just fine


dave

pettit

My Feedback: (23)

It's single edge razor blades for me to cut covering. They last quite a while and when they don't cut covering too well, use them for balsa.

Buy 'em by the 100's, maybe $6.00 a box.

AND, make sure to dispose of them properly. Don't just toss them into the trash can (you do havve a trash can?) They still can inflict serious damage if you push down the pile of trash in order to get that last batch into the can.

A small coffee can with a plastic top with a slot in it makes a good disposal vessel.

vonJaerschky

My Feedback: (3)

I'm not really looking for a cutting solution; I'm quite happy with keeping the sharpening stone by my side. I was just curious as to what are the physical properties of the material that dull blades so rapidly. It is not the underlying surface, as that would just dull the tip of the blade. The blade becomes dull when trimming a length of covering wether there is an uderlying surface or not.

STEVE LENZ

My Feedback: (45)

The covering has a mystery dulling agent in it put in by the stock holders of blade manufactures. Can I send all my dull blades and you can sharpen them for me? I am a recycle guy[:-]

vonJaerschky

My Feedback: (3)

Yes, I will resharpen for $1.00/blade, plus $10.00 shipping and handling for the first 100 blades, and then $2.00 S&H for every 100 blades on top of that. Tell all your friends!

BasinBum

My Feedback: (2)

Why does cardboard dull your knife faster than just about anything else? I buy #11's by the 100 and just keep changing them and throwin them in the trash (sorry Dick). Maybe I should get a very fine stone, good idea.

Cactus.

My Feedback: (1)

i only use 11's for tricky turny stuff, i like 10's co they are stronger..
anyway i had a think about this at work.
for it's thickness film is MUCH stronger than balsa and probably ply. so pressure vs area vs strength film is DAMN hard to cut and should dull the blade quick compared to woods.
besides, wood is made of cells which simply slice, film is solid molecules.

SDR-Hammer

Heck I heard blades will dull by just sitting in the open air. Not sure how much truth is behind that, but it could explain why scalpels are packaged airtight.

Also heard an un-provable myth that razor makers have the technology to make a blade that will not dull. But releasing it would destroy their zillion-dollar market?

AIRPLANENUTS

My Feedback: (2)

Try the Testor's version of the no.11 blade. It is made of carbon steel, and MUCH sharper. Doesn't seem to dull as fast, too!

STEVE LENZ

My Feedback: (45)

O I think I can get a better deal on E-bAY IN TOOL The last time I bought 100 #11 It was $8.00 +$2.00 shipping it will last me a year. If I can keep my wife and daughter away from my knife.[sm=spinnyeyes.gif]

Cactus.

My Feedback: (1)

theory has it air particles can hit the edge and blunt it..... thats why the FIRST 1kg weight is kept in a vacuum, it's no longer 1kg because the air has knocked metal from it

BasinBum

My Feedback: (2)

Another reason the Imperial system is better.

PLANE JIM

My Feedback: (109)

Some single edge blades made by certain manufactures get duller a whole lot quicker-we have a discount china made tool warehouse named Harbor Freight-the blades they handle are really cheap in price and even cheaper on quality-I really did not notice until I bought four boxes of those blades thinking I was getting a great deal-two cuts across monocoat and they are trashed

MrWhy

Actually the blade seems to dull quicker because of the heat-glue on the back side of the covering. No matter how sharp your scalpel is, the edge has tiny metal strains and grooves visible in a microscope. The glue and some plastic shavings sticks to this as you're cutting, effectively creating a dull edge. Actually, a cloth with acetone might often do as good a job as the sharpening stone when cutting film. Use it away from the edge.

jettstarblue

Air dulls the blades? Really? Maybe a little oxidation will take the ultra fine edge off, but the reason surgical blades are packaged that way is to keep them sterile.

As for the dulling of blades by film, beside the fact that film is a solid as compared to balsa, it's the mileage, or the fact that when you cut a piece of balsa it's 1/4" to maybe a couple of inches, when you are cutting film, it's yards at a time. Not to mention the fact that you are cutting film over some surface, like a ceiling tile, or building board.
Best thing to do is as mentioned, use a stone to keep the blade sharp.

BasinBum

My Feedback: (2)

When I saw this thread was revived I wanted to slit my wrists, with a dull blade of course.

jettstarblue

Why just the other day, I was telling my daughters how you could kill a man with a butter knife, or a popsicle stick.......

Nuker

JettstarBlue,

did you mention man or....... potential boyfriend(s)

jettstarblue

Actually, it was just my own inimitable way of saying "It's all great fun 'til someone looses an eye". Or "don't run with that loaded gun in your hands!"

jettstarblue

My avatar is a photo(shopped) of one of my lovely daughters uh, "playing".....

Guess this will effectively "kill" this thread.

rajul

My Feedback: (58)

I use the Higley film trimmer and a single razor blade can be reused 16 times