Sharpening X-acto blades?

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Rocketbuilder

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Here and other places I have heard references to sharpening X-acto type hobby knives. Can this be done? And if so, how do you go about doing it?
I know it would be easier to just buy new blades, but in my book cheap often outweighs easy.
Thanks. :)
 
Unless you know how to put a razor edge on a blade, forget it. It takes practice and lots of it. The best hobby knife for me is a quality break-away knife. Get the good blades of course Lowe's has them. Here's mine. I love it and I can make better cuts with it. That saw is pretty handy also.

DSCF2385.JPG

There might be a plethora of opinions here since I posted this thread regarding, "That Knife You Use".
https://www.rocketryforum.com/showthread.php?34819-THAT-KNIFE-YOU-USE
 
Use a leather strop. You run the blade backward against the leather, It re-aligns the molecules at the edge of the blade. It works great, you can get weeks of use out of a single blade. Search on here, or google it, there was a thread a while back about it. Fine edged blades like an X-acto don't get dull so much as they oxidize. You need a piece of raw, unfinished leather. Try it, you'll be amazed.

Here you go.

Chevis
 
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Very helpful link, thanks. :)
I'm not too keen on being burned at the stake for heresy, but I've got a knife like that somewhere, I just never thought of using it for rockets. I'm about to start on my first rocket with plywood fins, so I might be picking up a razor saw this weekend. Does Hobby Lobby carry them?
 
Use a leather strop. You run the blade backward against the leather, It re-aligns the molecules at the edge of the blade. It works great, you can get weeks of use out of a single blade. Search on here, or google it, there was a thread a while back about it. Fine edged blades like an X-acto don't get dull so much as they oxidize. You need a piece of raw, unfinished leather. Try it, you'll be amazed.

Here you go.

Chevis

Didn't refresh the page before replying, so I didn't see your post at first.
Thanks, I'd heard of a strop but had no idea what it was, and hadn't gotten around to finding out. I'd also never heard that the blades just oxidize, but that makes sense.
 
I'd call this cheap AND easy-https://www.micromark.com/no-11-blade-pkg-of-100,6543.html
I don't think I'm half way through my 100 pack from Micro mark that I bought years ago when they were even cheaper, and on sale...
 
Very helpful link, thanks. :)
I'm not too keen on being burned at the stake for heresy, but I've got a knife like that somewhere, I just never thought of using it for rockets. I'm about to start on my first rocket with plywood fins, so I might be picking up a razor saw this weekend. Does Hobby Lobby carry them?

The saw came from a real hobby shop that finally bit the dust recently. Not too many of them around anymore. HL prolly carries it but I never went looking for it nor did I have a reason, since I have one already. Can't be much help to you on that note. The knife is really easy to handle unlike those round handle ones. I never got the cut I wanted with a round handle knife. The cool thing about them is no sharpening needed. That and a good cutting mat is the ticket.
 
Don't listen to anyone who tells you it is difficult to learn to sharpen an x-acto blade or not worth the effort. It is very easy to learn how to put a wicked edge on an x-acto blade, and once you learn how to do it you will no longer think than a brand-new x-acto blade is sharp.

Sharpening tip number 1:

Use wet-dry sandpaper and small piece of plate glass as your sharpening tools. You will want a range of grits between 200 and 2000. I use 320, 600, and 1500 because that is what I have. Always keep the paper wet and it will stick to the glass.

Sharpening tip number 2:

Make yourself a strop. Get a piece of raw leather and rub some chrome green polishing compound into it. Raw leather is getting more and more difficult to find, and in a pinch you can take an old belt and rough it up with some 100 grit sandpaper. Chrome green is best, but just about any polishing compound or metal polishing paste will work in a pinch.

Sharpening tip number 3:

Sharpen the blade as little as possible. Only the edge is hardened, and you can sharpen away the hard steel. Keep the strop on your bench at all times and use it frequently. Just a few light passes will do wonders. Remember: when using the strop you lead with the heel and drag the edge.

Sharpening tip number 4:

The most common sharpening technique is not actually sharpening, but rather re-pointing. Drag the heel of the blade across 200 - 320 grit sandpaper to form a "drop point tip." A lot of people have difficulty picturing this. Think about how break-away blades work to expose a new tip. You are doing the same basic thing here, only removing far less blade material. After re-pointing, touch up the tip with 1500-2000 grit sandpaper. Just lay the blade face flat on the paper and draw it towards the tip, lifting the blade slightly towards the end of the stroke. What you are doing here is removing the rough edges created by the 200-320 grit sandpaper. Then hit the strop a few times.

Sharpening tip number 5:

This is the traditional sharpening step, and you will be amazed at how infrequently it needs to be done after following the previous tips.

The x-acto blade has a compound edge. There is the edge that you can see, and then another, steeper edge, that requires a jeweler's loop (or better) to see. It is fairly easy to "feel" the visible edge against the paper-on-glass. Feel the position of the visible edge, and then lift the blade up another 10-15 degrees and push the blade across the paper. Alternate sides. You should only need a half-dozen passes on each side on 1500-2000 grit sandpaper to produce a wicked edge. Finish up with a few passes on the strop.

Sharpening tip number 6:

You can adjust the angle in tip to suit your needs. If you want a sharper edge for more delicate work, use a shallower angle. For a longer-lasting edge on less-delicate work use a steeper angle.

Sharpening tip number 7:

Only perform this step after you have performed tip number 5 quite a number of times. Each time you perform that step you are increasing the size of the primary cutting edge. In this step you want to sand back the visible edge. Do about six passes on each side first with 300 grit, then 600 grit, and then finally 1500-2000 grit. For the cutting edge, do about six passes with 600 and then 6-12 with 1500-2000. Again, the grits here are only approximate and you can use what you have. Finish up on the strop.

Sharpening tip number 8:

If you have access to a jewelers loop or a small microscope (20x is fine) look at the edge while sharpening it. You will learn a *lot* about what each step is doing to the edge.

The only thing that is at all difficult about any of this is learning to hold the blade at a consistent angle in step 5.

Seriously, it takes less time to maintain the blade in your x-acto handle than it it does to replace it. And you will have a *much* better edge than a new blade at all times to boot.
 
I just use my 400 grit sand paper..have so many blades it's hard to keep track.I figure the ones with the tip broke aren't new
 
Never thought about sharpening an xacto before. But I think I will stick with wrapping the old one with tape and throwing it away. I was sharpening kitchen knives the other night and managed to slice open a knuckle. I don't want to see the damage I would do with an xacto blade...probably lose an eye!
 
Very helpful link, thanks. :)
I'm not too keen on being burned at the stake for heresy, but I've got a knife like that somewhere, I just never thought of using it for rockets. I'm about to start on my first rocket with plywood fins, so I might be picking up a razor saw this weekend. Does Hobby Lobby carry them?

Yes, they do... VERY handy tools to have...

I haven't tried the breakaway knives either... I DID try my brother's breakaway knife from Lowe's a couple weeks ago to cut drywall when I was doing some air conditioning work in the house here... it worked okay but kept slipping the blade back into the handle, no matter how tightly I tried to get the clamp screw... but I was using a lot of force on it... which is one thing that has worried me about these-- will the blade snap off inadvertantly while I'm working?? Apparently not since I was putting pretty good pressure on it with it stuck into the drywall a half inch deep... Since the blade kept slipping (this was a Kobalt knife that my brother uses in his car shop) I finally switched to a regular box knife to finish off...

Depending on the thickness of the plywood, you might well need something besides a razor saw though... they're only really made to cut straight down through the material, (all at once) and because of the saw backing frame can't cut "in the kerf"...

Good luck! OL JR :)
 
You guys go through all that for sharpening a hobby blade? OI!
MAN! I buy the off-brand blades, like at ACE Hardware, and use an EXTRA-FINE Arkansas sharpening stone, available at Lowes, Wal-Mart, etc. I put a drop of very light machine oil, like REM-OIL, on the stone and rub it in with m finger. This gets done once a year.
When I feel my blade isn't performing like I want, 3-5 strokes EDGE-FIRST at a very shallow angle on each side does the job quite nicely. I've used the same blade for over a year. Works great for me.
Maybe I'm lazy? lol
Eric:)
 
In support of the break away knife I use, I only use it to cut balsa with. And mine is not like the larger break away type one might use for cutting wall board. I found this one at Harbor Freight and it came with blades that were pretty crappy. But the design of the handle is durable, it has rubber grips for ease of handling and the blades don't slip. There are really cheap versions of these knives that I wouldn't trust using but this one suits me just fine. I've seen some even that have a locking mechanism to secure the blade.
 
Depending on the thickness of the plywood, you might well need something besides a razor saw though...
I agree, razor saws are pretty hard to use to cut plywood. I clamp the ply to a bench and use a coping saw and a sanding block to clean up the edge, works fine on 1/8 and 1/4-inch ply.
 
Scroll saw for plywood fins
Razor saws are great for heavy tubes. Any composites will eat the teeth off of them.
 
Micro Mark has this little gem of a tool for sharpening hobby blades. A little pricey, but quickly pays for itself in saved blades.

That's a neat tool... do you have one?? I have a question though... how does it index the blade to the stone to ensure the "exact angle" needed to give a 'razor edge' to the exacto blade?? They show the blade being sharpened in the ROUND knife handle sitting in a "V" shaped trench in the sharpening jig... unless I'm missing something, the knife COULD turn to virtually any angle resting in the "V" so long as its still touching the stone and therefore not EXACTLY duplicate the original angle on the blade...

Just curious... OL JR :)
 
Use a leather strop. You run the blade backward against the leather, It re-aligns the molecules at the edge of the blade. It works great, you can get weeks of use out of a single blade. Search on here, or google it, there was a thread a while back about it. Fine edged blades like an X-acto don't get dull so much as they oxidize. You need a piece of raw, unfinished leather. Try it, you'll be amazed.

Here you go.

Chevis

Stropping is geneally done with white jewelers rouge and a flesh side leather piece. (the inside surface of an old belt will work) A raw piece of just about any leather will do, just be sure to mount the Smooth (Hair) side down Rough (Flesh) side UP on the board. I like to mount the leather with contact cement on a stable surface (a 1/2" piece of wood or the top of an x-acto knife kit box work wonderfully)

Stropping is a Polishing process that removes the "factory edge" from any blade. The blade is pulled backwards at a preset angle to get varing degrees of razor sharpness. X-Acto and other hobby knife blades are factory ground at 10 degess on both sides of the blade. Most general purpose Knifes have either a 20/20 or 30/30 degree angle while Scalpel and most Razors have a 10/0 degree angles. I can not stress enough the importance of maintaining the angle during stropping both side of your blades. If you practice this it becomes almost second nature when you pick up the strop and knife. Once your strop has a good impregnation of the white jewelers rouge you will be able to maintain super sharpness by simply stropping you knife blade 10-20 strokes each side each time you pick up your knife. I'm currently using #11 X-acto blades I've had in the handle for over 10 years. Same with #16 and #24 blades.

I have many Folding knifes, Sheath Knifes, Chisels, Turning Tools and Hand Axe's that have never been on a sharpening stone or hit with a file since that were factory fresh.

My dad and I believe that if a knife doesn't shave hair is isn't sharp.

If just starting out with your X-acto blades I'd stick with the 10/10 angle, drawing the blade backwards toward yourself with a 20 count stroke until you feel the resistance on the strop. Yes it's a Drag form LOL! After about 4 rounds of 20 strokes each side. place a facial tissue on a cutting board with little to no pressure your stropped blade should cut a clean slit without tearing. If not continue 20 stroke/side rounds until a clean cut is obtained or the hair on your forearm is gone LOL!

If your looking for both scrap leather pieces and white jewelers rouge both can be purchased from Tandy Leather on-line or in their many local stores.

Sharpening Strops-a-sm_5 dif strops & cake rouge_10-26-06.jpg
 
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I read these old resurrected threads sometimes without realizing they're old, until I see that Luke Strawwalker has made a comment. Then I immediately look at the post date to see how many years ago it was posted.
 
I read these old resurrected threads sometimes without realizing they're old, until I see that Luke Strawwalker has made a comment. Then I immediately look at the post date to see how many years ago it was posted.

Sometimes resurrecting an old thread can be a good thing, particularly when it involves a technique or materal not often mentioned.

Stropping our X-Acto blades is one such technique that can save a good amount of Hobby funds without a lot of initial layout. As mentioned I'm still using a #11 X-Acto blade I put in my #1 knife handle in the mid 1980's. 10-20 strokes each side, each time it is picked up, keeps it's razor edge.
 
All that sharpening seems like a LOT of extra work. Don't have time for that!
Here's my knife. A little rusty but perfect for freeing fins off a laser cut sheet.

Cheap Knife.jpg

When it gets dull I brake off the top and have a new sharp blade.
A new tip really cheap if you get blades from Harbor Freight!
 
View attachment 307534

When it gets dull I brake off the top and have a new sharp blade.
A new tip really cheap if you get blades from Harbor Freight!

That's a lot like my knife mac. I love the grip. These knives wont roll around in your hand or worse, off the bench into your skin. I have never been able to accurately cut a straight line with an Xacto. Or get the cut angle like it should be.

Regarding those "very affordable" snap-off blades, I still have a pack I bought 5 years ago. They certainly won't break the bank.

DSCF2385.JPG
 
All that sharpening seems like a LOT of extra work. Don't have time for that!
Here's my knife. A little rusty but perfect for freeing fins off a laser cut sheet.

View attachment 307534

When it gets dull I brake off the top and have a new sharp blade.
A new tip really cheap if you get blades from Harbor Freight!

10-20 strokes per side takes no more then a minute, while ensuring a razor shape cutting edge every time the knife is used. Snap-off Box cutters have their place precision cutting isn't one of them.
 
10-20 strokes per side takes no more then a minute, while ensuring a razor shape cutting edge every time the knife is used. Snap-off Box cutters have their place precision cutting isn't one of them.

Well, you can do what you do and I'll do what I do!
Braking off a blade for a new tip is faster than a minute. I can do everything I need with the brake off blade knife.
I free up laser cut fins, cut body tubes, cut out parachutes and cut shroud lines and shock cords.
What else do yo need? Merry christmas, Micro Santa miester!
 
Odd discussion.

Here are two camps with two different paradigms.

We might as well be hosting a discussion of Mac versus PC - something equally useful.
 
Mac, as you can see in the pic, these Arapahoe fins are just the pits because I used a breakaway knife to cut them. LAWD! How much worser can they be! (all jokes aside) it's all about what works for you best. And if there really IS any lack of precision with the likes of these knives, I'll bet you a case of Estes BP F motors it would depend on the individual using them. If, for some reason, I can't quite get the right cut on an edge, corner, curve or whatever, it's nothing a little sanding won't take care of. If we think a breakaway knife is better, who's to say we're wrong? Oh yeah, THOSE GUYS! The sanctimonious elitist that think, "my way or no way."

Sorry, no pic today. TRF is having a senior moment I guess.
 
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